Nurse Anesthesia NCE Board Review
2 most important risk factors for NEC
2 most important risk factors = prematurity (less than 32 weeks) and low birth weight (less than 1500 g)
how long should Eptifibatide be held before neuraxial anesthesia?
8
how long should tirofiban be held before neuraxial anesthesia?
8 hrs
What Mapleson circuit is worst for controlled ventilation?
A
list the nerve types from MOST myelination to LEAST myelination
A B C - none
what part of the arm does an axillary block anesthetize?
Anesthetizes forearm and hand
Pneumatic bellows is an example of what gas law?
Boyle's law
Squeezing a BVM is an example of what gas law?
Boyle's law
Fasting guidelines
2 hrs clears 4 hrs breast milk 6 hrs non human milk, infant formula, solid food 8 hrs fried, fatty food
what is the equation for loading dose?
Loading dose = (Vd x desired Cp)/Bioavailability
what is the size of a normal dead space volume in ml/kg
2 ml/kg 150 ml in 70 kg adult
how does hypercarbia affect peripheral and pulmonary vasculature?
** hypercarbia has the opposite effect on pulmonary blood vessels than in peripheral circulation... in the lungs, CO2 is a direct acting vasoconstrictor where it can cause pulmonary HTN and increased RV workload
describe the largest ETT size that can fit in the following LMA sizes 1 1.5 2 2.5 3 4 5
1 --> 3.5 1.5 --> 4.0 2 --> 4.5 2.5 --> 5.0 3 --> 6.0 4 --> 6.0 5 --> 7.0
what is normal threshold potential for the ventricular myocyte in mV?
-70 mV
N2O boiling point
-88 C
what is normal resting membrane potential of the ventricular myocyte in mV?
-90 mV
what are some advantages of a piston ventilator?
-Accuracy in TV -Preserves cylinder O2 -Quiet -No PEEP Compressed by an electric motor.... This does not use oxygen as a drive gas so it won't consumption oxygen tank in event oxygen pipeline failure Allows for more precise Vt delivery d/t fresh gas decoupling
Normal QRS interval time
0.04-0.10 seconds
Normal PR interval
0.12-0.20 seconds
normal QTc = ______ seconds
0.36-0.46 seconds
blood partition coefficient of des
0.42
blood partition coefficient of N2O
0.46
blood partition coefficient of sevo
0.65
what local anesthetic is CI for epidural use and why?
0.75% bupivacaine is CI with epidurals because of toxicity associated with IV injection
describe the appropriate weight for the following LMA sizes 1 1.5 2 2.5 3 4 5
1 --> < 5 kg 1.5 --> 5-10 kg 2 --> 10-20 kg 2.5 --> 20-30 kg 3 --> 30-50 kg 4 --> 50-70 kg 5 --> 70-100 kg
what is the dose of protamine?
1 mg protamine for every 100 units of heparin predicted to be in circulation
what is the PISS configuration for air?
1,5
how long should Abciximab be held before neuraxial anesthesia?
1-2 days
describe the six functions of the kidneys
1. Maintenance of extracellular volume and composition -Aldosterone controls ECF volume (Na and H2O absorbed together) -ADH (vasopressin) control plasma osmolarity (H2O reabsorbed but not sodium) 2. BP long and intermediate regulation -Long term control via thirst and sodium and water excretion -Intermediate control via RAAS 3. Excretion of toxins and metabolites 4. Maintenance of acid base balance -Titrate hydrogen in the tubular fluid to create acidic or basic urine 5. Hormone production -Erythropoietin -Calcitriol - active vitamin D -Prostaglandins 6. Glucose homeostasis -The kidneys like the liver are capable of synthesizing glucose from amino acids and thereby prevent hypoglycemia during times of fasting
What does the lymphatic system do?
1. removes excess fluids and waste products from the body's tissues 2. helps the immune system fight infection Lymphatic system is a fluid scavenger... it removes fluid, protein, bacteria, and debris that has entered the interstitium it accomplishes this goal
blood partition coefficient of iso
1.46
Uterus gets ______% CO in pregnancy
10%
what coagulation factors make up the final common pathway? describe how these factors are activated
10,5,2,1 **think dollar signs Factor 5 is a positive feedback mechanism that accelerates the continued production of prothrombin activator, which activates factor 2 (thrombin) Prothrombin activator is what leads to thrombin activation from prothrombin Thrombin is a proteolytic enzyme that changes fibrinogen to fibrin monomer... in the presence of calcium, fibrin fibers are created Fibrin stabilizing factor (13) facilitates cross linkage of fibrin fibers which completes the clot
what is normal BUN?
10-20 mg/dL
start at ____ J for cardioversion?
100
what is the treatment for adrenal crisis?
100 mg hydrocortisone q 24 h, ECF volume expansion with D5NS, and HD support
Perioperative TET spell treatment
100% oxygen IV volume expansion Increase SVR w/ phenylephrine Reduce SNS stimulation to improve RVOT obstruction - deepen anesthesia, BB with short acting agent (esmolol) Inotropes worsen RVOT obstruction and are best avoided Avoid excessive airway pressure An infant may be placed in a knee chest position to mimic squatting
Normal 3 year old vitals
100/65, H100 R 30
Normal 12 year old vitals
110/70 H80 R 20
how many vertebrae are in the thoracic column?
12
what coagulation factors make up the intrinsic pathway? describe how these factors are activated
12,11,9,8 **count back from 12 and skip 10 Blood trauma and exposure to collagen activates factor 12, factor 12 activates factor 11, factor 11 activates 9, 9 activates 10, 10 activates prothrombin activator which activates factor 2 (thrombin)
What is the normal GFR?
125 mL/min
how long should ticlopidine be held before neuraxial anesthesia?
14 days
what is the treatment for a tension PTX
14 g angiocath 2nd intercostal space midclavicular line or 4th intercostal space anterior axillary line
Sevo VP
157
what is the pressure (PSI) and volume (L) in the air cylinder?
1900 PSI 625 L
what is the pressure (PSI) and volume (L) in the oxygen cylinder?
1900 PSI 660L
What are the vitamin K dependent clotting factors?
2, 7, 9, 10
what is the PISS configuration for oxygen?
2,5
which local anesthetic is good for an emergency C/S in a pt with an epidural? why?
2- chloroprocaine is good for an emergency C/S when an epidural is already in place because of its very fast onset It is metabolized by pseudocholinesterase in the plasma - minimal placental transfer, short duration
For angioplasty without stent wait ____ weeks before performing elective surgery
2-4
which local anesthetic reduces efficacy of epidural morphine?
2-chloroprocaine reduces efficacy of epidural morphine Antagonizes mu and kappa receptors in SC
Des boiling point
22 C
Iso VP
238
what coagulation factors make up the extrinsic pathway? describe how these factors are activated
3 (TF), 7, 4 3+4 = 7 TF activated by extrinsic pathway, TF activates factor 7, 7 activates 10 in the presence of factor 4 (calcium)
what are the 3 structural parts of the local anesthetic?
3 structures of the local anesthetic molecule = benzene ring, intermediate side chain, and tertiary amine Both amides and esters have the same tertiary amine NHR2
what is the PISS configuration for N2O?
3,5
Pts w/ bare metal stents need to wait at LEAST _____ days before elective surgery
30
what is naloxone duration of action?
30-45 min
Barotrauma risk increases when plateau pressure exceeds _______ cm H2O
35
what is normal FRC is ml/kg?
35 ml/kg
N2O VP
38770
what size double lumen tube is indicated for adult males adult females kids 10+ 8-9 yrs old
39-41 Fr for men 37-39 Fr for women Kids 10+ 28 or 32 8-9 year olds size 26 Insertion depth 27-29 cm
how many vertebrae are in the coccygeal column?
4 fused
Seizure prophylaxis with mag dose what is the treatment of toxicity? what other effects may magnesium have in the pregnant pt?
4 g loading dose over 10 min then infusion 1-2 g/hr Toxicity treatment = 10 ml 10% calcium gluconate Magnesium relaxes uterus and increases the risk of PPH
opioid withdrawal can last ______ days depending on the drug
4-10
Iso boiling point
49 C
how many half times does it take for a drug to be considered eliminated?
5
how many vertebrae are in the lumbar column?
5
how many vertebrae are in the sacral column?
5 fused
Risk of cerebral ischemia during CEA if stump pressure is less than 50 mmhg
50
What Mapleson circuit is best for spontaneous breathing?
A
what is the max % of receptors blocked for the following recovery test: hand grip same as pre induction
50%
what is the max % of receptors blocked for the following recovery test: head lift > 5 seconds
50%
what is the max % of receptors blocked for the following recovery test: holding tongue blade against force
50%
what is the max % of receptors blocked for the following recovery test: inspiratory force better than -40 cm H2O
50%
Sevo boiling point
59 C
After CABG, wait ___ weeks minimum for elective surgery
6
what is normal tidal volume in ml/kg?
6-8 ml/kg
_____ % of total body weight = water _____ % of total body weight = intracellular volume _____ % of total body weight = extracellular volume _____ % of total body weight = interstitial fluid _____ % of total body weight = plasma fluid
60 % of total body weight = water 40 % of total body weight = intracellular volume 20 % of total body weight = extracellular volume 15 % of total body weight = interstitial fluid 5 % of total body weight = plasma fluid
what is the max % of receptors blocked for the following recovery test: sustained DBS
60%
what is the max % of receptors blocked for the following recovery test: sustained tetanus at 50 Hz
60%
whats the 60/40/20 (15/5) rule?
60% of total body weight = water Total body water is divided into intracellular and extracellular volume Intracellular volume = 40% of TBW Extracellular volume = 20% Extracellular volume is divided into interstitial fluid and plasma fluid Interstitial fluid = 15% of TBW Plasma fluid = 4% of TBW 60/40/20/15/5 Water, intracellular, extracellular, interstitial, plasma WIEIP
what is normal vital capacity in ml/kg?
65-75 ml/kg
Des VP
669
how many vertebrae are in the cervical column?
7
how long should clopidogrel be held before neuraxial anesthesia?
7 days
what is the max % of receptors blocked for the following recovery test: VC > 20 ml/kg (normal is 60-70 ml/kg)
70%
what is the max % of receptors blocked for the following recovery test: no fade with TOF
70%
what is the pressure (PSI) and volume (L) in the N2O cylinder?
745 PSI 1590 L
what is the max % of receptors blocked for the following recovery test: Vt > 5 ml/kg
80%
Normal 1 year old vitals
95/60, H 120, R 40
Child transfusion triggers for less than 4 months old
< 13 if kid has severe CP disease < 10 if child presenting for major surgery or child with mild CP disease >15% blood volume lost
define hypotension in the newborn, 1 year old, and pediatric pt (whats the equation?)
<60 for newborn <70 for 1 yr < 70 + age x 2
what is treatment of hypercalcemia?
NaCl loop diuretics
osmotic pressure is a function of .......
A function of the number of osmotically active particles in solution
A 100% increase in creatinine indicates a _____% __________ in GFR
A 100% increase in creatinine indicates a 50% reduction in GFR
what does a dibucaine number of 80 mean?
A NORMAL dibucaine number is 80... this means that dibucaine has inhibited 80% of of the pseudocholinesterase in the sample and suggests NORMAL ENZYME is present
What is metabolic syndrome?
A cluster of conditions that increase the risk of heart disease, stroke, and diabetes. Group of characteristics common to pts w/ DM or those who are at high risk of developing DM Fasting glucose > 110 Abdominal obesity - waist greater than 40 inches in men, 35 in W Serum triglyceride levels > 150 Serum HDL < 40 in < and 50 in W BP > 130/85
Gastroschisis
A congenital defect where the abd wall does not develop fully.. There is no membrane covering (sac) to protect the viscera Only the bowel is involved
A cuff that is too small _________ SBP, a cuff that is too large __________ SBP
A cuff that is too small overestimates SBP, a cuff that is too large underestimates SBP
what does it mean if there is a decreased rate of rise of FA/Fi
A decreased rate of rise of FA/Fi means slower induction (curve is pushed down)
what is an adductor canal block?
A femoral nerve block that is lower in the thigh this will only affect senroy (saphenous) branch of the femoral nerve and motor is preserved
what is the best way to minimize intraoperative heat loss?
A forced air warmer is the best way to minimize intraoperative heat loss
Joule Thompson effect
A gas stored a high pressure that is suddenly released escaped from its contain into a vacuum ... it quickly loses speed and sig amnt of kinetic energy, resulting in a fall in temp Ex = oxygen cylinder one quicky feels cool to touch
Fibronectin
A glycoprotein that helps cells attach to the extracellular matrix. Procoagulant
neonates require a ________ dose for water soluble drugs why?
A high TBW means that they require higher doses of water soluble drugs to achieve a given plasma concentration
A laboring mom w preterm fetus should receive _____________ to hasten fetal lung maturation. this drug begins to help fetus after ____ hrs and peak effect is ____ hrs
A laboring mom w preterm fetus should receive a corticosteroid (betamethasone) to hasten fetal lung maturation. Steroids begin to help fetus after 18 hrs and peak effect is 48 hrs
is right to left or left to right shunt an acyanotic shunt? give examples of acyanotic shunts
A left to right shunt is an ACYANOTIC shunt Causes oxygenated pulmonary venous blood to return directly to the lungs instead of being pumped to the body Examples = VSD, ASD, PDA, coarctation of the aorta
why does an Rh negative mother need to receive Rhogam?
A person who is Rh negative can be sensitized by exposure to Rh positive blood during transfusion or pregnancy An RH negative mother can be sensitized by her Rh positive fetus... the mother will receive rhogam to prevent sensitization. If the mom becomes sensitized and develops antibodies, a subsequent pregnancy with an Rh positive fetus can cause erythroblastosis fetalis
whats a phase I block?
A phase I block is a normal response to sux. It is characterized by the absence of post tetanic potentiation and demonstrates a constant but diminished response to double burst stimulation The presence or absence of fade is what distinguishes between a phase I and II block
whats a phase II block?
A phase II block occurs with an excessive dose of sux.. It is characterized by fade with tetany as well as prolonged duration It is most likely from a high dose of sux actually antagonizing the presynaptic receptor The presence or absence of fade is what distinguishes between a phase I and II block
a pudendal nerve root is best for which stage of labor?
A pudendal nerve block is not useful during the first stage of labor which is pain from T10-L1 It's good for second stage of labor which is pain from T10-S4
temporal lobe
A region of the cerebral cortex responsible for hearing and language. hearing is only temporary... you lose it when your older
occipital lobe
A region of the cerebral cortex that processes visual information occipital... ocular
parietal lobe
A region of the cerebral cortex whose functions include processing information about touch and sensation if you are in a pair, you have lots of feelings/sensations about the other person and you want to touch them
how does a right to left shunt affect induction of anesthesia w/ volatile anesthetic? does it affect drugs with higher or lower solubility more?
A right to left cardiac shunt will slow the speed of induction with a volatile anesthetic with a LOW solubility MORE THAN one with a higher solubility
is right to left or left to right shunt a cyanotic shunt? give examples of cyanotic shunts
A right to left shunt is a CYANOTIC shunt (R-> L = REAL bad) Allows blood to bypass the pulmonary circulation and enter systemic circulation Examples = TOF, transposition of the great arteries, tricuspid valve abnormality (Ebstein's anomaly), truncus arteriosus, total anomalous pulmonary venous connection
describe the differences in the scavenger system: active vs passive closed vs open
A scavenger can be active or passive.. An active system uses suction, a passive system relies on positive pressure of fresh gas leaving the interface A scavenger can be closed or open system... a closed system uses valves, an open system is open to atm
Acute chest syndrome
A symptom associated with sickle cell anemia where sickle cells get trapped in the lung and cause infection Caused by thrombosis embolism and infection More common in kids Chest pain, cough, dyspnea, wheezing Common in postop period Causes = hypoventilation, narcs, splitting, pain
Thorpe Tube
A variable orifice, constant pressure flow metering device The variable orifice architecture allows constant gas pressure throughout wide range of flow rates The ball is read in the middle, everything else is measured at the top
CVP waveform A wave = C wave = X descent = V wave = Y descent =
A wave = RA contraction C wave = tricuspid elevation into RA, RV contraction X descent = downward movement of contracting RV, RA relaxation V wave = RA passive filling Y descent = RA empties through open tricuspid valve
how do the following CVP waveform correlate with the EKG? A wave = C wave = X descent = V wave = Y descent =
A wave = RA contraction Just after p wave C wave = tricuspid elevation into RA, RV contraction Just after QRS complex X descent = downward movement of contracting RV, RA relaxation ST segment V wave = RA passive filling Just after T wave begins - ventricular repolarization Y descent = RA empties through open tricuspid valve After T wave ends
what kind of pain does A delta fibers transmit?
A-delta fibers transmit fast pain that is sharp and well localized
what is the ACT goal before going on bypass?
ACT goal for bypass is > 400 seconds
what neurotransmitor(s) are released from postganglionic PNS nerves?
ACh
does ADH change serum osmolarity? why or why not?
ADH controls serum osmolarity because it just increases the absorption of water, not sodium
Where is ADH produced?
ADH is produced by the supraoptic nucleus and paraventricular nuclei in the hypothalamus.. Its released into circulation by the posterior pituitary gland
Where is ADH produced and released?
ADH is produced in the supraoptic and paraventricular nuclei of the hypothalamus... its released form the posterior pituitary gland
ADH regulates ___________ channels in the __________ of the kidney.. This facilitates _________ reabsorption and restores blood volume and serum osmolarity
ADH regulates aquaporin 2 channels in the collecting ducts.. This facilitates water reabsorption and restores blood volume and serum osmolarity
what nerves does the psoas compartment block block? when is this block performed? how is it done? what are the contraindications?
AKA lumbar plexus block Blocks lateral femoral cutaneous, obturator and femoral/saphenous nerves The block is used when neuraxial anesthesia is CI and or anesthesia to only one extremity is preferred 3 cm lateral to L4 and then 5 cm deep Copography is CI - retroperitoneal hematoma and renal capsular injection are risks
what is ANP and why is it elevated in pts with HF?
ANP is increased in pts with HF d/t atrial dilation - ANP causes natriuresis
which murmurs are heard during diastole?
ARDS - Aortic Regurgitation is a Diastolic murmur heard at the right Sternal border MSDA - Mitral Stenosis is a Diastolic murmur heard at the Apex and left Axilla
what drug is an alternative to tPA if it is contraindicated?
ASA
What drugs undergo zero order kinetics?
ASA phenytoin alcohol warfarin heparin theophylline
what kind of cardiac shunt can lead to paradoxical embolism?
ASDs can cause paradoxical embolism during valsalva like maneuvers if RAP is > LAP
which murmurs are heard at the right sternal boarder?
ASSS - Aortic Stenosis is a Systolic murmur heard at right Sternal border ARDS - Aortic Regurgitation is a Diastolic murmur heard at the right Sternal border
which murmurs occur during systole?
ASSS - Aortic Stenosis is a Systolic murmur heard at right Sternal border MRSA - Mitral Regurgitation is a Systolic murmur heard at the Apex and left Axilla
____________ is a naturally occurring anticoagulant that circulates in the plasma
AT III is a naturally occurring anticoagulant that circulates in the plasma
what type of anesthetic should be avoided in severe aortic stenosis?
AVOID SPINALS! Sympathectomy rapidly decreases SVR leading to profound hypotension, reduced CPP and CV collapse epidurals for discretion
cranial nerve VI
Abducens eye movement
Difficult invasive airway predictors
Abnormal neck anatomy - tumor, hematoma, etc Obesity Short neck Laryngeal trauma Limited access to CTM
Duchenne Muscular dystrophy what are signs and symptoms?
Absence of dystrophin destabilizes sarcolemma during muscle contraction and increases membrane permeability Increased creatinine kinase Cardiac myocyte and skeletal muscle are at risk for degeneration Mitral regurg, CM, conduction defects Muscle weakness leads to kyphoscoliosis and reduces pulmonary reserve
if a pt is on a thrombolytic agent, how long must you wait to administer neuraxial anesthesia?
Absolute contraindication to neuraxial anesthesia
Absorbed volume during TURP procedure can be _________ ml/min of resection time... reception time should be limited to ______ hour(s) and the height of the solution should be no more than ______ cm above the OR table
Absorbed volume can be 10-30 ml/min of resection time... reception time should be limited to one hour and the height of the solution should be no more than 30 cm above the OR table
what are 3 functions of bile?
Absorption of fat soluble vitamins (DAKE) - (how does this affect clotting?) Excretory pathway for bilirubin and products of metabolism Alkalinization of the duodenum
why are antibiotic prophylaxis given to pts who may have premature birth?
Abx prophylaxis for chorioamnionitis
what are the names of the enzyme that metabolizes ACh?
Acetylcholinesterase Type 1 cholinesterase True cholinesterase Specific cholinesterase Genuine cholinesterase
what determines the duration of action of anticholinesterases?
Acetylcholinesterase is an enzyme that hydrolyzes ACh into choline and acetate... this enzyme can be inhibited at the anionic site and/or the esteratic site The type of bond is what determines the drug's duration of action
what is the enzyme that metabolizes ACh? where is it located? what are the metabolites?
Acetylcholinesterase is strategically placed around the nicotinic receptors to hydrolyze the ACh choline and acetate
what enzyme metabolizes ACh? what are the end products?
Acetylcholinesterase metabolises ACh to choline and acetate
Ache inhibitors will have a ceiling effect. what does this mean?
Ache inhibitors will have a ceiling effect where adding more drug will not have any additional benefit
what is the mV of the active state of the sodium channel? what happens when threshold potential is reached?
Active state = -70 - +35 mV When threshold potential is reached, the channel opens The open channel allows Na+ to follow its concentration gradient (outside to inside)
what symptoms are associated with acute pericarditis?
Acute chest pain is seen w/ a pleural component - increased pain w/ inspiration and posture changes. Relieved by leaning forward. ST elevation can be seen w/ normal enzymes. May have fever. Usually resolves spontaneously
how dose acute vs chronic cocaine use affect MAC?
Acute intoxication = increased MAC Chronic use = decreased MAC
what are the side effects of naloxone?
Acute reversal of analgesia with naloxone activates the SNS, causing tachycardia and HTN A significant increase in afterload can precipitate cardiac failure and pulmonary edema Naloxone also causes nausea and vomiting
what arrhythmias does adenosine treat? which does it not?
Adenosine does not treat afib, torsades, or vtach Only SVT and WPW with narrow QRS
adrenal insufficiency
Adrenal insufficiency is characterized by destruction of all cortical zones... this manifests as decreased production of mineralocorticoids, glucocorticoids, and androgens
Adult values of hepatic metabolism are reached by about _____ year old
Adult values of hepatic metabolism are reached by about 1 year old
describe blood flow through the kidneys
Afferent arteriole -> glomerular capillary bed -> efferent arteriole -> peritubular capillary bed
what is the treatment for RDS?
After delivery, first treatment is CPAP but may require intubation with exogenous surfactant delivered via ETT SpO2 should be maintained while keeping in mind that hyperoxia in addition to prematurity and low birth weight may contribute to ROP Preductal and postductal oxygen saturation monitoring should be used Risk of PTX of PPV in pt with poor lung compliance An arterial line is needed for frequent ABG sampling and HD assessment
why should NSAIDS be avoided after the first trimester?
After the 1st trimester, NSAIDS can close the ductus arteriosus in the fetus
what happens after the acute phase of neurogenic shock?
After the acute phase, spinal reflexes return and may lead to spasticity
what are predictors of postoperative pulmonary complications?
Age > 60 CHF COPD Cigarette smoking Surgical site Surgery longer than 2.5 hrs general anesthesia
Post Intubation laryngeal edema risk factors
Age less than or equal to 4 years ETT too big ETT cuff volume too high Traumatic intubation or too many attempts Prolonged intubation Head or neck surgery Head positioning during surgery Hx of infectious or post intubation croup Trisomy 21 URI
what kind of ETCO2 waveform will you see with airflow obstruction? give some examples
Airflow obstruction - COPD, bronchospasm, kinked ETT Prolonged upstroke w/ increased alpha angle
compare lung compliance, airflow resistance, residual volume in the neonate versus adult
Airflow resistance is increased Residual volume is increased Neonates have a lower lung compliance Taken together with the higher chest wall compliance, chest wall collapse during inspiration occurs (paradoxical breathing) and reduced lung volumes
what can make airway edema even worse in the parturient?
Airway edema made worse by preeclampsia, tocolytics and prolonged tburg Airway manipulation causes tissue trauma and bleeding
what electrolyte abnormality can albumin administration cause?
Albumin binds calcium and can contribute to hypocalcemia
Albumin ____________ in the elderly what does this protein do?
Albumin decreases in the elderly... it binds acidic drugs Esp decr w poor nutrition
what are advantages of colloid administration?
Albumin has anti-inflammatory properties Increases plasma volume for 3-6 hrs Less peripheral edema Smaller volume needed
Albumin, although derived from blood products, does not contain ___________, and does not increase the risk of ________________
Albumin, although derived from blood products, does not contain antibodies, and does not increase the risk of infectious disease transmission
what is the most common cause of chronic hepatitis?
Alcohol abuse is the most common cause of chronic hepatitis
aldosterone is purely ________corticoid
Aldosterone = purely mineralocorticoid
Aldosterone antagonists
Aldosterone antagonists (spironolactone) inhibits K+ excretion and sodium reabsorption by the principal cells in the collecting ducts. Blocks aldosterone a mineralocorticoid receptors
does aldosterone change serum osmolarity? why or why not?
Aldosterone does not change serum osmolarity because water follows sodium in direct proportion
what kind of hormone is aldosterone? in what part of the adrenal gland is it produced?
Aldosterone is a steroid hormone that is produced in the zona glomerulosa of the adrenal gland
which opioid has the quickest onset and why? how long does it take to reach effect site equilibrium?
Alfentanil has the quickest onset due to its low degree of ionization (all about the pka!) It achieves effect site equilibrium in 1.4 min (compared to 6.8 min for fentanyl) Because its pka is 6.5, it is 89% unionized at physiological pH... more molecules are lipid soluble to enter the CNS
All blood types can get type _______ blood
All blood types can get type O blood
which is the only cranial nerve that is not part of the peripheral nervous system?
All of the cranial nerves are part of the PNS EXCEPT the optic nerve - the optic nerve is the only cranial nerve surrounded by dura
what receptors are associated with the Gq protein?
Alpha 1 Muscarinic 1,3,5 Vasopressin 1 (vessels) Histamine 1 Gq → increased phospholipase C → increased IP3, DAG, Ca++
what is the name of the protein that binds to basic drugs?
Alpha 1 acid glycoprotein
Alpha 1 acid glycoprotein ___________ in the elderly what does this protein do?
Alpha 1 acid glycoprotein INCREASES in the elderly... it binds basic drugs
describe how alpha 1 antagonists work
Alpha 1 antagonists decrease vascular calcium concentration and causes vasodilation and decreases SVR
What is alpha-1 antitrypsin deficiency?
Alpha 1 antitrypsin def is a metabolic liver disease that causes emphysema
what receptors are associated with the Gi protein?
Alpha 2 Muscarinic 2,4 Dopamine 2 Gi → decreased adenylate cyclase → decreased cAMP **notice 2 and 4
what is the mechanism of action of precedex?
Alpha 2 agonist
name 2 antifibrinolytics
Alpha antiplasmin Plasminogen activator inhibitor
what is the difference between alpha and beta half life?
Alpha distribution = redistribution phase Beta elimination = elimination phase
why is it best to measure RUE BP in pt with coarctation of the aorta?
Although rare, coarctation may occur proximal to the left subclavian artery, reducing perfusion to the left upper extremity - for this reason, the right upper extremity is the best site to measure BP
Annular space
Annular space =area between widest area of the indicator float and side wall of the flowmeter
describe the alveolar gas equation
Alveolar gas equation tells us the partial pressure of oxygen in the alveolus Alveolar oxygen = FiO2 x (Pb - PH2O) - (PaCO2/RQ) All oysters fall AWay from crazy racoons AO, FiO2, atm, water, CO2,RQ Pb = 760 PH2O = 47 RQ = 0.8.... CO2 production (200 ml/min)/oxygen consumption (250 ml/min) = FiO2 x 713 - CO2/0.8 The Alveolar gas equation shows that hypoventilation causes hypercarbia and hypoxemia, supplemental oxygen reverses hypoxia but not hypercarbia, and that hypercarbia can go undetected in the pt breathing supplemental oxygen
what are the various safety relief devices available for cylinders?
Always open cylinder slowly Fusible plug that melts at elevated temps... typically made from woods metal (bismuth, lead, tin cadmium... BLT w cheese) Valve that opens at increased pressure Frangible disk that ruptures under pressure
what drugs are nephrotoxic?
Aminoglycosides are nephrotoxic - gentamicin, tobramycin, amikacin Cyclosporine and tacrolimus can cause HTN and renal constriction and can be nephrotoxic
Specific heat
Amnt of heat needed to increase the temperature of 1 gram of a substance by 1 degree C
An L/S ratio of _____ or greater suggests fetal lung maturity... less than _____ suggests immature fetal lungs and may place the fetus at risk for RDS
An L/S ratio of 2.0 or greater suggests fetal lung maturity... less than 2 suggests immature fetal lungs and may place the fetus at risk for RDS
what are etiologies of total spinal?
An epidural dose injected into the SA space An epidural dose injected into the subdural space A single shot spinal after a failed epidural block
why are neonates more sensitive to sedative hypnotics?
An immature BBB allows the passage of drugs that would otherwise not be able to enter the brain.. This partially explains the higher sensitivity to sedative hypnotics
what does it mean if there is a increased rate of rise of FA/Fi
An increased rate of rise of FA/Fi means a faster induction (curve is pushed up)
what is the most common location for a leak to occur in the low pressure system?
An internal leak in the vaporizer is the most common location for leak to occur in low pressure system this leak can only be detected if the vaporizer is on
what are the effects/side effects of kappa receptor stimulation?
Analgesia Resp depression Sedation DYSPHORIA Hallucinations Delirium Miosis DIURESIS antishivering effect This is why meperidine is the ONLY opioid to reduce shivering
describe the signs and symptoms of local anesthetic as the concentration in plasma increases from the progression of analgesia to CV collapse
Analgesia tinnitus, numbness of lips and tongue, skm twitching, restlessness, vertigo, blurred vision, hypotension, myocardial depression seizures, loss of consciousness coma, respiratory arrest CV collapse
what are the effects/side effects of mu receptor stimulation?
Analgesia Bradycardia Respiratory depression Sedation Euphoria Prolactin release Mild hypothermia Urinary retention NV Decreased peristalsis Pruritus Miosis Increased biliary pressure by constricting the sphincter of Oddi
Total spinal differential diagnosis in pregnancy
Anaphylactic shock Eclampsia AFE
for what type of surgery is an supraclavicular block indicated?
Anesthetizes arm, elbow, FA, wrist and hand... NOT shoulder
for what type of surgery is an infraclavicular block indicated?
Anesthetizes elbow, FA, and hand... NOT above the elbow
what drugs should be avoided in baby with TOF? why?
Avoid morphine, meperidine, atracurium - histamine release causes vasodilation and reduces SVR
what hormones are secreted from the anterior pituitary gland?
Anterior pituitary gland hormones = Flat Pig Follicle stimulating hormone Luteinizing hormone Adrenocorticotropic hormone Thyroid stimulating hormone Prolactin Ignore Growth hormone
Cushing's syndrome
Anterior pituitary gland releases excessive ACTH which increases cortisol released from zona fasciculata of the adrenal cortex
what is Beck's syndrome?
Anterior spinal artery syndrome Occurs with ischemia to lower portion of anterior spinal cord Occlusion of artery of adamkiewicz Causes flaccid paralysis of LE, bowel and bladder dysfunction, loss of temp and pain sensation
Leads V3, V4 monitor what side of the heart and which coronary artery?
Anterior wall LAD
which sensory tract's second order neuron will synapse with the first order in the dorsal horn laminae I, IV, V, VI where do the pain neurons synapse?
Anterolateral system (spinothalamic tract) Pain neurons synapse in the substantia gelatinosa in laminae II and III
how does warfarin work?
Anti vitamin K drugs - inhibits vitamin k dependent clotting factors 2,7,9,10
give examples of conditions that increase dead space
Anticholinergics are bronchodilators and INCREASES dead space by increasing the volume of the conducting zone Positive pressure ventilation increases alveolar pressure and INCREASES dead space Hypotension DECREASES pulmonary blood flow and INCREASES dead space Neck extension INCREASES the volume of the conducting zone and INCREASES dead space
what is the treatment of choice for bradycardia seen w/ autonomic hyperreflexia and why?
Anticholinergics are treatment of choice... sympathomimetics increase BP further
anesthetic considerations in pts with pyloric stenosis
Anticipate full stomach - intubate awake or with RSI Postop apnea is common possibly d/t the fact that CSF pH remains alkalotic even after serum AB status is normalized
Protein S
Anticoagulant
List 4 natural anticoagulants
Antithrombin III Protein C Protein S Tissue pathway factor inhibitor
how does obesity and pregnancy affect the volume of the epidural space?
Any condition that increases intra-abdominal pressure, like obesity or pregnancy, puts back pressure on the epidural veins... this increases the volume of blood contained within and thereby reduces the volume of the epidural space
why should etomidate be avoided in pts w/ acute intermittent porphyria?
Any drug that increases ALA synthase will accelerate the production of heme precursors Porphyria is caused by a defect in heme synthesis and accumulation of heme precursors presents as abd pain, psych symptoms, delirium, seizures, neuropathy and coma
Causes of PAOP to be UNDERestimated
Aortic insufficiency
what occurs after the application of an aortic cross clamp?
Application of an aortic cross clamp creates a central HYPERvolemia by reducing venous capacity, shifting a greater proportion of the blood volume proximal to the clamp, VR increases Clamping starves distal tissues of oxygen and anaerobic metabolic causes increased lactic acid production, increased prostaglandins, activated complement, myocardial depressant factors, decreased temperature
what is the name of the pathway in the brain that is between 3rd and 4th ventricle?
Aqueduct of Sylvius
Arachidoinic acid is liberated from the cell membrane in the kidneys in response to _____, _______, and ___________
Arachidoinic acid is liberated from the cell membrane in response to ischemia, NE, and angiotensin II
from which major blood vessel does the artery of Adamkiewicz arise from? from which spinal segments? what part of the spinal cord does it supply?
Arises from the aorta Originates between T8-12 Supplies the anterior spinal artery and anterior ⅔ of the SC
As a general rule, preload responsiveness is expected to be present if a 250 cc bolus increases SV by _____% or more
As a general rule, preload responsiveness is expected to be present if a 250 cc bolus increases SV by 10% or more
As a general rule, the ventral portion of the arm is supplied by _______, _______ and _________ nerves (________ and ________ cords) and the dorsal portion is supplied by ________ and ________ nerves (_______ cord)
As a general rule, the ventral portion is supplied by median, ulnar and musculocutaneous nerves (lateral and medial cords) and the dorsal portion is supplied by radial and axillary nerves (posterior cord)
As air flow in a tube moves past the point of constriction, the pressure at the constriction ____________ and if the pressure inside the tube falls below atm pressure, then _________________
As air flow in a tube moves past the point of constriction, the pressure at the constriction decreases and if the pressure inside the tube falls below atm pressure, then air is entrained into the tube
Venturi effect
As air flow in a tube moves past the point of constriction, the pressure at the constriction decreases and if the pressure inside the tube falls below atm pressure, then air is entrained into the tube Adjusting the diameter of the constitution allows for control of the pressure drop and the amnt of air that is sucked into the tube
what happens to SBP, DBP, and MAP as the pulse moves from aortic root towards periphery
As the pulse moves from the aortic root towards the periphery, the systolic pressure increases, diastolic pressure decreases, and the pulse pressure widens.... MAP remains constant through the arterial tree At the aortic root, the SBP is the lowest, DBP is the highest, and PP is the narrowest At the dorsalis pedis, the SBP is highest, the DBP is lowest, and PP is widest
what considerations should be made for the parturient having general surgery?
Aspiration prophylaxis after 14 weeks RSI Smaller ETT Avoid hypoxemia, hypotension, hyperventilation and acidosis Left uterine displacement for second and third trimester Avoid NSAIDS after first trimester because it closes ductus arteriosus
PT/INR what pathway does it measure? what drug's therapeutic response does it measure? what is the normal value in seconds?
Assess extrinsic and common pathways Measures therapeutic response to warfarin Normal is 12-14 seconds
PTT what pathway does it measure? what drug's therapeutic response does it measure? what is the normal value in seconds?
Assess intrinsic and common pathways Measures therapeutic response to unfractionated heparin, but not LMWH Normal is 25-32 seconds
Associate von willebrand factor with ________________ Associate ADP and thromboxane A2 with ___________ and ____________
Associate von willebrand factor with plt adhesion Associate plt activation and aggregation with ADP and thromboxane A2
Eaton-Lambert Syndrome
Associated with destruction of presynaptic voltage gated calcium channels, increased sensitivity to sux, and close association w/ small cell lung carcinoma Caused by IgG mediated destruction of the presynaptic voltage calcium channels at the presynaptic nerve terminal... when the action depolarizes the nerve terminal, calcium entry into the presynaptic neuron is limited, thereby reducing the amnt of ACh released into the synaptic cleft
preeclampsia pathophysiology
Associated with increased thromboxane, vasoconstriction and proteinuria Abnormal placental implantation creates an environment characterized by increased vascular resistance and reduced placental blood flow - the placenta and fetus do not receive adequate oxygen and metabolic substrate to develop in a normal way The healthy placenta produces thromboxane and prostacyclin in equal amounts The pt with preeclampsia produces 7x more thromboxane than prostacyclin - this favors vasoconstriction, plt aggregation and reduced placental blood flow Diseased placenta releases cytokines that promotes endothelial dysfunction
describe characteristics of asthma what is the ABG like?
Asthma is REVERSIBLE airway obstruction. Symptoms improve after bronchodilator therapy ABG = resp alkalosis w/ hypocarbia. Increased CO2 means impending resp failure
what are symptoms of aortic stenosis
Asymptomatic until LV dysfunction occurs syncope angina dyspnea on exertion (SAD)
at rest, is sodium conductance high or low in the ventricular myocyte?
At REST, sodium conductance is low... it will only increase dramatically once the voltage gated sodium channels open in response to depolarization
Henry's law
At a constant temperature, the amnt of gas that dissolves in the solution is directly proportional to the partial pressure of that gas over the solution
how do pts with Guillan Barre respond to sux and NDNMB?
Avoid sux Increased sensitivity to NDNMB
Avoid sux for at least _____ months after SCI
Avoid sux for at least six months after SCI
describe characteristics of the kidney and fluid balance in the newborn when does GFR reach adult levels? when does tubular function reach adult levels?
At birth, newborns have decreased perfusion pressure, GFR, and diluting and concentrating ability Neonates do a poor job conserving water, so they are intolerant of fluid restriction, but they are also unable to excrete large amounts of water, so they don't do well with water overload either Newborns are obligate sodium losers (excertors) ... they lack the ability to retain water and glucose GFR imporaves in first few days of life and is adult levels by 8-24 days of life Renal tubular function continues to improve after birth and reaches adult levels by 2 yrs old
At the aortic root, the SBP is the ______, DBP is the _______, and PP is the ____________ At the dorsalis pedis, the SBP is ___________, the DBP is ________, and PP is ___________
At the aortic root, the SBP is the lowest, DBP is the highest, and PP is the narrowest At the dorsalis pedis, the SBP is highest, the DBP is lowest, and PP is widest
why is cisatracurium an ideal paralytic to use in the ped pt?
Atracurium and cisatracurium are useful in the neonate d/t their organ independent elimination
describe the electrical pathway of an orthodromic AVNRT arrhythmia
Atrium - AVN - ventricle - accessory pathway - atrium
describe the electrical pathway of an antidromic AVNRT arrhythmia
Atrium - accessory pathway - ventricle - AVN - atrium
Atropine is a ___________, so it DOES cross the BBB because of this, what side effects can you see?
Atropine is a tertiary ammonium, so it DOES cross the BBB Causes more sedation, mydriasis, tachycardia
why is attempting to convert oliguric to non-oliguric AKI with diuretics dangerous?
Attempting to convert oliguric and nonoliguric AKI with diuretics increases risk of additional renal injury as well as mortality
what conditions REDUCE pseudocholinesterase activity?
Atypical PChE Severe liver disease Chronic renal disease Organophosphate poisoning Burns Neoplasm Advanced age Malnutrition Pregnancy
what is atypical pseudocholinesterase?
Atypical PChE is a qualitative defect... pseudocholinesterase is produced in sufficient quantity, but the enzyme that is produced is not functional Atypical PChE variants cannot hydrolyze sux, so the duration is prolonged
what is a tentative diagnosis for atypical pseudocholinesterase?
Atypical PChE variants cannot hydrolyze sux, so the duration is prolonged - a tentative diagnosis is made if TOF stimulation response is absent
Lupus what are the two most common drug causes of lupus? what are complications of lupus?
Autoimmune disease characterized by proliferation of antinuclear antibodies Hydralazine and isoniazid are the most common causes of drug induced lupus Complications Restrive lung defect Pulmonary HTN Pericarditis Raynauds Nephritis Raynauds
Rheumatoid Arthritis how does it affect the airway? what are other complications of RA?
Autoimmune disease that targets synovial joints Stiffness improves with activity TMJ → limited mouth opening Cricoarytenoid joint → Decreased diameter of glottic opening Cervical spine → AO subluxation w/ flexion, limited extension Complications Anemia AR Pulmonary effusions Renal insufficiency
Myasthenia Gravis
Autoimmune disease where IgG antibodies destroy post junctional, nicotinic, acetylcholine receptors at the NMJ ACh is present in sufficient quantity, but there aren't enough receptors to translate the extracellular signal into an intracellular response... the manifestation is muscle weakness Thymus gland plays a role... thymectomy may be warranted
what kind of drugs should be avoided in someone with carcinoid syndrome?
Avoid drugs that can precipitate vasoactive substance release by the tumor Those that release histamine -Morphine, atracurium, thiopental, sux Those that stimulate SNS -Ketamine and ephedrine Those that argument hormone release - NE -Potentiate hormone release Sux induced fasciculations can cause hormone release from the tumor
what measures can be taken to reduce pulmonary risk in pt with URI?
Avoid mechanical irritation of the airway -> facemask best, LMA second best ETT increase chance of bronchospasm 10 fold Dexamethasone decreases risk of post intubation croup 0.25-0.5 mg/kg Propofol attenuates airway reactivity and reduce the risk of bronchospasm Pretreat w/ bronchodilator or glyco does not provide clear benefit
describe the anesthetic goals for aortic stenosis
Avoid tachycardia, which decreases the time for ventricular filling and decreases SV/CO. HR goal 70-80 Increase preload - adequate filling needed for a non compliant ventricle Increase or maintain SVR. Hypotension should be avoided - it decreases coronary perfusion pressure and increases the chance of myocardial ischemia
describe sensory and motor tests for the following nerves Axillary nerve Musculocutaneous nerve Median nerve Radial nerve Ulnar nerve
Axillary nerve Sensory test = pinch lateral aspect of shoulder Motor test = arm abduction/deltoid contraction Musculocutaneous nerve Sensory test =Pinch lateral aspect of forearm Motor test = elbow flexion Median nerve Sensory test =pinch index finger Motor test = thumb opposition Radial nerve Sensory test = pinch web space between thumb and finger Motor test = elbow extension, wrist and finger extension Ulnar nerve Sensory test =Pinch pinky finger Motor test = pinky finger abduction Mnemonic = push'er, pull'em, pinch me, pinch u Radial - tell pt to extend forearm against resistance Musculotcutenous - tell pt to flex forearm against resistance Median - pinch index finger Ulnar - pinch pink finger
What Mapleson circuit is worst for spontaneous breathing?
B
Using bourdon pressure gage to calculate how much oxygen is left in a cylinder is an example of what gas law?
Boyle's law
Brachial plexus consists of nerve roots _______-______
Brachial plexus consists of nerve roots C5-T1
give two examples of cutting tip needles
quinke pitkin K = cutting
HCTZ (hydrochlorothiazide)
thiazide diuretic
Indapamide
thiazide diuretic
In vivo, local anesthetics affect the peripheral nerves in the following order:
B fibers > C fibers > small diameter A fibers > large diameter A fibers
Metolazone
thiazide diuretic
in what situations can beta blockers cause HF
BB can cause HF if SVR is increased
what factors can cause the blood brain barrier to become dysfunctional?
BBB becomes dysfunctional at sites of tumors, injury, infarction or ischemia
Difficult mask ventilation predictors
BONES Beard obese (BMI 26+) no teeth elderly snoring
what is a normal BUN:Cre ratio? what is an increased ratio and what does it mean?
BUN:Creatinine ratio is normally 10:1... >20:1 suggests prerenal azotemia
How is NEC managed?
Babies are medically managed unless bowel perf Goal: rest bowel, prevent injury, correct/modify response NPO- baby can't have food Check stool for blood NG tube w/ suction to prevent/treat infection Monitor CBC, platelets Thermoregulation key to prevent further deterioration (radiant warmer) Measuring abd. girth for any changes that could be indicitive of NEC Often have a metabolic acidosis and require substantial fluid replacement These babies are premature so they are at risk for ROP --> Decrease FIO2 and maintain SPO2 in mid 90s
what is the point of baffles and wicks in the variable bypass vaporizer?
Baffles and wicks increase the surface area in the variable bypass vaporizers
what is baricity? what increases it? what decreases it?
Baricity describes the density of local anesthetic solution relative to CSF Dextrose increases baricity, water decreases it Hyperbaric sinks, hypobaric floats
what is Batson's plexus?
Batson's plexus is the network of epidural veins that drain the spinal cord and the meninges... it typically passes through the lateral and anterior regions of the epidural space
what congenital defects have a characteristic large tongue?
Beckwith syndrome Trisomy 21 Think Big Tongue
PDPH treatment
Bed rest, hydration, NSAIDS, caffeine, epidural blood patch, sphenopalatine ganglion block
Before 6 months of age, there is a _________ concentration of albumin and alpha 1 acid glycoprotein
Before 6 months of age, there is a lower concentration of albumin and alpha 1 acid glycoprotein
what components make up the high pressure system?
Begins at cylinder ends at cylinder regulators cylinder pressure regulator cylinder pressure gauge yoke block with check valves hanger yoke
what components make up the low pressure system?
Begins at flowmeter tubes, ends at common gas outlet Slightly above atm pressure but variable flowmeter tubes common gas outlet check valve vaporizers
what components make up the intermediate pressure system?
Begins at pipeline, ends at flowmeter valves pipeline pressure (50 psi), tank pressure = 45 psi oxygen flush valve pipeline inlets pressure gauges oxygen pressure failure device oxygen second stage regulator ventilator power inlet flowmeter valves
Diaphragm contraction increase Vt is an example of what gas law?
Boyle's law
the first stage of labor begins with ___________ and ends with _______________
Begins with cervical dilation w/ regular uterine contractions and ends with full cervical dilation (10 cm)... it can be divided into the latent and active phases
the third stage of labor begins with _______ and ends with ____________
Begins with delivery of baby and ends with the delivery of placenta
the second stage of labor begins with ________ and ends with ____________
Begins with full cervical dilation and ends with the delivery of baby
what is the purpose of the benzene ring of the local anesthetic?
Benzene ring is lipophilic and permits diffusion through lipid bilayers
what receptors are associated with the Gs protein?
Beta 1 Beta 2 Dopamine 1 Vasopressin 2 (renal) Histamine 2 Gs → increased adenylate cyclase → increased cAMP
how does beta 1 stimulation increase contractility?
Beta 1 stimulation increases contractility by activating adenylate cyclase and cAMP, which increases calcium concentration
what drug can mask effects of hypoglycemia and why?
Beta blockers can blunt the increased SNS that accompanies hypoglycemia and diminish hyperglycemia effects of endogenous epi
Bile is produced by _________, stored in the ______________, released into the duodenum through the ________________
Bile is produced by hepatocytes, stored in the gallbladder, releaed into the duodenum through the ampulla of vater
How is vecuronium eliminated?
Biliary excretion (primary) and some renal excretion (secondary) and some metabolism.
bleeding time is a measure of ________ function and is increased by _____________
Bleeding time is a measure of platelet function and is elevated by uremia
what does bleeding time monitor? what is normal time in minutes?
Bleeding time monitors platelet function Evaluates ability to form platelet plug Normal is 2-10 min
why are calcium channel blockers used in OB?
Block influx of calcium into uterine muscle Nifedipine given po Co admin w/ mag contribute to skm weakness
blood partition coefficient
Blood partition coefficient is a measure of solubility Anesthetic dissolved in blood/anesthetic inside alveolus The higher the number, the more soluble, the slower the onset
pts with mitral valve stenosis are prone to what dysrhythmia
Blood stasis in the LA is prone to thrombus formation Prone to afib
Blood type _______ can get AB
Blood type AB can get AB
Blood types ______ and _______ can get blood type A
Blood types A and AB can get blood type A
Blood types ______ and ________ can get Blood type B
Blood types B and AB can get Blood type B
what lab abnormalities will you see with hemophilia?
Both hemophilias will have long PTT and normal PT
P1 x V1 = P2 x V2
Boyle's Law
Generalized opioid receptor stimulation effects
Bradycardia Minimal effect on BP in healthy pts Decreased BP w/ morphine and meperidine likely d/t histamine release Dose dependent vasodilation Baroreceptor reflex NOT AFFECTED Myocardial contractility not affected Shifts CO2 response curve to the right and reduces ventilatory response to CO2 Decreases RR and increases Vt Increased PaCO2 increases ICP if ventilation is not maintained Edinger Westphal nucleus sitmulation incrases PNS sitmaiton of ciliary ganglion and oculomotor nerve (CN III) which leads to pupil constriction (miosis) Tolerance does not develop to miosis** Chemoreceptor trigger zone stimulation - area postrema of the medulla Possible interaction with vestibular apparatus Minimal effects on evoked potentials Constriction of sphincter of Oddi increases biliary pressure -Reversed by naloxone or glucagon -Meperidine causes the lowest incidence Prolonged gastric emptying Slowed peristalsis leading to constipation Urinary retention Histamine release - morphine, meperidine, codeine Inhibits cellular and humoral immune function Suppression of natural killer cell function Re-sets hypothalamic temperature set point which decreases core body temperature
list allllllll of the side effects of sux
Bradycardia -M2 stimulation on SA node -Increased risk w/ second dose -Kids have high vagal tone, so they are more susceptible Tachycardia -ACh action on sympathetic ganglia HTN -ACh action on sympathetic ganglia Masseter spasm, although a warning sign of MH, is also a normal SET of sux K+ release Increased intraocular pressure Increased intracranial pressure Increased intragastric pressure -Contraction of abd muscles Malignant hyperthermia Muscle pain -Young adults, esp female, undergoing ambulatory surgery have highest risk -Elderly, kids, preg = LOWEST risk
what are the 5 branches of the brachial plexus?
Branches = musculocutaneous, axillary, radial, median, ulnar (MARMU)
fibrinolysis
Breakdown and removal of a clot Fibrinolysis is the mechanism that limits the size of the clot mediated by plasmin, tPA, urokinase
Causes of elevated peak pressure with a normal plateau pressure What will the ETCO2 waveform look like??
Bronchospasm Aspiration of foreign body Kinked ETT
Amyotrophic lateral sclerosis (ALS) signs, symptoms, manifestations?
Bulbar muscle weakness increases risk of aspiration Extrajunctional receptor at the NMJ can cause life threatening hyperkalemia Increased sensitivity to NDNMB Does NOT affect cardiac muscle Weakness begins in hands and then eventually spreads to rest of body - pharynx, larynx and chest Sensation remains intact Respiratory failure is the most common cause of death Chest weakness reduce VC and max Ve Spasticity Hyperreflexia Loss of coordination Muscle weakness Atrophy
describe the maximum doses for the following local anesthetics Bupivacaine Bupivacaine with epi Lidocaine Lidocaine with epi Ropivacaine Chloroprocaine
Bupivacaine - 175 mg (2.5 mg/kg) Bupivacaine with epi 200 mg (3 mg/kg) Lidocaine - 300 mg (4.5 mg/kg) Lidocaine with epi - 500 mg (7 mg/kg) Ropivacaine - 200 mg (5 mg/kg) Chloroprocaine 800 mg (11mg/kg)
why is cardiac morbidity HIGHER w/ Bupivacaine?
Bupivacaine has a greater affinity for the voltage gated sodium channel in the active and inactive states. The result is that more bupivacaine remains at the receptor for a longer period of time.. This is why cardiac morbidity is higher w/ bupivacaine and why resuscitation efforts are so difficult
Bupivacaine has a greater _______ block compared to other LA
Bupivacaine has a greater sensory block compared to other LA
which opioid partial agonist is hard to reverse with naloxone and why?
Buprenorphine is difficult to reverse with naloxone d/t its high affinity for the mu receptor
Burst suppression occurs at BIS of _____ GA Bis value is ________
Burst suppression occurs at BIS of 20 GA Bis value is 40-60
How is atracurium eliminated?
By ester hydrolysis (nonspecific esterases) & Hoffman elimination (pH & temperature dependent degradation) A comes first in the alphabet, so it undergoes both processess
By inhibiting _________________, a single induction dose of etomidate will cause adrenocortical suppression for more than ___________ hrs... this can convert adrenal insufficiency to _____________
By inhibiting 11 beta hydroxylase, a single induction dose of etomidate will cause adrenocortical suppression for more than 8 hrs... this can convert adrenal insuf to adrenal crisis
how does arachidonic acid antagonize the effects of the RAAS on renal blood flow?
By producing vasodilating prostaglandins, arachidonic acid antagonizes the effects of RAAS on the renal blood flow
How is mivacurium metabolized?
By pseudocholinesterase
By setting the concentration on the dial, you are determining the __________ what does setting a higher % on the dial do on a variable bypass machine?
By setting the concentration on the dial, you are determining the splitting ratio.... Higher % means more gas flows over the bypass chamber and picks up more molecules
what kind of pain do C fibers transmit?
C fibers transmit slow pain that is dull and poorly localized
what is the relationship between CBF and CMRO2?
CBF is coupled to CMRO2 - the higher the need for oxygen, the more blood flow there will be to satisfy that need
what part of the brachial plexus does an interscalene block target?
C5,6,7 upper and middle trunks
what roots form the superior trunk of the brachial plexus?
C5-6 = superior trunk
what roots and cords form the axillary branch?
C5-6 → posterior cord → axillary
what roots and divisions form the lateral cord?
C5-C7 → anterior divisions of superior and middle trunk → lateral cord
what roots and cords form the musculocutaneous branch?
C5-C7 → lateral cord → musculocutaneous
what roots and divisions form the posterior cord?
C5-T1 → all posterior divisions → posterior cord
what roots and cords form the median branch?
C5-T1 → lateral and medial cord → median
what roots and cords form the radial branch?
C5-T1→ posterior cord → radial
what do the following dermatomes correlate with? C6 = C7 = C8 = T4 = T6 = T10 = T12 = L4 =
C6 = first digit thumb C7 = 2nd and 3rd digits C8 = 4th and 5th digits T4 = nipple line T6 = xiphoid process T10 = umbilicus T12 = pubic symphysis L4 = anterior knee
what roots form the middle trunk of the brachial plexus?
C7= middle trunk
what roots form the inferior trunk of the brachial plexus?
C8-T1 = inferior trunk
what roots and divisions form the medial cord?
C8-T1 → anterior division of inferior trunk → medial cord
what roots and cords form the ulnar branch?
C8-T1 → medial cord → ulnar
what kind of medication is contraindicated when treating malignant hyperthermia?
CALCIUM CHANNEL BLOCKERS ARE CONTRAINDICATED Life threatening hyperkalemia occurs when given w/ dantrolene
what enzyme stimulates gallbladder contraction and increases flow of bile to the duodenum?
CCK stimulates gallbladder contraction and this increases the flow of bile to the duodenum
what are signs and symptoms of CDH?
CDH is diagnosed at birth - the child will be in resp distress and have a scaphoid abd Other findings = barrel chest, cardiac displacement and fluid filled GI segments in the thorax
CDH most commonly occurs through the foramen of _______, usually on the ________ side of the diaphragm
CDH most commonly occurs through the foramen of Bochdalek, usually on the LEFT side of the diaphragm
what are complications of osmotic diuretics?
CHF pulmonary edema cerebral edema if BBB is disrupted
why is there increased RAAS activity in pts with CHF
CHF decreases renal blood flow, which causes increased activity of the RAAS
in general, the closer the LA's pka is to physiologic pH, the quicker the onset of action.. which LA is the exception to this rule? why?
CHLOROPROCAINE IS AN EXCEPTION It has a higher pka, but since it is not very potent, you have to give a larger dose... giving more molecules creates a mass effect
when do the follow labs increase, peak and return to baseline after an MI: CKMB Troponin I Troponin T
CKMB increases 3-12 hrs and peaks 24 h, baseline 2-3days Troponin I increases 3-12 hrs and peaks 24 h, baseline 5-10 days Troponin T increases 3-12 h and peaks 12-48 h, baseline 5-14 days
what is normal CMRO2?
CMRO2 = 3 ml/O2/100 g brain tissue/min
CMRO2 decreases by _____% for every 1 degree C _______ in temp
CMRO2 decreases by 7% for every 1 degree C decrease in temp
what is the relationship between CMRO2 and temperature?
CMRO2 decreases by 7% for every 1 degree C decrease in temp
Causes of reduced fetal variability
CNS depressant drugs - opioids, sedative, anesthetic agents, barbiturates, magnesium Hypoxemia Fetal sleep Acidosis Anencephaly Cardiac anomalies
how does CO change during the first stage of labor, second stage of labor, and third stage of labor? when does CO return to pre-labor and pre-pregnancy values?
CO is increased 20% first stage labor, 50% second stage labor, 80% third stage labor Returns to pre labor values in 24 hrs and prepreg values in 2 weeks
how does CO affect the oxyhemoglobin curve? how is CO poisoning treated?
CO shifts oxyhgb curve to the left CO is produced in soda lime, esp after desiccation. Production is highest with desflurane CO poisoning is treated with oxygen therapy
cite the soda lime reaction
CO2 + H2O → H2CO3 H2CO3 + NaOH ⇒ Na2CO3 + H2O + heat Na2CO3 + Ca(OH)2 → CaCO3 + 2 NaOH
describe how carbonic anhydrase inhibitors work
CO2 and water diffuse into the PCT cell... CA facilitates the production of H2CO3... H2CO3 dissociated into H and HCO3... HCO3 diffuses into the interstitium and then the blood... H is pumped back into the tubular lumen CA inhibitors Inhibit carbonic anhydrase in cells that make up the proximal tubule Inhibition of carbonic anhydrase reduces reabsorption of bicarb, water and sodium
CO2 diffuses across BBB and causes ___________ cerebrovascular resistance
CO2 diffuses across BBB and causes decreased cerebrovascular resistance
CO2 is mostly carried in the blood via ________
CO2 is mostly carried in the blood via bicarb. It is also bound to hgb and dissolved in plasma
CO2 narcosis when PaCO2 > ______
CO2 narcosis when PaCO2 > 90
what factors increase closing capacity?
COPD LVF obesity supine extremes of age pregnancy CLOSE-P
describe COPD
COPD is characterized by reduced max expiratory flow and slow forced emptying of the lungs that is NOT FULLY REVERSIBLE Decreased elastic recoil leads to air trapping and increased RV Secretions cause airflow obstruction and bronchospasm
what are causes are right axis deviation?
COPD, acute bronchospasm, cor pulmonale, plum HTN, plum embolism
what is the equation for cerebral perfusion pressure?
CPP = MAP - ICP or CVP , whichever is higher
what is the equation for coronary perfusion pressure?
CPP = aortic DBP - LVEDP
what is the normal range for cerebral autoregulation? what happens when the pressure is less or more than this range?
CPP autoregulation 50-150 mmhg Less than 50 and more than 150 → perfusion pressure dependent <50 = risk of cerebral hypoperfusion > 150 = risk of cerebral edema and hemorrhage
what is the purpose of CSF?
CSF cushions brain, provides buoyancy, delivers optimal conditions for neurological function
CSF is produced by _________ cells in the ___________________ at _____ ml/hr
CSF is produced by ependymal cells of the choroid plexus at 30 ml/hr
what are causes of early fetal deceleration?
Caused by fetal head compression Head compression increases vagal tone Onset and offset parallels uterine contractions Loses variability with each decel No risk of fetal hypoxemia
Systemic effects of neuraxial anesthesia CV respiratory CBS neuroendocrine GI
CV Sympathectomy = vasodilation Bradycardia d/t blockade of preganglionic cardioaccelerator fibers T1-4 and unloading of ventricular mechanoreceptors stimulated Bezold Jarisch reflex Resp Accessory muscle function is reduced by neuraxial block... impairment of the intercostal muscles (inspiration and expiration) as well as the abdominal muscles (ability to cough and clear secretions) will decrease pulmonary reserve... this is especially important for pt w/ severe COPD Loss of proprioception from chest may cause pt to complain of dyspnea Apnea is usually due to cerebral hypoperfusion, NOT d/t phrenic nerve paralysis CNS Reduces sensory input to RAS and can cause drowsiness Neuroendocrine Diminished response to surgical stress Reduces levels of circulating catecholamines, renin, angiotensin, glucose, thyroid stimulating hormone and growth hormone GI Increased peristalsis from decreased sympathetic input
what is normal CaO2 in mL/O2/dL
CaO2 = 20 mL/O2/dL
what determines CaO2?
CaO2 is determined by oxygen dissolved in plasma (PO2 x 0.003) and oxygen bound to hgb
How is calcitriol produced? what two organs are involved?
Calcitriol is synthesized from ingested vitamin D or after exposure to UV light In the liver, calciferol is converted to inactive vitamin D3 In the kidney, under the control of PTH, inactive vitamin D3 is converted to active vitamin D3
name the five second messengers
Calcium cGMP DAG cAMP IP3
Hyperkalemia treatment
Calcium insulin + D50 hyperventilation bicarb albuterol K sparing diuretics dialysis
why is magnesium sulfate given to an OB pt?
Calcium antagonist - relaxes smooth muscle in vasculature, airway and uterus Hyperpolarizes membranes in excitable tissue used for seziure prophylaxis if preeclampsia
why give calcium to treat hyperkalemia? what is the dose?
Calcium chloride 20 mg/kg Calcium gluconate 60 mg/kg Calcium stabilizes myocardium
Carcinoid syndrome is associated with secretion of vasoactive substances from _______________ cells... its usually associated with tumors of the ______________ but can also arise in other locations
Carcinoid syndrome is associated with secretion of vasoactive substances from enterochromaffin cells... its usually associated with tumors of the GIT but can also arise in other locations
do cardiac myocyte or skeletal muscle contain more mitochondria?
Cardiac myocytes contain MORE mitochondria when compared to skeletal muscle
what causes cardiac oscillations to be seen on the ETCO2
Cardiac oscillations Result from heart beating against lungs More common in kids d/t close proximity of the heart to the lungs
why is proper positioning of hyperthyroid pt esp important?
Careful with positioning.. Increased bone turnover = risk of osteoporosis
describe how motor signals are transmitted via the corticospinal tract
Carries motor signals from the cerebral cortex to the muscles of the body Motor neurons exit the precentral gyrus of the frontal lobe and pass through the pyramids of the medulla
what part of the adrenal gland secretes catecholamines? in what proportion?
Catecholamines secreted from medulla - epi 80% and NE 20%
what is anion gap vs non anion gap metabolic acidosis
Cause is aided by determining anion gap - major cation minus major anions (sodium - (chloride + bicarb)) Anion gap is caused by an accumulation of acids Non gap acidosis is caused by loss of bicarb or ECF dilution
what are causes of metabolic alkalosis?
Caused by increased bicarb and or loss of nonvolatile acids addition of bicarb loss of non volatile acid increased mineralocorticoid activity vomiting (produces H+ loss from the stomach) massive transfusion - liver converts citrate to bicarb, loss of gastric fluid - NG suction diuretics ECF depletion cushing's syndrome hyperaldosteronism
what are causes of late fetal deceleration?
Caused by maternal acidosis, preeclampsia, hypovolemia, hypotension Decreased uteroplacental perfusion leads to fetal compromise FHR falls after the peak of contraction then returns to baseline after contraction Gradual reduction in FHR There is risk of fetal hypoxemia and requires urgent fetal assessment
Causes of decreased SvO2
Causes of decreased SvO2 = increased oxygen consumption or decreased oxygen delivery Anemia Thyroid storm Stress Pain Shivering Fever Decreased PaO2, hgb, CO
Causes of increased SvO2
Causes of increased SvO2 = decreased oxygen consumption or increased oxygen delivery Cyanide toxicity - impaired O2 utilization (SNP) Sepsis - high CO + arterial admixture Hypothermia Increased PaO2, increased hgb, CO
cerebral herniation is a risk of increased _______ where is the most common site of herniation?
Cerebral herniation is a risk of increased ICP Most common site of transtentorial herniation = temporal uncus
what is cerebral oxygen delivery (NIRS)?
Cerebral oximetry (NIRS) measures regional cerebral oxygenation... its based on the fact that decreased oxygen delivery = increased extraction = decreased venous hgb saturation > 25% change from baseline suggests a reduction in cerebral oxygenation
causes of increased ICP
Cerebral swelling Tumor Increased cerebral blood flow Bleeding Increased CSF production by choroid plexus Reduced CSF removal by arachnoid villi Obstruction or reabsorption of CSF by bleeding, infection or tumor Passage of fluid across the BBB
Tetralolgy of Fallot characterized by what four cardiac defects?
Characterized by VSD, aorta that overrides the RV and LV, pulmonic stenosis (obstructs RV ejection), and RV hypertrophy V OAPS RVH RVOT, RVH due to high pressure load from RV obstruction, VSD due to septal malalignment, overriding aorta receives blood from both ventricles
Guillain Barre Syndrome
Characterized by an immunological assault on myelin in the peripheral nerves... the action potential cannot be conducted ascending paralysis that is proceeding by influenza like illness
DIC
Characterized by clotting and fibrinolysis that leads to hemorrhage and systemic thrombosis
V1/T1 = V2/T2
Charles' Law
LMA cuff rupture when placed in autoclave is example of what gas law?
Charles's Law
what is the problem with chest compression in someone w/ aortic stenosis?
Chest compressions do not generate enough pressure to overcome stenotic valve
describe how ACh is synthesized and released in the body
Choline + acetyl CoA (from mitochondria) (ChAT) → ACh Voltage gated calcium channels open in response to AP and release ACh filled vesicles
Chronic hepatitis = hepatic inflammation longer than ____ months
Chronic hepatitis = hepatic inflammation longer than 6 months
what are the intubating doses of the following Cisatracurium Vecuronium Atracurium Rocuronium =
Cisatracurium = 0.1 mg/kg Vecuronium = 0.1 mg/kg Atracurium = 0.5 mg/kg Rocuronium = 0.6 mg/kg
list the NDNMB from MOST to LEAST potent
Cisatracurium = vecuronium, atracurium, rocuronium
what stimulates the newborn to breath once born?
Clamping of the umbilical cord stimulates the newborn to breathe rhythmically and the acute increase in PaO2 promote continuous breathing
describe the mechanism of action of the following classes of antiarrhytmic drugs Class 1 = Class 2 = Class 3 = Class 4 =
Class 1 = sodium channel blockers Class 2 = beta blockers Class 3 = K channel blockers Class 4 = calcium channel blockers So be K cal
Classic foreign body aspiration presentation supraglottic versus infraglottic obstruction
Classic FBA presentation = cough, wheezing, and decreased breath sounds on the affected side (usually the right) Can quickly progress to hypoxia, cyanosis, AMS, cardiac arrest and death Supraglottic obstruction → stridor Infraglottic obstruction → wheezing
what is the classic triad of TURP syndrome? what are other s/sx?
Classic triad = HTN with increased PP, reflex bradycardia, change in mental status Sodium < 110 is associated with seizures, coma, and LV arrhythmias Other s/sx = restlessness, NV, cerebral edema, seizures, coma, hemolysis, CHF, pulmonary edema, MI
when does autonomic hyperreflexia most likely occur if during an operation?
Close postop monitoring - AH may present once anesthesia wears off
what is a closed circuit? list examples of closed circuits
Closed = complete rebreathing w/ a reservoir Circle system w/ very low FGF and APL closed
omphalocele may be associated with what other conditions?
Co existing diseases include trisomy 21, cardiac defects, Beckwith-Wiedemann syndrome
what are contraindications to neuraxial anesthesia?
Coagulopathy - risk of spinal or epidural hematoma Plt count < 100,000 PT, aPTT, and or bleeding time twice the normal value Increased ICP - increased chance of brain herniation w/ sudden changes in CSF pressure Sepsis - introduction of contaminated blood beyond BBB ... also worsens hypotension from neuraxial sympathectomy Infection at the puncture site Hypovolemia Valve lesions w/ fixed SV AS,MS, HCM Scoliosis, arthritis, spinal fusion, osteoporosis Difficult airway Full stomach Peripheral neuropathy Multiples sclerosis --> Exacerbates symptoms
_______________ at the site of vascular injury activates the platelets Activated platelets release ________ and _______________ ____________ and _________ activate nearby platelets and facilitate aggregation __________ also causes vasoconstriction Activated platelets release their contents and become ____________
Collagen at the site of vascular injury activates the platelets Activated platelets release ADP and thromboxane A2 ADP and TxA2 activate nearby platelets and facilitate aggregation TxA2 also causes vasoconstriction Activated platelets release their contents and become sticky
describe the process of platelet activation
Collagen at the site of vascular injury activates the platelets Activated platelets release ADP and thromboxane A2 ADP and TxA2 activate nearby platelets and facilitate aggregation TxA2 also causes vasoconstriction Activated platelets release their contents and become sticky
compare chest wall compliance in the neonate versus adult
Compared to the adult, chest wall compliance is increased due to the cartilaginous rib cage that provides less structural support and closing capacity is increased
what are special properties and considerations about flumazenil?
Competitive antagonist of GABA A receptor Reverses benzo overdose Initial dose 0.2 mg, then titrated in 0.1 mg increments High affinity, short duration (30-60 min) repeat dosing may be needed Reversal does not increase SNS tone, anxiety of neuroendocrine evidence of stress like naloxone does Reverses sedation effects more than amnestic effects
what are the consequences/signs and symptoms of complete SCI?
Complete SCI damages upper motor neurons which leads to flaccid paralysis and loss of sensation below the level of injury. Also loss of bowel and bladder function.
what is compliance?
Compliance = ∆V/∆P
what complications are associated with an axillary block?
Complications = hematoma and LA toxicity
how do conditions that increase dead space affect the volume of the conducting zone and/or pulmonary blood flow?
Conditions that INCREASE dead space tends to INCREASE the volume of the conducting zone or DECREASED pulmonary blood flow
what is the fourth source of heat loss in the OR? what is the mechanism?
Conduction = <5% Heat loss with direct contact
Ebstein's anomaly
Congenital defect of the tricuspid valve Usually also an ASD or PFO Characterized by downward displacement of the tricuspid valve and atrialization of the RV TR can be severe R to L shunt occurs at level of atria SVT is common RVF can occur
Tracheoesophageal fistula (TEF)
Congenital defect resulting in a connection between the esophagus and trachea
what kind of nerve fibers make up the dorsal column pathway?
Consists of large, myelinated, rapidly conducting fibers A beta
how does constriction of the afferent arteriole affect RBF and GFR?
Constriction of the afferent arteriole reduces RBF and GFR
how does constriction of the efferent arteriole affect hydrostatic pressure and GFR?
Constriction of the efferent arteriole increases hydrostatic pressure and GFR
what causes constrictive pericarditis?
Constrictive pericarditis is caused by fibrosis or in a condition in which the pericardium becomes thicker Caused by radiation, cardiac surgery, TB, RA, uremia Ventricles can't fully relax during diastole Arrhythmias from atrial distension
Describe propofol infusion syndrome what causes it? what are the signs and symptoms?
Contains long chain triglycerides - increased LCT load impairs oxidative phosphorylation and fatty acid metabolism - this starves cells of oxygen, esp in cardiac and skm Propofol infusion syndrome presents w/ acute refractory bradycardia that can lead to asystole + at least one of the following Metabolic acidosis (base def > 10 mmol/L) Rhabdomyolysis enlarged/fatty liver Renal failure HLD Lipemia (cloudy plasma/blood)
what is the second most common mechanism for heat loss in the OR? what is the mechanism?
Convection = 30% #2 source of heat loss Transfer of heat by movement of matter (air) Wind chill
what part of the brachial plexus is targeted by an infraclavicular block?
Cord level block
what are the 3 cords of the brachial plexus?
Cords = lateral, posterior, medial (lets play music)
what is the equation for coronary blood flow
Coronary blood flow = coronary perfusion/coronary vascular resistance
what is coronary reserve?
Coronary reserve is the difference between coronary blood flow at rest and max dilation
Correcting sodium too quickly can cause __________________
Correcting sodium too quickly can cause central pontine myelinolysis
what is the name of the drug that is given to hasten fetal lung maturity? why is it given? how long does it take to work? what other medication is giving in conjunction and why? after how many weeks gestation is this drug rarely given?
Corticosteroids (betamethasone) hasten fetal lung maturity Need 18 hrs to take effect, peak effect at 48 hrs Tocolytics stop labor for 24-48 hrs - they provide a bridge to allow the steroids to work - seldom given after 33 weeks
how does cortisol work intracellularly to exert its physiologic actions?
Cortisol does not interact with membrane bound receptors... it diffuses through the lipid bilayer and then binds with intracellular steroid receptors. By activating or inhibiting DNA transcription, cortisol influences protein synthesis inside the target cells... this is why there is such a slow onset for steroid meds
which steroid is purely mineralcordicoid? which are purely glucocorticoid? which has equal mineral and glucocorticoid effects?
Cortisol has equal glucocorticoid (anti inflammatory) and mineralocorticoid (sodium retaining effects) effects Aldosterone = purely mineralocorticoid Dexamethasone, betamethasone, and triamcinolone are purely glucocorticoid
what are the physiologic effects of cortisol?
Cortisol has equal glucocorticoid (anti inflammatory) and mineralocorticoid (sodium retaining effects) effects Energy mobilization - increased blood sugar Protein catabolism Antiinflammatory effects - reduces cytokines via epi and beta 2 receptor on mast cells Cortisol improves myocardial performance by increasing the number and sensitivity of beta receptors on the myocardium Cortisol is also required for the vasculature to response to vasoconstrictive effects of catecholamines
Creatinine clearance _________ as we age
Creatinine clearance decreases as we age
how are creatinine clearance and BUN affected during pregnancy?
Creatinine clearance increases as a function of increased intravascular volume and CO in preg... this DECREASES creatinine and BUN
what is the most sensitive indicator of renal function and drug clearance in the elderly?
Creatinine clearance is the most sensitive indicator of renal function and drug clearance in the elderly
what lab test is the most useful indicator of GFR?
Creatinine clearance is the most useful indicator of GFR
creatinine is produced by __________
Creatinine is produced by skeletal muscle - it is constant and directly proportional to muscle mass
what is the relationship between creatinine and skeletal muscle mass?
Creatinine is produced by skeletal muscle - it is constant and directly proportional to muscle mass
cricoid pressure for RSI should be how many N and kg? what consequences are associated with cricoid pressure?
Cricoid pressure for RSI should be 20 N (2 KG) before asleep and 40 N (4 KG) after asleep Associated with REDUCED LES TONE and esophageal rupture if pt vomits
describe cricothyrotomy
Cricothyrotomy is done by creating a small HORiZONTAL incision through the CTM and then inserting am ETT through the hole Make a 2- to 3-cm midline vertical incision through the skin from the caudal end of the thyroid cartilage to the cephalic end of the cricoid cartilage Make a 1- to 2-cm transverse incision through the cricothyroid membrane
Factors that increase risk of PDPH
Cutting tip Needle orientation - perpendicular worse than parallel Use of air for LOR - can create pneumocephalus Younger age Female Pregnancy
what is normal CvO2 in mL/dL
CvO2 = 15 ml/dL
how do NSAIDS affect renal vascular resistance, RBF, and GFR?
Cyclooxygenase inhibition by NSAIDS increases renal vascular resistance and reduces RBF and GFR
What Mapleson circuit is best for controlled ventilation?
D
describe management techniques to decrease cerebral edema
D5LR contains glucose and in the setting of cerebral ischemia, glucose makes it worse because excess glucose is converted to lactic acid Neck flexion/extension compressed jugular veins and reduced venous drainage from the brain Lasix decreases CSF production and reduces cerebral edema Osmotic diuretics -Avoid if BBB is disrupted -Mannitol can transiently increase blood volume and stress a failing heart Dexamethasone and methylprednisolone reduce cerebral edema caused by mass lesions
list as many hypotonic solutions as you can
D5W NaCl 0.45%
what is the treatment for diabetes insipidus?
DDAVP
Conditions that impair AO mobility
DJD RA ankylosing spondylitis trauma surgical fixation down syndrome klippel feil DM (joint glycosylation) Goldenhar
what is normal DO2 in ml/min
DO2 = 1000 ml/min
volume % is an example of which law?
Dalton's law of partial pressures Volume % is a way to communicate a solution's concentration - is expressed as a volume fraction over a denominator of 100% Volume % = partial pressure/total pressure x 100
Describe West zone 1
Dead space Alveolar pressure > Arterial pressure > venous pressure
what pulmonary changes are associated with the elderly pt? -dead space -PaO2 -lung elasticity -chest wall compliance -pulmonary reserve
Dead space is increased in the elderly Aging is associated with reduced PaO2, lung elasticity, and CW compliance All of these changes together reduce pulmonary reserve and increase the risk of resp failure
how is CO changed in the elderly? how does this affect IV versus inhalation induction?
Decreased CO in elderly = faster inhalation induction and slower IV induction
why do elderly pts have a decreased chest wall compliance?
Decreased CW compliance - its stiffer and less able to expand This is due to increased calcification of joints, diaphragm flattening, increased AP diameter, decreased intervertebral disc height, decreased resp muscle strength from decreased muscle mass, decreased elastic recoil
Describe the following lung values in obstructive lung disease FRC FEV1 FEV1/FVC FEF 25-75% RV TLC
Decreased FEV1/FVC, decreased FEF25-75 Increased RV, FRC, TLC if gas trapping
when the fetus is transitioning to extrauterine life, what causes the foramen ovale to close?
Decreased PVR + increased SVR causes LA pressure to be greater than RA pressure and the flap valve closes the foramen ovale
when the fetus is transitioning to extrauterine life, what causes the ductus arteriosus to close?
Decreased PVR causes reversal of blood flow through the ductus arteriosus and causes DA closure Decreased circulating PgE1 (which is released from the placenta) causes DA closure
what are the side effects associated with using distilled water for TURP procedure?
Distilled water can cause hemolysis Hyponatremia, hemolysis, hemoglobinuria
how does cirrhosis affect the following: SVR CO RAAS blood volume peripheral blood flow response to vasporessors cardiac function hepatic vascular resistance pulmonary funciton renal function coagulation neuro status
Decreased SVR, increased CO, increased RAAS, increased blood volume, increased peripheral blood flow and shunting, decreased response to vasopressors, diastolic dysfunction, increased hepatic vascular resistance and back pressure to organs, esophageal varices - bleeding, splenomegaly - thrombocytopenia, decreased oncotic pressure, decreased protein binding, decreased Vd, ascites , portal HTN Hepatopulmonary syndrome - pulmonary vasodilation = shunting Restrictive ventilatory defect - ascites and pulmonary effusion Hepatic encephalopathy - increased ammonia = cerebral edema and increased ICP Bleeding = increased nitrogen load and encephalopathy Renal hypoperfusion Hepatorenal syndrome - decreased GFR = renal failure Anemia Reduced coagulation factor production Thrombocytopenia
how are albumin and pseudocholinesterase levels affected during pregnancy?
Decreased albumin and pseudocholinesterase activity occurs in pregnancy
how do elderly individuals respond to ADH and aldosterone
Decreased aldosterone sensitivity in elderly = inability to conserve sodium Decreased ADH Reduced response
what things cause the pulse ox to be inaccurate?
Decreased perfusion Methylene blue, ICG, IV dyes Nail polish CPB, LVAD Motion artifact - shivering, movement, positioning
what are causes of reduced uterine blood flow?
Decreased perfusion - maternal hypotension - sympathectomy, hemorrhage, aortocaval compression Increased resistance - uterine contraction, HTN conditions that increase SVR
how are the metabolism of sux and roc affected by liver failure?
Decreased pseudocholinesterase activity can occur with liver failure (sux), decreased biliary excretion (roc) and large Vd
Incompetent unidirectional valve findings
Decreased slope during inspiratory phase w/ a wide beta angle There is CO2 in the limb w/ the faulty unidirectional valve The waveform may or may not reach zero depending on the FGF
why does osteodystrophy occur in someone with CKD?
Decreased vitamin D production and secondary hyperparathyroid
what is the LPM and PSI that the oxygen flush valve delivers?
Delivers flow 35-75 LPM Oxygen pressure is 50 PSI
what components make up the delivery part of the anesthesia machine?
Delivery = how the prepared gases are brought to the pt Breathing circuit
Depolarization
Depolarization occurs when there is a reduced polarity across the cell membrane - there is less of a charge difference between inside and outside of the cell
what is the difference between a descending vs ascending bellows? how do they respond differently to a circuit leak?
Descending bellows fall with expiration, rise with inspiration (opposite of ascending) A descending bellows may continue to rise and fall, even with a circuit disconnect (ascending bellows is what we normally see) Ascending bellows do NOT fill if circuit leak
Poiseuille's Law
Describes the laminar flow of fluid through a tube Flow = (Pi x radius ^4 x pressure difference)/ (8 x viscosity x length) R = 1^4 = 1x1x1x1 = 1 R = 2^4 = 2x2x2x2 = 16 R = 3^4 = 3x3x3x3 = 81
Bernoulli's Principle
Describes the relationship between pressure and velocity of a moving fluid or gas If fluid velocity is high, then pressure exerted on the walls of the tube is low and vice versa Fluid moves faster (velocity increases) at a point of constriction and there is a pressure drop at this point of constriction
Fick's law of diffusion
Describes the transfer of gas through a tissue medium
what is the hepatic metabolism of volatile anesthetics?
Desflurane - 0.02% Iso - 0.2% Sevo - 2%
where in the body do the divisions of the brachial plexus turn into cords?
Divisions turn into cords when the brachial plexus goes under the pectoralis minor muscle
Max Allowable Blood Loss
Determine the estimated blood volume and then use this in the equation EBV x (starting hgb - target hgb)/starting hgb
how does dextran affect blood viscosity and for what procedures may it be used for?
Dextran reduce blood viscosity... it is used to improve microcirculatory flow during some vascular surgeries
what is the pathophysiology of diabetes insipidus? what causes it?
Diabetes insipidus is caused by either inadequate ADH production or renal tubules that don't respond to ADH Tremendous water loss - 18+ L per day polyuria
how is malignant hyperthermia diagnosed?
Diagnosed via halothane contracture test
congenital diaphragmatic hernia
Diaphragm doesn't fully develop allowing abdominal organs to migrate into the chest cavity CDH is a diaphragmatic defect that allows the abdominal contents to enter the thoracic cavity Mass effect of abd contents within the chest impairs lung development, leading to pulmonary hypoplasia... one or both lungs can be affected
what CV changes are associated with the elderly pt? -systolic function -diastolic function -conduction system -artery and vein quality and compliance -myocardial quality and compliance -BP -pulse pressure -SV -HR -CO -exercise tolerance -cardiac reserve -baroreceptor sensitivity -SNS tone vs PNS tone -catecholamine (NE/epi) plasma concentration -autonomic function -thermoregulation -fluid status
Diastolic dysfunction Systolic function is usually preserved Fibrosis of cardiac conduction system --> arrhythmias Loss of elastin in arteries Veins stiffer - reduces venous capacitance...Manifests as greater BP lability Changes in blood volume cause drastic changes in preload Decreased arterial compliance increases SVR, increases PP, increases myocardial wall tension and causes eccentric hypertrophy Decreased myocardial compliance --> Impaired relaxation causes diastolic dysfunction Dependent on atrial kick Myocardial hypertrophy Reduced ventricular compliance impairs relaxation Increased BP Reduced arterial compliance Increased pulse pressure Arterial stiffness increases SBP more than DBP NO CHANGE IN SYSTOLIC FUNCTION Decreased diastolic function Reduced compliance, increased stiffness Decreased SV Reduced exercise tolerance and cardiac reserve Decreased HR Decreased responsiveness to catecholamines Decreased ability to respond to hypotension, hypovolemia, hypoxemia Decreased CO Prolonged circulation time Decreased baroreceptor sensitivity Increased incidence of orthostatic hypotension Increased SNS tone Higher NE concentration in the plasma --> Blunted by the effect that they have reduced beta receptor sensitivity Decreased PNS tone Decreased response to catecholamines Decreased autonomic function Impaired thermoregulation increases risk of hypothermia Dehydration ---> Risk of F and E imbalance Reduced baroreceptor response--> Syncope and HD compromise
Drugs that undergo capacity dependent hepatic elimination
Diazepam Rocuronium Lorazepam Methadone Phenytoin
what does a dibucaine number of 20 mean?
Dibucaine does NOT inhibit ATYPICAL enzyme... if the dibucaine number is 20, this means atypical enzyme is present
what is the dibucaine test? what is a normal value? what is abnormal?
Dibucaine test is a definitive diagnosis for atypical pseudocholinesterase Dibucaine is an amide local anesthetic that inhibits NORMAL pseudocholinesterase ...Dibucaine will have NO effect on atypical PChE A NORMAL dibucaine number is 80... this means that dibucaine has inhibited 80% of of the pseudocholinesterase in the sample and suggests NORMAL ENZYME is present Dibucaine does NOT inhibit ATYPICAL enzyme... if the dibucaine number is 20, this means atypical enzyme is presen
Osmosis
Diffusion of water through a selectively permeable membrane
Dihydropyridine CCB
Dihydropyridine CCB (suffix dipine) targets vasculature, decrease calcium concentration and SVR Think when you DIE you vasodilate. The DIhydropyridines have DI pine in them
how does temperature affect vapor pressure
Directly proportional to temperature Increased temp = increased VP
what components make up the disposal part of the anesthesia machine?
Disposal = How gases are removed from the OR Scavenger
what are the 4 different irrigation fluids used for TURP procedure and what are drawbacks of using each type of fluid?
Distilled water can cause hemolysis Glycine → transient blindness, Increased ammonia → decreased LOC Sorbitol → hyperglycemia, Osmotic diuresis, Lactic acidosis NS → risk of electrocution. Can only be used with bipolar electrocautery
why should you not correct the PaCO2 in pts with chronic COPD?
Do not correct PaCO2 in the pt with chronic resp acidosis.. These pts normally retain bicarb and if you return their CO2 to normal than you've created a metabolic alkalosis
what condition may lead to complete HB when floating a PAC?
Do not float a PAC in pt with LBBB... advancing the catheter into the RV can cause a RBBB, putting pt into complete HB
Mediastinoscopy indications
Done to diagnose and stage lung cancer
Dorsal nerve root carries _________ information Ventral nerve root carries __________ information
Dorsal carries sensory information Ventral carries motor information
what are the sensory tracts of the spinal cord?
Dorsal column → fine touch and proprioception Lateral spinothalamic tract (anterolateral system)→ pain and temp Ventral spinothalamic tract → crude touch and pressure
Dose -10 cc/kg which will increase hgb ______ g/dl
Dose -10 cc/kg which will increase hgb 1-2 g/dl
propofol infusion syndrome risk factors?
Dose > 4 mg/kg/hr or 67 mcg/kg/min Infusion duration longer than 48 hrs Children Inadequate oxygen delivery Sepsis Significant cerebral injury
when does drug induced hepatitis usually present?
Drug induced hepatitis usually presents 2-6 weeks after the insult but can be as long as 6 months
what drugs may cause apoptosis?
Drugs that antagonize the NMDA receptor, stimulate GABA or both may cause apoptosis Examples = halogenated anesthetics, N2O, propofol, ketamine, etomidate, barbiturates, benzos
what are causes of respiratory acidosis?
Due to increased CO2 production, decreased CO2 elimination, rebreathing sepsis overfeeding malignant hyperthermia intense shivering prolonged seizure activity thyroid storm burns airway obstruction increased dead space increased Vd/Vt ARDS COPD respiratory center depression drug overdose inadquate NMB reversal incompetent one wave valve exhausted soda lime
what is the duration of action of methadone?
Duration is 3-6 hrs
What is modulation?
During modulation, the pain signal is modified (inhibited or augmented) as it advances towards the cerebral cortex
what layers does the needle go through via the paramedian approach? midline approach?
During paramedian approach, the needle only goes through the ligamentum flavum, whereas during the midline approach the needle also goes through supraspinous and interspinous ligament
what is calcium induced calcium release?
During phase 2 of cardiac cycle, calcium enters the cell. This turns on RyR2. even more calcium is released from SR. Calcium binds to troponin C and causes contraction. Most calcium is then returned to sarcoplasmic reticulum via SERCA 2 pump.
what is the equation for dynamic airway compliance?
Dynamic compliance = Vt/ (peak pressure - PEEP)
EBV Premie _______ ml/kg Full term neonate _______ ml/kg Infant _________ ml/kg Adult ________ ml/kg
EBV Premie 100 ml/kg Full term neonate 90 ml/kg Infant 80 ml/kg Adult 70 ml/kg think grade values
ECF % Premie _____% Neonate _____% Child _____% Adult _____%
ECF % Premie 60% Neonate 40% Child 20% Adult 20% 60..40..20 There is a diuresis after birth that reduces ECF volume In the premature neonate, ECF is larger than ICF A higher ICF provides an intravascular volume reserve in times of fever, fasting and diarrhea
EEG suppression occurs occurs at _____ C
EEG suppression occurs occurs at 20 C
what local anesthetics make up EMLA cream
EMLA cream contains a 50/50 % mixture of lidocaine and prilocaine Analgesia within 1 hour Max effect after 2-3 hrs
ETOH inhibits ______ receptors and potentiates ______ receptors
ETOH inhibits NMDA receptors and potentiates GABA.
what are s/sx of ETOH withdrawal and when do symptoms begin?
ETOH withdrawal - s/sx begin 6-8 hrs after BAC returns to near normal Tremors, SNS activation, NV, insomnia, confusion, agitation Delirium tremors 2-4 days without ETOH - seizures
each spinal nerve is formed by 2 nerve roots - what are they called?
Each spinal nerve is formed by a posterior dorsal nerve root and anterior ventral nerve root
where in the body do the trunks of the brachial plexus turn into the divisions?
Each trunk turns into an anterior and posterior division underneath the clavicle and over the first rib C5-6 → superior trunk → anterior and posterior divisions of superior trunk C7 → middle trunk → anterior and posterior divisions of middle trunk C8-T1 → inferior trunk → anterior and posterior divisions of inferior trunk
theres an association between oat cell lung carcinoma and which NM disease?
Eaton Lambert Syndrome
What is eaton-lambert syndrome? is the pt sensitive to sux, NDNMB, or both?
Eaton Lambert Syndrome is caused by IgG mediated destruction of the presynaptic voltage gated calcium channels at the PREsynaptic nerve terminal. When an AP is generated, calcium release is limited and therefore there is a reduced amnt of ACh released into the synaptic cleft Patients are sensitive to sux AND NDMB - the doses should be reduced Reversal with neostigmine may be inadequate Think.... IgG EATS UP the presynaptic calcium channels and ACh When you eat a lot and you are really full so you don't want to move... this is why you should avoid ALL paralytics
compare myasthenia gravis and Eaton Lambert Syndrome
Eaton-Lambert Syndrome Associated with destruction of presynaptic voltage gated calcium channels, increased sensitivity to sux, and close association w/ small cell lung carcinoma To compare, MG is associated with destruction of the nicotinic receptor, bulbar muscle weakness and diagnosed w/ Tensilon test
what kind of bond does edrophonium form with acetylcholinesterase?
Edrophonium forms an ELECTROSTATIC bond the anionic site and a hydrogen bond at the esteratic site... these are WEAK bonds, which explains why it has a short duration of action
Drugs that INCREASE the amount of ACh (acetylcholinesterase inhibitors)
Edrophonium, Neostigmine, pyridostigmine, and physostigmine Notice most end in -stigmine Think stigMINE ... acetylCHOLINE (rhymes?)
ED50
Effective dose in 50% of the population
define elimination half life
Elimination half life = the time it takes for 50% of the drug to be removed from body after rapid IV injection
what are special properties and considerations about ketamine?
Emergence delirium Good analgesic (somatic pain>visceral pain) Opioid sparing Blocks central sensitization and wind up in the dorsal horn of the SC Increases CMRO2, CBF, ICP, IOP Increases EEG activity Can cause nystagmus Promotes bronchodilation Treats severe depression Increases SNS tone (avoid in CAD) Increases CO, HR, SVR, PVR (avoid if severe RVF) A myocardial depressant if pt is catecholamine depleted (sepsis) or has sympathectomy - the above effects are only if intact SNS Maintains resp drive (brief apnea w/ induction) Airway reflexes intact Increases oral and pulmonary secretions
what are high cardiac risk procedures?
Emergency surgery Open aortic surgery Peripheral vascular surgery Long surgical procedures w/ significant volume shifts and or blood loss
what is the dose of FFP in kids? what is the indications for FFP administration?
Emergency warfarin reversal Correction of coagulopathy with increased PT or PTT Correction of coagulopathic bleeding if > 1 blood volume has been replaced and coagulation studies not easily obtained NOT indicated for expansion of intravascular volume
Examples of decreased airway compliance
Endobronchial intubation Pulmonary edema Pleural effusion Tension PTX Atelectasis Chest wall edema Abd insufflation Ascites Tburg Inadequate muscle relaxation
what in the body produces endogenous heparin?
Endogenous heparin is produced by basophils, mast cells and the liver
what is the name of the endogenous opioids that stimulate the following receptors mu delta kappa
Endorphins stimulate mu receptor Enkephalins stimulate delta receptor Dynorphins stimulate kappa receptor
Endothelial injury exposes _____________ and platelets adhere to this via _________ receptors vWF is synthesized and released from the endothelium - it __________ to platelets and ___________ them
Endothelial injury exposes collagen and platelets adhere to collagen via Gp receptors vWF is synthesized and released from the endothelium - it binds to platelets and anchors them
describe the process of platelet adhesion
Endothelial injury exposes collagen and platelets adhere to collagen via Gp receptors vWF is synthesized and released from the endothelium - it binds to platelets and anchors them
what medications should be AVOIDED in LAST?
Epi can actually HINDER resuscitation of LAST and REDUCES the effectiveness of lipid emulsion therapy Avoid beta blockers and calcium channel blockers - these enhance LA induced Cardiac arrhythmias
Neuraxial anesthesia consideration in the elderly -how doe they respond to epi test dose? -how do they respond to LA? -how is their epidural space different -CSF volume
Epi test dose has higher rate of false negative results due to decreased beta receptor sensitivity Epidural anesthesia is associated with a greater spread of LA due to reduced epidural space volume Spinal anesthesia is associated with greater spread of LA due to reduced CSF volume Increased sensitivity of neurons to LA Increased difficulty to place block due to less space, decreased intervertebral disc height, and calcification
compare and contrast the following in epiglottitis vs croup -caused by what kind of organism -age onset -onset of symptoms -airway structures affected -presentation -treatment
Epiglottitis is caused by bacterial organisms, croup is caused by viral organisms Epiglottitis age is 2-6 yr old, coups age is < 2 yr old Epiglottitis is rapid onset less than 24 hrs, croup is gradual onset 24-72 hrs Epiglottitis affects supraglottic structures, croup affects laryngeal structures Epiglottitis Presentation = high fever, tripod position (helps breathing), 4 D's → drooling, dysphoria, dyspnea, dysphagia, Thumb sign = swollen epiglottis Croup presentation = mild fever, inspiratory stridor, barking cough epiglottis treatment = oxygen, urgent airway management → tracheal intubation, tracheostomy, abx if bacterial, induction w/ spontaneous RR, CPAP 10-15 prevents airway collapse, ENT surgeon MUST be present, post op ICU care croup treatment = oxygen, racemic epi, steroids, humidification, fluids, intubation rare
Where is erythropoietin produced? what stimulates its production?
Erythropoietin is synthesized in the kidney and is secreted in response to hypoxia
how does CKD affect erythropoietin?
Erythropoietin production is reduced - this contributes to a normocytic normochromic anemia
what is likely a key diagnosis of esophageal atresia before the fetus is born? how can diagnosis be confirmed once baby is born?
Esophageal atresia prevents fetus from swallowing amniotic fluid, thus maternal polyhydramnios is a key diagnosis Confirm diagnosis by the inability to pass a gastric tube into the stomach
How do osmotic diuretics work?
Essentially increase the osmolarity of the blood and hence the kidney filtrate. This reduces the countercurrent effect, resulting in decreased water reabsorption where the nephron is freely water-permeable Inhibit reabsorption in the proximal tubule and the loop of henle Water excretion is greater than electrolyte excretion
what is the part of the ester local anesthetic that increases their allergic potential?
Ester LA are derivatives of PABA, which is what causes the allergy
Estimation of BP equation for peds
Estimation of BP = 70+ age x 2
Etiologies of cirrhosis
Etoh abuse Alpha 1 antitrypsin def Biliary obstruction Chronic hepatitis Right sided HF
why does etomidate cause adrenal suppression?
Etomidate inhibits 11 beta hydroxylase, which is the enzyme needed for cortisol and aldosterone synthesis A single dose of etomidate suppresses adrenocortical function for 5-8 hrs AVOID in pts with Addison's disease, adrenal suppression states, and those who are relying on their intrinsic stress responses (acute renal failure and sepsis)
what is the third most common mechanism for heat loss? what is the mechanism?
Evaporation = 20% Water loss Latent heat of vaporization - energy to vaporize water
airway considerations in pt w/ preeclampsia
Even more swelling of airway = even harder intuition
give example of Joule Thompson effect
Ex = oxygen cylinder one quicky feels cool to touch
what can cause exacerbations of lupus?
Exacerbations caused by PISSED CHIMP Preg, infection, surgery, stress, enalapril, captopril, hydralazine isoniazid, methyldopa, procainamide
give an example of adiabatic process
Example = very rapid expansion or compression of gas where there is no transfer of energy
what is a potential danger of using the oxygen flush valve too often?
Excessive use can lead to awareness
The pancreas produces both endocrine and exocrine hormones. where are the endocrine secreted and where are the exocrine secreted?
Exocrine are secreted into the duodenum for digestion Endocrine are secreted into systemic circulation for metabolism
what are advantages of crystalloid administration?
Expands ECF Restores 3rd space losses
What are extrajunctional receptors? how are they formed? why are they dangerous?
Extrajunctional receptors have a structural change that impacts how it response to sux They are formed by denervation or prolonged immobility These receptors predispose the patient to hyperkalemia w/ sux because they remain open for a longer period of time
Describe the following lung values in restrictive lung disease FRC FEV1 FEV1/FVC FEF 25-75%
FRC is decreased but remains unchanged relative to the other volumes and capacities (FEV1/FVC is unchanged) FEV1 is decreased FEF 25-75% reflects airflow resistance in medium airways, which is NOT a problem for restrictive disease, so this will be normal Decreased FRC, FEV1, RV, FRC, TLC Normal FEV1/FVC and FEF 25-75 FEV1 and FVC less than 70% is diagnostic for RLD.
cranial nerve VII
Facial - controls most facial expressions Facial movement (except chewing) and eyelid closing Face sensation
what does ADH do?
Facilitates reabsorption of water in nephron of kidney ADH (vasopressin) control plasma osmolarity (H2O reabsorbed but not sodium)
list as many procoagulants as you can
Factors I-XIII Fibrinogen vWF Fibronectin
A delta fibers
Fast pain, temp, touch
What of the following values characterized metabolic syndrome? Fasting glucose > _________ Abdominal obesity - waist greater than ___________ inches in men, ________ in W Serum triglyceride levels > ________ Serum HDL < ______ in < and _____ in W BP > ____________
Fasting glucose > 110 Abdominal obesity - waist greater than 40 inches in men, 35 in W Serum triglyceride levels > 150 Serum HDL < 40 in < and 50 in W BP > 130/85
whose at risk for biliary stones?
Fat, female, 40
the femoral nerve turns into the _______ nerve the sciatic nerve turns into the _______ nerve and the _______ nerve the common peroneal nerve turns into the _______ nerve and _______ nerve the tibial nerve turns into the _______ nerve and the _______ nerve
Femoral → saphenous nerve Sciatic → common peroneal and tibial nerves Common peroneal → superficial and deep peroneal Tibial → sural and posterior tibial
Drugs that undergo perfusion dependent hepatic elimination
Fentanyl Lidocaine Propofol Ketamine Bupivacaine Metoprolol Propranolol Nifedipine Diltiazem Verapamil Meperidine Morphine
what is the lifespan of fetal RBC? what is the lifespan of adult RBC?
Fetal RBCs have a lifespan of 70-90 days, which is shorter than hgb A (120 days)
what is fetal ion trapping and how does it occur?
Fetal acidosis increases concentration gradient and can cause fetal ion trapping of local anesthetics Non-ionized drugs tend to cross the placenta more easily than ionized drugs, however the fetus usually has a lower pH than the mother, leading to "ion trapping."
what HR is considered fetal bradycardia? what are causes of fetal bradycardia?
Fetal bradycardia = < 110 Caused by fetal acidosis and asphyxia, maternal hypoxemia and drugs that decrease uteroplacental perfusion
the fetal circulation occurs in __________. the adult is in series
Fetal circulation occurs in parallel (adult = series)
what HR is considered fetal tachycardia? what are causes of fetal tachycardia?
Fetal tachycardia = >160 d/t fetal hypoxemia or arrhythmias, maternal fever, chorioamnionitis, atropine, ephedrine, terbutaline
how do you calculate FiO2 when using the Thorpe tube combination of air and oxygen?
FiO2 = (airflow rate x 21) + (oxygen flow rate x100)/total flow rate
what is factor 13?
Fibrin stabilizing factor (13) facilitates cross linkage of fibrin fibers which completes the clot
diffusion hypoxia is an example of what law?
Fick's law of diffusion
drug transfer across a placenta is an example of what law?
Fick's law of diffusion
when the fetus is transitioning to extrauterine life, what causes PVR to decrease? what causes SVR to increase?
First breath causes lung expansion increases PaO2 decrease PVR When the placenta separates from the uterine wall, SVR increases
describe the vascular changes that occurs as the fetus transitions to extrauterine life? what causes the fetal shunts to close?
First breath causes lung expansion increases PaO2 decrease PVR When the placenta separates from the uterine wall, SVR increases Decreased PVR + increased SVR causes LA pressure to be greater than RA pressure and the flap valve closes the foramen ovale Decreased PVR causes reversal of blood flow through the ductus arteriosus and causes DA closure Decreased circulating PgE1 (which is released from the placenta) causes DA closure
what is the first line treatment for uremia increased bleeding time?
First line treatment is desmopressin Dialysis improves bleeding time - should be done within 24 hrs of surgery
first order kinetics
First order kinetics describes a situation where a constant FRACTION of drug is metabolized per unit time Less drug than enzyme, no saturation occurs
describe the first, second and third order neurons of the dorsal column sensory pathway
First order neuron -Enters SC via DRG -Relays sensory info from dorsal column to medulla -Ascends SC on same side it entered -Synapses with second order neurons in the medulla Second order neuron -Crosses over to contralateral side in the medulla and then ascends towards thalamus -Synapses w/ third order neuron in the thalamic relay station Third order neuron -Travel towards somatosensory cortex in post central gyrus in parietal lobe
first order neuron
First order neuron extends from the periphery to the dorsal horn - the cell body is in the dorsal root ganglion
why does hgb F not bind 2,3 DPG?
Hgb A has 2 alpha and 2 beta chains, hgb F has 2 alpha and 2 gamma chains This is why 2,3 DPG does not bind to hgb F
What is flail chest?
Flail chest results when cracked ribs move in during inspiration, while the rest of the rib cage moves out. wThe flail region moves out during expiration. Vt is reduced. causes a Restrictive lung disease
Ohm's law
Flow = pressure gradient/resistance Flow is directly proportional to pressure gradient and inversely proportional to resistance
Ohm's Law
Flow = pressure gradient/resistance MAP = (COxSVR)/80 + CVP
Poiseuille's Law
Flow = πR^4∆P/8nl
Flow is directly proportional to ____________ and inversely proportional to ___________
Flow is directly proportional to pressure gradient and inversely proportional to resistance
according to Bernoulli's principle, how does fluid velocity change at a point of constriction? how does pressure change at a point of constriction?
Fluid moves faster (velocity increases) at a point of constriction and there is a pressure drop at this point of constriction
what kind of ventilatory defect occur in someone with CKD? why?
Fluid overload creates a restrictive ventilatory defect
Central pontine myelinolysis
Focal central demyelination of pons (anterior brain stem) due to rapid IV correction of hyponatremia, often in malnourised patients (alcoholics, those with liver disease)
describe anesthetic management for diastolic HF
For Diastolic HF, increased preload may be required to stretch a non compliant ventricle. LVEDP does not corrleate with LVEDV. Keep afterload increased in order to perfuse the thick myocardium. Contractility is usually normal. HR should be slow normal to increase diastolic filling time and CPP.
what is the bioavailability for IV meds
For IV meds, the bioavailability is 1
describe anesthetic management for systolic HF
For Systolic HF, their preload is high - diuretics may be beneficial. Decrease afterload to decrease myocardial workload, but maintain CPP augment contractility w/ inotropes. HR is usually higher d/t increased SNS tone... if EF is low, higher HR is needed to preserve CO
For caudal anesthesia, a T10 block will require ______ ml/kg
For caudal anesthesia, a T10 block will require 1 ml/kg
For drug eluding stents, wait ___ mo for first generation or ____ mo for current generation before elective surgery
For drug eluding stents, wait 12 mo for first generation or 6 mo for current generation before elective surgery
what does it mean when a drug is said to have a high hepatic extraction ratio?
For drugs with HIGH hepatic extraction ratios (>0.7), clearance is dependent on liver BLOOD FLOW Increased liver blood flow = increased drug clearance perfusion dependent drug elimination
what does it mean when a drug is said to have a low hepatic extraction ratio?
For drugs with LOW hepatic extraction ratios (<0.3), clearance is dependent on liver ENZYMES Since only a small amnt of drug is removed per unit time, alterations in blood flow minimally affect clearance Enzyme induction = increased clearance Enzyme inhibition = decreased clearance capacity dependent drug elimiantion
For every 10 cm change, the BP changes by _______ mmhg For every inch, BP changes by ______ mmhg
For every 10 cm change, the BP changes by 7.4 mmhg For every inch, BP changes by 2 mmhg
4-2-1 rule
For maintenance IV fluid calculation: 4 mL/kg/hr for first 10 kg 2 mL/kg/hr for next 10 kg 1 mL/kg/hr thereafter
what is the differential block that occurs with spinal anesthesia?
For spinal anesthesia, autonomic fibers are blocked first, sensory fibers blocked second, motor fibers blocked last This is because different types of nerves have different sensitivities to LA block Autonomic block is 2-6 dermatomes higher than sensory block, sensory block is 2 dermatomes higher than motor block
describe how to position the ultrasound for an interscalene block what muscles and landmarks will you see on the ultrasound?
For ultrasound technique, it is placed mid clavicular fossa and directed slightly caudal. Horizontal position Use an in-plane approach From medial to lateral - SCM, SCM, C5,6,7, MSM
what is FEV1? what is the normal value? what number indicates severely decreased?
Forced exp volume in 1 second (FEV1) is the volume of air that can be exhaled in 1 second Normal is >80% predicted Effort dependent Declines w/ age Severely decreased = < 35% It
what is FEF 25-75? what is this test most sensitive for?
Forced expiratory flow @ 25-75% VC is the average forced exp flow during the middle half of the forced expiratory volume (FEV) measurement This test is the most sensitive for small airway disease (obstruction)
Partial pressure
Fractional amnt of pressure that a single gas exerts within a gas mixture
What is a frangible disk?
Frangible disk that ruptures under pressure
Bezold-Jarisch reflex causes
From drop in pressure in LV baroreceptors Bradycardia HoTN Coronary vasoDILATION
what is the weight of a full N2O tank? empty?
Full weight = 20 pounds empty weight = 14 pounds
describe the anesthetic goals for someone with mitral stenosis
Full, slow, constricted = goals Avoid increases in PVR Conditions that increase PVR = acidosis, hypercapnia, hypoxia, hypercarbia, lung hyperinflation, nitrous oxide, Tburg position Nitrous oxide increases PVR and increases workload of RV and should be avoided Tachycardia decreases diastolic filling time and should be avoided. This increases LA pressure - AVOID it Maintain preload - the LV is chronically underfilled, so maintain it in order to maintain CO
what is the I-f channel called the funny channel?
Funny channel because it is activated by hyperpolarization, not depolarization
How does a fusible plug work? what is it made out of?
Fusible plug that melts at elevated temps... typically made from woods metal (bismuth, lead, tin cadmium... BLT w cheese)
name some inhibitory receptors
GABA A Glycine K channels
what is the mechanism of action of etomidate?
GABA-A agonist
What is the filtration fraction? what is the normal value?
GFR/RPF 20% 20 % of the renal blood flow is filtered by the glomerulus and 80% is delivered to the peritubular capillaries
what does somatostatin do?
GH inhibiting hormone Inhibits both insulin and glucagon Inhibits splacnich BF, gastric motility and gallbladder contraction
Abciximab
GP IIb/IIIa inhibitor - inhibit plt aggregation via surface receptors
Eptifibatide
GP IIb/IIIa inhibitor - inhibit plt aggregation via surface receptors
Tirofiban
GP IIb/IIIa inhibitor - inhibit plt aggregation via surface receptors
what causes gap metabolic acidosis in CKD?
Gap metabolic acidosis is result of accumulation of non volatile acids
what herbal therapies inhibit plt aggregation? name 3 what is the protocol if your pt is on them and you want to give them a neuraxial block?
Garlic, ginkgo, ginseng Porceed w/ neuraxial if pt is not on any other blood thinners
what is diffusion hypoxia?
Gas containing areas of the body can absorb up to 30 L of nitrous oxide and most of this is eliminated within five minutes after N2O is d/c. This tremendous volume of N2O is transferred to the alveoli where it dilutes alveolar oxygen
Oxygen tank explodes in a heated environment is an example of what kind of gas law?
Gay Lussac's Law
P1/T1 = P2/T2
Gay-Lussac's Law
what is the best anesthesia type for pts at risk of autonomic hyperreflexia?
General or spinal anesthesia prevents AH better than epidural anesthesia
describe the pathway the follows with a Gi protein
Gi → decreased adenylate cyclase → decreased cAMP
what 2 things determine glomerular filtration?
Glomerular filtration is dependent on renal blood flow and the hydrostatic pressure at Bowman's capsule
cranial nerve IX
Glossopharyngeal sensory and motor Gag reflex, posterior ⅓ of tongue sensation
how is airway anatomy different in the neonate compared to the adult?
Glottic opening is more cephalad Vocal cords have an anterior slant --> make make it difficult to pass ETT Right and left mainstem bronchi take off at the same angle Vocal cord position is at C3-4 (C5-6 in adult) Epiglottis is omega or U shaped Epiglottis is long and stiff The infant tongue is large relative to oral volume The infant neck length is shorter → a more acute angle is needed to visualize the glottis
Hormones and drugs that increase serum glucose
Glucagon Catecholamines Cortisol GH Beta agonists
Drugs that relax the sphincter of Oddi and reduce biliary
Glucagon Glycopyrrolate Atropine Naloxone Nitroglycerine
what does glucagon do? in what situations is it given IV? what is a key SE?
Glucagon is a catabolic hormone that promotes energy release from adipose and the liver Glucagon 1-5 mg IV increases myocardial contractility, HR, and AV conduction by increasing intracellular concentration of cAMP.. It does this independently of the ANS Useful for BB overdose, CHF, low CO after MI or CPB, improving MAP during anaphylaxis Given during ERCP to relax biliary sphincter NV = key side effect
Glucagon → ______ cells Insulin → ______ cells Somatostatin → _______ cells Pancreatic polypeptide → ________ cells
Glucagon → alpha cells Insulin → beta cells Somatostatin → delta cells Pancreatic polypeptide → PP cells
signs and symptoms of Cushings syndrome
Glucocorticoid effects -Hyperglycemia -Weight gain -Increased risk of infection -Osteoporosis -Muscle weakness -Mood disorder Mineralocorticoid effects -HTN -Hypokalemia -Metabolic alkalosis Androgen effects -Hirsutism -Hair thinning -Acne -Amenorrhea -Gynecomastia -Impotence
when does hgb F get replaced by hgb A?
Hgb F is replaced by hgb A in the first 2 months of life By six months, hgb F is completely replaced
describe why tylenol can cause liver failure? what is the treatment?
Glutathione is a substrate for many phase 2 conjugation reactions Acetaminophen toxic metabolite = NAPQI Overdose will overwhelm the livers supply of glutathione and increase the toxic metabolite Treatment = N acetylcysteine within 8 hrs
glycopyrrolate is best for ...... what does glyco NOT do that other anticholinergics can?
Glyco is best for increased HR (not as much as atropine), antisialagogue (not as much as scopolamine) NO sedation, NO mydriasis and NO nausea prevention
Drugs that BLOCK ACh (anticholinergics)
Glycopyrrolate, scopolamine, atropine
describe anesthetic goals of pt with hypertrophic CM w/ LVOT obstruction
Goals = increased systolic volume (increased preload, decreased HR), decreased contractility, increased Ao pressure Interventions = beta blockers, CCB, volume resuscitation, phenylephrine
what are the hemodynamic goals for baby with TOF? -SVR -PVR -HR -contractility -preload
Goals is to minimize right to left shunt Increase SVR, decrease PVR, maintain contractility and HR, increase preload Decreased SVR and increased myocardial contractility will cause decreased BP and SpO2 The degree of RVOT strongly correlates with amnt of shunt... with increasing RVOT obstruction, more deoxygenated blood is shunted through the VSD out into the aorta --> The body compensates with erythropoiesis, however this leads to polycythemia and increases risk of thromboembolism and stroke
Hypothyroid signs and symptoms
Goiter wt gain muscle fatigue lethargy dry/thick skin dry brittle hair constipation delayed gastric emptying large tongue
why can goiter increase airway risk?
Goiter can cause tracheal deviation
describe the process of platelet aggregation
Gp receptors link the platelets together to form plug
what is the role of GpIb and GpIIb-IIIa
GpIb attaches an activated plt to vWF GpIIb-IIIa links the platelets together to form a plug
describe the pathway the follows with a Gq protein
Gq → increased phospholipase C → increased IP3, DAG, Ca++
what are causes of hyperthyroid?
Graves disease Myasthenia gravis multi-nodular goiter carcinoma pregnancy pituitary adenoma amiodarone
how does a gravid uterus affect cardiac deviation?
Gravid uterus causes left axis deviation
a gravid uterus will shift a diaphragm cephalad. how does thing change lung volumes in the parturient?
Gravid uterus shifts diaphragm cephalad Reduces FRC and ERV FRC is less than CC so airway closure occurs during tidal breathing TLC and VC are unchanged
when during the pregnancy is the GREATEST risk of teratogenicity?
Greatest risk of teratogenicity is during the time of organogenesis - day 13 -60
how should one assess NMB recovery in the neonate?
Grimacing Elbow and hip flexion Knees to chest TOF > 9 Max insp force less than -25 cm H2O **neonates cannot lift head
Fetal risk of general surgery during pregnancy
Growth restriction Low birth weight Demise Increased risk of preterm labor (highest incidence = intraabdominal and pelvic surgery)
describe the pathway the follows with a Gs protein
Gs → increased adenylate cyclase → increased cAMP
what drug therapy does ACT guide? what is normal in seconds? what should the value be before starting CPB?
Guides heparin dosing Normal is 90-120 seconds Should be > 400 before staring CPB
what are signs and symptoms of intracranial HTN?
HA NV Papilledema Focal neuro def Decreased LOC Seizure Coma
give 4 examples of thiazide diuretics
HCTZ, metolazone, indapamide, chlorthalidone
Adrenal crisis s/sx
HD instability and collapse fever hypoglycemia impaired mental status
what are special properties and considerations about etomidate?
HD stability = key benefit Can cause myoclonus Increases PONV Decreases CBF via cerebral vasoconstriction Decreases ICP CPP remains stable No analgesia AVOID in pts with Addison's disease, adrenal suppression states, and those who are relying on their intrinsic stress responses (acute renal failure and sepsis) Also avoid in pts with acute intermittent porphyria
Hyperthyroid signs and symptoms
HTN afib arrhythmias increased Vd goiter wt loss muscle weakness heat intolerance moist warm skin fine hair diarrhea tremor exophthalmos hypercalcemia
What are thiazide diuretics used for?
HTN mobilize edema fluid HF osteoporosis
Conn's syndrome signs and symptoms
HTN from sodium and water retention hypokalemia from K wasting metabolic alkalosis from H+ wasting Hypokalemia can cause muscle weakness and cramping, increased sensitivity to non depolarizing NMB, U wave on ekg- avoid hyperventilation
what is the etiology of HTN associated with CKD?
HTN is the result of RAAS activation and causes sodium and fluid overload
why should HTN associated with autonomic hyperreflexia be promptly treated? what is the med of choice?
HTN needs to be promptly treated because it can cause stroke, LVF, and pulmonary edema Nitroprusside is tx of choice d/t faster onset
what are risk factors for ischemic stroke?
HTN** -Most important Smoking DM HLD Excessive ETOH Elevated homocysteine levels
what are 3 hallmark characteristics of preeclampsia? what are other signs and symptoms?
HTN, proteinuria and edema that occurs 20 weeks after preg Enhanced platelet aggregation Decreased prostacyclin More common in moms < 20 years old and > 35 years, chronic renal disease
what is the metabolite that causes halothane hepatitis?
Halothane is metabolized to inorganic fluoride ions and TFA... TFA can produce an immune response
Haptic blood flow is __________ in the elderly how does this effect drug elimination?
Haptic blood flow is reduced Less drug delivered = prolonged elimination, esp those with high hepatic extraction ratio - fent, lido, metoprolol
what is the mechanism of action of versed?
Has an imidazole ring that has increased water solubility in acidic pH because the ring is open. When injected into physiological pH, the ring closes and the drug becomes lipophilic GABA-A agonist that increases the frequency of channel opening leading to neuronal hyperpolarization Most GABA A agonists increase channel open TIME... versed increases channel open FREQUENCY (Barb likes it long, Ben likes it fast)
what are causes of hypothyroid?
Hashimoto thyroiditis iodine deficeincy neck radiation thyroidectomy
describe anesthetic considerations in baby with TEF/EA intubation vent mode OGT? G tube? open or closed w induciton ETT position
Head up and frequent suctioning to minimize gastric aspiration Awake intubation PPV causes gastric distension which decreases thoracic compliance and increases PIP required for ventilation Placement of a g tube allows for gastric decompression If pt already has g tube, open it to atmosphere before induction If ETT is placed too high, resp gas is delivered to the stomach, if too low, endobronchial intubation is likely Right lung compression during surgical repair is common - right mainstem intubation will cause rapid desat The proper tip of the ETT should be below the fistula and above the carina
Hypermagnesemia EKG changes
Heart block Cardiac arrest
how does latent heat of vaporization apply to variable bypass vaporizers? what is the name of the device that compensates for this phenomenon?
Heat is carried away by the vaporized molecules and this causes anesthetic liquid to cool cooling decreases vaporizer pressure and ultimately vaporizer output the temperature compensating valve adjusts the ratio of vaporizing chamber flow to bypass flow and guarantee constant vaporizer output over wide range of temps - it is either a bimetallic strip or an expansion element
temperature compensating valve
Heat is carried away by the vaporized molecules and this causes anesthetic liquid to cool... cooling decreases vaporizer pressure and ultimately vaporizer output... the temperature compensating valve adjusts the ratio of vaporizing chamber flow to bypass flow and guarantee constant vaporizer output over wide range of temps Either bimetallic strip or expansion element
describe the LV pressure volume loop Height = Width = Lower left corner = Lower right corner = Left straight side = Right straight side = Top curve =
Height = pressure Width = volume Width = SV Lower left corner = ESV Lower right corner = EDV Left straight side = isovolumetric relaxation Right straight side = isovolumetric contraction Top curve = ventricular ejection
Reynolds number
Helps us predict what type of flow pattern will occur in a particular situation Reynolds number = (density x diameter x velocity)/viscosity Laminar is less than 2,000, turbulent is greater than 4,000
HELLP syndrome signs/symptoms who is at risk treatment
Hemolysis, elevated liver enzymes, low plt count Develops in 10% of those with pre eclampsia Epigastric pain and upper abd tenderness Definitive treatment = delivery of baby At higher risk for DIC and intra-abd bleeding from liver
Hemophilia A = factor ______ deficiency Hemophilia B = factor _______ deficiency
Hemophilia A = factor 8 deficiency Hemophilia B = factor 9 deficiency
oxygen solubility is an example of what law?
Henry's law Multiplying PaO2 by oxygen solubility coefficient (0.003) allows us to calculate how much oxygen is dissolved in our blood
Hep B and C can be transmitted via ___________, A and E are transmitted by _____________
Hep B and C can be transmitted via blood transfusion, A and E are transmitted by oral fecal route
which drugs undergo ZERO placental transfer?
Heparin Insulin Glycopyrrolate NMB HI Good Naps
Heparin inhibits the __________ and ____________ pathways. It binds to ________________ and accelerates the anticoagulant ability by 1,000
Heparin inhibits the intrinsic and final common pathway. It binds to antithrombin and accelerates the anticoagulant ability of AT by 1,000 The heparin AT complex neutralizes thrombin and factors X, XII, XI, and IX and inhibits platelet function
how does heparin exert its anticoagulant effects?
Heparin inhibits the intrinsic and final common pathway. It binds to antithrombin and accelerates the antigoalant ability of AT by 1,000 The heparin AT complex neutralizes thrombin and factors X, XII, XI, and IX and inhibits platelet function
what is the most common form of viral hepatitis?
Hepatitis A is the most common form of viral hepatitis
Manifestations of brain herniation at the temporal uncus
Herniation of this part puts pressure on oculomotor nerve (CN III) and manifestations = fixed, dilated pupil
Hypotonic
Hypotonic = osmolarity lower than plasma
hgb F shifts the oxyhgb curve to the _______ why?
Hgb F is shifted left on oxygen hemoglobin curve, which benefits fetus by creating an oxygen partial pressure gradient across the uteroplacental membrane that facilitates passage of O2 from the mother to the fetus
why does hgb F have a higher affinity for oxygen?
Hgb F is unable to bind 2,3 DPG, which explains why it has a higher affinity for oxygen
General risk factors for cardiac risk
High risk surgery Hx of ischemic heart disease Hx of CHF Hx of CVA DM Creatinine > 2
Neonates have a higher ratio of _____________ relative to the size of _________, therefore the oxygen supply contained within the FRC is quickly depleted... the neonate therefore desats faster during apnea
Higher ratio of alveolar ventilation relative to the size of FRC, therefore the oxygen supply contained within the FRC is quickly depleted... the neonate therefore desats faster during apnea
Critical temp
Highest temp where a gas can exist as a liquid
how do highly vascular areas affect local anesthetics?
Highly vascular areas remove LA at a faster rate than sites with less blood flow - this reduces LA duration and increases its plasma concentration
How is cisatracurium eliminated?
Hoffman elimination It does NOT undergo ester hydrolysis Cis is Hoffy
what two things will affect Hoffman elimination?
Hofmann elimination is dependent on pH and temperature
how long should IV heparin be held before neuraxial anesthesia? after block placement? after indwelling catheter is removed?
Hold 2-4 hrs before block placement Hold 1 hr after block placement Hold 2-4 hrs after indwelling catheter is removed
how long should warfarin be held before neuraxial anesthesia?
Hold 5 days before block placement Catheter can be removed once INR < 1.5
Hydralazine
Hydralazine = arteriodilater. Decreases SVR via increased nitric oxide
compare hydrophilic versus lipophilic opioids how long do they stay in the CSF? onset time? duration? respiratory depression? NV?
Hydrophilic opioids are more water soluble They stay in the CSF for a longer period of time, have extensive CSF spread, wide band of analgesia, more rostral spread (towards the brain), works mostly in substantia gelatinosa rexed lamina II and III, onset is 30-60 min, duration is 6-24 hrs, less systemic absorption, early and late respiratory depression, higher incidence of NV and pruritus Lipophilic opioids are more fat soluble They stay in the CSF for a shorter period of time, they have minimal CSF spread, narrow band of analgesia, less rostral spread, works in both substantia gelatinosa and systemically, have fast onset of 5-10 min, work shorter duration 2-4 hrs, more systemic absorption, early resp depression, no late, lower incidence of NV and puriritis
_____________ pressure across the glomerulus determines GFR
Hydrostatic pressure across the glomerulus determines GFR
what type of IV fluid is associated with increased risk of renal morbidity?
Hydroxyethyl starches are associated with an increased risk of renal morbidity
Conditions that increase PVR
Hypercarbia Hypoxemia Acidosis Atelectasis Hypothermia Vasoconstrictors Pain Tburg Light anesthesia Increased SNS tone
why does hypercarbia increase the incidence of LAST?
Hypercarbia increases cerebral blood flow and increases drug delivery to the brain Hypercarbia also decreases protein binding and increases the free fraction available to enter the brain
what physiologic factors increase the risk of LAST?
Hypercarbia, hyperkalemia, and metabolic acidosis
characteristics of Hyperglycemic hyperosmolar state
Hyperglycemia > 600 significantly increases serum osmolarity glycosuria leads to dehydration and hypovolemia Mile metabolic acidosis with no anion gap
Consequences of massive transfusion
Hyperglycemia from dextrose additive to stored blood Hyperkalemia from administration of older blood -Dysfunctional cell membranes -Administration to neonates can cause cardiac arrest from hyperkalemia Hypocalcemia Alkalosis from citrate metabolism to bicarb in the liver Hypothermia from transfusion of cold blood
Hyperglycemia worsens neuro outcomes after ____________ injury
Hyperglycemia worsens neuro outcomes after ischemic brain injury
what electrolyte disturbance most notoriously occurs with CKD and when is dialysis indicated?
Hyperkalemia from impaired K secretion Dialysis when K > 6
why does hyperkalemia increase the incidence of LAST?
Hyperkalemia raises resting membrane potential, making them more likely to depolarize
Hyperpolarization
Hyperpolarization takes place when there is an increased polarity across a membrane - there is a larger charge difference between the inside and outside of the cell
an unstable hyperparathyroid pt presents for emergency surgery. what is the best option for this pt?
Hyperthryoid pt presenting for non emergency surgery should be cancelled and managed medically until a euthryoid state is achieved... if the pt presents for an emergency operation, esmolol is the best option for treatment
what lab values are associated with hyperthyroid? hypothyroid?
Hyperthyroid = low TSH + high T3/4 hypothyroid = high TSH plus low T3/4
Hypertonic
Hypertonic = osmolarity higher than plasma
what kind of fluid supports hemodynamics in TBI pt and creates osmotic effect that reduces brain water
Hypertonic saline supports hemodynamics in TBI pt and creates osmotic effect that reduces brain water
What is chronic bronchitis? how are these pts managed when on the vent
Hypertrophied bronchial mucosa and chronic inflammation. Cough and sputum production for more than 3 mo for 2 years Polycythemia for compensation for hypoxia Hypercarbia causes increased PVR and plum HTN Pulm HTN can cause RHF Any intervention that increases EXPIRATORY time is useful, such as a slower RR. this minimizes air trapping and auto PEEP Slow inspiratory flow helps gas redistribute from high compliance areas to those with longer time constants Insp flow is how fast the Vt is delivered to the pt Increasing expiratory time is another way to say shorten inspiratory time
what factors reduce PVR?
Hyperventilation nitric oxide NTG increased PO2 hypocarbia alkalosis decreased intrathoracic pressure PDE inhibitors CCB ACE inhibitors
what rhythm disturbance might hyperventilation cause?
Hyperventilation shifts k into cells = hypokalemia = can prolong QT
describe management techniques to decrease CBF
Hyperventilation to 30-35 mmhg of CO2 constricts cerebral blood vessels and reduces ICP Nitroprusside should be avoided because it dilates cerebral vasculature and increases ICP Avoid hypoxia which will increase CBF Avoid HTN - BP beyond limit of autoregulation increases ICP Elevate HOB > 30 degrees PEEP increases thoracic pressure and reduced venous outflow away from the brain
how does hypocalcemia affect threshold potential?
Hypocalcemia DECREASES TP
Conditions that decrease PVR
Hypocarbia Adequate oxygenation Alkalosis Hemodilution Vasodilators Nitric oxide
why does hypocarbia decrease risk of LAST?
Hypocarbia decreases cerebral blood flow and reduces drug delivery to the brain... hyperventilation may be helpful
what physiologic factors DECREASE risk of LAST?
Hypocarbia, hypokalemia, and CNS depressants CNS depressants such as benzos and barbiturates increase seizure threshold
cranial nerve XII
Hypoglossal tongue movement
Hypoglycemia s/sx present when glucose falls less than ______ in neonates... GA will mask these signs what is treatment for hypoglycemia?
Hypoglycemia s/sx present when glucose falls less than 40... GA will mask these signs Treatment = 10% dextrose 2 ml/kg, then the dose is doubled (4 ml/kg) in order to provide adequate substrate to the brain. After the bolus a D10 infusion at 8 mg/kg/min is titrated to maintain serum glucose greater than 40
why does hypokalemia decrease risk of LAST?
Hypokalemia lowers resting membrane potential, requiring a larger stimulus to depolarize the nerve
which vasopressor is the best choice to use in someone who abuses cocaine and why?
Hypotension wont respond to ephedrine in chronic cocaine abusers due to catecholamine depletion - phenylephrine = best option
Hypothermia = core temp less than ______ C who is at biggest risk for hypothermia?
Hypothermia = core temp less than 36 C Pts at extremes of age are at greatest risk
what will interfere with the accuracy of BIS?
Hypothermia, EMI, encephalopathy interfere w/ BIS
list the consequences of hypercarbia
Hypoxemia Increased myocardial oxygen demand Hyperkalemia hypercalcemia Decreased oxygen carrying capacity Acidosis causes vasodilation and myocardial depression CO2 activates the SNS and increases catecholamine release. Unless acidosis is severe, this predominates Increased ICP Decreased LOC
what is a consequence of hypoxia in the newborn?
Hypoxemia leads to acidosis and possibly return to fetal circulation
what are the signs and symptoms of opioid induced skm rigidity?
Hypoxia Hypercapnia Increased oxygen consupmtion Decreased SvO2 Decreased thoracic compliance Decreased FRC Decreased Ve Increased CVP Increased PAP Increased PVR Increased intracranila pressure Increased gastric pressure w/ mask ventilation
what factors increase PVR?
Hypoxia hypercarbia nitrous oxide hypothermia high PEEP SNS stimulation pain increased intrathoracic pressure ketamine desflurane high airway pressures
what conditions decrease cardiac contractility?
Hypoxia and acidosis Hypercapnia Hyperkalemia Myocardial ischemia Hypocalcemia Volatile anesthetics Propofol Beta blockers CCB
how does the newborn respond to hypoxia? at how many weeks does respiratory control mature?
Hypoxia causes apnea Respiratory control doesn't mature until 42 weeks post conceptual age... before maturation, hypoxemia depresses ventilation and after maturation hypoxemia stimulates ventilation
Hypoxia prevention safety device
Hypoxia prevention safety device prevents you from accidentally setting a hypoxic mixture with the flow control valves... it limits N2O flow to 3x oxygen flow. Its either pneumatic or mechanical
What is hypoxic pulmonary vasoconstriction? what happens when HPV is impaired?
Hypoxic pulmonary vasoconstriction minimizes shunt by diverting pulmonary blood flow away from unventilated alveoli. It is a local reaction that occurs in response to alveolar oxygen tension (NOT ARTERIAL PO2!) Agents that impair HPV increases shunt fraction and reduces PO2
what are the six nerves that arise from the lumbar plexus?
I invariably get lazy on fridays Iliohypogastric Ilioinguinal Genitofemoral Lateral femoral cutaneous Obturator Femoral
Tip of the PAC should be in lung zone ______
III
IM dose of sux for neonates is ____ mg/kg, for older kids is ____ mg/kg
IM dose of sux for neonates is 5 mg/kg, for older kids is 4 mg/kg
what is ischemic optic neuropathy? what are the risk factors for developing ION?
ION is the most common cause of perioperative vision loss... occurs most often after spinal surgery Risk factors Prone Wilson frame Long duration of anesthesia Large blood loss Low ratio of colloid to crystalloid resuscitation Hypotension Male obese Diabetes HTN Smoking Old age Atherosclerosis
Ranked LA injection sites from most vascular and highest Cp to least
IV Tracheal Interpleural Intercostal Caudal Epidural Brachial plexus Femoral Sciatic Subcutaneous I Think Illogical Imposters Can't Educate But Fabulous Schools Should
what is the treatment for hyperkalemia?
IV calcium chloride or calcium gluconate hyperventilation glucose + insulin albuterol neb sodium bicarb lasix volume resuscitation hemodialysis hemofiltration
treatment for retained placenta
IV nitroglycerin → provides uterine relaxation for placental extraction D&C
what is the treatment for DIC
IVF, FFP, platelets, cryo, IV heparin, LMWH
what would happen if acetylcholinesterase did not rapidly metabolize ACh at the NMJ?
If ACh was allowed to bind to the receptor for a longer period of time, the muscle would contract once and not be able to be stimulated again until ACh dissociated from the receptor (this is how sux causes paralysis)
If PIP and PP are both increased, then total compliance is ________ OR Vt is _________
If PIP and PP are both increased, then total compliance is decreased OR Vt is increased
If PIP is increased and there is no change in PP then resistance is _______ OR inspiratory flow rate has ________
If PIP is increased and there is no change in PP then resistance is increased OR inspiratory flow rate has increased
Eisenmenger syndrome
If PVR increases due to pulmonary vascular disease a left to right shunt can be converted to a right to left shunt At birth, shunts flow in a left to right direction; eventually, there will be increased blood in the pulmonary circulation, leading to pulmonary hypertension. this will reverse the shunt from right to let, causing cyanosis, RVH, polycythemia, clubbing
If barotrauma exists, you should aim to reduce plateau pressure by what interventions?
If barotrauma exists, you should aim to reduce plateau pressure by reducing Vt, inspiratory flow, and PEEP... sedation is also helpful
according to Bernoulli's principle, what is the relationship between fluid velocity and pressure exerted on the walls of a tube?
If fluid velocity is high, then pressure exerted on the walls of the tube is low and vice versa
how long should LMW heparin be held before a neuraxial block, before removing an indwelling catheter, after an indwelling catheter has been removed? for prophylactic (1x) dosing and therapeutic (2x) dosing
If on prophylactic dosing (1x daily) hold for 12 hrs before block placement If on therapeutic dosing (2x daily) hold for 24 hrs before block placement Hold 12 hrs before removing indwelling catheter Hold 2 hrs after indwelling catheter has been removed If prescribed after single shot block If on prophylactic dosing (1x daily) hold for 6-8 hrs If on therapeutic dosing (2x daily) hold for 24 hrs
why is it bad to leave an oxygen tank open on the back of the anesthesia machine?
If oxygen pressure fails and the aux oxygen tank is open, the oxygen pressure failure device won't activate until the oxygen pressure from the tank is less than 20 psi
is BP falsely increased or decreased if the cuff location is above the heart? what about below?
If the BP cuff location is above the heart, the BP reading will be falsely decreased (less hydrostatic pressure) If the BP cuff location is below the heart, the BP reading will be falsely increased (more hydrostatic pressure)
If the isoflurane dial is set to 2%, then how much of the fresh gas existing the vaporizing chamber is saturated with isoflurane?
If the isoflurane dial is set to 2%, then 100% of the fresh gas existing the vaporizing chamber is saturated with isoflurane
Immediately after vascular injury, the vessel _______________ to reduce blood flow to the area, a result of ______________, ______________, and release of ___________________. ______________ reduces blood loss and helps procoagulants remain in the affected area, so they can do their job
Immediately after vascular injury, the vessel contracts to reduce blood flow to the area, a result of SNS reflex, myogenic response, and release of thromboxane A2. vascular spasm reduces blood loss and helps procoagulants remain in the affected area, so they can do their job
Placenta accreta
Improper implantation of placenta into the myometrium with little or no intervening decidua Placenta accreta = when it attaches to surface of myometrium Uterine contractility is impaired and potential for tremendous blood loss Neuraxial anesthesia is safe but GA is preferred
Improved neuro outcomes if _____ C for _______ hrs after hospital admission in pt with cerebral hypoxia
Improved neuro outcomes if 34 C for 12-24 hrs after hospital admission
In a 70 kg adult, total blood volume is about _____ L and plasma volume is about ______ L
In a 70 kg adult, total blood volume is about 5 L and plasma volume is about 3 L Remember 60/40/20 (15/5) 60% of TBW = water 60% of 70 kg = 42 L Total body water is divided into intracellular and extracellular volume Intracellular volume = 40% of TBW or 28 L Extracellular volume = 20% of TBW or 14 L Extracellular volume is divided into interstitial fluid and plasma fluid Interstitial fluid = 15% of TBW or 11 L Plasma fluid = 4% of TBW or 3 L
what factors increase aldosterone release?
In addition to RAS stimulation, aldosterone release is increased by hyperkalemia and hyponatremia
how and why do the orientation of the parturient's rib change?
In early pregnancy relaxin relaxes the ligaments in the ribcage, allowing the ribs to assume a more horizontal position to increase AP diameter of the chest, giving lungs more space
what drugs should be avoided in someone with hyperthyroid?
In hyperthyroid pt avoid sympathomimetics, anticholinergics, ketamine and pancuronium
what is a possible dangerous SE of sux on the kid's HR who is less than 5 yrs old?
In kids less than 5 years old, sux can cause bradycardia or even asystole Atropine 0.02 mg/kg IV pretreatment
in order to increase HR, what must happen to the rate of phase 4 depolarization, threshold potential, and/or resting membrane potential?
In order to INCREASE HR.... the rate of phase 4 depolarization must increase the Threshold potential becomes more negative (shorter distance between RMP and TP) OR the Resting membrane potential becomes less negative (shorter distance between RMP and TP)
describe the following changes that occur in pregnancy: SV intravascular volume HR vascular smooth muscle hgb concentration
In preg, SV increases as a function of increased intravascular volume and HR increase to satisfy higher metabolic demand Vascular smooth muscle is relaxed from increased progesterone stimulating NO release - this reduces SVR Dilutional anemia contributes to SVR
which way does the oxyhemoglobin curve shift in pregnancy?
In pregnancy, right shift of oxy hgb curve/increased P50 shifts right to release more oxygen to the baby
Law of Laplace
In spheres and cylinders, the law of laplace illustrates the relationship between wall tension, internal pressure and radius
In the LV pressure volume loop, which corners does the MV open and close? AV?
In the LV pressure volume loop, the MV opens in the bottom left corner and closes in the bottom right corner and the AV opens in the upper right corner and closes in the upper left corner
why does hypoxia decrease cardiac contractility
In the absence of oxygen, the cardiac myocytes convert to anaerobic metabolism. In this situation, intracellular lactate increases, leading to acidosis and impaired enzymatic function.
In the absence of vascular injury, the endothelium inhibits plt function by secreting _________ and _______________
In the absence of vascular injury, the endothelium inhibits plt function by secreting prostaglandin I2 and nitric oxide Prostaglandin I2 inhibits vWF adherence, TxA2 activation, and release of storage granules Nitric oxide inhibits TxA2
what happens to total body fat as we age? how does this affect lipophilic and hydrophilic drugs?
In the elderly, total body fat is increased - this accounts for increased Vd for lipophilic drugs like prop TBW and blood volume are decreased Smaller Vd for hydrophilic drugs like roc
Physiologic anemia of the infant
In the first 2 months of life, erythrocytes containing hgb F are replaced by those that produce hgb A By six months, hgb F is completely replaced Physiologic anemia occurs when the baby is 2-3 months old Birth hgb = 17 Month 2-3 = hgb 10 Month 4-6 = erythropoiesis increases and hgb concentration begins to rise After 6 months P50 is the same as the adults
what is the active metabolite of morphine? in what patient population does it accumulate?
In the liver, morphine is converted to morphine-3 and morphine-6-glucuronide M6G is an active metabolite that accumulates with renal failure and chronic morphine administration
what is the primary determinant of BP in the neonate?
In the neonate, HR is the primary determinant of BP and CO
how do the angles of the mainstem bronchi differ in the neonate? at what age does it change to be more like the adult?
In the neonate, the right mainstem bronchus takes off at the same angle as let mainstem Up to age 3 years, both bronchi take off at 55 degrees In the adult, the right bronchus takes off at 25 degrees and the left at 45 degrees
what causes fade that is seen during TOF stimulation?
In the nerve, there are TWO supplies of ACh... some that is available for immediate release, and some that must be mobilized before it can be made available for immediate release After an action potential , ACh available for immediate release is released... some of the ACh goes on to stimulate the Nm receptor, and some bind to prejunctional Nn receptors to cause mobilization of ACh Fade that is seen during TOF stimulation is caused by ANTAGONISM of PREsynaptic Nn receptors - this is how NDNMB cause fade
why do you not see fade with sux?
In the nerve, there are TWO supplies of ACh... some that is available for immediate release, and some that must be mobilized before it can be made available for immediate release After an action potential , ACh available for immediate release is released... some of the ACh goes on to stimulate the Nm receptor, and some bind to prejunctional Nn receptors to cause mobilization of ACh AGONISM of the presynaptic nicotinic receptor PREVENTS fade, which is why sux does not cause fade
how do NSAIDS cause kidney damage?
In the presence of NSAIDS, inhibition of cyclooxygenase reduces prostaglandin synthesis and contributes to renal vasoconstriction, ipmairing renal blood flow
how do NSAIDS cause renal vasoconstriction?
In the presence of NSAIDS, inhibition of cyclooxygenase reduces prostaglandin synthesis and contributes to renal vasoconstriction, ipmairing renal blood flow
Describe the CO2 dissociation curve
In the presence of oxygenated hgb, CO2 dissociation curve shifts right and hgb has a DECREASED affinity for CO2. this occurs in the lungs In the presence of deoxygenated hgb, the CO2 dissociation curve shifts left and hgb has an increased affinity for CO2. this happens in the tissues.
what drug is preferred in the setting of hypovolemia and bradycardia in the neonate? why?
In the setting of hypovolemia and bradycardia, epinephrine is preferred over atropine since epi augments contractility
What is transduction?
In transduction, injured tissues release a variety of chemicals that activate peripheral nerves and/or cause an immune cells to release proinflammatory compounds... these peripheral nerves transduce this "chemical soup" into an action potential so that the extent of the injury is ultimately interpreted by the brain Inflammation contributes to a reduced threshold to pain stimulus (allodynia) and increased response to a pain stimulus (hyperalgesia)
Inability to achieve _____ METS = increased perioperative risk
Inability to achieve 4 METS = increased perioperative risk
what is the mV of the inactive state of the sodium channel? what happens to the sodium channel now?
Inactive state +35- -70 mV The channel is closed The inactivation gate plugs the channel until resting membrane potential is re-established The return of RMP converts the channel from inactive to resting state... at this point the nerve is ready to be stimulated again
what is the stimulus for erythropoietin? what does erythropoietin do?
Inadequate oxygen delivery to the kidney causes it to release erythropoietin EPO stimulates stem cells in the bone marrow to produce erythrocytes
Inadvertent stimulation of ___________ nerve through bladder wall during TURP procedure can cause LEG movement which can cause ___________
Inadvertent stimulation of obturator nerve through bladder wall can cause LEG movement which can cause bladder puncture
why does hyperkalemia impair cardiac contractility?
Increase RPM Voltage gated sodium channels fire in response to depolarization, but they cannot fire again until the cell has repolarized. If RPM increases to a level that exceeds where these channels would otherwise repolarize, they'll get stuck in the closed and inactive state The myocyte cannot be depolarized and therefore cannot contract
what are hemodynamic goals for the baby with TOF?
Increase SVR Decrease PVR Maintain contractility and HR Avoid SNS stimulation, ephedrine, dobutamine and epi Increase preload Avoid dehydration
Causes of increased ETCO2
Increased CO2 production and delivery to the lungs, decreased alveolar ventilation, equipment malfunction Increased BMR (increased VO2) MH Fever Thyrotoxicosis Sepsis Seizures Laparoscopy Tourniquet or vascular clamp removal Sodium bicarb administration Anxiety Pain Shivering Increased muscle one after NMB reversal Medication SE Hypoventilation CNS depression Residual NMB COPD High spinal Neuromuscular disease Metabolic alkalosis if spontaneous ventilation Rebreathing CO2 absorbent exhaustion Unidirectional valve malfunction Leak in breathing circuit Increased apparatus dead space
how do the following affect GFR: increased MAP afferent arteriole dilation efferent arteriole dilation
Increased MAP increases GFR Afferent arteriole dilation increases GFR Efferent dilation decreases GFR
what pulmonary changes are associated with the elderly pt? -Ve -lung compliance -lung elasticity -dead space -alveolar surface area -VQ matching -Aa gradient -RV -CW complaince -WOB -response to hypoxia -protective airway reflexes -resp muscle stregnth -FRC -closing capactiy -VC -TLC
Increased Ve (to offset dead space) Increased lung compliance Decreased lung elasticity ( the tendency for an inflated lung to return to its original shape during exhalation) Loss of elastic recoil promotes small airway collapse which causes Increased dead space, Decreased alveolar surface area, VQ mismatch, Increased Aa gradient, Decreased PaO2, Altered lung volume and capacities Gas trapping and RV INCREASES, similar to emphysema Decreased CW compliance - its stiffer and less able to expand WOB is increased - caution w/ resp depressant Decreased response to hypoxia - chemoreceptors less sensitive Increased risk of hypoventilation, apnea, reap failure Decreased protective airway reflexes Reduced efficiency of cough and swallowing Greater stimulus needed to elicit a cough Increases aspiration risk Decreased respiratory muscle strength Increased residual volume, FRC and closing capacity Decreased VC and ERV Unchanged TLC
primary versus secondary causes of Conn's syndrome
Increased adoltersone release from adrenal gland = primary Increased aldosterone stimulus from extra adrenal origin = secondary
what causes an increased alpha angle on the ETCO2 waveform?
Increased alpha angle is caused by expiratory airflow obstruction like COPD, bronchospasm or kinked ETT
what are disadvantages of the Mapleson circuit?
Increased apparatus dead space Requires high FGF to prevent rebreathing Loss of heat and humidity Inefficient use of inhaled anesthetics Risk of environmental pollution Unrecognized kinking of fresh gas hose in Bain circuit
how does MAP change in pregnancy? SBP? DBP?
Increased blood volume + decreased SVR = no MAP change Decreased DBP
how does intravascular volume change in a pregnant pt and what is the reason for this change? what is a side effect of this change?
Increased intravascular volume prepares mom for hemorrhage with labor Increased plasma volume more than RBCs causes dilutional anemia
what are signs and symptoms of chronic hepatitis? lab values?
Increased liver enzymes and bilirubin Jaundice fatigue thrombocytopenia glomerulonephritis neuropathy arthritis myocarditis PT is prolonged and albumin is decreased
Consequences of uncontrolled labor pain
Increased maternal catecholamines - HTN and reduced uterine blood flow Maternal hyperventilation = left shift of oxygen hgb curve - reduced delivery of oxygen to the fetus
Factors that increase ADH release
Increased osmolarity of the ECF -Shrinks osmoreceptors in the hypothalamus Decreased blood volume -Unloading of baroreceptors in the carotids, transverse aortic arch, great veins, and RA stimulate ADH release
why are OB pts susceptible to rapid desaturation on induction of anesthesia?
Increased oxygen consumption relative to FRC contributes to rapid arterial desat in the OB patient
how does increased plasma protein levels affect plasma oncotic pressure and GFR?
Increased plasma protein increases plasma oncotic pressure and reduces GFR
at how many weeks pregnant does progesterone begin to increase?
Increased progesterone begins at 8-12 weeks
how does MAC and local anesthetic sensitivity change during pregnancy? why?
Increased progesterone explains the increase sensitivity to LA and MAC decrease by 30-40% Increased epidural vein volume decreases the volume of the subarachnoid and epidural spaces = Increased LA sensitivity
why do parturients have increased risk of difficult intubation?
Increased progesterone, estrogen and relaxin cause vascular engorgement and hyperemia... combined with increased ECF, this leads to upper airway swelling -- affects nasal passages, oropharynx, epiglottis, larynx, and trachea 8x higher failed intubation Narrow glottic opening requires downsized ETT Airway manipulation causes tissue trauma and bleeding
Consequences of decreased GFR
Increased risk of fluid overload Decreased elimination of hydrophilic drugs and hydrophilic metabolites of lipophilic drugs
if child has URI, there is increased risk of.....
Increased risk of pulmonary complications Increased airway reactivity (bronchospasm) laryngospasm mucous plugging of airway atelectasis desaturation events postop hypoxia
how do temperature changes affect the solubility of a substance?
Increased temp decreases solubility, decreased temp increases solubility This is why anesthetic emergence takes longer in a hypothermic pt
what are signs/symptoms of hyperthyroid? how does it affect: metabolism oxygen consumption CO2 production vasculature Ve GI
Increased thyroid hormone = increases BMR, increased oxygen consumption and increased CO2 production Vasodilation results from increased oxygen consumption.. This helps improve tissue blood flow and oxygen delivery Increased CO2 production requires that the pt increase Ve Thyroid hormone excess increases the sensitivity of neuronal synapses in the spinal cord leading to tremors Intestinal hypermotility results in diarrhea - risk of fluid and electrolyte imbalance
what factors increase Reynolds number (more turbulent?) what factors decrease Reynolds number? (more laminar)
Increased viscosity decreases Reynolds number Increased density, diameter and velocity increases Reynolds number
why are beta 2 agonists given to OB pts? what 2 drugs are specific to OB what are possible SE?
Increases intracellular cAMP and relaxes the uterus Increases progesterone release Ex = terbutaline and ritodrine Side effects Hyperglycemia from glycolysis in liver Hypoglycemia for newborn Hypokalemia from intracellular shift Beta 2 agonists cross the placenta and increase HR
What does aldosterone do?
Increases reabsorption of sodium and increases secretion of potassium Aldosterone controls ECF volume (Na and H2O absorbed together)
for what type of surgery is an interscalene block indicated?
Indicated for shoulder, arm and elbow surgery - often spares the lower trunk, so not an ideal block for procedures below elbow
at what age is MAC at its highest level?
Infant 2-3 months
Leads II, III, aVF monitor what side of the heart and which coronary artery?
Inferior wall RCA
What is the most common method of exhaled gas analysis in the OR
Infrared absorption
Malignant hyperthermia
Inherited disease of SKM characterized by disorder of calcium homeostasis Exposure to halogenated volatiles and/or sux activates the defective ryanodine receptor (RYR1), which stimulates the sarcoplasmic reticulum to release way too much calcium into the cell
How do thiazide diuretics work?
Inhibits Na-Cl cotransporter in the distal tubule... inhibition of this will activate the Na Ca antiporter.. This increases calcium reabsorption and calcium concentration
Tissue pathway factor inhibitor
Inhibits VIIa-tissue factor complex Anticoagulant
what does pancreatic polypeptide do?
Inhibits pancreatic exocrine secretion, gallbladder contraction, gastric acid secretion and gastric motility
what kind of injury will occur if it is above the decussation of the corticospinal tract? below?
Injury above decussation leads to spastic paralysis on the contralateral side Injury below the decussation leads to flaccid paralysis on ipsilateral side
what part of the body does the saphenous nerve innervate?
Inner calf
what factors are INSIDE of the platelet, and what are their roles?
Inside the platelets are: -actin and myosin -thrombosthenin -ADP -calcium -fibrin stabilizing factor -serotonin -growth factor Helps plt contract to form the plt plug assist w/ plt contraction plt aggregation and activation cross linked fibrin activate nearby plts helps repair damaged vessel walls
Hormones and drugs that decrease serum glucose
Insulin Somatostatin Volatile anesthetics Beta antagonists
what does insulin do? what stimulates its release?
Insulin = anabolic hormone Promotes energy storage Stimulates H/K pump - decreases serum K Release is stimulated by glucose... anything that increases glucose will increase insulin release -PNS stimulation after eating a meal -SNS stimulation
what are contraindications for combitube?
Intact gag Prolonged use >2-3 hrs due to ischemia risk Esophageal disease like Zenker's diverticulum Ingestion of caustic substances Provides secure airway so ok to use if full stomach**
what interincisor gap indicates difficult intubation?
Interincisor gap should be 2-3 finger lengths or 4 cm
what is the purpose of the intermediate chain of the local anesthetic?
Intermediate chain makes it the ester or amide. It also determines the metabolism and allergic potential Amides have NH in the intermediate chain
what is the fluid called that is BETWEEN cells?
Interstitial fluid is the space between the cells
what site of IM sux administration has the fastest onset?
Intralingual administration via submental approach has the fastest onset
why is intraoperative hypoglycemia hard to diagnose?
Intraoperative hypoglycemia can be hard to diagnose As serum glucose falls, the SNS is activated and circulating epi stimulates gluconeogenesis and glycolysis in the liver to restore normal serum glucose Anything that blunts SNS response can mask signs of intraoperative hypoglycemia GA, diabetic autonomic neuropathy, beta blockers
what are intrinsic causes of AKI?
Intrinsic injury - parenchymal Injury to tubules, glomerulus, or interstitial space Due to ischemia, nephrotoxic drugs (IV contrast dye, abx, NSAIDS)
Vaso-occlusive crisis
Ischemia and pain caused by sickle-shaped red blood cells that obstruct blood flow to a portion of the body. Sickled cells impair tissue perfusion and cause ischemic injury treatment = analgesics
what is the MAC of iso sevo des N2O
Iso 1.2 Sevo 2.0 Des 6.6 N2O 104
what is coronary steal?
Isoflurane is the most potent coronary artery vasodilator, it may produce coronary steal As myocardial oxygen demand increases, healthy vessels dilate Severely stenotic vessels are maximally dilated beyond the point of stenosis... when myocardial demand increases, the diseased vessels will not be able to dilate any further. The idea behind coronary steal is that coronary blood flow would be preferentially directed to healthy tissue - taken from the poor and given to the rich.
what are absolute indications for one lung ventilation?
Isolation to avoid contamination Control of distribution of ventilation Unilateral bronchopulmonary lavage Pulmonary infection bronchopleural fistula massive hemorrhage large unilateral lung cysts or bullae life threatening hypoxemia r/t lung disease pulmonary alveolar proteinosis Most indications that improve surgical exposure are RELATIVE indications, such as esophageal resection for thoracic aneurysm repair
Isotonic
Isotonic = osmolarity equal to plasma
in what situations does the hypoxic prevention safety device NOT prevent a hypoxic mixture?
It CANNOT prevent a hypoxic mixture when there is an oxygen pipeline crossover, leak distal to flowmeter valve, administration of a third gas, or defective mechanic or pneumatic components
what are NPO guidelines for parturients?
It doesn't matter when mom last drank she is always considered a full stomach Mom can eat until an epidural is placed Drink clears throughout labor
It emits 2 wavelengths of light - oxyhemoglobin absorbs near infrared light (________ nm) and deoxygenated blood better abords red light (_______ nm)
It emits 2 wavelengths of light - oxyhemoglobin absorbs near infrared light (940 nm) and deoxygenated blood better abords red light (660 nm)
What is cystic fibrosis?
It is a genetic disorder of the cell membranes. Causes thick, sticky mucus to build up in air passages and pancreas. recessive genetic disorder that affects chloride channels causing excessive pulmonary secretions that plug the airways and creates obstructive lung disease
why is creatinine a good indicator of GFR?
It is constant and directly proportional to muscle mass It undergoes renal filtration but not reabsorption, which makes it a good indicator of GFR
how is resting membrane potential of the ventricular myocyte established?
It is established by chemical force, electrostatic counterforce, and sodium/potassium ATPase
What is the pneumotaxic center?
It is located in the pons and it limits inspiration The pneumotaxic center inhibits the DRG (inhibits the pacemaker) Sounds like PNA.... PNA INHIBITS inspiration
what are 3 functions of calcitriol?
It stimulates the intestine to absorb Ca2+ It stimulates bone to store Ca2+ It stimulates the kidneys to reabsorb calcium and phosphate
give 3 examples of the venturi effect
Jet ventilation, venturi mask, nebulizer
K + sparing diuretics
K + sparing diuretics -(triamterene, amiloride)inhibits K+ excretion and sodium reabsorption by the principal cells in the collecting ducts. Independent from aldosterone
in neonate with CDH, PIP should be kept less than ______ cm H2O why?
Keep PIP less than 30 cm H2O to minimize barotrauma and risk of PTX of the good lung - this may require permissive hypercapnia - it may increase PVR but this is the lesser of 2 evils
describe anesthetic management and considerations in the neonate with CDH
Keep PIP less than 30 cm H2O to minimize barotrauma and risk of PTX of the good lung - this may require permissive hypercapnia - it may increase PVR but this is the lesser of 2 evils Avoid conditions that increase PVR -Hypoxia -Acidosis -Hypothermia Abd closure may increase PIP - the surgeon may make a temporary ventral hernia to fix this A pulse ox on the lower extremity can warn of increased intra abdominal pressure A right to left shunt through the ductus arteriosus will lead to hypoxemia and cyanosis and this give rise to a positive feedback loop which increases PVR even further Use the right upper extremity to monitor pre ductal spo2 and bp. Preductal spo2 should be > 90% Surgery is delayed 5-15 days to allow for stabilization of HD status May require one lung ventilation
what induction agent is the best choice for baby with TOF? why?
Ketamine 1-2 mg IV or 3-4 mg IM is the best induction agent - it increases SVR and reduces shunting
what two drugs can be used to treat opioid induced hyperalgesia caused by remifentanil?
Ketamine and magnesium sulfate can be used to attenuate opioid induced hyperalgesia associated with remifentanil At resting membrane potential, the NMDA receptor is plugged by magnesium... increasing magnesium concentration near the receptor limits receptor activation
ketamine is an attractive option with someone who has adrenal insufficiency, but why should it be used with caution?
Ketamine is an attractive option but be cautioned that its negative inotropic properties can be unmasked in this pte population
what are characteristics of ketoacidosis?
Ketoacidosis, hyperosmolarity from increased glucose, dehydration Acetone = fruity breath Gap acidosis Metabolic acidosis causes kussmaul respirations > 250 blood sugar
Myasthenia gravis signs, symptoms, manifestations?
Key feature = SKM weakness that get worse later in the day or that develops w/ exercise.. Periods of rest allow for recovery of skm function Diplopia Ptosis Bulbar muscle weakness → dysphagia, dysarthria, difficulty handling salvia DOE Proximal muscle weakness
Kidney failure that requires dialysis is GFR < _____
Kidney failure that requires dialysis is GFR < 15
Kidneys receive _____% of CO
Kidneys receive 20% of CO
what are indications for bronchial blocker?
Kids less than 8 requires nasotracheal intubation tracheostomy has a single lumen ETT requires intubation after surgery and want to avoid changing the tube
Examples of increased airway resistance
Kinked ETT ETT cuff herniation Bronchospasm Bronchial secretions Compression of the airway Foreign body aspiration
what congenital defects have a characteristic cervical spine anomaly?
Klippel file Trisomy 21 Goldenahr Think kids try gold
what is Kussmaul's sign
Kussmaul's sign = paradoxical increase in CVP and JVD during inspiration. Its the result of RV filling defect - in this case impaired RV compliance.
what pathophysiology causes Kussmaul's sign
Kussmaul's sign = paradoxical increase in CVP and JVD during inspiration. Its the result of RV filling defect - in this case impaired RV compliance. Seen in constrictive pericarditis and infective endocarditis Avoid bradycardia in these situations Maintain afterload
give examples of diseases of chest wall, mediastinum and pleura that result in RLD
Kyphoscoliosis Ankylosing spondylitis Flail chest PTX Pleural effusion Pneumomediastinum Mediastinal mass NM disorders - muscular dystrophy, GBS, spinal cord transection Increased intraabdominal pressure - preg, ascites, obesity
L to R cardiac shunt will occur when _______ is greater than _______
L to R cardiac shunt will occur when SVR is greater than PVR Think R is PVR and L is SVR Whatever comes first is when that factor is greater
Tuffier's Line
L4-5 interspace, correlates with iliac crest
what nerve roots make up the sacral plexus?
L4-S4
which drugs can undergo placental transfer and can be dangerous?
LA (except chloroprocaine due to rapid metabolism) IV anesthetics Volatile anesthetics Opioids Benzos Atropine Beta blockers Magnesium
describe the guarded receptor hypothesis
LA can only bind to sodium channels in their active (open) and inactive (closed refractory) states LA cannot bind to sodium channels in their resting states
how do local anesthetics affect the cardiac/vascular system?
LA disrupt hemodynamics by altering the cardiac action potential, myocardial performance, and vascular resistance Decreases conduction velocity, AP duration, effective refractory period Impairs intracellular calcium regulation and therefore depresses myocardium Higher concentrations decrease SVR
what part of the local anesthetic profile determines its potency?
LA lipid solubility determines potency More drug inside the nerve means more molecules available to bind to receptor
what part of the local anesthetic determines its onset of action?
LA pka determines onset of action If the pka of the local anesthetic is closer to the pH of the blood, a larger fraction of molecules will exist as the lipid soluble, uncharged base in this situation, more molecules are diffusing across the axolemma = faster onset of action
what part of the local anesthetic profile determines its duration of action?
LA protein binding determines DOA Increased protein binding = increased duration of action
what is the most significant risk factor w/ a bier block?
LAST
what is the dose of 20% lipid emulsion therapy for the treatment of LAST?
LAST is treated with 20% lipid emulsion at an initial dose of 1.5 ml/kg over one min and then 0.25 ml/kg/min Continue infusion for 10 min after achieving HD stability
describe the treatment for LAST
LAST is treated with 20% lipid emulsion at an initial dose of 1.5 ml/kg over one min and then 0.25 ml/kg/min Continue infusion for 10 min after achieving HD stability If lipid emulsion doesn't work prepare for bypass Avoid beta blockers and calcium channel blockers - these enhance LA induced Cardiac arrhythmias Treat LAST seizures with benzos Hypoxia and acidosis worsens symptoms of LAST Epi can actually HINDER resuscitation of LAST and REDUCES the effectiveness of lipid emulsion therapy
Therapeutic index what does it mean when a drug has a narrow TI? wide?
LD50/ED50 (think LED) TI is a measure of drug safety Narrow TI = narrow margin of safety Wide TI = wide margin of safety
Remi infusion should be dosed on ______ body weight in obese
LEAN
the LV subendocardium is best perfused during what phase of the cardiac cycle?
LV subendocardium is best perfused during diastole
List complications of HTN
LVD IHD CHF arterial aneurysm stroke ESRD
which beta blockers have mixed alpha beta effects
Labetalol and carvedilol are the two with mixed alpha beta blocking effects
what Reynolds number indicated laminar vs turbulent flow?
Laminar is less than 2,000, turbulent is greater than 4,000
what are the landmarks used when doing an axillary block?
Landmarks = axillary artery pulse
what are the landmarks used for the supraclavicular block?
Landmarks = clavicle and subclavian artery
what are the landmarks used for the interscalene block?
Landmarks = clavicular head of the sternocleidomastoid, clavicle, and cricoid cartilage
what are the landmarks used for the infraclavicular block?
Landmarks = coracoid process and clavicle
when does large A wave occur in CVP waveform?
Large A wave occurs when the atria contracts against a high resistance - either at the valve or a non compliant ventricle Tricuspid stenosis, diastolic dysfunction, MI, chronic lung disease leading to RV hypertrophy, AV dissociation, junctional rhythm, PVCs
Large amounts of protein in the urine suggests __________ injury
Large amounts of protein in the urine suggests glomerular injury
what are the motor tracts of the spinal cord?
Lateral corticospinal tract → limb motor Ventral corticospinal tract → posture motor
what nerve roots make up the following nerves: lateral femoral cutaneous obturator femoral
Lateral femoral cutaneous L2-3 Obturator L2-4 Femoral L2-4
Leads I, avL, V5, V6 monitor what side of the heart and which coronary artery?
Lateral wall CxA
what is a metabolite of both cisatracurium and atracurium? what is dangerous about this metabolite?
Laudanosine is a metabolite of both cis and atracurium (A>C)... it is a CNS stimulant and can cause seizures... only a concern w/ prolonged infusions in the ICU
what does a left shift of the CO2 response curve mean? what factors cause a left shift of the CO2 response curve?
Left shift means that the respective center is MORE sensitive to CO2 hypoxemia, salicylates, surgical stimulation, metabolic acidosis, increased ICP, fear anxiety Things that cause stimulation
what are advantages of the Mapleson circuit?
Less airway resistance - good for peds Convenient Easily scavenged Bain circuit prevents heat loss
Lethal triad of trauma
Lethal triad of trauma = acidosis, hypothermia, coagulopathy Enzymatic structure impairs hemostatic mechanism Enzymes impaired by hypothermia
what are signs and symptoms of biliary stones?
Leukocytosis fever RUQ pain pain worse with inspiration = murphy's sign
why is lidocaine not an ideal local anesthetic for labor pain?
Lidocaine is not popular for labor analgesia d/t strong motor block - makes it good for C/S
what is the likely cause of NEC?
Likely the result of early feeding in premature baby impaired absorption by the gut leads to stasis, bacterial overgrowth, and infection
autonomic hyperreflexia is more likely to develop with injuries above _______
Likely to develop w/ injuries above T6, unlikely below T10
what are disadvantages of crystalloid administration?
Limited ability to expand plasma volume Increases plasma volume for 20-30 min Higher potential for peripheral edema Metabolic acidosis Dilutional effect of albumin can reduce oncotic pressure Dilutional effect on coagulation factor
Difficult LMA placement predictors
Limited mouth opening Upper airway obstruction Altered pharyngeal anatomy Poor lung compliance Increased airway resistance Lower airway obstruction
what is the relationship between PaCO2 and CBF?
Linear relationship between PaCO2 and CBF pH of CSF around arterioles controls CVR 1 mmhg increase in PaCO2 = 1 ml/100g brain tissue/min increase Max vasodilation occurs at PaCO2 of 100 mmhg and max vasoconstriction at 25 mmhg
what other syndromes are malignant hyperthermia linked to?
Linked to King Denborough syndrome, central core disease, multiminicore disease
Liquids boil at _______ temps when they are at a higher altitude why?
Liquids boil at lower temps when they are at a higher altitude d/t reduced atm pressure
describe the significance of local anesthetics being weak bases and what happens when they are injected around a nerve
Local anesthetics are weak bases - when they are placed into a solution, they dissociate into an uncharged base and its conjugate acid When the LA is injected around the nerve, the LA rapidly dissociates into an uncharged base and an ionized, conjugate acid (LA+) Since LA are weak bases with pka values higher than 7.4, we can predict that > 50% of the LA will exist as the ionized, conjugate acid The uncharged base enters the axolemma by diffusing through the lipid rich axolemma... once inside, a new equilibrium is established The ICF is more acidic than ECF, so there is a greater fraction of the ionized, conjugate acid inside the cell It is the ionized, conjugate acid portion that binds to the LA binding site (alpha subunit) on the inside of the voltage gated sodium channel
where is the alpha subunit of the sodium channel located in which LA bind to?
Local anesthetics bind to the alpha sub unit on the INSIDE of the sodium channel... the cell cannot depolarize and the AP cannot be propagated
how do local anesthetics affect threshold potential and resting membrane potential?
Local anesthetics have NO effect on EITHER threshold potential OR resting membrane potential Remember K + regulates RMP, and Ca+ regulates TP
Local anesthetics injected into the epidural space need to first diffuse through the ___________ before they can block the nerve roots
Local anesthetics need to first diffuse through the dural cuff before they can block the nerve roots
to which subunit of the sodium channel do local anesthetics bind to? what effect does this cause?
Local anesthetics reversibly bind to the alpha subunit of the voltage gated sodium channel plugging the sodium channel reduces sodium conductance
describe how local metabolism and the myogenic response help autoregulate coronary blood flow
Local metabolism = most important regulator. Adenosine = byproduct of ATP metabolism and is a potent coronary vasodilator. increased CO2 from metabolism will cause dilation. Vasodilation will flush out the products of metabolism, a way of regulating vasodilation and constriction Hypocarbia causes coronary vasoconstriction Myogenic response = vessels innate ability to maintain constant vessel diameter. When diameter is increased, it has a tendency to contract and vice versa
where in the body are muscarinic 2 receptors located? what effects are elicited when stimulated?
Located in myocardium and causes decreased contractility, HR, and CV
where in the body are alpha 1 receptors located? what effects are elicited when stimulated?
Located in the arteries and causes vasoconstriction. Located in the eye and causes mydriasis contraction in the GI sphincters decreased GI motility and tone increased sweat gland secretion***
where in the body are muscarinic 3 receptors located? what effects are elicited when stimulated?
Located in the bronchial tree and causes bronchoconstriction
where in the body are beta 1 receptors located? what effects are elicited when stimulated?
Located in the heart and kidneys. Causes increased contractility, HR, conduction speed, and renin release.
where in the body are beta 2 receptors located? what effects are elicited when stimulated?
Located in the myocardium, skeletal muscle, pancreas and bronchial tree. Causes vasodilation and bronchodilation. Causes increased insulin release
where in the body are dopamine receptors located? what effects are elicited when stimulated?
Located in the renal and mesenteric vascular beds. Causes vasodilation
where in the body are alpha 2 receptors located? what effects are elicited when stimulated?
Located in veins, renal tubules, medulla, vagus nerve (to increase PNS tone), locus coeruleus, dorsal horn of the spinal cord, platelets, salivary glands, and GIT. vasoconstriction diuresis via ADH inhibition decreased insulin release reduced SNS outflow (medulla) sedation (locus coeruleus) hypnosis (locus coeruleus) analgesia (dorsal horn of SC) antishivering depressed LOC in the pancreas, it causes inhibition of insulin release (hyperglycemia). It also promotes platelet aggregation. Presynaptically located, NE releasing neurons in the CNS and PNS, producing a negative feedback mechanism
Hypocalcemia EKG changes
Long QT
do elderly have a faster or slower recovery from volatile anesthetic? why?
Longer recovery from volatile anesthetics Increased body fat, decreased gas exchange, decreased hepatic metabolism
which leads should you look at to determine axis?
Look at leads I and avF to determine axis
what is the most common cause of a vaporizer leak?
Loose filler cap = most common cause of vaporizer leak
when does loss of A wave occur in CVP waveform?
Loss of A wave occurs when synchronized contraction of RA is lost Afib, V pricing when underlying rhythm is asystole
what are side effects and complications of carbonic anhydrase inhibitors?
Loss of bicarb to the urine produces alkaline urine and a mild hyperchloremic metabolic acidosis Complications = metabolic acidosis, hypokalemia In pts with COPD, loss of bicarb ions in the urine (reduced buffer) may exacerbate CNS depression from hypercarbia
describe CSF flow through the brain
Love My 3 Silly 4 Lorn Magpies Lateral ventricles Monroe (foramen) Sylvius (aqueduct) 4th ventricle Luschka Magendie
Risk factors for the development of RDS in the neonate
Low birth wt Low gestational age Oxygen toxicity Barotrauma from PPV Endotracheal intubation Maternal diabetes
what drug characteristics favor placental transfer?
Low molecular weight High lipid solubility Unionized Nonpolar
how is lymph returned to venous circulation
Lymph is returned to the venous circulation by way of the thoracic duct at the junction of the internal jugular and subclavian vein
MAC decreases ____% for each decade of life after 40 years old
MAC decreases 6% for each decade of life after 40 years old
how is MAC affected by acute ETOH vs chronic ETOH?
MAC is increased for chronic ETOH abuse that is not intoxicated decreased for acute intoxication
describe how MAC varies with age
MAC varies w/ age Infant 1-6 months → MAC higher than adult Infant 2-3 months → MAC is at the highest level Neonate (0-30 days) → MAC is lower than the infant Premature → MAC is lower than the neonate
Tranylcypromine
MAOI
isocarboxazid
MAOI
phenelzine
MAOI
what are causes of systolic HF?
MI valve insufficiency dilated CM
what are causes of diastolic HF?
MI valve stenosis HTN hypertrophic CM cor pulmonale obesity
which murmurs are heard at the apex and left axilla?
MSDA - Mitral Stenosis is a Diastolic murmur heard at the Apex and left Axilla MRSA - Mitral Regurgitation is a Systolic murmur heard at the Apex and left Axilla
Mag levels (mEq/L) 2-3.5 = ________ 4-6 = ________ 6.5-7.5 = ________ > 10 = ________
Mag levels (mEq/L) 2-3.5 = seizure prophylaxis 4-6 = loss of patellar reflex, NV, diplopia, somnolence 6.5-7.5 = skm weakness, apnea > 10 = CA
what does magnesium cause muscle weakness
Magnesium is an antagonist for calcium which is why it causes muscle weakness and acts synergistically with NMB
Magnesium levels (mg/dL) 1.8-3 = ________ 4 = ________ 8 = ________ 10 = ________ 15 = ________ >18 = ________ > 25 = ________
Magnesium levels (mg/dL) 1.8-3 = normal 4 = tocolysis 8 = anticonvulsants 10 = loss of patellar tendon reflex 15 = respiratory depression >18 = apnea > 25 = CA
list the anatomy of the airway as it progresses from the trachea as the airway progresses, what happens to cross sectional area and airflow velocity?
Main bronchi → secondary bronchi → tertiary bronchi → terminal bronchioles → respiratory bronchioles → alveolar ducts cross sectional area INCREASES airflow velocity DECREASES
what does Mallampati assess?
Mallampati assesses tongue versus oral cavity - remember PUSH - pillars, uvula, soft palate, hard palate
what does the mandibular protrusion test assess?
Mandibular protrusion test assesses function of TMJ. class 3 is the worst.
describe components of a Mapleson circuit? how is mapleson E different from the others?
Mapleson circuits have: reservoir bag fresh gas inlet corrugated circuit tubing APL valve NO unidirectional valves or CO2 absorbent Mapleson E does not have APL or reservoir bag ***
what electrolyte disturbances can occur with massive transfusion?
Massive transfusion is associated with hypocalcemia, metabolic acidosis and or metabolic alkalosis
in what circumstance between mom and fetus causes ion trapping the most?
Maternal alkalosis and fetal acidosis is the circumstance that creates the strongest gradient for passage of local anesthetic from mother to fetus
Indications for GA for CS
Maternal hemorrhage Fetal distress Coagulopathy Pt refusal of regional CI to regional
at what mmhg does max oxygen loading occur?
Max O2 loading occurs at 100 mmhg
propofol infusion syndrome treatment
Maximize gas exchange Cardiac pacing PDE inhibitors Glucagon ECMO CRRT
N2O irreversibly inhibits vitamin B12. what are the potential consequences of this?
May cause megaloblastic anemia Neuropathy Immunocompromised Impaired DNA synthesis Concern of teratogenicity Possible risk of spontaneous abortion
what EKG changes can methadone cause?
May increase QT interval and can lead to torsades
list as many isotonic solutions as you can
NaCl 0.9% LR Plasmalyte A Albumin 5% Volven 6% Hespan 6%
list as many hypertonic solutions as you can
NaCl 3% D5 NaCl 0.9% D5 NaCl 0.45% D5LR Dextran 10%
Volume of distribution
Measure of apparent space in the body available to contain the drug Vd describes the relationship between a drug's plasma concentration following a specific dose
what is Mendelson Syndrome what are risk factors for Mendelson Syndrome?
Mendelson Syndrome = chemical aspiration pneumonitis. RF = pH < 2.5 and gastric volume > 25 ml
describe the relative potencies of the opioids with morphine being 1
Meperidine 0.1 Morphine 1 Hydromorphone 7 Alfentanil 10 Fentanyl 100 Remifentanil 100 Sufentanil 1000
why is giving meperidine dangerous to give along with MAOIs?
Meperidine is a weak serotonin reuptake inhibitor. Since MAO deaminates serotonin in the synaptic cleft, co administration of meperidine and an MAO inhibitor can cause serotonin syndrome
what is the active metabolite of meperidine? in what patient population does it accumulate?
Meperidine is demethylated in the liver to its active metabolite normeperidine... this metabolite is half as potent as its parent compound and accumulation in patients with renal failure or the elderly and increases the risk of seizures
what makes meperidine unique? why does it cause mydriasis and elevate HR?
Meperidine is unique because it is constructed from an atropine like ring... this explains why meperidine caseus mydriasis and elevates HR
describe the pkas for the following local anesthetics Mepivacaine Lidocaine Ropivacaine Bupivacaine Chloroprocaine
Mepivacaine = 7.6 Lidocaine = 7.9 Ropivacaine = 8.1 Bupivacaine = 8.1 Chloroprocaine = 8.7
why does metabolic acidosis increase the incidence of LAST?
Metabolic acidosis decreases the convulsion threshold and favors ion trapping inside the brain
how does metabolic acidosis affect cerebral blood flow? metabolic alkalosis?
Metabolic acidosis does not affect cerebral blood flow - this is because H+ does not pass through the BBB
what metabolic compensation occurs for respiratory alkalosis?
Metabolic compensation = kidneys excrete HCO3 to return pH to normal.. This can take several days
what metabolic compensation occurs for respiratory acidosis?
Metabolic compensation = when kidneys excrete hydrogen and conserve bicarb to return pH to normal
how does methemoglobin affect the pulse ox?
Methemoglobin aborms 660 and 940 nm wavelengths equally, so pulse oxy will not be correct and always read SpO2 85%
how is methemoglobin formed?
Methemoglobin is formed when the iron on the hemoglobin molecule becomes oxidized to its ferric form (Fe+3). It decreases the oxygen carrying capacity and shifts the oxyhemoglobin dissociation curve to the left
What structures make up the brain stem?
Midbrain, pons, medulla, reticular activating system
3rd space loss fluid calculation
Minor = 3-4 ml/kg/hr Moderate = 5-6 Major = 7-10
what effect occurs when you mix acetylcholinesterase inhibitors?
Mixing AChE inhibitors will yield an additive effect (not synergistic)
What is the Monro-Kellie doctrine?
Monro-Kellie doctrine states that brain, blood and CSF are regulated to the confines of the cranium.. Increase in one must be accompanied by a decrease in another and if not ICP increases
describe considerations for GA for CS what should induction be like? how high should you run your anesthetic gas? why? Increased risk of neonatal acidosis if time between uterine incision and delivery is more than _____ min
Mortality is 17x higher w/ GA in pregnant pt Induce with RSI Use lose concentration of volatile (0.8 MAC) + 50% nitrous Volatiles reduce uterine contractility Hyperventilation will reduce uterine blood flow Increased risk of neonatal acidosis if time between uterine incision and delivery is more than 3 min
what are special properties and considerations about precedex?
Most closely resembles natural sleep Sedation is from decreased SNS tone and decreased level of arousal Pts easily aroused Does not provide reliable amnesia Brady and hypotension Rapid administration causes HTN from alpha 2 stimulation in the vasculature, which occurs before the centrally mediated reduction in SNS tone Once CNS effects kick in, central alpha 2 effects predominate No resp depression Decreases CBF No change in CMRO2 - there is UNcoupling between CMRO2 and CBF No change in ICP Antishivering effect by impairing thermoregulatory response Reduces emergence delirium in kids Analgesia effect via alpha 2 stimulation in the dorsal horn of the SC (decreases substance P and glutamate release) Does not impair evoked potentials - good for wake up test for scoliosis surgery Good as nasal and buccal route for kids (3-4 mcg/kg 1 hr before surgery)
what is the most common cause of diabetes insipidus? what are other causes?
Most common cause = pituitary surgery Other causes = TBI, subarachnoid hemorrhage
what are the two most common causes of CKD?
Most common cause is DM, second most common cause is HTN
what is the most common cause of morbidity and mortality in pt w/ neurogenic shock?
Most common cause of M&M is ineffective alveolar ventilation and inability to clear pulmonary secretions
Hashimoto thyroiditis
Most common cause of goiter and primary hypothyroidism in adults in developed countries. Autoimmune disorder with circulating antithyroid antibody.
what is the most common cause of perioperative kidney injury?
Most common cause of perioperative kidney injury is ischemia reperfusion injury
signs and symptoms of subarachnoid hemorrhage
Most common sign of SAH = intense HA, worst in my life Loss of consciousness 50% of time Focal neuro def NV Photophobia Fever Signs of meningitis if blood irritates subarachnoid space
what are signs and symptoms of carcinoid syndrome?
Most common signs = flushing and diarrhea Histamine -Bronchoconstriction -Vasodilation -Hypotension -flushing head and neck Kinins and Kallikrein -Bronchoconstriction -Vasodilation -Hypotension -Flushing head and neck -Increases histamine release from mast cells Serotonin -Bronchoconstrcition -Vasoconstriction -HTN -SVT -Increased GI motility -Diarrhea -Abd pain
what should you do if there is a pipeline crossover?
Most critical actions when there is a pipeline cross over Disconnect pipeline supply Turn on the oxygen tank The auxiliary oxygen flowmeter on the anesthesia machine is supplied by the pipeline***** If there is an oxygen crossover, then the wrong gas will be given to the pt if this is used Conserve tank by using low flows Hand ventilate to conserve oxygen... on many anesthesia machines, oxygen is what drives the bellows Convert to TIVA
Most of the filtered sodium is reabsorbed in the __________
Most of the filtered sodium is reabsorbed in the proximal tubule.. Water follows sodium in the same proportion
what sensory and motor innervation does the sciatic nerve supply?
Motor innervation to posterior thigh Motor and sensory innervation to lower leg and foot via common peroneal and tibial nerves Innervates biceps femoris, semitendinosus and semimembranosus
what sensory and motor innervation does the obturator nerve supply?
Motor to hip adductors, sensory to distal inner thigh and part of hip
what sensory and motor innervation does the femoral nerve supply?
Motor to sartorius and quadriceps, sensory to anterior thigh
what are the 4 types of opioid receptors
Mu delta kappa ORL1
what are the 3 mechanisms by which methadone works?
Mu receptor agonism NMDA receptor antagonism monoamine uptake inhibition
what is beck's triad? what is it a sign of?
Muffled heart tones, JVD, hypotension Sign of cardiac tamponade
what effects do muscarinic receptors have in the body
Muscarinic 2 → Located in myocardium and causes decreased contractility, HR, and CV Muscarinic 3 → Located in the bronchial tree and causes bronchoconstriction Muscarinic receptors also cause miosis, GI relaxation, increased motility, increased secretion of sweat glands***
how do muscarinic antagonists differ in someone w/ a heart transplant?
Muscarinic antagonists will NOT affect HR in heart transplant
in general, do central or peripheral muscles respond more quickly to the onset of NMB? which recover first?
Muscle groups will respond differently to NMB in terms of onset and duration.... More CENTRAL muscles are paralyzed FASTER and recover SOONER than peripheral muscles
what are signs and symptoms of hypocalcemia?
Muscle spasms tetany laryngospasm mental status changes hypotension, prolonged QT paresthesia ckvostek and trousseau
what are signs and symptoms of adrenal insufficiency?
Muscle weakness/fatigue Hypotension Hypoglycemia Hyponatremia Hyperkalemia Metabolic acidosis Anorexia and weight loss Nv Hyperpigmentation of knees, elbows, knuckles, lips, cheeks
which terminal branch of the brachial plexus often needs to be blocked separately with an axillary block?
Musculocutaenous nerve often needs to be blocked separately
how do patients with myasthenia gravis respond to sux?
Myasthenia gravis is associated with resistance to sux due to a reduced number of nicotinic receptors at the NMJ receptor
Myocardial oxygen extraction is ____%
Myocardial oxygen extraction is 70%
how can rhabdomyolysis cause kidney failure?
Myoglobin from rhabdo can cause kidney failure
OSHA recommends that anesthetic gas exposure should not exceed the following for N2O and halogenated anesthetics?
N2O alone should be less than 25 ppm Halogenated anesthetics alone should be less than 2 ppm Halogenated agents with N2O should be less than 0.5 ppm
describe specific concerns about N2O
N2O is not flammable but does support combustion N2O irreversibly inhibits vitamin B12 may increase ICP diffuses into air containing spaces diffusion hypoxia
what is the emergency airway of choice for peds?
NEEDLE CRIC is the emergency airway of choice for kids less than 6 years old
name some stimulatory receptors
NMDA Nicotinic Sodium channels Dendritic spine function and mobility
what is the mechanism of action of ketamine?
NMDA receptor antagonist
what drugs can cause methemglobinemia?
NTG nitroprusside sulfonamides phenytoin benzocaine cetacaine prilocaine EMLA cream
what are signs and symptoms of hyponatremia?
NV skm weakness mental status changes seizures coma cerebral edema
list the following fluids in order from highest to lowest tonicity D5+NaCl 0.45% albumin 5% D5W NaCL 3%
NaCL 3% D5+NaCl 0.45% albumin 5% D5W
what is the morphology produced of an orthodromic AVNRT arrhythmia?
Narrow QRS
Hyperkalemia EKG changes
Narrow peaked t Short QT Wide QRS Low P amplitude Wide PR Nodal block Sine wave fusion of QRS and T → VF or asystole
Retrograde intubation contraindications
Neck flexion deformity Unable to ID landmarks (obese) Pretracheal mass (goiter) Tracheal stenosis under the puncture site Tumor that obstructs the path of the wire Coagulopathy Infection (pretracheal abscess)
Why does Desflurane need to be heated and pressurized?
Needs to be heated and pressurized because it is not very potent and excessive cooling would take place if used with variable bypass Also, des VP is 3-4 x higher than the other volatiles and will boil JUST above room temp (22 C)... this is why the variable bypass would be inefficient and the concentration would be not precise
what is negative pressure pulmonary edema?
Negative pressure pulmonary edema increases interstitial lung water. This creates a Restrictive lung disease
Neonatal surface area is _______ of the adult and the oxygen consumption is _________ It is metabolically more efficient for the neonate to increase _____ as opposed to its ______
Neonatal surface area is ⅓ of the adult and the oxygen consumption is double It is metabolically more efficient for the neonate to increase RR as opposed to its Vt
Neonate intubation position
Neonate intubation position → head on bead with shoulder roll Infant has large occiput Sniffing position will place glottic opening in a more anterior position
what is the amount of dead space in the neonate compared to the adult?
Neonates and adults have the same amnt of dead space (2 ml/kg)
Pts less than ______ weeks post conceptual age should be admitted for 24 hr observation w/ apnea monitor
Neonates are at risk of apnea after surgery and anesthesia Pts less than 60 weeks post conceptual age should be admitted for 24 hr observation w/ apnea monitor The younger the child, the greater the risk
Drugs that require fat for redistribution and termination of effect will have a _______ duration of action in the neonate why?
Neonates have a greater % of TBW and a lower % of fat and muscle mass
Neonates have a greater % of total body ________ and a lower % of _______ and _______ mass how does this affect drug dosing for lipid vs water soluble drugs?
Neonates have a greater % of total body water and a lower % of fat and muscle mass Drugs that require fat for redistribution and termination of effect have a longer duration of action A high TBW also means that they require higher doses of water soluble drugs to achieve a given plasma concentration Drugs that require fat for redistribution and termination of effect will have a LONGER duration of action
why are neonates prone to oxygen desaturation?
Neonates have a much higher oxygen consumption and CO2 production - The oxygen consumption is twice that of the adult This coupled with immature homeostatic mechanisms places neonate at risk with even minor physiological perturbations Neonates have an increased alveolar ventilaion to FRC ratio Higher ratio of alveolar ventilation relative to the size of FRC, therefore the oxygen supply contained within the FRC is quickly depleted... the neonate therefore desats faster during apnea
how does the neonate respond to an increased afterload?
Neonates have a poorly compliant ventricle, so they are unable to significantly increase contractility to overcome an elevated afterload The non compliant LV is sensitive to an increased afterload, so increasing HR is the best way to support BP
Neonates who do not produce enough surfactant are at risk for ________ why?
Neonates who do not produce enough surfactant are at risk for RDS The alveoli are stiff and non compliant... tension inside small alveoli increase and favors their collapse. Larger alveoli become over distended as they accept gas from collapse alveoli - this promotes atelectavisi, reduces surface area where gas exchange takes place, and creates VQ mismatch Hypoxemia leads to acidosis and possibly return to fetal circulation
what is the dose of the following: neostigmine physostigmine edrophonium
Neostigmine = 0.05 mg/kg Physostigmine = 0.2 mg/kg Edrophonium = 0.5 mg/kg (move decimal of neostigmine)
what kind of bond does neostigmine, pyridostimine, and physostigmine form with acetylcholinesterase?
Neostigmine, pyridostigmine, and physostigmine form CARBAMYL ESTER bond at the esteratic site... these are STRONG bonds, which explains why these drugs have a longer duration of action
what two nerves can the NIBP injure?
Nerve injury d/t NIBP tends to affect ulnar or median nerve
How long can neurogenic shock last?
Neurogenic shock can las 1-3 weeks
compare neurogenic vs hypovolemic shock
Neurogenic shock is characterized by bradycardia, hypotension, hypothermia w/ pink and warm extremities Hypovolemic shock presents w/ tachycardia, hypotension, and cool, clammy extremities
describe systemic effects of diabetes joints CV system wound healing eyes hemodynamics GI system pulmonary system kidneys
Neuropathy, retinopathy, nephropathy, CAD, PVD, CVA, stiff joint syndrome, poor wound healing and infection, cataracts, glaucome Painless MI Reduced vagal tone - tachycardia Orthostatic hypotension Delayed gastric emptying - aspiration Impared resp compensation to hypoxia and hypercarbia - increased sensitivity to anes drugs Regional may worsen defects with diabetic polyneuropathy Glycosylation of joints - stiff joint syndrome with reduced ROM and AO Prayer sign increased risk of DI Assess renal function Osmotic diuresis - F and E abnormality
Cauda equina syndrome what are the signs and symptoms what causes it what can be used to treat it?
Neurotoxicity is the result of exposure to high concentrations of LA Increased risk with 5% lidocaine and spinal microcatheters Microcatheters focal local anesthetic on a small area of the cord, exposing this region to a higher concentration of LA Signs and symptoms = bowel and bladder dysfunction, sensory def, weakness, and or paralysis Treatment = supportive
why should you never withdraw an epidural catheter through a needle?
Never withdraw epidural catheter through the needle - this can share the catheter and leave fragments in the pt
how do newborns handle sodium?
Newborns are obligate sodium losers (excertors) ... they lack the ability to retain water and glucose
what is nitric oxide role is coagulation
Nitric oxide inhibits TxA2
what are benefits and drawbacks of calcium hydroxide (ambsorb plus)?
No CO production Very little/no compound A production Lower risk of fire compared to soda lime Lower CO2 absorption capacity - requires more frequent replacement Higher cost
describe properties of propofol
No analgesia Anticonvulsant properties Myoclonus can occur infusions can change urine color → green or cloudy from phenol excretion and increased uric acid excretion respectively Antioxidant properties - free radical scavenger Supports bacterial growth and should be d/c within 6 hrs (infusion every 12 hrs) Causes pain on injection 10 mg has antipruritic effect 10-20 mg can be used for PONV or infusion of 10 mcg/kg/min
if a pt is allergic to an ester local anesthetics, can they receive an amide local anesthetic?
No cross sensitivity between allergy classes - ester allergic pts can get amides
TRALI - transfusion related lung injury
Non cardiogenic pulmonary edema Neutrophil activation in lungs cause endothelial injury Hypoxemia, acidosis, and death Caused by donor antibodies, highest with FFP and plts
Non-dihydropyridines CCB
Non-dihydropyridines CCB (verapamil, diltiazem) targets myocardium, decreases SVR, contractility, HR, CV
Phentolamine
Nonselective α-blocker Give to patients on MAO inhibitors who eat tyramine containing foods Toxicity: orthostatic hypotension, reflex tachycardia
Phenoxybenzamine
Nonselective α-blocker Irreversible Used preoperatively for pheochromocytoma to prevent catecholamine (hypertensive) crisis Toxicity: orthostatic hypotension, reflex tachycardia
what is the normal size of the aortic valve? what size indicates aortic stenosis?
Normal AV size = 2.5-3.5 cm2. AS is severe when < 0.8 cm2
what is normal BP? stage 1 HTN? stage 2? stage 3?
Normal BP <120/<80 Stage 1 HTN = 130-139/80-89 Stage 2 HTN = >140/>90 Stage 3 HTN crisis = >180/>120
normal EF = ____% when is LV dysfunction present?
Normal EF is 60-70% LV dysfunction is present when < 40% EF
what is normal fetal HR?
Normal FHR is 110-160.. This indicates normal acid base balance and normal uteroplacental perfusion
what is normal GFR?
Normal GFR is 120 ml/min
Normal GFR is reached by _____ months of age, normal tubular function is reached by ______ years of age
Normal GFR is reached by 8-24 months of age, normal tubular function is reached by 2 years of age
Normal H/H Newborn = _____ 3 mo = _____ 6-12 mo = _____ Adult F = _____ Adult M = _____
Normal H/H Newborn = 14/45 3 mo = 10/30 6-12 mo = 11/33 Adult F = 12/37 Adult M = 14/42
what is normal fetal HR variability?
Normal HR variability is 6-25 BPM Suggests intact CNS, SNS and PNS
what is normal ICP? What is intracranial HTN?
Normal ICP is 5-15 mmhg, intracranial HTN is > 20
what is normal SvO2 %
Normal SvO2 is 65-75%
what is normal bicarb levels?
Normal bicarb level is 22-26 mEq/L
Normal cerebral blood flow = ______ ml/100 g tissue/min or ______% of CO what cerebral blood flow will have evidence of ischemia?
Normal cerebral blood flow = 55 ml/100 g tissue/min or 15% of CO 20 = evidence of ischemia
what is the normal plasma value of platelets?
Normal platelet value = 150,000-300,000
what is the normal mitral valve size? what size indicates stenosis?
Normal valve size is 4-6 cm2, stenosis is < 1 cm2
from which approach to the brachial plexus is the intercostobrachial nerve anesthetized?
Not anesthetized with any approach to the brachial plexus A field block is required to block this nerve May foster tolerance for upper arm tourniquet of an awake pt
what are causes of auto PEEP
Not enough time to get air out High Ve Large Vt fast RR decreased expiratory flow decreased airway diameter from bronchoconstriction airway collapse inflammation increased airway resistance secretions obstructed ETT fighting the vent Treatment = disconnect vent
latent heat of vaporization
Number of calories required to convert one gram of a liquid to vapor without a temp change in the liquid
how does obesity affect pseudocholinesterase activity
Obesity INCREASES PChE activity
describe obstructive lung disease
Obstructive lung disease is characterized by small airway obstruction and increased resistance to expiratory flow. Getting air out is the problem
what is an increased risk of left IJ insertion?
Obtaining central line access via the left IJ has the added risk of puncturing the thoracic duct - this can cause chylothorax (lymph in the chest)
what is anterior spinal artery syndrome? what can cause it? what are the signs and symptoms?
Occlusion of the artery of Adamkiewicz during aortic cross clamping can cause anterior spinal artery syndrome, which results in flaccid paralysis w/ bowel and bladder dysfunction... sensory is preserved
when does pyloric stenosis present?
Occurs 2-12 weeks of life
Postoperative delirium in the elderly - when does it occur? -how does it present? -what are risk factors? -what is the treatment?
Occurs in the early postop period Presents as disordered behavior, perception, memory, psychomotor skills Risk factors = DELIRIUM -Drugs (anesthetic agents) -Electrolyte imbalance -Lack of drugs (withdrawal) -Infection (UTI/resp) -Reduced sensory input -Intracranial dysfunction -Urinary retention and fecal impaction -Myocardial event, male gender Treat underlying cause, give antipsychotics, minimize polypharmacy
what causes low ETCO2?
Occurs w/ hyperventilation, decreased CO2 production, or increased alveolar dead space Hyperventilation Light anesthesia Metabolic acidosis Decreased CO2 production Hypothermia Increased alveolar dead space Hypotension, pulmonary embolism Inadequate LMA seal
what are causes of respiratory alkalosis?
Occurs when alveolar ventilation exceeds CO2 production iatrogenic (mechanical ventilation) hypoxia pain anxiety pregnancy drugs - progesterone, salicylates, ASA pulmonary embolism reduce mechanical dead space with the same alveolar ventilation - removing HME changing from mask to ETT
Pyloric stenosis
Occurs when hypertrophy of the pyloric muscle creates a mechanical obstruction at the gastric outlet between the stomach and the duodenum
What is myxedema coma? what are s/sx? how does it affect: cardiac system pulmonary system liver/GI hormone secretion sensitivity to drugs adrenal function?
Occurs with end stage hypothyroid Coma Lack of thyroid hormone decreases HR, contractility, and CO Pleural and pericardial effusions occur In the liver, decreased metabolism manifests as slowed biotransformation reactions Inappropriate secretion of ADH is common - these pts retain free water.. This contributes to dilutional hyponatremia and edema Increased aspiration risk from delayed gastric emptying Increased sensitivity to NMB from muscle weakness Decreased adrenal function - hypotension unresponsive to pressors.. Can be treated w/ steroids
what causes high ETCO2 w/ normal plateau?
Occurs with increased CO2 production or decreased alveolar ventilation Increased CO2 production MH Sepsis, Fever hyperthyroidism Decreased alveolar ventilation Hypoventilation narcotics
Adiabatic process
Occurs without gain or loss of energy Example = very rapid expansion or compression of gas where there is no transfer of energy
what is the treatment for carcinoid syndrome?
Octreotide is a primary treatment for carcinoid syndrome Somatostatin (octreotide) inhibits the release of vasoactive substances from tumor Antihistamines - H1 and H2 - diphenhydramine + ranitidine or cimetidine Steroids 5 HT 3 antagonists Phenylephrine or vasopressin for hypotension
cranial nerve III
Oculomotor eye movement and pupil constriction
Cranial Nerve 1
Olfactory sense of smell
One MET equals ______ ml/kg/min
One MET equals 3.5 ml/kg/min
what kind of insulin can be given IV?
Only rapid acting regular insulin can be given IV
Postoperative cognitive dysfunction -when is the onset? -what is the presentation? -what are risk factors? -what is the treatment?
Onset is weeks to months after surgery Presentation is subtle and difficult to pinpoint - impaired cognition, comprehension, psychomotor skills RF Advanced age* Pre existing cog deficit Long duration of surgery High ASA status Low level of education No specific treatment, most cases resolve after about 3 months
what is an open circuit? list examples of open circuits
Open circuit = no rebreathing and no reservoir Examples: Insufflation simple face mask NC open drop
what is opioid induced skeletal muscle rigidity?
Opioid induced skeletal muscle rigidity causes sustained musclar contraction of the muscles in the abdomen, thorax and throat. Contraction is an ATP dependent process, so oxygen consumption increases Decreased chest wall compliance increases intrathoracic pressure.. This can elevate ICP
Butrophanol
Opioid partial agonists
buprenorphine
Opioid partial agonists
nalbuphine
Opioid partial agonists
describe what opioid partial agonists are what is their benefit? what are the drawbacks? what effect do they have on opioids already given? what about the opioid dependent pt? who are they useful for?
Opioid partial agonists produce analgesia with a reduced risk of respiratory depression Have a ceiling effect beyond which additional analgesia is not possible Reduce the efficacy of previously administered opioids Can cause acute opioid withdrawl in the opioid dependent patient Can cause dysphoric reactions Carry a low risk of dependence Are used in pts who cannot tolerate a full opioid agonist
where are opioid receptors located?
Opioid receptors are located in the brain, spinal cord, and periphery
what are the enzymatic reactions that occur after an opioid binds to an opioid receptor?
Opioids are linked to G proteins... when an opioid binds, adenylate cyclase activity is decreased, cAMP is decreased, calcium conduction is decreased (this decreases neurotransmitter release), K+ conduction increases (this hyperpolarizes the nerve, so there is less response to stimulation)
do opioid cross the placenta? what is the significance of this?
Opioids cross the placenta, so the fetus of an opioid dependent mother is also dependent Naloxone also crosses the placenta. It can cause a state of acute withdrawl in both mom and baby
what are special properties and considerations about versed?
Opioids potentiate respiratory depression - pts w/ COPD are more sensitive Anterograde amnesia Anticonvulsant Anxiolysis Antispasmodic No analgesia
Osmolality
Osmolality = osmoles/kg
Osmolarity
Osmolarity = osmoles/L
Osmotic pressure
Osmotic pressure = the pressure of a solution against a semipermeable membrane that prevents water from diffusing across that membrane A function of the number of osmotically active particles in solution
what part of the body does the sural nerve innervate?
Outside of ankle
what part of the body does the superficial peroneal nerve innervate?
Outside of calf
What is the Tensilon test?
Overdose of anticholinesterases cause cholinergic crisis and muscle weakness Can be difficult to differentiate from myasthenic crisis Diagnosis is made via Tensilon test give 1-2 mg of edrophonium.... If muscle weakness is made WORSE then the pt has cholinergic crisis.... An anticholinergic should be given to this point... improvement in muscle strength means that the pt is having an exacerbation of myasthenic symptoms
what is the equation for oxygen consumption?
Oxygen consumption (VO2) = CO x (CaO2 - CvO2) x 10 VO2 = 3.5 ml/kg/min or 250 ml/min V CO x oxygen difference (10)
by how much does oxygen consumption increase in the pregnant patient at term, the first stage of labor and the second stage of labor?
Oxygen consumption increases 20% term, 40% first stage of labor, 75% second stage
what is the equation for CaO2?
Oxygen content (CaO2) tells us how much oxygen is in 1 dL of blood CaO2 = (1.34 x hgb x SaO2) + (PaO2 x 0.003) Can the orange hot spider only play one 003
what is the equation for DO2?
Oxygen delivery = DO2, how much O2 is delivered to the tissue per min DO2 = CaO2 x CO x 10 DOCOCO (10)
Oxygen pressure failure device AKA Fail Safe
Oxygen pressure failure device monitors oxygen pressure (NOT CONCENTRATION). It activated when oxygen pressure in the intermediate pressure system falls below 20 psi If oxygen pressure fails and the aux oxygen tank is open, the oxygen pressure failure device won't activate until the oxygen pressure from the tank is less than 20 psi NOT activated by a pipeline cross over
the oxyhemoglobin curve plots ________ vs _______________
Oxyhgb curve plots SaO2 vs PaO2
why is oxytocin a unique hormone when it comes to feedback signaling? what stimulates oxytocin release?
Oxytocin is unique because it is part of a positive feedback loop Uterine contraction increases oxytocin release which simulates more uterine contractions
Boyle's law
P1 x V1 = P2 x V2 The only gas law with an inverse relationship - as pressure goes up, volume goes down Boyle's law is bizarre, it makes me PeeVed
Gay Lussac's Law
P1/T1 = P2/T2 Direct relationship - as one variable gets larger so does the other increased temp = increased volume
What is P50 on a oxyhemoglobin dissociation curve? what is the value of in mmhg?
P50 = PO2 where hgb is 50% The normal P50 is 26.7 mm Hg.
what is the A-a gradient? what conditions INCREASE the gradient? in what situations can the pt be hypoxic but A-a gradient is normal?
PAO2 - PaO2 = 10-15 mmHg it will be NORMAL for hypoxic mixture and hypoventilation. It will be INCREASED by diffusion limitation, VQ mismatch and shunt The A-a gradient is increased by aging ( CC > FRC), vasodilators (decreased HPV), R→ L shunt (atelectasis, PNA)
what values are indications for mechanical ventilation? PCO2 inspiratory force VC RR
PCO2 > 60 Insp force < 25 VC < 15 ml/kg RR > 40
Causes of PAOP to be OVERestimated
PEEP Diastolic dysfunction Impaired LV compliance L to R cardiac shunt Tachycardia PPV COPD Pulm HTN Non west zone 3 PAC placement
what placental abnormality is associated with painless vaginal bleeding
Placenta previa
what factors can decrease renal perfusion, leading to increased renin release?
PEEP can decrease VR and may reduce CO... by extension, this decreases renal perfusion and stimulates renin release Hemorrhage PEEP CHF Liver failure w/ ascites Sepsis Diuresis
what are the effects of PGE2 and PGI2 on the kidneys?
PGE2 and PGI2 vasodilate renal arteries
risk factors for the development of placental abruption
PIH Preeclampsia Chronic HTN Cocaine use Smoking Excessive ETOH
in what situation can the PISS system be bypassed?
PISS can be bypassed w/ more than one washer between hanger yoke and tank stem
which division of the ANS has long preganglionic fibers and short postganglionic fibers?
PNS
which division of the ANS is AKA craniosacral?
PNS
what do C fibers mediate?
POSTganglionic SNS slow pain **only nerves w/ no myelination
in the ANS, what type of fibers are the preganglionic fibers? what type are the postganglionic fibers?
PREganglioic fibers are MYELINATED B fibers POSTganglionic fibers are UNMYELINATED C fibers
what do B fibers mediate?
PREganglionic SNS
how does CKD affect PT,PTT, and platelet count?
PT,PTT, and platelet count are normal
what are complications of a supraclavicular block?
PTX = Greatest risk Stellate ganglion block/ horner's syndrome Subclavian artery injection
Ideal gas law
PV=nRT Conceptually, P = T/V
is PVR high or low in the fetus? why?
PVR is high in the fetus - the lungs are collapsed and filled w/ fluid so there is very little pulmonary blood flow
what are respiratory compensation for metabolic alkalosis?
PaCO2 increases as a function of decreased minute ventiation
PaO2 less than _____ mmhg causes cerebral ______ and _______ CBF
PaO2 less than 60 mmhg causes cerebral vasodilation and increases CBF
Allodynia
Pain due to a stimulus that does not normally provoke pain
during modulation, how is pain inhibited? how is it augmented?
Pain is INHIBITED when spinal neurons release GABA and glycine (both inhibitory neurotransmitters) AND when the descending pathway releases NE, 5-HT and endorphins Pain is AUGMENTED by central sensitization and wind up
what are the four processes through which pain is transmitted?
Pain is transmitted via transduction, transmission, modulation, and perception
where do pain signals come from during the first stage of labor? what is the pain quality?
Pain signals travel to nerve roosl T10-L1 via visceral C fibers Pain is dull, diffuse, and crampy
how does the neonate respond to pain? what can be a dangerous SE of uncontrolled pain?
Pain will still activate the SNS which manifests as tachycardia and HTN The combo of HTN, an immature cerebral autoregulatory response, and a fragile cerebral vasculature predispose the neonate to intracerebral hemorrhage
what is a theoretical complication of lipid emulsion therapy?
Pancreatitis is a theoretical complication from HLD
how does pancuronium affect HR
Pancuronium is a vagolytic Beneficial for aortic regurg and bradycardia Harmful for pts w/ hypertrophic cardiomyopathy --> Tachycardia reduces BF through the LVOT
medulla oblongata
Part of the brainstem that controls vital life-sustaining functions such as heartbeat, breathing, blood pressure, and digestion. autonomic integration
Placental abruption
Partial or complete separation of placenta from the uterine wall prior to delivery Results in hemorrhage and fetal hypoxia Risk of amniotic fluid embolism leading to DIC
Partial pressure = _________ % x _______ pressure
Partial pressure = volume % x total pressure
what is peak inspiratory pressure? What factors affect PIP? is it dynamic or static?
Peak inspiratory pressure is the maximum pressure in the pts airway during inspiration Because air is flowing into the airway during inspiration, PIP is affected by airway resistance as well as chest/lung compliance
describe how to position the ultrasound for an infraclavicular block what muscles and landmarks will you see on the ultrasound?
Pectoralis major, pectoralis minor, subclavian artery, lateral, posterior, medial cords Hyperechoic nerves
what neurotransmitter is released from preganglionic ANS nerves?
Preganglionic neuron releases ACh onto a type N receptor in the ganglion
what is pain perception?
Perception describes the processing of afferent pain signals in the cerebral cortex and the limbic system This is how we "feel" about pain
why might someone with CKD get pericarditis?
Pericarditis can occur from uremia
describe the first, second and third order neurons of the spinothalamic tract
Peripheral receptors - free nerve endings First order neuron -Enters SC via DRG -May ascend or descend 1-3 levels on same side via the Lissauer tract before synapsing w/ second order neuron in the dorsal horn laminae I, IV, V, VI -Pain neurons synapse in the substantia gelatinosa in laminae II and III Second order neuron -Crosses to contralateral side of the SC and then ascends towards the brain via 2 pathways - the anterior spinothalamic tract and the lateral spinothalamic tract -Synapse in the RAS and the thalamus Third order neurons -Tactile signals relay to the thalamus and postcentral gyrus in parietal lobe -Pain fibers synapse w/ the third order neuron in the RAS
what sensory and motor innervation does the peroneal nerve supply?
Peroneal nerve = dorsiflexion and eversion of the foot TIPPED
How doe the phases of the ventricular action potential match up to the QRS?
Phase 0 - rapid depolarization - QRS Phase 1 - initial repolarization - QRS Phase 2 - plateau - QT interval Phase 3 - final repolarization - T wave Phase 4 - resting phase - T → QRS
describe the ventricular action potential
Phase 0 = sodium in (voltage gated sodium channels open when TP is reached at -70 mV) Phase 1 = chloride in, potassium out (voltage sodium channels are inactivated, cell becomes slightly less positive) Phase 2 = calcium in, potassium out (plateau phase, delays repolarization, prolongs absolute refractory period. This allows sustained contraction for ventricles) Phase 3 = potassium out Phase 4 = sodium out and potassium in via Na/K ATPase pump
what processes encompass phase 1 drug metabolism?
Phase 1 drug metabolism = modification - oxidation, reduction, hydrolysis Oxidation - adds oxygen Reduction - adds electron Hydrolysis - adds water to split it apart
describe phase 1,2,3, and 4 of the ETCO2 waveform
Phase 1 represents exhalation of anatomical dead space... this if the flat region before the waveform becomes positive Phase 2 represents exhalation of anatomical dead space + alveolar gas... this is illustrated by upstroke Phase 3 represents exhalation of alveolar gas.... This is illustrated by plateau Phase 4 represents inspiration of fresh gas that does not contain CO2... this is illustrated by the return o f the waveform to baseline
Phase 2 drug metabolism
Phase 2 drug metabolism = conjugation Results in water soluble, inactive agent
describe the action potential in the SA node
Phase 4 = spontaneous depolarization. sodium and calcium in The membrane is leaky to sodium sodium progressively enters the cell making it more positive The I-f channel is activated At -50 mV calcium channels open and further depolarize the cell Phase 0 = depolarization. Calcium in Calcium entry via voltage gated calcium channels Sodium and T type calcium channels close Phase 3 = repolarization K+ channels open and K+ goes out, making the cell interior more negative
what drug can DECREASE the duration of NDNMB
Phenytoin
what kind of bond do organophosphates and echothiophate form with aceytylcholinesterase?
Phosphorylation is the STRONGEST bond that forms at the esteratic site... it is NON-COMPETITIVE inhibition, unlike the others
what are complications that can occur w/ interscalene block?
Phrenic nerve block The phrenic nerve is blocked nearly 100% of the time Only an issue w/ reduced pulmonary reserve like COPD PTX Cupola of the lung is just medial to the first rib and is higher on the right side.... Get a chest xray if you suspect PTX Horner's Syndrome Stellate ganglion, located at C7, is often blocked and results in ptosis, miosis, anhidrosis (diminished sweating, drooping eyelids, pinpoint pupil) Indicates successful block Seizure As little as 1 ml of LA injected into vertebral artery can cause this RLN injury Presents as hoarseness Hypotensive bradycardic episodes Bezold jarisch reflex... slows an empty heart to allow it adequate time to fill s/sx = bradycardia, hypotension, syncope
which acetylcholinesterase inhibitor DOES cross the BBB and why?
Physostigmine is a tertiary amine (not charged) and WILL pass the BBB
piercing what ligament contributes to loss of resistance when placing an epidural?
Piercing ligamentum flavum is what contributes to loss of resistance
what congenital defects have a characteristic small mandible?
Pierre robin Goldenhar Tracher collins Cri Du chat Think please get that chin
describe the pressure relief valves on the piston vent
Piston vent has 2 pressure relief valves ... one negative that opens at -8 cm H2O and one positive that opens at 75 cm H2O
what is the treatment for Guillan Barre?
Plasmapheresis and or IV IgG
________________ is a proteolytic enzyme that degrades fibrin into fibrin degradation products
Plasmin is a proteolytic enzyme that degrades fibrin into fibrin degradation products
list 3 natural fibrinolytics
Plasminogen tPA Urokinase
______________ is a proenzyme that is synthesized in the liver.. It is incorporated into the clot as its being formed, but it lays dormant until activated
Plasminogen is a proenzyme that is synthesized in the liver.. It is incorporated into the clot as its being formed, but it lays dormant until activated
what is plataeu pressure? is it dynamic or static?
Plateau pressure is the pressure in the small airways and alveoli after the target Vt is delivered Since there is no airflow at this time, airways resistance does not affect plateau pressure... therefore, plateau pressure reflects the elastic recoil of the lungs and thorax during the inspiratory pause (no gas is moving in or out of the lungs)
platelet dose for peds maintain plt count > _____________
Platelet dose = 5 ml/kg or 1 pack/10kg Maintain count > 50,000
what is the normal platelet lifespan
Platelet lifespan is 8-12 days (1-2 weeks)
Platelets are cleared by _______________ in the _____________ and the ______________
Platelets are cleared by macrophages in the reticuloendothelial system and the spleen
Platelets are produced by _______________ in the _______________
Platelets are produced by megakaryocytes in the bone marrow
do platelets undergo cell division? why or why not?
Platelets don't have a nucleus - they don't contain DNA and they don't undergo cell division
Platelets have _______________ on their external membrane, which causes them to be repelled by healthy vascular endothelium and adhere to injured endothelium
Platelets have glycoproteins on their external membrane, which causes them to be repelled by healthy vascular endothelium and adhere to injured endothelium
what is on the surface of the platelet which is a substrate for prostaglandin synthesis? these prostglandins produce ____________, which activates platelets
Platelets have phospholipids on their outside, a substrate for prostaglandin synthesis... they produce thromboxane A2 which activates platelets
_____________ is proportional to the degree of chronic hypoxemia in baby with TOF
Polycythemia is proportional to the degree of chronic hypoxemia
Portal vein pressure > _______ mmhg = portal HTN
Portal vein pressure > 20-30 = portal HTN
what intrinsic muscles of the airway abduct the vocal folds and cause the glottis to become wider?
Posterior CricoArytenoid = Please Come Apart
what hormones are secreted from the posterior pituitary gland?
Posterior pituitary hormones - POV Oxytocin ADH (vasopressin)
C fibers
Postganglionic ANS fibers Slow pain, temp, touch
define potency
Potency = dose required to achieve a given clinical effect x axis of dose response curve
Potentiation
Potentiation is the effect of one drug that is enhanced by a drug that has no effect of its own (1+0=3)
who is at risk for AKI during the perioperative period?
Pre Existing kidney disease prolonged renal hypoperfusion CHF advanced age sepsis jaundice high risk surgery
Necrotizing enterocolitis
Pre-term infants have lower immune function, bacteria proliferate in bowel and cause ischemia and air in the bowel. Serious inflammatory condition of the intestines. Necrosis of the bowel
which drug is good for adrenocortical deficiency (such as Addison's disease) and why?
Prednisone is good for adrenocortical deficiency (addison's disease) because it is an analog of cortisol
what is preductal and postductal oxygen saturation monitoring and why is it used?
Preductal and postductal oxygen saturation monitoring should be used in baby with RDS Preductal pulse ox is placed on right upper extremity and postductal is placed on a lower extremity A difference between the values suggests pulmonary HTN, right to left cardiac shunt and return to fetal circulation via PDA
why is preductal measurement of SpO2 preferred in babies with ROP?
Preductal spo2 is preferred because it best predicts the oxygen saturation in the retinal vessels
neonates are preferential _______ breathers up till 5 months old
Preferential nose breather up till 5 months old Most infants convert to oral breathing if nasal passages are obstructed Bilateral choanal atresia may require emergency airway management if the infant is unable to mouth breath
B fibers
Preganglionic ANS fibers
what situations exacerbate symptoms of myasthenia gravis?
Pregnancy Infection Electrolyte abnormalities Surgical and psychological stress Aminoglycoside abx Pregnancy will exacerbate symptoms... anti-AchR igG antibodies will cross the placenta, which can cause weakness in the neonate for 2-4 weeks after delivery
pregnancy creates a _________coagulable state
Pregnancy creates hypercoagulable state... DVT is 6x higher Mom makes more clots but does break then down faster
Preload
Preload is the ventricular wall tension at the end of diastole, just before contraction
Fluids with glucose should be reserved for which pt populations
Premature Less than 48 hrs old Small for gestational age Newborn of diabetic Kids with DM who received insulin on day of surgery Kids who receive glucose based parenteral nutrition
Premature = less than ______ weeks gestation
Premature = less than 37 weeks gestation
what are the 2 most significant risk factors for ROP?
Prematurity and hyperoxia are the 2 most significant risk factors The higher PaO2 progresses an abnormal growth pattern where the vessels are at risk of vasoconstriction, bleeding, scar formation, fibrosis and retinal detachment
risk factors for the development of retinopathy of prematurity
Prematurity and hyperoxia are the 2 most significant risk factors mechanical ventilation blood transfusion intraventricular hemorrhage sepsis vitamin E def
describe pre, intra, and post op actions of ERAS
Preop → fluid and carb loading, abx prophylaxis, avoiding premeds, thromboprophylaxis Intraop → mid-thoracic epidural anesthesia, short acting drugs, goal directed fluid therapy, normothermia, PONV prophylaxis Postop → opioid sparing analgesia, judicious fluid administration, encourage gut motility, early oral intake, early ambulation
how does bladder perforation, a complication of TURP procedure, present? what should be done for treatment?
Presentation = abd and shoulder pain... emergent cysto or ex lap
s/sx of post intubation croup when do s/sx occur?
Presentation = hoarseness, barky cough, stridor Occurs 30-60 m post extubation
pyloric stenosis presentation
Presentation is non bilious projectile vomiting
How is rocuronium eliminated?
Primarily biliary (50-70%) and secondarily by renal (10-25%) and hepatic metabolism (10-20%)
anesthetic considerations for foreign body aspiration -primary goal -mechanical ventilation? -best induction method? -gold standard procedure? -what kind of maintenance anesthesia? -why might not the pt immediately improve?
Primary goal is to prevent complete airway obstruction and prevent foreign body from migrated distally in the airway PPV can push the foreign body deeper into the bronchial tree, increasing difficulty of retrieval. Sevo induction that preserves spontaneous RR is the best approach Rigid bronchoscopy is the gold standard Induce with sevo, then TIVA Pts may not improve immediate after the FB is removed due to residual lung inflammation
primary hemostasis
Primary hemostasis describes the formation of the platelet plug → adhesion, activation, aggregation
how long should SQ unfractionated heparin for DVT prophylaxis be held before neuraxial anesthesia?
Proceed w/ neuraxial anesthesia if pt has normal clotting mechanism and not on any other blood thinners
what should you do if you want to perform an epidural and your pt is currently taking ASA and/or NSAIDs?
Proceed with neuraxial anesthesia if pt has normal clotting mechanism and if pt is not on any other blood thinners
what components make up the processing part of the anesthesia machine?
Processing = how anesthesia machine prepares gases before delivered to pt Inside machine to common gas outlet
ANP is produced in the ________ in response to ________ ANP stimulates ______________ How does ANP affect the RAAS?
Produced in the myocardium in response to atrial distension It simulates sodium and water excretion in the CD ANP provides negative feedback to RAAS - it inhibits renin release
how does progesterone affect Ve? how does it affect acid base balance?
Progesterone = resp stimulant.. Increases Ve by 50%... PaCO2 falls and resp alkalosis develops... renal compensation occurs Tidal volume increases more than RR
how does progesterone affect SVR and PVR?
Progesterone increases NO release and decreases response to angiotensin and NE ⇒ decreased SVR and PVR
how does pregnancy affect LES tone? why? how is gastric pH and volume changed?
Progesterone reduces LES tone increased gastrin reduces gastric pH Increased gastric volume from increased gastrin
what kind of egg allergy should avoid propofol?
Prop is made from egg lecithin which is found in the egg yolk... most ppl are allergic to the egg white. If they're allergic to egg white they're ok to get prop.
what are the pros and cons of pencil point needles?
Pros = lower risk of PDPH, more tactile feel, needle less likely to deflect, less likely to injure cauda equina False = requires more force
what are the pros and cons of cutting tip needles?
Pros = requires less force Cons = higher risk of PDPH, less tactile feel, needle more easily deflected, more likely to injure cauda equina
what pts are at risk for endocarditis and need abx prophylaxis?
Prosthetic heart Valve replacement Unrepaired cyanotic congenital heart disease Repaired congenital heart defect repair less than 6 mo old Repaired CHD if residual defects Heart transplant w/ valvuloplasty Previous IE
what does protamine do and how does it work?
Protamine reverses heparin... its highly alkaline w/ a strong positive charge that neutralizes heparin's negative charge and creates a neutralization reaction to stop heparin
Antithrombin III
Protein that prevents abnormal clotting by inhibiting thrombin. Anticoagulant
what causes a third degree heart block? what part of the conduction system is effective? what is the treatment if the pt is symptomatic?
Ps and Qs don't agree Fibrotic degeneration of the atrial conduction system Use pacer or isoproterenol Can lead to CHF
what are the names of the enzyme that metabolizes sux?
Pseduocholinesterase Type 2 cholinesterase False cholinesterase Butyrylcholinesterase Plasma cholinesterase
where is pseudocholinesterase produced?
Pseudocholinesterase is produced in the liver and serves as an indicator of hepatic synthetic function
Pseudocholinesterase is ___________ in elderly how does this affect the duration of sux?
Pseudocholinesterase is reduced in elderly Can prolong sux druation
what does a pt need to get done before receiving tPA and why?
Pt needs emergent non contrast CT before tPA can be given to rule out hemorrhage etiology
what are symptoms of Horner's Syndrome?
Ptosis, anhidrosis, miosis, enophthalmos Very homely PAM Vasodilation, horner, ptosis, anhidrosis, miosis
how do pts with Eaton Lambert Syndrome respond to NDNMB and sux
Pts are sensitive to both sux AND NDNMB
why is giving pts with severe CHF so dangerous?
Pts w/ CHF rely on elevated circulating catecholamines - anesthesia techniques that disrupt this can cause CV collapse
how does liver cirrhosis affect a pts pulmonary status? HD status? GFR?
Pts with cirrhosis experience pulmonary vasodilation, right to left shunting, and hypoxemia... they hyperventilate in attempt to offset reduced PaO2.. this creates resp alkalosis HD circulation is common... SVR decreases w/ reciprocal increase in CO GFR is reduced
how do patients with extrajunctional receptors respond to non-depolarizing neuromuscular blockers?
Pts with extrajunctional receptors are RESISTANT to NONdepolarizing NMB - their potency is reduced
Side effects of mag administration
Pulmonary edema Hypotension Skm weakness - synergism with nondepolarizers CNS depression Reduced responsiveness to ephedrine and phenylephrine
what is pulsus paradoxus? with what pathophysiology is it seen?
Pulsus paradoxus is seen with constrictive pericarditis - this is a decrease in SBP > than 10 mmhg during inspiration. Indicative of impaired diastolic filling.
what kind of arterial waveform will you see in someone with aortic stenosis?
Pulsus parvus waveform - narrow pulse pressure, small amplitude Pulsus tardus - slow upstroke Dicrotic notch may not be present
what is the equation for static airway compliance?
Static compliance = Vt (plateau pressure - PEEP)
if child has URI, what are good reasons to cancel surgery?
Purulent nasal discharge Fever > 38 C or 100.4 F Lethargic Persistent cough Poor appetite Wheezing and rales that do not clear with cough Child less than 1 yr old or previous premie
when should the oxygen flush valve NOT be pushed and why
Pushing it during the inspiratory cycle can lead to barotrauma... since the ventilator spill valve is closed during inspiration, it exposes the pt to the high pressure
R to L cardiac shunt will occur when ______ is greater than _______
R to L cardiac shunt will occur when PVR is greater than SVR Think R is PVR and L is SVR Whatever comes first is when that factor is greater
Universal RBC and plasma donors
RBC --> O neg plasma --> AB pos
universal RBC and plasma acceptors
RBCS --> AB positive Plasma --> O negative
what are complications that can occur with a premature birth?
RDS intraventricular hemorrhage NEC hypoglycemia hypocalcemia hyperbilirubinemia
what are signs and symptoms of RDS in the newborn?
RDS diagnosis made soon after birth as neonate exhibits signs of resp distress grunting to keep alveoli open tachypnea intercostal and subcostal retractions nasal flaring ABG show hypoxemia, hypercarbia and mixed acidosis
how does renal failure affect the dosing of acetylcholinesterase inhibitors?
RF will prolong the duration of action of both AChE inhibitors AND NMB so dose adjustment is not needed
what nerve innervates the majority of the intrinsic muscles of the airway
RLN
what nerve is at risk for being injured during thyroid surgery? how does unilateral vs bilateral injury present? what ETT is used to help prevent injury?
RLN injury is a risk of thyroid surgery Unilateral = hoarseness Bilateral = airway obstruction Use NIMS tube
how is Vt and RR different in the neonate compared to adult?
RR is higher in the neonate to meet the increased O2 consumption and CO2 production Vt is similar to adult
what is the cornerstone treatment for post intubation croup?
Racemic epinephrine and dexamethasone serve as the cornerstone treatment for post intubation corrupt Racemic epi → 0.5 ml of 2.25% solution in 2.5 ml of 0.9% NaCl Dexamethasone → 0.25-0.5 mg/kg IV
____________ nerve → palmar side of thumb (C6) ____________ nerve → tip of index finger (C7) ____________ nerve → tip of pinky finger (C8)
Radial → palmar side of thumb (C6) Median → tip of index finger (C7) Ulnar → tip of pinky finger (C8)
what is the number 1 source of heat loss in the OR? what is the mechanism?
Radiation = 60% Number 1 source of heat loss Most heat lost through skin
Four mechanisms of heat transfer in order of importance
Radiation > convection > evaporation > conduction RCEC rad convicts even conduct
Total spinal presentation
Rapid progression of sensory and motor block Dyspnea, difficulty phonating, hypotension Loss of consciousness from cerebral hypoperfusion
according to Fick's law of diffusion, rate of transfer is direction proportional to...... and inversely proportional.....
Rate of transfer is directly proportional to Partial pressure difference Diffusion coefficient (solubility) Membrane surface area Rate of transfer is inversely proportional to Membrane thickness Molecular transfers
what drugs REDUCE pseudocholinesterase activity?
Reglan Esmolol Echothiophate Oral contraceptives Cyclophosphamide Neostigmine MAOIs
what kind of hypertrophy does regurgitant valve lesions lead to? stenotic?
Regurgitant lesions = volume overload = eccentric hypertrophy Stenotic lesions = pressure overload = concentric hypertrophy
what happens after the release of an aortic cross clamp?
Release of the aortic cross clamp creates a central HYPOvolemia by restoring venous capacity, shifting a greater proportion of blood to the lower body, capillary leak contributes to loss of intravascular volume, VR decrease
what neurotransmitor(s) are released from postganglionic SNS nerves?
Releases mainly NE BUT will release ACh at sweat glands, piloerector muscles and smoke vessels *******
what muscles and landmarks will you see on the ultrasound when doing a femoral nerve block?
Remember VAN - vein, artery, nerve Two muscle layers = fascia lata, fascia iliaca Triangle shape makes a SAIL Sartorius Adductor longus Inguinal ligament
what enzyme hydrolyzes remifentanil?
Remi is hydrolyzed in the plasma by erythrocyte and tissue esterases
How is pancuronium eliminated?
Renal (primary)
Renal blood flow decreases _____% per decade
Renal blood flow decreases 10% per decade
what structures make up the renal cortex? the renal medulla?
Renal cortex contains glomeruli, prox tubes and distal tubes Renal medulla contains loop of henle and collecting ducts
Repolarization
Repolarization is the restoration of membrane potential towards RMP following depolarization
resection of the parathyroid glands can cause what electrolyte abnormality? for how long?
Resection of parathyroid glands can cause hypocalcemia for 6-12 hrs after surgery
Residual NMB is defined as TOFR < ____>
Residual NMB is defined as TOFR < 0.9
what are the effects/side effects of delta receptor stimulation?
Resp depression Analgesia Urinary retention Puririts NO EUPHORIA! NO SEDATION!
what respiratory compensation occurs for metabolic acidosis
Respiratory compensation → PaCO2 decreases as a function of increased minute ventiation. PaCO2 will decrease by 1 mmhg for every HCO3 decrease of 1 mEq/L
Resting membrane potential
Resting membrane potential is the difference in electrical potential between the inside and outside of the cell. The inside of the cell is negative relative to the outside of the cell
is the sodium channel open or closed at resting membrane potential? what is the mV of resting state?
Resting state = -70 mV At resting membrane potential, the channel is closed
Describe restrictive lung disease how should you manage these pts on the vent?
Restrictive lung disease reduces ALL lung volumes. Small lung volumes is the problem FEV1 and FVC less than 70% is diagnostic for RLD. Reduced FRC = faster desat Use smaller Vt and faster RR Prolong inspiratory time (IE 1:1)
anesthetic considerations for placental abruption
Results in hemorrhage and fetal hypoxia Risk of amniotic fluid embolism leading to DIC Vag delivery is possible is fetus is stable Obtain large bore IV access and have blood products available Prepare for cesarian section
what is a semi closed circuit? list examples of semi closed circuits
Semi closed = partial rebreathing w/ a reservoir examples Circle system when FGF < Ve
how does volatile anesthetics affect the following parts of the brain: Reticular activating system → Hippocampus → Spinothalamic tract → Ventral horn in SC →
Reticular activating system → unconsciousness Hippocampus → Amnesia Spinothalamic tract → analgesia Ventral horn in SC → immobility
Reynold's number
Reynold's number is used to predict if flow will be laminar or turbulent
Reynolds number = (________ x _________ x ________)/___________
Reynolds number = (density x diameter x velocity)/viscosity Increased viscosity decreases Reynolds number Increased density, diameter and velocity increases Reynolds number
which main bronchus is 2.5 cm long and has a 25 degree angle take off? which is 5 cm long with a 45 degree take off?
Right main bronchus is 2.5 cm long and 25 degree angle take off, left is 5 cm long and 45 degree take off Left is longer and more acute angle because of the heart Right = more prone to choking and mainstem ETT Equal take off up to 3 years old
how do right to left shunts affect the induction of anesthesia w/ IV anesthetics
Right to left shunts will speed IV aesthetic onset
what factors increase risk of having premature birth?
Risk is increased with multiple gestations and premature rupture of membranes
why is 2-chloroprocaine CI for spinal anesthesia?
Risk of arachnoiditis when used for spinal anesthesia because of its preservatives
Drawbacks of GA for CS
Risk of difficult mask ventilation, DL, intuition Risk of aspiration Potential MH Absence of maternal awareness Neonatal resp and CNS depression
Risk of perioperative MI is greatest if surgery is done < ____ mo after event
Risk of perioperative MI is greatest if surgery is done < 3 mo after event
what are the five roots of the brachial plexus?
Roots = C5,C6,C7,C8,T1
what are the five parts to the brachial plexus?
Roots, trunks, division, cords, branches (randy travis drinks cold beer)
Ropivacaine has less __________ block when compared to bupivacaine
Ropivacaine has LESS motor block when compared to bupivacaine
what should be ruled out in pt with preclampsia before performing a neuraxial block
Rule out thrombocytopenia (<100,000) before neuraxial anesthesia
anesthetic considerations in pt with preeclampsia
Rule out thrombocytopenia (<100,000) before neuraxial anesthesia Even more swelling of airway = even harder intuition Exaggerated response to sympathomimetics and methergine No need for anti HTN meds if BP less than 160/110.. If greater, give meds to prevent CVA, MI and placental abruption
S1 is closure of the _________ valves and marks onset of ________
S1 = closure of mitral and tricuspid valves Marks onset of systole
where does the dural sac end?
S2 correlates with superior iliac spine
S2 is closure of the _________ valves and marks onset of ________
S2 = closure of aortic and pulmonary valves Marks onset of diastole
S3
S3 = flaccid and inelastic heart Think heart failure Heard in the middle of diastole
S4
S4 = stiff heart Caused by atrial systole Heard before S1
Intraoperative BP control for cerebral aneurysm
SBP goal 120-150 A high/normal BP is needed to perfuse collateral circulation if a clamp is used Controlled hypotension if no clamp BP too high increases risk of re-bleeding BP too low inadequate
SCI with neurogenic shock is characterized by what symptoms below level of injury? why do these symptoms occur?
SCI w/ neurogenic shock is characterized w/ sympathectomy below the level of injury, which manifests as the triad of hypotension, brady and hypothermia Impaired cardiac accelerators Decreased SNS tone Inability to vasoconstrict leads to hypothermia and blood flow to redistribute towards the periphery and allowing more heat to escape
what are causes of hyponatremia?
SIADH CHF cirrhosis TURP syndrome Cushings excessive water intake
what is a semi open circuit? list examples of semi open circuits
Semi open = no rebreathing w/ a reservoir FGF > Ve Examples Mapleson circuit Circle system when FGF > Ve
what are signs and symptoms of hypocalcemia?
SKM cramps nerve irritability paresthesia tetany chvostek sign trousseau sign laryngospasm mental status changes seizures long QT interval
describe the position of the sniffing position
SNIFFING POSITION entails cervical flexion (chin to chest) and AO extension (extends head on neck)
which division of the ANS has short preganglionic fibers and long postganglionic fibers?
SNS
which division of the ANS is AKA thoracocolumnar (T1-L3)?
SNS
what conditions increase cardiac contractility?
SNS stimulation Catecholamines Calcium Digitalis PDE inhibitors
Causes of PVCs
SNS stimulation Hypoxia, hypercarbia Acidosis Light anesthesia Valvular heart disease MI CM Long QT Hypokalemia Hypomagnesemia Digitalis toxicity Caffeine Cocaine Alcohol Mechanical irritation
recite normal values for SV EF SVR CO CI PVR
SV = Normal 50-110 ml/beat EF = 60-70% SVR = 800-1500 dynes/sec/cm5 CO = 5-6 L/min CI = 2.8-4.2 L/min/m2 PVR = 150-250 dynes/sec/cm5
what characteristics of SV and SVR in the neonate?
SV is fixed and SVR is low
is SVR high or low in the fetus? why?
SVR is low in the fetus - the placenta provides a large, low resistance vascular bed
where does the sacral hiatus and sacrococcygeal ligament correspond with?
Sacral hiatus and sacrococcygeal ligament = S5
what hormones are secreted from the zona glomrulus, zona fasciculata, and zona reticularis?
Salt, sugar, sex/GFR zona glomrulus = aldosterone zona fasciculata = cortisol zona reticularis = androgens
eclampsia
Same and preeclampsia but + seizures HTN, proteinuria and edema + seizures
give examples of chronic intrinsic lung disease
Sarcoidosis Drug induced pulmonary fibrosis (amio)
What is sarcoidosis?
Sarcoidosis is a chronic granulomatous disorder that results in the development of granulomas that may progress to fibrosis. Can affect the lungs, heart, CNS, skin, eyes. Often on steroids - continue therapy. Causes Restrictive lung disease
what things decrease anesthetic potency? saying decreased potency is the same thing as saying _____ MAC
Saying decreased potency is the same thing as saying increased MAC Chronic ETOH Increased CNS neurotransmitters Acute amphetamine intoxication Acute cocaine intoxication MAOIs Ephedrine Levodopa Hypernatremia Increased in infants 1-6 mo Hyperthermia Red hair
what things increase anesthetic potency? saying increased potency is the same thing as saying _____ MAC
Saying increased potency is the same thing as saying decreased MAC Anesthetic potency is increased by lithium clonidine Acute ETOH intoxication IV anesthetics N2O Opioids Alpha 2 agonist Lithium Lidocaine Hydroxyzine Hyponatremia Older age (decreases 6% per decade after 40) Hypotension (MAP less than 50) Hypoxia Anemia CP bypass Metabolic acidosis Pregnancy → postpartum 24-72 hrs PaCO2 > 95 mmhg
what is another name for second degree heart block, type 1
Second degree HB type 1 = Wenckebach
where do the neurons of the spinothalamic sensory pathway desiccate? which order neuron is it?
Second order neuron Crosses to contralateral side of the SC and then ascends towards the brain via 2 pathways - the anterior spinothalamic tract and the lateral spinothalamic tract
where do the neurons of the dorsal column sensory pathway desiccate? which order neuron is it?
Second order neuron crosses over to contralateral side in the medulla and then ascends towards thalamus
Second order neuron
Second order neuron extends from the dorsal horn to the thalamus - the cell body is in the dorsal horn
What is transmission?
Second phase of nociception where pain impulse moves from the spinal cord to the brain During transmission, the pain signal is relayed through the 3 neuron afferent pain pathway along the spinothalamic tract first, second, third order neuron
what can cause secondary hyperparathyroidism in CKD?
Secondary hyperparathyroidism occurs as a result of impaired active vitamin D3 production and hyperphosphatemia
what sensory and motor innervation does the lateral femoral cutaneous nerve supply?
Sensory to lateral thigh, no motor innervation
what sensory and motor innervation does the posterior femoral cutaneous nerve supply?
Sensory to posterior thigh
Leads V1, V2 monitor what side of the heart and which coronary artery?
Septum LAD
how does serum creatinine and GFR change as we age?
Serum creatinine remains stable as we age --> Muscle mass is reduced so body produces less creatinine and GFR is reduced so we excrete less creatinine GFR decreases by 1 ml/min/year after age 40 Normal GFR is 120 ml/min
how does severe kidney disease affect erythropoietin and what is a consequence of this?
Severe kidney disease reduces EPO production and leads to chronic anemia
in severe coarctation of aorta that presents early in life, what is the baby dependent on for survival? what medication should be given until surgical correction?
Severe obstruction will present very early in life - in this situation, the lower body perfusion DEPENDS on the PDA DA closure can cause HD collapse Prostaglandin E1 maintains DA patency
Transient neurologic symptoms what are the signs and symptoms when is the onset what causes it what can be used to treat it?
Severe pain in butt that radiates to legs Pain can be treated w/ NSAIDS, opioids, and trigger point injections Develops within 6-36 hrs Persists for 1-7 days Lidocaine is the most common cause Other causes = pt positioning, stretching of sciatic pain, myofascial strain, muscle spasm **highly unlikely that neurotoxicity causes TNS
why give glucose and insulin to treat hyperkalemia? what is the dose?
Shifts K+ into cells Glucose 0.5 g/kg as 10% solution Insulin 1 unit per 2-5 g glucose
what are complications of ESWL?
Shock can cause R on T Any internal organ in path of shock is at risk for perf Skin bruising Petechiae Hematuria
Hypercalcemia EKG changes
Short QT
how does the body regulate short, intermediate, and long term BP control?
Short term control is via baroreceptor reflex Intermediate control via RAAS Long term control via thirst and sodium and water excretion
thyroarytenoid muscle
Shortens and relaxes the vocal cord adducts the vocal cords and narrows the glottis ThyroARytenoid = they adduct and relax innervated by RLN
how does increased osmolarity in the ECF stimulate ADH release?
Shrinks osmoreceptors in the hypothalamus
what are side effects of acetylcholinesterase inhibitors?
Side Effects = SLUDE Salivation, lacrimation, urination, defecation, emesis Miosis → pupil constriction BRONCHOSPASM!! If it ends in STIGMINE , think SLUDE Other mnemonic = DUMBBELLS Diarrhea, urination, miosis, bradycardia, bronchoconstriction, emesis, lacrimation, laxation, salvivlation SLUDE is DUMBBELLS
which acetylcholinesterases do NOT cross the BBB and why?
Since edrophonium, neostigmine, and pyridostigmine are quaternary amines, they will NOT pass the BBB (charged)
how are highly protein bound drugs different in neonates?
Since they have a lower concentration of plasma proteins there will be an increased free fraction of highly protein bound drugs
what HR patterns are predictive of poor fetal status?
Sinusoidal pattern and absent baseline variability are predictive of poor fetal status
Layers from skin to spinal cord
Skin subQ tissue supraspinous ligament interspinous ligament epidural space dura mater subdural space arachnoid mater subarachnoid space pia mater spinal cord
A alpha fibers
Skm motor, proprioception
A gamma fibers
Skm tone
what is a possible SE of giving SMALL doses of atropine? how does this happen?
Small doses of atropine can actually cause bradycardia (presynaptic M1 inhibition, which normally reduces ACh via negative feedback)
Difficult intubation predictors
Small mouth opening Long incisors Prominent overbite High, arched palate High mallampati Retrognathic jaw (lower jaw is set way farther back than upper jaw) Inability to subluxed jaw Short thick neck Short or long TMD Decreased cervical mobility
why give sodium bicarb to treat hyperkalemia? what is the dose?
Sodium bicarb 1-2 mmol/kg shifts K into the cells
what metabolic disturbance can excessive sodium chloride administration cause?
Sodium chloride can cause hyperchloremic metabolic acidosis
Sodium nitroprusside
Sodium nitroprusside dilates both arteries and veins equally. It increases nitric oxide and decreases venous return
Solubility
Solubility is the tendency of a solute to dissolve in a solvent
SpO2 90% = PaO2 ______ mmhg SpO2 80% = PaO2 ______ mmhg SpO2 70% = PaO2 ______ mmhg
SpO2 90% = PaO2 60 mmhg SpO2 80% = PaO2 50 mmhg SpO2 70% = PaO2 40 mmhg 4,5,6,7,8,9
Benefits of GA for CS
Speed of onset Secured airway Greater HD stability
give 3 examples of pencil point needles?
Sprotte, Whitacre, Pencan
define steady state how many half lives does it take to get to steady state?
Steady state is when the rate of administration = rate of elimination and is achieved after 5 half times
Horner's Syndrome
Stellate ganglion, located at C7, is often blocked w/ brachial plexus blocks and results in ptosis, miosis, anhidrosis (diminished sweating, drooping eyelids, pinpoint pupil) Indicates successful block
what is the biggest risk of awareness during cardiac bypass procedure?
Sternotomy is greatest risk of awareness during CABG. second most common is rewarming.
what is the treatment for adrenal insufficiency?
Steroid replacement - 15-30 mg cortisol equivalent per day
__________ are associated with poor neurological outcome in pts w/ traumatic brain injury
Steroids are associated with poor neurological outcome in pts w/ traumatic brain injury
what drug should be avoided in pts w/ TBI
Steroids should NOT be used for traumatic brain injury D5LR contains glucose and in the setting of cerebral ischemia, glucose makes it worse because excess glucose is converted to lactic acid
Oxytocin (Pitocin) what causes endogenous release? how can it be administered? why is it given? when is it given during CS? what are side effects?
Stimulates smooth muscle to contract. Helps in birthing process/ expel placenta. First line uterotonic Exogenous oxytocin released following cervix, vagina, and breast stimulation Can be given IV or directly injected into the uterus Given to induce or augment labor, stimulate uterine contraction, combat uterine hypotonia and hemorrhage Give after delivery of placenta during CS SE = water retention, hyponatremia, hypotension, reflex tachycardia, coronary vasoconstriciton, NV
what are triggers of autonomic hyperreflexia?
Stimulation of hollow organs - bladder, bowel, uterus Bladder catheterization BM Childbirth Cutaneous stimulation
How do loop diuretics work?
Stops the reabsorption of sodium in the ascending loop of henle Inhibit the Na-K-2Cl transporter in the medullary region of the thick ascending limb of the loop of henle
Factors that stimulate glucose release
Stress Trauma Sepsis Beta agonists
how does the neonate respond to stress?
Stress is more likely to activate the parasympathetic nervous system The ANS is immature and there is a predominance of PNS → stress causes bradycardia which in turn reduces CO Stressful situations like suctioning or direct laryngoscopy may cause bradycardia since the SNS is less mature than the PNS Atropine may be given before induction to mitigate this
recite the following equations SV EF SVR MAP CO CI PVR
Stroke volume = CO x (1000/HR) SV = EDV-ESV EF = SV/EDV x 100 EF = [(EDV-ESV)/EDV]x 100 SVR = [(MAP-CVP)/CO] x 80 MAP = [(COxSVR)/80] + CVP CO = HR x SV CI = CO/BSA PVR = (MPAP-PAOP)/CO x 80
coarctation of the aorta is strongly correlated with what genetic abnormality?
Strongly associated with Turner syndrome
Subarachnoid bleed = _________ bleed, Subdural bleed = __________ bleed
Subarachnoid bleed = arterial bleed Subdural bleed = venous bleed
Central line insertion site to vena cava and right atrial junction in cm Subclavian _____ cm Right IJ ____ cm Left IJ _____ cm Femoral _____ cm Right median basilic _____ cm Left median basilic ______ cm
Subclavian 10 cm Right IJ 15 cm Left IJ 20 cm Femoral 40 cm Right median basilic 40 cm Left median basilic 50 cm
list opioids in order from MOST to LEAST potent
Sufentanil (10 mcg) > fentanyl (100 mcg)= remifentanil (100 mcg) > alfentanil (1000 mcg) > hydromorphone (1.4 mg) > morphine (10 mg) > meperidine (100 mg)
what components make up the supply part of the anesthesia machine?
Supply = how gases enter the anesthesia machine Pipeline to back of anesthesia machine
Schwann cells
Supporting cells of the peripheral nervous system responsible for the formation of myelin.
Treatment for hypermagnesemia
Supportive measures Diuretics facilitate mag excretion IV calcium antagonizes mag
what are the five ligaments of the spinal column ordered from the closest to the skin from the farthest - posterior to anterior
Supraspinous interspinous ligamentum flavum posterior longitudinal ligament anterior longitudinal ligament
what does surfactant do? do larger or smaller alveoli have a greater amount of surfactant? as alveolar radius decreases, what happens to surface tension?
Surfactant reduces alveolar surface tension and reduces alveolar collapse Each alveoli contains the same amnt of surfactant... larger alveoli have a relatively smaller concentration of surfactant and smaller alveoli have a relatively larger concentration of surfactant As alveolar radius decreases so does its surface tension.. This prevents smaller alveoli from collapsing and emptying into larger alveoli
what is thyroid storm? what can trigger it? when is it most likely to occur in the surgical pt? what are signs and symptoms? what drug should be avoided?
Surge of thyroid hormone Occurs in times of stress Perioperatively 6-18 hrs post surgery s/sx = fever, HTN, CHF, shock, confusion, agitation, NV Under anesthesia, it mocks MH AVOID ASA which increases T4 from plasma proteins
anesthesia considerations for baby with omphalocele
Surgery for this condition is less urgent than it is for gastroschisis... it requires a cardiac workup first Closure may be staged
Malignant hyperthermia signs and symptoms what are early signs, what are late signs?
Sustained muscle contraction Accelerated metabolic rate and rapid ATP depletion Increase oxygen consumption Increased CO2 and heat production Mixed respiratory and metabolic acidosis Sarcolemma breaks down K+ and myoglobin leak into systemic circulation Rigidity from sustained contraction Early signs are the result of hypermetabolism Tachycardia increased ETCO2 masseter spasm Warm soda lime Tachypnea Irregular rhythm Later signs Hyperthermia Cola urine from rhabdo DIC Muscle rigidity
what neuromuscular blockers release histamine? how long does the histamine release last?
Sux atracurium mivacurium
Sux increases serum K+ by ______ mEq/L for _____ min
Sux increases serum K+ by 1 mEq/L for 15 min
why is sux relatively contraindicated in younger kids?
Sux is CI in young kids because of the possibility of hyperkalemic rhabdomyolysis in pts w/ undiagnosed muscular dystrophy
where does the third order neuron of the spinothalamic tract sensory pathway synapse in the brain?
Synapse in the RAS and the thalamus Tactile signals relay to the thalamus and postcentral gyrus in parietal lobe Pain fibers synapse w/ the third order neuron in the RAS
Synergism
Synergism is when two drugs given at the same time has a greater effect than the sum of their individual effect (1+1=3)
what are disadvantages of colloid administration?
Synthetic colloids = risk of renal injury Coagulopathy ** not voluven most w/ dextran Potential for anaphylaxis, biggest risks with dextran
whats an increased risk of synthetic colloids? what is the dose of synthetic colloids that should not be exceeded?
Synthetic colloids increase risk of coagulopathy - dose should not exceed 20 ml/kg
what kind of hypertrophy does systolic HF cause? diastolic?
Systolic HF causes eccentric hypertrophy diastolic causes concentric hypertrophy
where do pain signals come from during the second stage of labor? what is the pain quality?
T10-S4 Adds in pain impulses from vagina, perineum and pelvic floor Pain impulses travel from perineum to S2-4 posterior nerve roots via pudendal nerve Pain is sharp and well localized
from what root does the intercostobrachial nerve arise?
T2
T3 vs T4: which is a prohormone? which is more protein bound? which is directly released from the thyroid? which is more potent? which has a longer half life? which is biologically active? which is produced by extrathyroid conversion?
T4 is a prohormone. It is directly released from the thyroid... think of it as a delivery vehicle (T4....4 seats in a car, the car is full!) T4 is more protein bound compared to T3 T4 is less potentant than T3 T4 has longer half life than T3 ( days compared to 1 day) T3 has greater biological activity T3 is produced by extrathyroid conversion from T4 T3 concentration is highest in the target cell T3 has higher potency, shorter half life, less protein bound, smaller concentration in the blood
what are causes of SIADH?
TBI - most common cancer - small cell lung carcinoma non cancerous lung disease carbamazepine
TBW % Premie _____% Neonate _____% Child _____% Adult _____%
TBW % Premie 85% Neonate 75% Child 60% Adult 60%
what should be done before cardioversion for someone w/ chronic afib?
TEE
what does the thyromental distance measure? how many cm/fingerbreadths indicate difficult intubation?
TMD = tip of thyroid cartilage to tip of mentum (chin). Should be 6-9 cm. (3 finger breadths = 6 cm)
Examples of R->L shunts
TOF Foramen ovale Eisenmenger's Syndrome Tricuspid atresia Ebsetins anomoly
describe TTJV what PSI is used? why must the pressure be so high? what are the risks of TTJV?
TTJV involves placing a large bore needle through the CTM. the jet ventilator is used to ventilate the pt and requires high pressure oxygen (50 PSI or wall pressure). The pressure must be high because the airway diameter is narrow. Expiration is passive. Upper airway obstruction limits or prevents exhalation and can lead to barotrauma. Ventilation is not controlled so there is a risk for hypercapnia.
TXA
TXA = plasminogen activator inhibitor
what is the equation to calculate how many minutes you have left in an oxygen tank?
Tank capacity (L)/ full tank pressure (PSI) = contents remaining (L)/gauge pressure (PSI) contents remaining (L) / flow rate (LPM) = min left before tank expires
what part of the brachial plexus does an axillary block target?
Targets 4 terminal branches of the brachial plexus... every one except the axillary nerve
what nerve is targeted in a popliteal nerve block? what muscles and landmarks will you see on the ultrasound?
Targets sciatic nerve in the proximal popliteal fossa A triangle is formed in the posterior knee with the base being the popliteal crease and the apex being formed by the biceps femoris and semitendinosus muscle 7 cm up, 1 cm to the right of the knee crease Nerves are above popliteal vein
what part of the brachial plexus is targeted by a supraclavicular block
Targets the trunks/divisions of the brachial plexus
according to law of laplace, surface tension of a sphere = (_______ x _______)/2
Tension = (pressure x radius)/2
according to law of laplace, surface tension of a cylinder = (_______ x _______)
Tension = pressure x radius
what lab tests evaluate GFR
Tests of GFR = BUN and creatinine clearance
what lab tests evaluate renal tubular function
Tests of tubular function = fractional excretion of sodium and urine osmolarity
what will trigger a TET spell?
Tet spells triggered by exercise, crying, defecation, IV placement, during induction
at rest, does PNS or SNS tone dominate in the heart?
The ANS modulates the HR. at rest, PNS tone exceeds SNS tone PNS via vagus nerve SNS via cardiac accelerators T1-4
The CO in the newborn is _____ ml/kg/min - this accounts for a faster circulation time
The CO in the newborn is 200 ml/kg/min - this accounts for a faster circulation time
what is the dorsal respiratory group?
The DRG is the respective pacemaker (dorsal = inspiration) Pain in the back... when it hurts, you INSPIRE sharply
what is FRC?
The FRC is the lung volume where the inward elastic recoil of the lungs is balanced by the outward elastic recoil of the chest. It is the volume of air in the lungs at end expiration FRC = RV + ERV
which branch of the SLN is only sensory and which is only motor?
The INTERNAL branch of the SLN is ONLY SENSORY The EXTERNAL branch of the SLN is ONLY MOTOR
Meyer Overton rule
The Meyer Overton rule states that lipid solubility is directly proportional to the potency of an inhaled anesthetic
what drugs can cause a PDA to close? what can cause it to open?
The PDA can be closed with indomethacin, a prostaglandin synthetase inhibitor The PDA can be opened with prostaglandin E1
Transposition of the great arteries
The RV gives rise to the aorta and the LV gives rise to pulmonary artery Unoxygenated Blood circulates through systemic circulation but not pulmonary circulation Oxygenated blood circulates through pulmonary circulation but not systemic circulation Outside of the womb, the baby is depending on blood flow through cardiac shunts or else death is imminent
Normal neonate vitals
The SBP in the newborn is around 70 mmhg A neonate with a SBP > 80 mmhg = HTN Normal neonate HR is 140 RR is 40-60
what does the T tubule system and sarcoplasmic reticulum do in the cardiac myocyte?
The T-tubule system and the sarcoplasmic reticulum work to maintain calcium homeostasis for contraction and relaxation
what is the ventral respiratory group?
The VRG is responsible for expiration (ventral = expiration) ventral is your belly reason... many want to EX out their belly
what is the functional unit of the liver?
The acinus is the functional unit of the liver
is concentration of pseudocholinesterase higher or lower in the neonate? how does this affect sux?
The activity of pseudocholinesterase is reduced in the neonate, but it is clinically irrevelent and the duration of sux is still similar to that of the adult
what nerve directly innervates the adrenal medulla?
The adrenal medulla is directly innervated by preganglionic myelinated B fibers that release ACh. it then releases 80% epi, 20% NE
L/S ratio
The amount of Lexithin and sphingomyelin found in the amniotic fluid > 2:1 = Mature lungs
what lab values measure the intrinsic and extrinsic pathways respectively?
The intrinsic pathway is longer and is measured by PTT The extrinsic pathway is shorter and is measured by PT
What is a Bain system? what modified Mapleson system is it?
The bain system uses a coaxial design where fresh gas is delivered to the pt through the inner tube and exhaled gas travels through the outer tube The Bain system is a modified Mapleson D. it can be used for spontaneous as well as controlled ventilation
What does the Bainbridge reflex do?
The bainbridge reflex occurs when the VR is too high. It minimizes venous congestion and promotes forward flow by increasing HR via vagus nerve inhibition.
The balance between _______ and ______ is important in the pt with congenital heart disease
The balance between PVR and SVR is important in the pt with congenital heart disease
in the sitting position, describe the characteristics of blood flow, PCO2, and PO2 in the apex vs the base of the lung describe ventilation vs perfusion in the apex vs the base in the sitting position
The base of the lungs has a higher proportion of blood flow and partial pressure of CO2 compared to the apex (when in the sitting position) the apex has a higher proportion of PO2 In the apex (non dependent) , V > Q, in the base (dependent) V<Q (when sitting) Think of a slinky being held Perfusion is the best at the base d/t gravity, ventilation is the best as the base d/t higher alv compliance
Leak in sample line during positive pressure ventilation ETCO2 waveform
The beginning of the plateau is low because of the dilation of alveolar gas as atmospheric air is aspirated into the sample line Positive pressure during inspiration pushes the CO2 rich gas through the sample line, which results in peak at the end of the plateau Not seen w/ spont ventilation, because there is no positive pressure This pattern may also occur in obese and pregnant pts
where is the best place to monitor the recovery of neuromuscular blockade for emergence?
The best place to measure RECOVERY from block is the ulnar nerve OR posterior tibial nerve to monitor adductor pollicis and flexor hallucis respectively
where is the best place to monitor the onset of neuromuscular blockade for intubation?
The best place to monitor ONSET of block for intubation = facial nerve, to monitor the orbicularis oculi
what causes increased alpha angle on the ETCO2 waveform
The beta angle is increased is some, but not all, etiologies of rebreathing
what does the bezold jarisch reflex do?
The bezold jarisch reflex slows the heart in the setting of profound hypovolemia. The idea is that the HR slows down to allow itself adequate time to fill Hypotension, coronary artery vasodilation and bradycardia are manifestations Via vagal stimulation
why is there a black box warning for the use of sux in kids under 8 years old?
The black box warning of sux warns of hyperkalemia associated with the undiagnosed muscular dystrophy in children under 8 years old
how does the amount of blood flow to an area affect local anesthetics?
The blood flow to the area where local anesthetic is injected affects duration of action AND the concentration of LA in the blood and LAST risk increased blood flow = decreased duration of action and increased plasma concentration
what does circumflex artery supply
The circumflex artery supplies the left lateral wall of the LV
The __________ artery supplies the left lateral wall of the LV The ___________ artery supplies the anterior wall of the LV, anterior ⅔ of the septum and a small portion of the anterior RV The _____________ artery supplies the posterior wall of the LV, most of the RV and the posterior ⅓ of the septum
The circumflex artery supplies the left lateral wall of the LV The left anterior descending artery supplies the anterior wall of the LV, anterior ⅔ of the septum and a small portion of the anterior RV The right coronary artery supplies the posterior wall of the LV, most of the RV and the posterior ⅓ of the septum
The combination of a ____________ and _____________ block provides complete anesthesia to the lower leg, ankle and foot... this enhances tolerance of a lower leg tourniquiet
The combination of a sciatic (popliteal) and saphenous block provides complete anesthesia to the lower leg, ankle and foot... this enhances tolerance of a lower leg tourniquiet
what is the dose of sux in neonates? what is the rationale for the difference between the dose for neonate vs adult?
The combination of an increased ECF and normal sensitivity to sux necessitates an increased dose of 2 mg/kg → its duration is similar between neonates and adults
explain what the concentrating effect is
The concentrating effect explains why nitrous oxide has a faster onset compared to desflurane even though it has a higher partition coefficient The higher the concentration of an inhalation anesthetic is delivered to the alveoli, the faster its onset of action When pt is breathing RA, the primary gas in the alveolus is nitrogen. Because N2O is 34 times more soluble in blood than nitrogen, when it is introduced into the lung the volume of it going from the alveoli to the pulmonary blood is much higher than the amnt of nitrogen moving in the opposite direction - this causes the alveoli to SHRINK and the reduction in the alveolar volume causes a relative increase in FA
what is the purpose of nerve myelination?
The conduction velocity of a nerve is increased by myelination
what is the context sensitive half time of remi?
The context sensitive half time of remi is 4 min, regardless of infusion duration
where in the body do the cords of the brachial plexus turn into the branches?
The cords turn into the branches in the axilla
The corticospinal tract travels from the _________ to the _________
The corticospinal tract travels from the cortex to the spine makes sense that its a motor tract
what determines the depth of anesthesia?
The depth of anesthesia is determined by the partial pressure of anesthetic agent in the brain and not the volume percent. When you set the vaporizer, you're setting the volume percent.
how is desflurane affected if you deliver it in Denver, CO?
The depth of anesthesia is determined by the partial pressure of anesthetic agent in the brain and not the volume percent.. When you set the vaporizer, you're setting the volume percent. At sea level its not a problem, but when you go up in elevation, it can lead to UNDERdosing of desflurane (the variable bypass vaporizers compensate automatically so sevo and iso are not affected) Volume % x total gas pressure = partial pressure of that particular gas Ex = 6% des at sea level 0.06 x 760 mmhg = 45.6 mmhg 6% in denver 0.06 x 620 mmhg = 37.2 mmhg
during pain modulation, where does the descending inhibitory pain pathway begin? where does it project to?
The descending inhibitory pain pathway begins in the periaqueductal gray and the rostroventral medulla. It projects to the substantia gelatinosa
how does the dose of NDNMB for neonates differ than that for adults? why?
The dose for NDNMB is the same for neonates and adults on a mg/kg basis Neuromuscular blocking drugs are highly water soluble.. They do not easily pass through lipid membranes and are therefore confined to the ECF... neonates have a larger ECF volume, therefore NMB have a LARGER Vd → this argues for a larger dose of the NDNMB HOWEVER the neonatal NMJ is immature and is MORE sensitive to NDNMB (and equally sensitive to sux). So because of these forces counterbalancing each other, the dose for NDNMB is the same for neonates and adults. Because the receptors have an equal sensitivity to sux in addition to the increased Vd, a bigger sux dose is needed
in what situations (pH,pka) does the ionized form of the drug predominate?
The drug is a weak base and the pH of the solution is < than the pka of the drug (base dissolved in acid) The drug is a weak acid and the pH of the solution is > than the pka of the drug (acid dissolved in base)
in what situations (pH,pka) does the unionized form of the drug predominate?
The drug is a weak base and the pH of the solution is > than the pka of the drug (base dissolved in base) The drug is a weak acid and the pH of the solution is < than the pka of the drug (acid dissolved in acid)
how long does the effect of hyperventilation on cerebral blood flow last?
The effect of hyperventilation on cerebral blood flow is transient and only lasts 6-20 hrs
The epidural space neighbors the ______ mater and terminated at the _____________ ligament
The epidural space neighbors the dura mater and terminates at the sacrococcygeal ligament
What is the Hamburger shift?
The exchange for Cl (into the RBC) and HCO3- (diffuses out of the RBC) when CO2 undergoes conversion to bicarb When bicarb shifts in or out of the RBC, chloride goes in the opposite direction for electrical neutrality (Chloride or hamburger shift) COBI
Glycocalyx
The external surface of a plasma membrane that is important for cell-to-cell communication The glycocalyx forms a protective layer on the interior wall of the blood vessel
what activates the extrinsic pathway?? what activates the intrinsic pathway?
The extrinsic pathway is activated when coagulation is initiated outside of the intravascular space The intrinsic pathway is activated when coagulation is initiated inside of the vascular space
what is the frank starling mechanism? what two things does it relate?
The frank starling mechanism relates ventricular volume to ventricular output The greater the tension produced in the cardiac sarcomere, the greater the force of contraction If the sarcomere is under stretched, there is no room for contraction. If it is overstretched, cross bridges cannot form
what channel/ion is the primary determinant of the pacemaker of the SA node?
The funny current (I-f) is the primary determinant of the pacemakers intrinsic HR. this is what sets the rate of spontaneous phase 4 depolarization in the SA node
what factors can interrupt the glycocalyx?
The glycocalyx forms a protective layer on the interior wall of the blood vessel. Its integrity is interrupted with sepsis, ischemia, DM, major vascular surgery
as alveolar compliance increases, what happens to ventilation?
The greater the alveolar compliance, the greater the alveolar ventilation
what on the dose response curve represents efficacy?
The height of the plateau on the dose response curve on the y axis represents efficacy Higher plateau = greater efficacy, lower plateau = less efficacy Once plateau is reached, giving more doses of the drug will NOT elicit further effect
The liver receives blood from the portal vein and hepatic artery what percent of blood flow and oxygen content does each contribute?
The hepatic artery provides 25% of liver blood flow and 50% of oxygen content The portal vein provides 75% of liver blood flow and 50% of oxygen content
The ideal bladder length equals _____% of the extremity circumference and ideal bladder width is ______% of the extremity circumference
The ideal bladder length equals 80% of the extremity circumference and ideal bladder width is 40% of the extremity circumference LW 80 40
Retinopathy of prematurity
The immature retinal blood vessels are at risk for vasoconstriction and hemorrhage Dysfunctional healing creates scars... as the scars retract, they pull on the retina, causing retinal detachment and blindness Causes abnormal vascular development in the retina
why do neonates have a faster inhalation induction than the adult?
The increased ratio of alveolar ventilation relative to the size of FRC also explains quicker inhalation induction
what are complications associated with infraclavicular block?
The infraclavicular block has a higher risk of intravascular injection and pt discomfort PTX is also complication
in a Thorpe tube, which end is the internal diameter the narrowest and which is it the widest?
The internal diameter is narrowest at the base and widens along its ascent
The ______________is a monitor of renal perfusion and solute concentration. Its located in the distal tubule, specifically the region that passes between the afferent and efferent arterioles
The juxtaglomerular apparatus is a monitor of renal perfusion and solute concentration. Its located in the distal tubule, specifically the region that passes between the afferent and efferent arterioles
what are the two structures that the kidney is divided into? which is the outer region and which is the inner region?
The kidney is divided into the cortex and medulla... the cortex is the outer region and the medulla is the inner region
what are the cells that are responsible for removing bacteria that enter the liver from the intestine?
The kupffer cells are responsible for removing bacteria and viruses that enter the liver from the intestine
The laryngeal position in the infant is __________ (in the adult it is ________).. The laryngeal position is the same once the child is ________ years old
The laryngeal position in the infant is C3-4 (in the adult it is C5-6).. The laryngeal position is the same once the child is 5-6 years old
what does LAD artery supply?
The left anterior descending artery supplies the anterior wall of the LV, anterior ⅔ of the septum and a small portion of the anterior RV
how does lipid emulsion therapy treat local anesthetic toxicity?
The lipid emulsion acts as a lipid sink that sequesters the LA and reduces plasma concentration. It also increases calcium influx and intracellular calcium concentration and impairs LA binding to sodium channels
what two organs do NOT require insulin for glucose uptake and why is this important?
The liver and the brain do not require insulin for glucose uptake - this is important for the brain because it requires steady supply of glucose... cerebral function declines when blood sugar is less than 50
The liver receives blood from the _________ vein and _________ artery
The liver receives blood from the portal vein and hepatic artery
where is the location of Omphalocele
The location of the defect is midline and involves the umbilicus
What is the Haldane effect?
The lower the PO2 and hemoglobin saturation with O2, the more CO2 can be carried in the blood. Haldane effect states that in the presence of deoxygenated hgb, the CO2 dissociation curve shifts to the left. AKA, in the deoxygenated state, hgb is able to carry more CO2. This allows hgb to load more CO2 at the tissue level and release more CO2 in the lungs Lower PO2 means more CO2 is carried and vice versa
what nerve roots make up the lumbar plexus?
The lumbar plexus arises from the anterior (ventral) rami of L1-4
The ___________ in the distal tubule contains chemoreceptors that monitor [Na] and [Cl] in the tubular fluid
The macula densa in the distal tubule contains chemoreceptors that monitor [Na] and [Cl] in the tubular fluid
The mean electrical vector on EKG points __________ areas of hypertrophy and _________ from areas of infarction
The mean electrical vector on EKG points TOWARDS areas of hypertrophy and AWAY from areas of infarction
what is use dependent block? aka phasic blockade
The more frequently the nerve is depolarized and the voltage gated sodium channels open, the more time there is available for LA binding to occur and the faster the nerve will become blocked This is called a use dependent or phasic blockade
what is the most common cause of toxic plasma concentration of local anesthetic?
The most common cause of toxic plasma concentrations is inadvertent IV injection during regional anesthesia
what are side effects of neuraxial opioids?
The most common side effects of neuraxial opioids = pruritus, resp depression, urinary retention, NV 2-chloroprocaine reduces efficacy of epidural opioids Epidural morphine may reactivate herpes Peristalsis slows w/ neuraxial opioids and gastric emptying time is increased Any opioids that enter systemic circulation can cross placenta
what is the MOST frequent symptom of LAST? what is the exception?
The most frequent symptom is seizure. Bupivacaine is the exception - cardiac arrest can occur before seizure
where is the most important site of pain modulation?
The most important site of modulation is the substantia gelatinosa in the dorsal horn (rexed lamina II and III)
the myocyte is permeable to only what electrolyte?
The myocyte is permeable to potassium, but no other electrolytes or proteins. Because the cell continuously leaks potassium, it loses positive charges. This is why the cell is negative and the outside is positive. This also explains why potassium is the primary determinant of RMP
what explains why the ventricular myocyte is negative and outside is positive?
The myocyte is permeable to potassium, but no other electrolytes or proteins. Because the cell continuously leaks potassium, it loses positive charges. This is why the cell is negative and the outside is positive. This also explains why potassium is the primary determinant of RMP
what is the narrowest point of the airway in the neonate?
The narrowest point of the airway is the cricoid → resistance to passage of ETT beyond the vocal cords is due to the cricoid ring. Cricoid tissue is prone to inflammation and edema formation which can lead to stridor and obstruction Remember Poiseulle's law - small changes in the radius can significantly increase resistance to airflow (radius to the 4th power)
how is the neonatal myocardium different than the healthy adult?
The neonatal myocardium lacks the contractile elements to significantly adjust contractility or SV → the ventricle is non compliant
why do some neonates get jaundice?
The neonate cannot conjugate bilirubin due to a reduction in glucuronyl transferase... this is the same enzyme that metabolizes acetaminophen
why is the neonate prone to resp fatigue, distress, and failure?
The neonate diaphragm has 25% type 1 fibers whereas the adult has 55% The intercostal muscles are inadequately developed, so they contribute little to ventilation The neonate's diaphragm has more type II (fast twitch) than type I (slow twitch) fibers. Because of this neonates are more likely to experience resp fatigue
The neonate's diaphragm has more type ____ (fast twitch) than type ______ (slow twitch) fibers. Because of this neonates are more likely to experience resp fatigue
The neonate's diaphragm has more type II (fast twitch) than type I (slow twitch) fibers. Because of this neonates are more likely to experience resp fatigue The intercostal muscles are inadequately developed, so they contribute little to ventilation The ribs are more horizontal and made of more cartilage - they are less able to significantly augment thoracic volume
what structures make up the nephron?
The nephron is the functional unit of the kidney - it consists of the glomerulus, proximal tubule, loop of henle, distal tubule and collecting duct
What does the oculocardiac reflex do? what causes it or increases its risk?
The oculocardiac reflex (five and dime) causes bradycardia, hypotension, junctional rhythm, AV block and asystole Transmitted via the trigeminal nerve (via long and short ciliary nerves, ciliary ganglion, and gasserian ganglion) and then efferent via vagus nerve Occurs or is made worse by traction to the EOM, pressure on eye or orbital tissue, strabismus surgery, hypercarbia, hypoxemia, and light anesthesia
which is the only gas law that demonstrates an inverse relationship?
The only gas law with an inverse relationship - as pressure goes up, volume goes down Boyle's law is bizarre, it makes me PeeVed
what is the optimal epidural catheter insertion depth? what can happen if the catheter is in too far? in too deep?
The optimal epidural catheter insertion depth is 3-5 cm inside the epidural space too shallow means higher incidence of inadequate analgesia (epidural failure) too deep means catheter may enter an epidural vein or exit through an intervertebral foramen
oncotic pressure
The osmotic pressure in the blood vessels due only to plasma proteins (primarily albumin) --> causes water to rush back into capillaries at end.
why does the desflurane vaporizer have to be recalibrated at different elevation levels?
The output varies inversely with elevation... the vaporizer should be recalibrated when it's going to be used at high elevations variable bypass vaporizers automatically compensate
what is the oxygen analyzer? where is it located? what can it detect?
The oxygen analyzer would be the first monitor to detect a pipeline cross over It resides in the inspiratory limb Monitors oxygen concentration Can detect a leak in the breathing circuit Most common = y piece, second most common = CO2 canister
what is neonate versus adult oxygen consumption in ml/kg/min
The oxygen consumption for neonate is twice that of the adult Neonate = 6 ml/kg.min Adult = 3 ml/kg/min
where should the oxygen flow meter be positioned on the anesthesia machine and why?
The oxygen flow meter should be positioned all the way to the right, closest to the common gas outlet... this minimizes but does not eliminate the risk of hypoxic mixture in the event of a flow meter leak
What is the FEV1/FVC ratio? what is the normal percentage?
The percentage of the FVC expired in one second. 75-80%
The perineum is innervated by the___________ nerve which derives from which dermatomes?
The perineum is innervated by pudendal nerve which derives from S2-4
where are the peripheral chemoreceptors located and what do they do?
The peripheral chemoreceptor are located in the carotid bodies and responds to PO2 Hypoxemia (PO2 < 60) increases Ve (AKA hypoxic ventilatory response)
what damage can a leak in the bellows do to the pt? what will happen to the FiO2 in the circuit?
The pneumatic bellows is compressed by the ventilator drive gas a leak in the bellows creates a direct line of communication between the ventilator drive gas and the breathing circuit... this can cause barotrauma. If there is a bellows leak and oxygen is used as the ventilator drive gas, the FiO2 in the breathing circuit my increase.
at what point in the anesthesia machine does the pressure drop from wall pressure or cylinder pressure 1900 psi to 50 psi (pipeline) or 45 psi (cylinder) pressure respectively?
The pressure change occurs at the DISS and the PISS - cylinder pressure drops to 45 psi from 1900 psi, pipeline pressure is now 50 psi
if baby has TEF, where is the proper location of the ETT tip?
The proper tip of the ETT should be below the fistula and above the carina
what is treatment for apnea after surgery and anesthesia in the neonate?
The prophylactic caffeine 10 mg/kg IV is the treatment of choice Theophylline can be sued but is associated with greater toxicity risk
describe signs and symptoms of Eaton-Lambert Syndrome
The proximal muscles are affected most and weakness is worse in the morning and gets better throughout the day Resp muscles and diaphragm become weak ANS dysfunction causes orthostatic hypotension, slowed gastric motility and urinary retention Anticholinesterases are NOT part of treatment Pts are sensitive to both sux AND NDNMB Volatile anesthetics provide enough relaxation for most Reversal w/ anticholinesterases may be inadequate despite proper dosing
what is neurogenic shock? what are the characteristic signs and symptoms?
The pt with an acute C7 transection will endure neurogenic shock, characterized by bradycardia, hypotension, hypothermia w/ pink and warm extremities
what are all of the different things that the pulse ox is a monitor of?
The pulse ox is a non invasive monitor of hemoglobin saturation, HR, fluid responsiveness (pulse pressure variation), and perfusion
What is the Beer-Lambert Law?
The pulse oximeter utilizes the Beer Lambert law, which relates the intensity of light transmitted through a solution and the concentration of the solute within the solution The pulse ox looks at the ratio of light absorption during the peak of the waveform relative to the trough of the waveform... at the peak of the waveform, the ratio of arterial to venous blood is increased
What is the pumping effect? what factors enhance the pumping effect?
The pumping effect can increase vaporizer output... PPV or using the oxygen flush valve will cause vaporizer to re-enter the vaporizer chamber and lead to pumping effect. Enhanced by low FGF, low concentration dial setting, low levels of anesthetic liquid in vaporizing chamber
The HR is increased or decreased by manipulating:
The rate of spontaneous phase 4 depolarization Resting membrane potential Threshold potential
why does hypercapnia impair cardiac contractility?
The result of the accumulation of volatile acids. Acidosis = impaired contractility
What is ion trapping?
The result of varying concentration of a drug in compartments with different pH's Maternal alkalosis and fetal acidosis is the circumstance that creates the strongest gradient for passage of local anesthetic from mother to fetus
which side of the RLN loops around the subclavian artery and which side loops around the aortic arch?
The right RLN loops under the subclavian artery, the left loops under the aortic arch Think left is the side of your heart, think heart and aorta together The left RLN is more susceptible to injury (you can break your heart)
What does the right coronary artery supply?
The right coronary artery supplies the posterior wall of the LV, most of the RV and the posterior ⅓ of the septum
is there a bigger risk of epidural with block placement or catheter removal?
The risk of epidural hematoma is similar to block placement and catheter removal
where in the body do the roots of the brachial plexus turn in to trunks?
The roots turn into trunks just beyond the lateral border of the scalene muscles
what nerves are blocked with a sciatic nerve block? what is this block useful for?
The sciatic nerve is actually the tibial and peroneal nerve contained within a sheath Useful for procedures on the back of the thigh, lower leg, ankle or foot
explain what the second gas effect is
The second gas effect explains how nitrous oxide hastens the onset of a second gas and why alveolar oxygen might transiently increase
what does the slope of the dose response curve represent? what does it mean when the slope is steeper?
The slope of the dose response curve tells us how many receptors must be occupied to elicit a clinical effect A steep slope implies that most of the receptors need to be occupied until you see the effect of the drug... once the effect is observed, only small doses are needed to have profound clinical effect
what are the 3 states that the sodium channel can exist in? in which states can a LA bind to the sodium channel?
The sodium channel can exist in 3 states - resting, active, and inactive LA preferentially bind to the alpha subunit of the sodium channel in the ACTIVE and INACTIVE state Think - DON'T BOTHER ME WHEN I'M RESTING! if the word has "active" in it.... it can bind
how does the sodium potassium ATPase work?
The sodium/potassium ATPase pump removes the sodium that enters the cell during depolarization and returns potassium that has left the cell during repolarization For every 3 sodium it removes it brings back 2 potassium into the cell
how many paired spinal nerves are there?
The spinal cord has 31 paired spinal nerves
The spinothalamic tract travels from spine to thalamus
The spinothalamic tract travels from spine to thalamus makes sense that its a sensory tract
what does the stellate ganglion provide sympathetic innervation to? what happens when the stellate ganglion is blocked?
The stellate ganglion provides sympathetic innervation to ipsilateral upper extremity and portion of head and neck Often blocked as consequence from BP peripheral block Blockade manifests as Horner's syndrome Ptosis, anhidrosis, mitosis, enophthalmos Very homely PAM Vasodilation, horner, ptosis, anhidrosis, miosis
what is the shape of the subglottic airway in the neonate vs the adult?
The subglottic airway shape in the neonate is like a funnel (more like a cylinder in the adult) → resistance to ETT insertion
how does the Tec 6 vaporizer work? to what temperature and pressure is it set at?
The tec 6 des vaporizer injects anesthetic vapor into the FGF.. the chamber that contains the anesthetic agent is pressurized to 2 atm and heated to 39 degrees F
Boiling point
The temperature at which a liquid changes to a gas
which side of IJ insertion has greatest risk of cylothorox and why?
The thoracic duct is larger on the left side = greater risk of chylothorax during left IJ insertion
Dalton's law of partial pressures
The total gas pressure in a container is equal to the sum of the partial pressures exerted by each gas
Dalton's law of partial pressures
The total pressure is equal to the sum of the partial pressures exerted by each gas in the mixture P total = P1+P2+P3
after injection of local anesthetic for a bier block, how long must the tourniquet be inflated before it can be let down? why? how should you proceed if your pt is having tourniquet pain?
The tourniquet must remain inflated for a min of 20 min after LA injection - this allows enough time for the LA to absorb into the tissues... if the cuff is deflated too soon or it flails, the LA is washed into systemic circulation where it can produce seizure or CV collapse Inflate distal, then inflate proximal cuff... then deflate distal... if tourniquet pain, inflate distal then deflate proximal
which drugs cannot be used in someone with a heart transplant and why?
The transplanted heart is dependent on preload because the HR is fixed (no ANS input) Drugs that indirectly stimulate SAN cannot be used (atropine, glyco, ephedrine)
what muscles and landmarks will you see on the ultrasound for supraclavicular block?
The trunks and divisions of the brachial plexus are located lateral to the hypoechoic pulsating subclavian artery, just superior to the first rib
what blood vessels return deoxygenated blood from the fetus to the placenta? what blood vessels supply oxygen to the fetus?
The umbilical arteries return deoxygenated blood from the fetus to the placenta → this blood has low PaO2 and increased PaCO2 The umbilical vein supplies oxygen to the fetus... the umbilical arteries return deoxygenated blood to the placenta
unitary hypothesis
The unitary hypothesis states that all anesthetics share a similar mechanism of action but each may work at a different site
what is modern anesthetic theory?
The unitary hypothesis states that all anesthetics share a similar mechanism of action but each may work at a different site
how does the ventilator drive gas effect the bellows? where is it located? how does it affect the ventilator spill valve?
The ventilator drive gas compresses the bellows it is located OUTSIDE of the bellows and the pt breathing circuit is INSIDE the bellows. The drive gas also opens and closes the ventilator spill valve during inspiration, the drive gases closes the spill valve.. This makes sure that the Vt goes to the pt and NOT the scavenger during exhalation, the flow of the drive gas stops and the spill valve opens... then exhaled Vt first fills the bellows and then the rest goes to the scavenger.
The vessel rich group accounts for only ____% of body weight and receives ____% of CO
The vessel rich group accounts for only 10% of body weight yet received 75% of CO
why might a single shot spinal after a failed epidural call a total spinal?
The volume given during an epidural had to go somewhere - it may compress the SA space and reduce its volume... this would create a higher than expected spread with a given local anesthetic dose You'll puncture the dura during a single shot spinal... it's possible the LA from failed epidural leaks through the hole to enter the SA space
what are the two subunits on the Nm channel that must be occupied in order for the channel to open and depolarization to occur?
There are 2 alpha subunits on this receptor and both must be occupied by an agonist (ACh or sux) for the channel to open
what is the differential block that occurs with epidural anesthesia?
There is NO autonomic differential block with epidural anesthesia, but sensory block will be 2-4 dermatomes higher than motor block
in pt with coarctation of aorta, what happens to: LV afterload SBP in upper extremities SBP in lower extremities
There is an increased LV afterload due to the obstruction of blood flow at the level of the coarctation SBP is elevated in upper extremities SBP is reduced in the lower extremities
anesthesia considerations for baby with gastrochisis
These babies are at a higher risk of fluid and heat loss IVF should be 150-300 ml/kg/day Closure may be staged After delivery, abd contents are placed in a bag to minimize water and heat loss Maintain PIP less than 30... if greater surgery will require staging Increased abd pressure decreases venous return, cardiac output and systemic perfusion Measure spo2 on the lower extremity to monitor for impaired venous return N2O will distend bowel and may injure the surgical closure Expect major F&E shifts
how to pts with myasthenia gravis respond to NDNMB and sux?
These pts are SENSITIVE to NDNMB and RESISTANT to sux
why do steroid medications have a slower onset of action?
They diffuse through the lipid bilayer and then binds with intracellular steroid receptors. By activating or inhibiting DNA transcription, they influence protein synthesis inside the target cells... this is why there is such a slow onset for steroid meds
How do thiazide diuretics affect blood sugar?
Thiazide diuretics are unique because they will increase serum glucose... hyperglycemia = side effects
Thiazide diuretics
Thiazide diuretics inhibits Na Cl transporter in the distal convoluted tubule = diuretics HCTZ, metolazone, indapamide, chlorthalidone
Clopidogrel
Thienopyridine derivatives - inhibit plt aggregation by blocking ADP transferase
Ticlopidine
Thienopyridine derivatives - inhibit plt aggregation by blocking ADP transferase
give two examples of Thienopyridine derivatives how do these drugs work?
Thienopyridine derivatives - inhibit plt aggregation by blocking ADP transferase Clopidogrel Ticlopidine
Prostaglandin F2 - Hemabate/Carboprost what does it do? what are SE? in whom should it be avoided?
Third line uterotonic 250 mcg IM or injected into uterus SE = NV diarrhea, hypotension, HTN avoid is asthma!
Third order neuron
Third order neuron extends from thalamus to the cerebral cortex - the cell body is in the thalamus
Is pyloric stenosis a surgical emergency?
This condition is a MEDICAL emergency, not surgical Surgical correction should be postponed until F,E and AB status is corrected/optimized
Conn's disease
This condition is caused by the growth of an aldosterone secreting tumor Conn's disease occurs with excessive aldosterone production - it causes sodium retention and potassium los
tolerance develops to all effects of opioids EXCEPT what
Tolerance develops to all effects of opioids EXCEPT miosis and constipation
Threshold potential
Threshold potential is the internal voltage at which the cell depolarizes. Depolarization is all or nothing
how do thrombolytic agents work? name 4
Thrombolytic agents - activate plasminogen TPa, streptokinase, alteplase, urokinase
what are the effects of thromboxane A 2 on the kidneys?
Thromboxane A2 constricts renal arteries
how does thromboxane A2 affect renal vasculature?
Thromboxane A2 is a renal vasoconstrictor - its production is increased in times of renal ischemia
what intrinsic muscles of the airway adduct the vocal folds and cause the glottis to become more narrow?
ThyroARytenoid = they adduct and relax Lateral CricoArytenoid = Lets Close Airway
what sensory and motor innervation does the tibial nerve supply?
Tibial nerve = plantar flexion and inversion of the foot TIPPED
Tibial nerve innervates _________ Sural nerve innervates _________ Superficial peroneal nerve innervates _________ Deep peroneal nerve innervates _________
Tibial nerve → heel Sural nerve → lateral foot Superficial peroneal nerve → dorsum of foot Deep peroneal nerve → webspace between first and second toe
______________ is released by the injured tissue over a period of days, which activates plasmin
Tissue plasminogen activator (tPA) is released by the injured tissue over a period of days, which activates plasmin
how do the kidneys alter acid base status
Titrate hydrogen in the tubular fluid to create acidic or basic urine
how to bronchioles compensate for increased dead space?
To compensate, bronchioles constrict to minimize dead space
how does the pulmonary vascular compensate for shunt?
To compensate, hypoxic pulmonary vasoconstriction reduces pulmonary blood flow to areas of the lung that do not receive ventilation
what is tolerance? why does tolerance to occur?
Tolerance occurs when a higher dose is needed for a given effect This occurs d/t receptor desensitization and increased synthesis of cMAP... NOT enzyme induction
what is SIADH? what is the pathophysiology? what are signs and symptoms?
Too much ADH = too much water SIADH has ADH in it... too much ADH even in the name! The body retains too much water Hyponatremia Decreased urine
what causes acromegaly? what are signs/symptoms/complications of acromegaly?
Too much growth hormone d/t pituitary adenoma Distorted facial features = difficult mask Large tongue, epiglottis = DI OSA HTN, CAD, arrhythmias Glucose intolerance SKM weakness
A beta fibers
Touch, pressure
what is tracheal perfusion pressure and why is this significant in the pediatric pt?
Tracheal perfusion pressure is 25 cm H2O - using an ETT that is too large or injecting too much air into the cuff will reduce tracheal perfusion and cause edema and increased WOB, causing postintubation croup Goal is to maintain air leak less than 25
what kind of sensory information does the dorsal column transmit to the brain?
Transmits mechanoreceptive sensation → fine touch, proprioception, vibration and pressure Capable of 2 point discriminaiton
what kind of sensory information does the spinothalamic (anterolateral system) transmit? what kind of nerve fibers?
Transmits pain, temp, crude touch, tickle, itch, sexual sensation Consists of smaller, myelinated slow conducting fibers A delta fibers No two point discrimination
Increased _________ pressure predisposes an aneurysm to rupture
Transmural pressure
what causes TURP syndrome?
Transurethral prostatic resection often opens the extensive network of venous sinuses in the prostate & potentially allows systemic absorption of the irrigating fluid (2 L or more) Due to a large volume of hypo-osmolar irrigation solution
what is the treatment for reduced erythropoietin production associated with CKD? what is a SE of this treatment
Treatment = EPO or darbepoetin ** can cause HTN
what are treatment options for pts w/ myasthenia gravis?
Treatment = anticholinesterases, immunosuppression, thymectomy, plasmapheresis Oral pyridostigmine
what is the treatment for hypocalcemia?
Treatment = calcium and vitamin D
what is the treatment of hypermagnesemia?
Treatment = calcium chloride
what is the treatment for lupus?
Treatment = hydrocortisone and cyclophosphamide, NSAIDS, immunosuppressant, antimalarials
Diabetic ketoacidosis (treatment)
Treatment = volume resuscitation, insulin, K+ after acidosis subsides
treatment of Hyperglycemic hyperosmolar state
Treatment = volume resuscitation, insulin, correct electrolytes
what is the treatment for orthodromic AVNRT arrhythmia?
Treatment is to block conduction at the AVN pathway Vagal manuvers Amio Adenosine Beta blockers Verapamil Cardioversion
what is the treatment for antidromic AVNRT arrhythmia?
Treatment is to block conduction in the accessory pathway Procainamide Amio Cardioversion Drugs that increase the refractory period for the AVN will favor conduction THROUGH the accessory pathway in this situationIIII
when does large V wave occur in CVP waveform?
Tricuspid regurg allows a portion of the RV volume to pass through the closed but incompetent valve during RV systole Occurs also w/ acute increase in IV volume and RV papillary muscle ischemia
cranial nerve V
Trigeminal - chewing face & mouth touch & pain V1 = ophthalmic V2 = maxillary V3 = mandibular Both sensory and motor - facial sensation, anterior ⅔ tongue sensation, chewing movement
why do pts with trisomy 21 have increased risk of upper airway obstruction?
Trisomy 21 persons with macroglossia which increases risk of upper airway obstruction
cranial nerve IV
Trochlear eye movement
what are the 3 trunks of the brachial plexus?
Trunks = superior, middle, inferior
what are the names of the cells that produce surfactant?? at how many weeks gestation do these cells begin to make surfactant in the neonate?
Type 2 pneumocytes begin producing surfactant between 22-26 weeks, w/ peak production occurring at 35-36 weeks
what type of TEF is most common
Type C is the most common The upper esophagus ends in a blind pouch and the lower esophagus communicates with the distal trachea
compare and contrast type I vs type II muscle fibers
Type I muscle fibers are slow twitch that are built for endurance - they are resistant to fatigue Type II muscle fibers are fast twitch that are built for short bursts of heavy work - they tire easily
Oligodendrocytes
Type of glial cell in the CNS that wrap axons in a myelin sheath. increases conduction velocity
blood typing vs screening vs crossmatching
Typing Determines the presence of ABO and Rh D antigens in the recipients blood... this takes five min Screening Determines the presence of the most clinically significant antibodies.. This takes 45 min Crossmatching Provides the most accurate determination of compaltiily by mixing recipients plasma with blood in the actual unit that will be transfused.. This takes 45 min
describe how norepi and epi are synthesized in the body
Tyrosine (tyrosine hydroxylase) → DOPA (DOPA decarboxylase) → DA (dopamine beta hydroxylase) → NE (phenylethanolamine N-methyltransferase in ADRENAL MEDULLA) → epi **increased calcium from AP causes NE vesicles to fuse with nerve terminal and release contents
what is the rate limiting step in NE synthesis?
Tyrosine hydroxylase
Hypokalemia EKG changes
U wave ST depression Flat T wave Long QT interval
Is uterine blood flow autoregulated?
UBF is not autoregulated... it's dependent on maternal MAP, CO and uterine vascular resistance
how does phenylephrine affect uterine blood flow?
UBF is not reduced by phenylephrine
A basic drug will be highly _________ in basic pH
UNionized
how is the ultrasound positioned when performing an axillary block? what muscles and landmarks will you see on the ultrasound?
Ultrasound probe is placed vertically under armpit You'll see coracobrachialis, humerus, and nerves surrounding the axillary artery
what are causes of variable fetal decelerations?
Umbilical cord compression No consistent pattern between FHR and uterine contraction Umbilical compression causes baroreceptor mediated reduction in HR Decels are usually self limiting Maintain variability during deceleration Fetal compromise prolongs FHR recovery time There is risk of fetal hypoxemia and requires urgent fetal assessment
Ductus venosus
Umbilical vein → inferior vena cava Oxygen rich blood bypasses the liver
what is the essential triad of general anesthesia?
Unconsciousness Amnesia Immobility
Under ischemic conditions in the kidney the arachidonic acid pathway favors production of vasoconstrictors - ______________ and _____________
Under ischemic conditions the pathway favors production of vasoconstrictors - thromboxane A2 and PGF2
under control of ________ hormone, the kidneys convert inactive vitamin D3 to its active form
Under the control of parathyroid hormone, the kidneys convert inactive vitamin D3 to active vitamin D3 (1,25 [OH]2 vitamin D3)
where in the body is inactive vitamin D converted to its active form? what hormone is needed for this reaction to take place?
Under the control of parathyroid hormone, the kidneys convert inactive vitamin D3 to active vitamin D3 (1,25 [OH]2 vitamin D3)
how does decreased blood volume increase ADH release?
Unloading of baroreceptors in the carotids, transverse aortic arch, great veins, and RA stimulate ADH release
what is unstable angina?
Unstable angina is defined as angina at rest new onset angina (<2 mo) increasing symptoms (intensity, frequency, duration) duration exceeds 30 min symptoms have become less responsive to medical therapy
Retrograde intubation indications
Unstable cervical spine (most common) Upper airway bleeding - can't visualize glottis Retrograde intubation is best for pts when intubation has failed but ventilation is still possible - takes 5-7 min Can be done in awake pt
Until retinal maturation is complete, supplemental oxygen should be minimized to maintain spo2 between _____% and _____% up to ______ weeks post conception to minimize risk of the development of retinopathy of prematurity
Until retinal maturation is complete, supplemental oxygen should be minimized to maintain spo2 between 85% and 93% up to 44 weeks post conception
give examples of acute intrinsic lung disease
Upper airway obstruction (neg pressure pulmonary edema) Aspiration Reexpansion of collapsed lung
list the conditions for which sux is contraindicated
Upper or lower motor neuron injury SCI Burns - Hyperkalemia may persist for several years after a burn! SKM trauma CVA Prolonged chemical denervation (magnesium, long term NMB infusion, clostridial toxin) Tetanus Severe sepsis Muscular dystrophy Any muscle atrophy from any cause 24 hrs after Denervation injury and within the past year
Total spinal management
Vasopressors, IVF, left uterine displacement, leg elevation If pt loses consciousness, intubate
what is vasospasm? what causes it? when is it most likely to occur?
Vasospasm = delayed contraction of cerebral arteries... can lead to cerebral infarction Free hgb in contact w/ outer surface of the cerebral arteries cause them to spasm Most likely to occur 4-9 days after SAH
list all of the complications that occur with CKD?
Uremic syndrome -s/sx = anemia, fatigue, NV, anorexia, coagulopathy Uremia increases bleeding time Gap metabolic acidosis is result of accumulation of non volatile acids Secondary hyperparathyroidism occurs as a result of impaired active vitamin D3 production and hyperphosphatemia Erythropoietin production is reduced - this contributes to a normocytic normochromic anemia Fluid overload creates a restrictive ventilatory defect Fluid overload also contributes to HF and pulmonary edema HTN is the result of RAAS activation and causes sodium and fluid overload Pericarditis can occur from uremia Hyperkalemia from impaired K secretion Osteodystrophy from decreased vitamin D production and secondary hyperparathyroid Uremia impairs nerve conduction, ANS dysfunction - reduced baroreceptor reflex, delayed gastric emptying, Sensory and motor peripheral neuropathy Seizures, encephalopathy, coma Impaired WBCs = high irks of infection
Urinary excretion rate = _________ - _______ + __________
Urinary excretion rate = filtration - reabsorption + secretion
how does urine glucose change during pregnancy and why?
Urine glucose increases d/t increased GFR and reduced reabsorption
Urokinase is produced by the __________ and released into circulation which also activates _____________
Urokinase is produced by the kidneys and released into circulation which also activates plasmin
Hyperglycemic hyperosmolar state is usually caused by ______________
Usually caused by insulin resistance or inadequate production Enough insulin is produced to prevent ketosis but not hyperglycemia
how does uterine contraction affect preload?
Uterine contraction causes autotransfusion and increases preload
Uterus blood flow _________ ml/min during preg (______% of CO)
Uterus blood flow 500-700 ml/min during preg (10% of CO)
VACTERL association
V = Vertebral anomalies A = Anal atresia, imperforate anus C = Cardiac anomalies TE = Tracheoesophageal fistula R = Renal and or radial anomalies L = Limb defects 25-50% of kids with TEF suffer from other congenital anomalies, known as VACTERL About 20% of neonates with EA have a significant cardiac defect (ASD VSD TOF aortic coarctation)
Charles's Law
V1/T1 = V2/T2 Direct relationship - as one variable gets larger so does the other increased temp = increased volume
Best leads to monitor for intraoperative ST changes
V3>V4>V5>III>aVF If pt has an abnormal EKG, then the best lead to monitor is the region at greatest risk of ischemia
what is normal VO2 in ml/min
VO2 = 250 ml/min
what is normal oxygen consumption in ml/kg/min and ml/min
VO2 = 3.5 ml/kg/min or 250 ml/min
cranial nerve X
Vagus Sensory and motor Swallowing, bradycardia, sensation below epiglottis Responsible for 75% of all PNS activity
what is the end product of norepi metabolism?
Vanillylmandelic acid is the end product of NE metabolism by COMT and MAO
during what weeks post conception is the baby at risk for retinopathy of prematurity?
Vasculogeneisis occurs between 16 and 44 weeks post conception - its during this time that the pt is at risk for ROP
Conditions that increase SVR
Vasoconstrictors Fluid bolus Increased SNS tone Pain Anxiety
In pt with autonomic hyperreflexia, what are the signs and symptoms? what occurs above and what occurs below the level of injury?
Vasodilation above level of injury Vasoconstriction below level of injury → risk of severe HTN Brady via baroreceptor reflex
what factors in the body counterbalance clot formation
Vasodilation washes out ADP and TxA2 Antithrombin inactivates thrombin Tissue factor pathway inhibitor neutralizing tissue factor Protein C and S inhibit factors 3, 5, and 7
which vasopressor preferentially constricts the efferent arteriole and maintains GFR and UOP the best?
Vasopressin preferentially constricts efferent arteriole.. It maintains GFR and UOP better than NE and phenylephrine
what is the equation for volume of distribution
Vd = amount of drug/desired plasma concentration
Complications of an elevated plateau pressure
Vent associated lung injury PTX Pneumothorax Pneumomediastmnum subQ emphysema
Ventricular function curve illustrates the relationship between _________ and ____________
Ventricular function curve Illustrates the relationship between ventricular volume and output Increased ventricular volume = larger CO
cranial nerve VIII
Vestibulocochlear sensory - hearing and balance
what is the most common cause of URI
Viral infection is the most common cause
what is the relationship between viscosity and temperature?
Viscosity is inversely proportional to temp Decreased temp = increased viscosity and resistance
Viscosity is the result of __________ from intermolecular forces as fluids pass through a tube
Viscosity is the result of friction from intermolecular forces as fluids pass through a tube
how do volatile anesthetics affect SSEPS?
Volatile agents decrease amplitude and increase latency of SSEPs
Conditions that decrease SVR
Volatile anesthetics Propofol Decreased SNS tone Histamine Anaphylaxis Hemodilution Sepsis
what factors PROLONG the duration of neuromuscular blockade?
Volatile anesthetics (Des>sevo>iso>N2O>prop) Verapamil Amlodipine Lidocaine Quinidine Cyclosporine Tamoxifen Clindamycin Tetracycline Aminoglycosides Dantrolene Increased lithium Increased Mag (=decreased ACh release from presynaptic nerve) Decreased calcium (=decreased ACh release from presynaptic nerve) Decreased K+ (decreases RMP) Hypothermia (decreases metabolism and clearance) Women more susceptible than men
how do volatiles affect QT interval?
Volatile anesthetics increase the duration of myocardial repolarization by impairing an outward K+ current. This prolongs the QT interval
how do volatile anesthetics most likely work?
Volatile anesthetics most likely exert their effects by stimulating and inhibiting a variety of stereoselective receptors. The primary target in the brain is GABA A. The primary target in the SC is stimulation of glycine receptors and inhibition of NMDA receptors and sodium channels. Volatile anesthetics produce immobility in the ventral horn of the SC
how do volatile anesthetics affect respiratory tone?
Volatiles are bronchodilators, so airway diameter increases
how do volatile anesthetics affect Vt and RR? Ve?
Volatiles decrease tidal volume and increased RR, leading to increased dead space ventilation Ve is reduced → Vt gets smaller and there is partial compensation by increasing RR
which volatile anesthetic affects hypoxic ventilatory drive the LEAST
Volatiles impair response to CO2 and increase apneic threshold Desflurane affects hypoxic ventilatory response the LEAST
how do volatile anesthetics affect coronary blood flow?
Volatiles increase coronary blood flow in excess of myocardial oxygen demand. They preferentially dilate the small cardiac vessels
how do volatile anesthetics affect cerebral blood flow, CMRO2, CSF production, CVR?
Volatiles uncouple metabolism from cerebral blood flow - they supply the brain w/ more blood flow than it actually needs. Since ore blood is delivered to the brain per min, CBV increases CMRO2 decreases CVR decreases CSF production decreases
Volume % = ________ pressure/_______ pressure x 100
Volume % = partial pressure/total pressure x 100
what is the diffusing capacity of CO?
Volume of CO that can transverse alveolocapillary membrane Tests lungs ability to exchange gas
What is forced vital capacity? what is the normal value in L?
Volume of air that can be exhaled after deep inhalation effort dependent Normal 3.7-4.8L
what metabolic disturbances are associated with pyloric stenosis?
Vomiting causes the infant to lose H+ and electrolytes so he will commonly present with -Metabolic alkalosis -Hyponatremia -Hypokalemia -Alkaline urine If vomiting persists and dehydration is not corrected, impaired tissue perfusion increases lactate production and produces metabolic acidosis - this is a LATE finding
what kind of arrhythmia is WPW? via what bundle?
WPW is associated with AV reentry Via kent bundle Delta wave
Walking up _____ flights of stairs w/o stopping = 4 METS or 1000 ml O2/min
Walking up 4 flights of stairs w/o stopping = 4 METS or 1000 ml O2/min
according to the law of laplace, Wall tension = (__________x ____________)/(___________ x 2)
Wall tension = (LV pressure x radius)/(LVwall thicknessx2) Wall tension/stress is reduced by Decreased intraventricular pressure Decreased radius Increased wall thickness
according to the law of laplace, LV wall tension/stress is reduced by... _______ intraventricular pressure _______ radius _______ wall thickness
Wall tension/stress is reduced by Decreased intraventricular pressure Decreased radius Increased wall thickness
what should you do when your CO2 absorbent is exhausted?
When CO2 absorbent is exhausted, the baseline of ETCO2 doesn't return to zero... you'll need to increase FGF Increasing Ve does not preventing rebreathing
what does it mean if resting membrane potential is closer to threshold potential? farther?
When RMP is CLOSER to TP, the cell is EASIER to depolarize When RMP is FARTHER from TP, the call is HARDER to depolarize
what Vd would indicate a lipophillic drug? what does this mean as far as dose amount?
When Vd exceeds total body water (> 0.6 L/kg or > 42 L) it is lipophilic It will need a bigger dose to achieve a specific plasma concentration
what Vd would indicate a hydrophillic drug? what does this mean as far as dose amount?
When Vd is less than total body water (< 0.6 L/kg or < 42 L) it is lipophilic It will need a smaller dose to achieve a specific plasma concentration
what is a benefit of combining neuraxial opioids with local anesthetics?
When combined with local anesthetics, neuraxial opioids create a denser block Intrathecal opioids diffuse into systemic circulation and work on opioid receptors throughout the body
what does it mean when the dose response curve shifts right?
When curve shifts right, there is DECREASED affinity, LOWER potency, and HIGHER required dose
why is it dangerous for pregnant pt to lie supine?
When supine, the OB pt's gravid uterus compresses vena cava and aorta... this decreases VR and blood flow to uterus/ LE Decreased CO compromises fetal perfusion and can cause mother to lose consciousness Relieve compression with right torso tilted 15 degrees
ACh or Sux will bind to 2 alpha subunits on the Nm receptor at the NMJ and the channel to open. What happens next after these agonists bind? -what happens to sodium? -what happens to calcium? -what happens to potassium? -where is calcium released from? -what is the ultimate response?
When the agonist binds, the channel opens, sodium and calcium enter the cell and K+ leaves the cell. Depolarization of the myocyte causes calcium release from the endoplasmic reticulum into the cytoplasm where it engages w/ myofilaments and causes muscle contraction
what does it mean when the dose response curve shifts left?
When the curve shifts left on the dose response curve, there is INCREASED affinity for the receptor, HIGHER potency, and LOWER required dose
when the expiratory valve malfunctions, when does the ETCO2 waveform look like?
When the expiratory valve is the problem, the ETCO2 will have a beta angle on the inspiratory phase the baseline of the ETCO2 does not return to 0
what can happen if the negative pressure relief valve fails on the scavenger? what happens when the positive relief valve fails?
When the negative pressure relief valve fails, it's possible for the vacuum to remove gas from the breathing circuit When the positive pressure relief valve fails, fresh gas can accumulate inside the breathing circuit and cause barotrauma
what happens to the drug when the pKa and the pH are the same
When the pka and pH are the same, 50% of the drug will be ionized and the other 50% will be unionized It is the UNIONIZED portion that is lipophilic, active, and crosses lipid bilayers like BBB, GIT, and placenta
When the unidirectional valve is stuck open, ___________ occurs, when stuck closed, ____________ can occur
When the unidirectional valve is stuck open, re-breathing occurs, when stuck closed, airway obstruction can occur
how does stimulation of beta 2 receptors affect coronary blood flow?
coronary vasodilation
While NO anesthetic is proven to be a teratogen in humans - it wise to stick with drugs with a long track record of safety, like ____________________
While NO anesthetic is proven to be a teratogen in humans - it wise to stick with drugs with a long track record of safety, like prop, opioids, NMB, inhalation agents
what is the morphology produced of an antidromic AVNRT arrhythmia?
Wide QRS anti = bad
why can bupivacaine be a more dangerous local anesthetic?
With bupivacaine, cardiac toxicity occurs before seizures
What does the baroreceptor reflex do?
With increased BP, the baroreceptor reflex will decrease HR and SVR via the carotid sinus nerves (nerve of Hering) and the glossopharyngeal nerve in the internal carotid artery by sending impulses to the nucleus tractus solitarius in the medulla. In the transverse aortic arch, the impulses are sent via the vagus nerve. The NTS in the medulla decreases SNS tone and increases PNS tone in response to increased BP (and vice versa for decreased BP)
Xerostomia
Xerostomia = dry mouth!
zero order kinetics
Zero order kinetics describes a situation where a constant AMOUNT of drug is metabolized per unit time Happens when there is more drug than enzyme - the biotransformation process is saturated. Not enough enzyme is available to metabolize all of the drug that is delivered to it
What is emphysema?
a condition in which the air sacs of the lungs are damaged and enlarged, causing breathlessness. Enlarged and destructed airways Surface for gas exchange is reduced and dead space increases Pulmonary HTN from destruction of capillary bed Generally normal PO2 or slightly reduced PaCO2 is normal or slightly decreased from hyperventilation
Conn's syndrome
a disorder of the adrenal glands due to excessive production of aldosterone
What is autonomic dysreflexia?
a life-threatening emergency in spinal cord injury patients that causes a hypertensive emergency; it occurs AFTER spinal shock has resolved; the symptoms are severe headache, diaphoresis, nausea, nasal congestion, and bradycardia
What is tubuloglomerular feedback?
a paracrine signaling mechanism through which changes in fluid flow through the loop of Henle influence GFR The macula densa in the distal tubule contains chemoreceptors that monitor [Na] and [Cl] in the tubular fluid Decreased sodium and chloride in the distal tubule will stimulate renin release Tubuloglomerular feedback about the sodium and chloride composition in the distal tubule affects arteriolar tone... this creates a negative feedback loop that adjusts renal vascular resistance and renin secretion in an effort to maintain renal blood flow
what are later signs and symptoms of opioid withdrawal?
abd cramping and NV
posterior cricoarytenoid
abducts vocal folds and widens the glottis Posterior CricoArytenoid = Please Come Apart innervated by RLN
Caudal anesthesia contraindications
absolute Spina bifida Meningomyelocele of sacrum Meningitis Relative Pilondial cyst Abnormal superficial landmarks Hydrocephalus Intracranial tumor Pregressive degenerative neuropathy
what are relative and absolute CI for ESWL?
absolute CI = Pregnancy and risk of bleeding relative CI= pacer/ICD, calcified aneurysm, UTI, obstruction beyond renal stone, morbid obesity
how does methemoglobin affect pulse ox?
absorbs 660 and 940 nm equally.... This 1:1 ratio will read as 85% no matter what
how does carboxyhemoglobin affect pulse ox?
absorbs 660 nm to the same degree as oxyhemoglobin... Carboxyhemoglobin and oxyhemoglobin look the same to the pulse oximeter... it will OVERESTIMATE the SpO2
list 2 examples of carbonic anhydrase inhibitors
acetazolamide and dorzolamide
Thalamus
acts as a relay center and directs sensory impulses to the cerebrum the thalamus is a throughway
what are some uses for loop diuretics?
acute pulmonary edema AKI CHF hypercalcemia HTN
lateral cricoarytenoid muscle
adducts the vocal folds and narrows the glottis Lateral CricoArytenoid = Lets Close Airway innervated by RLN
Where is aldosterone produced?
adrenal cortex
what conditions increase FRC?
advanced age COPD (air trapping) prone sitting lateral obstructive lung disease PEEP sigh breaths
what are risk factors for the development of halothane hepatitis?
age > 40 Female > 2 exposures genetics obesity CYP2E1 induction (alcohol, isoniazid, phenobarbital)
aldosterone stimulates the ______________ pump in the ________ cells of the distal tubules and collecting ducts aldosterone facilitates ________ and ________ reabsorption and __________ excretion
aldosterone stimulates the Na/K+ pump in the principle cells of the distal tubules and collecting ducts aldosterone facilitates Na and H2O reabsorption and K+ excretion
what plasma protein do local anesthetics preferentially bind to?
alpha 1 acid glycoprotein
Prazosin
alpha 1 receptor blocker with NO reflex tachycardia unlike the non selective blockers
basal ganglia
fine control of movement gangs are stealthy and must have fine control of movement
Graves disease
an autoimmune disorder that is caused by hyperthyroidism and is characterized by goiter and/or exophthalmos
what are signs and symptoms of uremic syndrome associated with CKD?
anemia fatigue NV anorexia coagulopathy
What is the apneustic center?
antagonizes the pneumotaxic center The apneustic center stimulates the DRG (stimulates pacemaker) When your pt is apnic you want to STIMULATE them to breathe
where is the site of CSF reabsorption?
arachnoid villi
what is a dermatome?
area of skin that is innervated by a dorsal nerve root from the spinal cord
what are consequences/signs/symptoms of respiratory alkalosis?
arrhythmias decreased coronary blood flow decreased myocardial contractility decreased P50 inhibition of respiratory drive cerebral vasoconstriction (decreased CBF, decreased ICP) neuronal irritability confusion decreased serum K decreased serum Ca
what determines hydrostatic pressure across the glomerulus
arterial BP afferent arteriole resistance efferent arteriole resistance
what are signs/symptoms/consequences of respiratory acidosis?
arterial hypoxemia increased P50 myocardial depression vasodilation SNS stimulation tachycardia increased myocardial oxygen consumption decreased myocardial oxygen supply vasoconstriction (from SNS) arrhythmias prolonged QT increased Ve (CO2 is resp stimulant) activates H+/K+ pump - buffers CO2 acid in exchange for releasing K+ into plasma ionized calcium competes with H+ for binding sites on plasma proteins ⇒ acidosis causes the protein to buffer H+ and release calcium = increased inotropy increased CBF and volume = increased ICP CO2 activates the SNS and increases catecholamine release CO2 is resp stimulant
What is the Law of Laplace?
as the radius of a sphere or cylinder becomes larger, the wall tension increases as well Tension = pressure x radius for a cylinder (divide by 2 if a sphere)
describe signs and symptoms associated with Guillan Barre
ascending paralysis that is proceeding by influenza like illness Persists for about 2 weeks and ends with full recovery in about 4 weeks Flaccid paralysis begins in distal extremities and ascends bilaterally towards the proximal extremities, trunk and face Intercostal muscle weakness impairs ventilation Difficulty swallowing Paresthesia, numbness , pain ANS dysfunction Increased aspiration risk Upregulation of postjunctional adrenergic receptors → susceptibility to exaggerated response to indirect sympathomimetics
name the 4 types of glial cells in the CNS
astrocytes ependymal cells microglial oligodendrocytes
what are beta 1 selective blockers?
atenolol acebutolol betaxolol bisoprolol esmolol metoprolol (MABE AB)
halothane hepatitis is a ____________ response
autoimmune
what are causes of adrenal insufficiency?
autoimmune destruction of both adrenal glands HIV TB exogenous steroid administration, infection Surgery radiation
Pons
autonomic integration
what clinical scenarios stimulate the bainbridge reflex?
autotransfusion during childbirth, rapid IV administration
Factors that affect the spread of spinal anesthesia
baricity of LA patient position dose site of injection
what reflex is poorly developed in the neonate and fails to increase HR in the setting of hypovolemia?
baroreceptor
Optimally damped aline
baseline is established after 1 oscillation
Over damped aline
baseline is re-established w/ no oscillations SBP is underestimated, DBP is overestimated and MAP is accurate Caused by air bubbles or clots in pressure tubing or low flush bag pressure
Under-damped aline
baseline re-established after several oscillations SBP is overestimated, DBP is underestimated and MAP is accurate
which local anesthetics can produce methemoglobinemia?
benzocaine cetacaine EMLA cream prilocaine BECEP
what are some causes of aortic stenosis?
bicuspid valve calcification of valve leaflets rheumatic fever infective endocarditis
What do hepatocytes produce?
bile thrombopoietin alpha 1 acid glycoprotein factor VII
what are complications of TURP?
bladder perforation bleeding hypothermia TURP syndrome
NSAIDS and ASA mechanism of action
inhibit cycloxygenase
what is the treatment for thyroid storm?
block synthesis (PTU) block release (radioactive iodine) block T4-->3 (PTU, propranolol), beta blocker (esmolol, propranolol) active cooling glucocorticoids
what is drug clearance directly proportional to?
blood flow to the clearing organ extraction ratio drug dose
what electrolyte primarily regulates threshold potential?
calcium
Acetazolamide
carbonic anhydrase inhibitor
Dorzolamide
carbonic anhydrase inhibitor
what are signs and symptoms of hyperkalemia?
cardiac rhythm disturbances long PR peaked T wave flat p wave wide QRS sine wave VF
Bezold-Jarisch reflex
causes a paradoxical slowing of the HR in response to a round reduction in venous return, the heart slows to allow adequate fill time. bradycardia
what are type 2 pneumocytes?
cells in the lung that produce surfactant they are capable of producing type 1 pneumocytes, which are the cells that provide surface area for gas exchange
what are type 1 pneumocytes?
cells in the lung that provide surface for gas exchange
what are type 3 pneumocytes?
cells in the lungs that are macrophages to fight lung infection and produce an inflammatory response
what situations increase risk of PTX?
central line insertion peripheral nerve block shoulder arthroscopy radical neck dissection mastectomy axillary lymph node dissection mediastinoscopy laparoscopy nephrectomy chest trauma barotrauma
cerebral function declines when blood sugar is less than ________
cerebral function declines when blood sugar is less than 50
what are the five determinants of cerebral blood flow?
cerebral metabolic rate for oxygen cerebral perfusion pressure venous pressure PaCO2 PaO2
which local anesthetic undergoes the least amount of placental transfer?
chloroprocaine
what are signs and symptoms of esophageal atresia?
choking, coughing, and cyanosis during oral feeding
where is the site of CSF production?
choroid plexus
what are causes of left axis deviation?
chronic HTN, LBBB, AS, AI, MR
what neuromuscular blockers are classified as benzylisoquinolones
cisatracurium atracurium mivacurium CAM
what drugs are metabolized by Hoffman elimination?
cisatracurium atracurium (+Hoffman)
what plexus gives rise to the pudendal nerve?
coccygeal plexus
cerebral cortex
cognition sensation movement
esophageal atresia
congenital absence of part of the esophagus
aryepiglottic muscle
constricts laryngeal opening innervated by RLN AryepiglottiC = Arytenoids Close
Midbrain
contains auditory and visual tracts
Reticular Activating System (RAS)
controls arousal (wakefulness and alertness), consciousness and sleep RAS = Rest, Arousal,Sleep
how does stimulation of alpha 1 receptors affect coronary blood flow?
coronary vasoconstriction
what does hypocapnia do to coronary blood flow?
coronary vasoconstriction
how does stimulation of adenosine receptors affect coronary blood flow?
coronary vasodilation
what intrinsic muscles of the airway elongate (tenses) the vocal ligament?
cricothyroid muscle
what measures fibrin degradation products?
d-dimer
what causes a second degree heart block, type 2? what part of the conduction system is effective? what is the treatment if the pt is symptomatic?
d/t structural conduction defect or infection Affects bundle branches Atropine not effective Often symptomatic Use pacer
what causes a second degree heart block, type 1? what part of the conduction system is effective? what is the treatment if the pt is symptomatic?
d/t structural conduction defect, MI, BB, CCB, sympathy lyrics Affects AV node - longer, longer, longer drop then you have wenckebach If symptomatic give atropine
When V/Q = infinity, this area of the lung is called ______
dead space When you are dead, you are infinitely dead The larger the number, the more dead space Dead space = ventilation without perfusion
Anesthetic management for increased ICP
decrease CBF decrease CSF decrease cerebral edema decrease cerebral mass Avoid bucking and coughing
Causes of decreased ETCO2
decreased CO2 production and delivery to the lungs, increased alveolar ventilation, equipment malfunction Decreased BMR (decreased VO2) Increased anesthetic depth Hypothermia Decreased pulmonary blood flow Decreased CO Hypotension Pulmonary embolus VQ mismatch Med side effect Hyperventilation Inadequate anesthesia Metabolic acidosis if spontaneous ventilation Ventilator disconnect Esophageal intubation Poor seal w/ ETT or LMA Sample line leak Airway obstruction Apnea
describe the pathophysiology of Parkinson's Disease what are the treatment options?
decreased dopamine in the basal ganglia, increased GABA in the thalamus levodopa and carbidopa Selegiline = MAO B inhibitor... reduces dopamine metabolism. No risk of tyramine induced HTN crisis Dopamine agonists Anticholinergics
According to law of Laplace, LV wall stress is REDUCED by.... incr/decr intraventricular pressure incr/decr radius incr/decr wall thickness
decreased intraventricular pressure decreased radius increased wall thickness Wall stress = (intraventricular pressure x radius)/ventricular thickness
what conditions decrease stroke volume
decreased preload decreased contractility decreased serum calcium increased afterload
how does respiratory alkalosis affect cerebral blood flow?
decreases it
Amyotrophic lateral sclerosis (ALS)
degenerative disorder of motor neurons in the spinal cord and brainstem Causes progressive degeneration of motor neurons in the corticospinal tract
what does plasmin do?
degrades fibrin mesh converts fibrin to fibrin degradation products, measured by d-dimer
what does a BUN more than 20 mg/dL signify? more than 40?
dehydration high protein diet GIB hematoma breakdown trauma sepsis decreased GFR >40 = decreased GFR
what is the treatment for preeclampsia?
delivery of baby. Can be managed conservatively with bed rest.. No need for anti HTN meds if BP less than 160/110.. If greater, give meds to prevent CVA, MI and placental abruption
what is a myotome?
depicts the muscle innervated by the ventral root from the spinal cord
What is the Bohr effect?
describes how changes in acid (PCO2 or H) alter the carrying capacity of oxygen in the blood. It explains why hgb releases oxygen at the tissue level and binds oxygen in the lungs bOHr = Oxygen + Hgb
what causes hypernatremia?
diabetes insipidus impaired thrust sodium bicarb administration
diabetic ketoacidosis is usually caused by ____________
diabetic ketoacidosis is usually caused by an infection
what are early signs and symptoms of opioid withdrawal?
diaphoresis insomnia restlessness
What is transpulmonary pressure? is it negative or positive?
difference between alveolar pressure and intrapleural pressure Alveolar pressure - Intrapleural pressure Transpulmonary pressure is always positive during tidal breathing. It is ONLY negative during a forced expiration it is positive to keep the airways open
ETCO2 waveform in pt w/ single lung transplant
different time constants The first peak is alveolar gas from the transplanted lung.. It has a normal time constant The second peak is alveolar gas from the diseased lung.. Because air is trapped in the sick lung, there is a longer time constant during exhalation
describe the pathophysiology of alzheimers disease what is the treatment?
diffuse beta amyloid plaques and neurofibrillary tangles in the brain Treatment is aimed at restoring ACH concentration
what is the mechanism of action of propofol?
direct gaba agonist that increases chloride conductance and causes neuronal hyperpolarization
which sensory tract transmits information faster - dorsal column or spinothalamic tract?
dorsal column spinothalamic tract transmits sensory info ½ to ⅓ as fast as the dorsal column
what does the plateau of the dose response curve represent?
efficacy
cricothyroid muscle
elongates, tenses the vocal ligaments CricoThyroid =Cords Tense innervated by external SLN
Amygdala
emotion appetite responds to pain and stress Amy is emotional and eats when she is stressed
What is the conus medullaris and where is it located?
end of the spinal cord L1
what are causes of mitral stenosis?
endocarditis calcification of the mitral annulus (atherosclerosis) rheumatic fever RA SLE congenital
The placenta normally implants into the ______________ of the uterus
endometrium
how does hemodialysis help treat hyperkalemia?
enhances K+ elimination
how does lasix help treat hyperkalemia?
enhances K+ elimination
how does volume resuscitation help treat hyperkalemia?
enhances K+ elimination
Remi contains an _______ linkage, so it's susceptible to hydrolysis by erythrocyte and tissue esterases
ester
Cocaine
ester type LA that inhibits NE reuptake into presynaptic SNS neuron... flooding synaptic cleft with NE increases SNS tone
what drugs does non specific esterases metabolize?
etomidate (+hepatic) esmolol remifentanil atracurium (+Hoffman)
what are causes of hypermagnesemia?
excessive administration RF adrenal insufficiency
Postpneumonectomy pulmonary edema risk factors
excessive hydration PIP > 25 right lobectomy or pneumonectomy
what are causes of rebreathing CO2?
exhausted CO2 absorbent incompetent expiratory valve hole in the inner tube of a Bain system inadequate FGF w/ Mapleson circuit
what nerve innervates the cricothyroid muscle?
external SLN
what can cause BILATERAL RLN injury?
external pressure from an airway device thyroid or parathyroid surgery tumor
microglial cells
extremely small glial cells that remove cellular debris from injured or dead cells
what do A delta fibers mediate?
fast pain temperature touch
in general, which gender do opioids have greater analgesic potency, slower onset of action, longer duration of action, and lower postop opioid consumption
female
give examples of drugs with high hepatic extraction ratio
fent, lido, metoprolol
Urokinase
fibrinolytic
tPA
fibrinolytic
paracerivcal block is best for which stage of labor? what is a risk that comes with paracervical block?
first stage of labor high risk of fetal bradycardia
what is treatment for SIADH?
fluid restriction hypertonic saline demeclocylcine - decreases responsiveness to ADH
what is the name of the pathway in the brain that is between the lateral third ventricle?
foramen of monro
give 3 examples of loop diuretics
furosemide, bumetanide, ethacrynic acid
the wave of depolarization throughout the cardiac myocyte is transferred via what?
gap junctions
Scopolamine, atropine and glyco all equally decrease _______
gastric H secretion
compare and contrast gastrochisis and omphalocele
gastrochisis is associated with prematurity, omphalocele is associated with trisomy 21 gastrochisis is only abdominal contents with no sac covering, omphalocele may be bowel and liver covered with sac omphalocele is not as much of a surgical emergency as gastrochisis gastrochisis location is to the right of the umbilicus and omphalocele is in the center
Astrocytes
glial cell Astrocytes provide metabolic support to the neurons
Ependymal cells
glial cell involved in CSF production
what is the name of the enzyme that conjugates bilirubin? what else does this enzyme metabolize?
glucuronyl transferase acetaminophen
what is the name of the neurotransmitter that stimulates NMDA receptor?
glutamate
what is drug clearance inversely proportional to?
half life drug concentration in the central compartment
if pulmonary rupture occurs when floating a PAC, what is the classic presentation?
hemoptysis
what are the most common serious complications of mediastinoscopy? what other complications can occur?
hemorrhage and PTX chylothorax (thoracic duct injury) left recurrent laryngeal nerve injury innominate artery compression (decreased carotid blood flow and cerebral blood flow) air embolism
what are the name of the cells that produce bile?
hepatocytes
Omphalocele
herniation at the umbilicus (a part of the intestine protrudes through the abdominal wall at birth) The defect will involve the bowel but sometimes the liver too
what is the P50 of fetal hgb vs adult hgb?
hgbF has a P50 value of 19 mmhg which is lower than the adult's which is 26.5 mmhg
what causes increased rate of rise of FA/FI
high FGF high alveolar ventilation low FRC decreased time constant decreased anatomic dead space low solubility low CO low Pa-Pv increased alveolar ventilation
highest incidence of preterm labor occurs with which surgery in the parturient?
highest incidence = intraabdominal and pelvic surgery
what is the BEST predictor of bleeding during surgery?
history and physical
how does SLN injury present?
hoarseness the vocal cords cannot be tensed by the cricothyroid muscle
what are side effects of anticholinergics?
hot as hare, blind as a bat, mad as a hatter, red as a beet, dry as a bone..... Can't SEE PEE SHIT SPIT!!! Mydriasis → pupil dilation (when you're crazy, mad as a hatter, your eyes get BIG) BRONCHODILATION! (ANTIcholinergics are ANTI bronchospasm) Anticholinergics are the rhymes... rhymes are weird... we are ANTI rhymes
how does hypercalcemia affect threshold potential?
hypercalcemia INCREASES TP
what are the side effects associated with using sorbitol for TURP procedure?
hyperglycemia Osmotic diuresis Lactic acidosis
what are complications of thiazide diuretics?
hyperglycemia hypercalcemia hyperuricemia hypokalemia hypochloremic metabolic alkalosis hypovolemia HLD sexual dysfunction
what are complications of K+ sparing diuretics?
hyperkalemia metabolic acidosis gynecomastia libido changes nephrolithiasis
how does hyperkalemia affect the ventricular resting membrane potential?
hyperkalemia INCREASES RMP (RMP becomes less negative) When serum potassium increases, RMP becomes MORE POSITIVE (less negative and the myocyte is EASIER to depolarization
what are causes of hypercalcemia?
hyperparathyroidism cancer thyrotoxicosis thiazide diuretics immobilization
what are signs and symptoms of serotonin syndrome?
hyperthermia mental status changes hyperreflexia seizures death
what factors cause CMRO2 to increase?
hyperthermia seizures ketamine N2O
what electrolyte disturbances prolong QT interval?
hypokalemia hypomagnesemia
how does hypokalemia affect the ventricular resting membrane potential?
hypokalemia DECREASES RMP (RMP becomes more negative) When serum potassium decreases, RMP becomes MORE NEGATIVE and the myocyte is MORE RESISTANT to depolarization
what are causes of hypocalcemia?
hypoparathyroidism vitamin D def renal osteodystrophy pancreatitis sepsis
what are prerenal causes of AKI?
hypoperfusion Due to hypovolemia, decreased CO, systemic vasodilation, renal vasoconstriction, or increased intraabdominal pressure
what are side effects of protamine?
hypotension (histamine release) pulmonary HTN allergic reaction (NPH insulin, fish allergy)
what factors will decrease CMRO2?
hypothermia halogenated anesthetics propofol etomidate barbiturates
complications of loop diuretics
hypovolemia ototoxicity reduced lithium clearance
consequences of respiratory acidosis
hypoxemia increased P 50 cardiac and smooth muscle depression SNS stimulation increased alveolar ventilation increased K concentration increased calcium concentration increased ICP depressed LOC
what are signs and symptoms of methemoglobin?
hypoxia cyanosis chocolate colored blood tachycardia tachypnea mental status changes coma and death
consequences of uremia on the CNS/ANS in those with CKD
impaired nerve conduction ANS dysfunction - reduced baroreceptor reflex, delayed gastric emptying Sensory and motor peripheral neuropathy
alpha 2 antiplasmin
inactivates plasmin Alpha 2 antiplasmin inhibits the action of plasmin on fibrin
Plasminogen
inactive precursor of plasmin Fibrinolytic
what factors cause a slower rate of rise of FA/Fi?
increased CO increased FRC decreased FGF decreased alveolar ventilation increased anatomical dead space high gas solubility high CO high Pa-Pv difference high time constant
Atropine is best for .....
increased HR sedation (not as much as scopolamine) antisialagogue (not as much as scopolamine or glyco) mydriasis (not as much as scopolamine) preventing nausea (not as much as scopolamine)
how does increased atm pressure affect boiling point?
increased atm pressure = increased BP
how does the following change in the elderly? lean body mass BMR total body water blood volume plasma volume body fat
increased body fat decreased lean body mass decreased BMR decreased total body water decreased blood volume decreased plasma volume
Hyperalgesia
increased sensitivity to pain
As pka gets farther away from physiologic pH, the degree of ionization ________
increases
what are unique considerations about thiazide diuretics
increases calcium reabsorption and calcium concentration can cause hyperglycemia
how does respiratory acidosis affect cerebral blood flow?
increases it
what causes acute pericarditis?
infection SLE scleroderma trauma radiation for cancer.
give 3 examples of glycoprotein IIb/IIIa antagonists how do these drugs work?
inhibit plt aggregation via surface receptors Tirofiban Eptifibatide Abciximab
glycine channels are inhibitory or excitatory?
inhibitory
How does unfractionated heparin work?
inhibits IIa by binding to ATIII
what are the most sensitive indicators of recovery from NMB? what is the max % of receptors blocked for these tests?
inspiratory force better than -40 cm H2O hand grip same as pre induction head lift >5 seconds holding tongue blade against force The MAX % of receptors blocked at this point is 50%
what can extracellular fluid volume be further divided into?
interstitial and plasma fluid 60/40/20/15/5 Water, intracellular, extracellular, interstitial, plasma WIEIP
what can total body water be further divided into?
intracellular and extracellular fluid 60/40/20/15/5 Water, intracellular, extracellular, interstitial, plasma WIEIP
what factors abolish cerebral autoregulation?
intracranial tumors head trauma volatile anesthetics
A basic drug will be highly _________ in an acidic pH
ionized
How does LMW heparin work?
irreversibly inhibits IIa and Xa
what volatile anesthetic preserves hepatic blood flow the best?
isoflurane
why hyperventilate someone with hyperkalemia?
it shifts K+ into the cells
what part of the body produces the hormone renin?
juxtaglomeular apparauts of the kidneys
what two drugs will increase BIS value?
ketamine and N2O Most anesthetic lower frequency and increase amplitude
cricothyrotomy contraindications
kids, because they have more pliable and mobile laryngeal and cricoid cartilage AND the thyroid isthmus covers the CTM
what drugs will impair the baroreceptor reflex?
labetalol, sevoflurane, propofol (variable)
Re < 2000
laminar flow
what are the 2 subsets of the first stage of labor?
latent phase 0-4 cm active phase 4-10 cm
Where is angiotensinogen produced?
liver
Where is plasminogen synthesized?
liver
what situations decrease albumin levels
liver disease renal disease old age malnutrition pregnancy
where are the central chemoreceptors located and what do they do?
located in the medulla and responds to PaCO2 AND PO2. it is stimulated by the pH of the CSF Bicarb doesn't diffuse across BBB, so it does not acutely affect the central chemoreceptor Increased PCO2 will increased [H+] concentration in CSF and increase Ve
Bumetanide
loop diuretic
Ethacrynic acid
loop diuretic
what are signs and symptoms of hypermagnesemia?
loss of deep tendon reflexes resp depression cardiac arrest heart block
the higher the MAC, the ______ the potency
lower
where does extrahepatic clearance of propofol occur?
lungs
what equation allows you to predict how long your vaporizer agent will last?
mL of liquid anesthetic used per hr = vol % x FGF LPM x 3
Cerebellum
maintains equilibrium, regulates muscle tone, coordinates voluntary muscle movement bells move back and forth
what is the V3 branch of the trigeminal nerve called and what does it innervate?
mandibular sensory to anterior 2/3 of tongue
give 3 examples of osmotic diuretics
mannitol, glycerin, isosorbide
what is the V2 branch of the trigeminal nerve called and what does it innervate?
maxillary sensory to turbinates and septum
Hippocampus
memory and learning youll remember it if you see a hippo on a campus
what factors increase risk of uterine atony?
multiparity multiple gestations polyhydramnios prolonged oxygen infusion prior to surgery
what conditions are associated with reduced myocardial compliance?
myocardial hypertrophy, fibrosis and aging These pts are more likely to experience reduce CO w/ rhythm disturbances (junctional, afib)
coarctation of the aorta (CoA)
narrowing (coarctation) of the aorta Occurs when the aorta narrows in the area of the ductus arteriosus Since the aorta is narrowed, the LV must generate a higher pressure to overcome the increased aortic resistance Severe narrowing can limit the amount of blood delivered to the lower half of the body
what are signs and symptoms of hypercalcemia?
nausea abd pain HTN psychosis mental status changes seizure short QT
what is the functional unit of the kidney?
nephron
what are treatment options for vasospasm?
nimodipine + triple H therapy (hemodilution to 30 hct, hypervolemia, HTN) Frequent neuro exams w/ transcranial doppler
latent heat of vaporization
number of calories needed to convert 1 g of liquid into a vapor w/o a temp change
What are the post-renal causes of AKI?
obstruction
Addison's disease
occurs when the adrenal glands do not produce enough of the hormones cortisol or aldosterone Addison's disease is usually the result of adrenocortical insufficiency
how should you position the cylinder when changing it if there is no holder?
on its side
what is the V1 branch of the trigeminal nerve called and what does it innervate?
ophthalmic sensory to anterior 1/3 of nasal septum
what drugs are NOT associated with apoptosis?
opioids dexmedetomidine xenon
cranial nerve II
optic nerve sense of vision only nerve surrounded by dura
Glycerin
osmotic diuretic
Isosorbide
osmotic diuretic
Mannitol
osmotic diuretic
are vaporizers in or out of circuit
out
what does a BUN less than 8 mg/dL signify?
overhydration malnutrition severe liver disease
what is the first device in the anesthesia machine that would be the first to detect a pipeline cross over?
oxygen analyzer
what are causes of non gap metabolic acidosis?
pH < 7.35 and anion gap < 14 Mnemonic = HARDUP Hypoaldosteronism acetazolamide renal tubular acidosis diarrhea ureterosigmoid fistula pancreatic fistula
what are causes of anion gap metabolic acidosis?
pH < 7.35 and anion gap > 14 Mnemonic = MUDPILES Methanol uremia diabetic ketoacidosis paraldehyde isoniazid lactate (decreased DO2, sepsis, cyanide poisoning) ethanol ethylene glycol salicylates (inhibit krebs cycle)
what are triggers of sickle cell disease?
pain dehydration hypoxemia acidosis hypothermia
Murphy's sign
pain with palpation of the RUQ during inspiration, indicative of cholecystitis
placenta percreta
perforation of uterus by placenta Placenta percreta =when it extends beyond the uterus
What is a shunt?
perfusion without ventilation
where specifically in the brain are opioid receptors located?
periaqueductal gray locus coeruleus rostral ventral medulla
which route of local anesthetic administration is LAST most frequently associated with?
peripheral nerve blocks
what enzyme metabolizes cAMP?
phosphodiesterase III
which acetylcholinesterase inhibitor can be used to treat post op shivering?
physostimine, since it crosses BBB
what is the organ of respiration in the fetus?
placenta
Placenta previa
placenta attaches to the lower uterine segment and partially or completely covers the cervical os Potential for hemorrhage Often requires CS
Placenta increta
placenta penetrates into myometrium Placenta increta = when it invades myometrium
von Willebrand factor
plasma protein secreted by endothelial cells; facilitates adherence of platelets to damaged vessel wall Procoagulant
Protein C
plasma protein that inhibits clotting Anticoagulant
Fibrinogen
plasma protein that is converted to fibrin in the clotting process Procoagulant
Aminocaproic acid
plasminogen activator inhibitor
what can be used to reverse clopidogrel?
plt transfusion
Glyoc does not pass the BBB because it is a ______________
quaternary ammonium
what are causes of hypomagnesemia?
poor intake alcohol abuse diuretics critical illness common with hypokalemia
what are physiologic consequences that occur in the neonate with CDH? pulmonary PVR airway
poor pulmonary vascular development increased pulmonary vascular resistance pulmonary HTN impaired airway development and airway reactivity
where does the third order neuron of the dorsal column sensory pathway synapse in the brain?
post central gyrus in parietal lobe
what does the internal branch of the SLN innervate?
posterior side of the epiglottis to the top side of the vocal folds (sensory)
what electrolyte primarily determines resting membrane potential of the ventricular myocyte?
potassium
Amiloride
potassium sparing diuretic Amiloride and triamterene inhibit K secretion and sodium reabsorption in the CD.. their function is INDEPENDENT of aldosterone
Triamterene
potassium sparing diuretic Amiloride and triamterene inhibit K secretion and sodium reabsorption in the CD.. their function is INDEPENDENT of aldosterone
Spironolactone
potassium sparing diuretic Spironolactone is an aldosterone antagonist... it inhibits K secretion and sodium reabsorption in the CD
what populations have decreased concentration of alpha 1 acid glycoprotein?
pregnancy and neonates
what are the two types of nicotinic receptors located at the NMJ?
prejunctional Nn receptors on the presynaptic nerve and the Nm at the motor end plate The postsynaptic nicotinic receptor Nm is a pentameric ligand gated ion channel located in the motor end plate at the NMJ. it is comprised of 5 subunits that align circumferentially around an ion conducting pore
gastrochisis is highly associated with ___________
prematurity Other congenital anomalies are rare
Vapor pressure
pressure exerted by a vapor in equilibrium with its liquid or solid phase inside of a closed container Directly proportional to temperature Increased temp = increased VP
what is alveolar pressure? is it negative or positive?
pressure inside the lungs Alveolar pressure is negative with inspiration and positive with expiration. With no airflow, its zero.
what is intrapleural pressure? is it negative or positive?
pressure within the pleural cavity Intrapleural pressure is always negative, it is ONLY positive during a forced expiration the negative pressure keeps the lungs inflated
risk factors for the development of placenta previa
previous CS, multiple births
where specifically in the spinal cord are opioid receptors located?
primary afferent neurons in dorsal horn the interneurons
Hypothalamus
primary neurohormonal organ
what clinical scenarios will stimulate the bezold jarisch reflex?
profound hypotension massive hemorrhage CA under spinal anesthesia shoulder arthroscopy + PNB + sitting
what 3 pathways promote renal vasodilation?
prostaglandins ANP dopamine receptors
what enzyme metabolizes 2-chloroprocaine?
pseudocholinesterase
How are ester local anesthetics metabolized?
pseudocholinesterase Pseudocholinesterase def increases DOA cocaine is also metabolized by the liver
Ductus arteriosus
pulmonary artery → proximal descending aorta Lower oxygen blood bypasses the lungs and is delivered to the lower body
what conditions reduce FRC?
pulmonary edema obesity general anesthesia pregnancy neonates supine lithotomy Tburg paralysis inadequate anesthesia excessive IVF high FiO2 reduced pulmonary compliance
Dexamethasone
purely Corticosteroid
betamethasone
purely Corticosteroid
triamcinolone
purely corticosteroid
during mediastinoscopy, how should you monitor for innominate artery compression?
put pulse ox or arterial line on the RIGHT SIDE and place NIBP cuff on the left arm to measure BP if compressed
what are risk factors for laryngospasm?
recent URI exposure to second hand smoke reactive airway disease GERD less than 1 yr old light anesthesia w/ concurrent airway manipulation saliva or blood in the upper airway hyperventilation hypocapnia surgical procedures involving the airway
what is the most common cause of increased dead space?
reduced CO/hypotension
what factors increase renin release?
reduced renal perfusion SNS beta 1 activation decreased sodium and chloride delivery to the distal tubule
vocalis muscle
relaxes, shortens the vocal ligaments VocaLis = Vocal cords reLax innervated by RLN
How does PNS decrease HR?
release ACh, ACh binds to muscarinic receptors, decrease Na+ permeability and increases K+ permeability (takes much longer to reach threshold, lower RMP) PNS via ACh slows HR by increasing potassium conductance and hyperpolarizing the SAN. this decreases resting membrane potential and reduce the rate of spontaneous phase 4 depolarization
How does the SNS increase HR?
release NE, NE binds to beta1 receptors, increase activity of F-type Na+ channels (reaches threshold quicker) SNS stimulation via NE increases HR by increasing sodium and calcium conductance.. This increases the rate of spontaneous phase 4 depolarization
what are causes of hyperkalemia?
renal failure K+ sparing diuretics acidosis sux tumor lysis
what hormone is produced by the juxtaglomerular appartus?
renin
what is the treatment for hypernatremia?
restore sodium balance by manipulating serum osmolality and fluid balance with sodium restriction IVF selection based on tonicity diuretics
what is the treatment for hyponatremia?
restore sodium balance with water restriction IVF selection based on tonicity diuretics
what is the treatment for TURP syndrome when sodium is > 120? <120?
restrict fluids and give lasix if na > 120... if less than 120 give 3% saline at < 100 m/hr and dc when Na is greater than 120
what are consequences of fluid overload associated with CKD?
restrictive ventilatory defect HF pulmonary edema
Foramen ovale
right atrium → left atrium Oxygen rich blood bypasses the lungs and is preferentially delivered to the heart and developing brain
what does a right shift of the CO2 response curve mean? what factors cause a right shift of the CO2 response curve?
right shift means resp center is LESS sensitive to CO2 s/p carotid endarterectomy and sevo, opioids, metabolic alkalosis
what are the side effects associated with using NS for TURP procedure?
risk of electrocution Can only be used with bipolar electrocautery
what neuromuscular blockers are classified as aminosteroid?
rocuronium vecuronium pancuronium
Acute hemolytic reaction signs/symptoms treatment
s/sx = hemoglobinuria, hypotension, bleeding, fever, chills, CP, dyspnea, nausea, flushing Can cause RF, DIC, HD instability Tx = stop infusion, maintain UO w/ fluids, alkalize urine w/ sodium bicarb, sens urine and plasma hgb samples to the blood bank, check plts, PT, fibrinogen, send unused blood to blood bank and double check cross match, support HD
TACO - transfusion associated circulatory overload
s/sx = pulmonary edema, hypervolemia, LVF, MR, increased PAOP, increased BNP
Scopolamine is best for ......
sedation antisialagogue mydriasis nausea prevention
where specifically in the periphery are opioid receptors located?
sensory neurons immune cells
What does the RLN innervate?
sensory to below the level of the vocal cords to the trachea motor for all of the intrinsic muscles of the airway EXCEPT the cricothyroid muscle
What does the trigeminal nerve innervate?
sensory to most of the head by the 3 branches and motor to the muscles of mastication sensory to the nares, anterior ⅓ of septum, turbinates, and anterior ⅔ of tongue V1 = ophthalmic V2 = maxillary V3 = mandibular V1,2,3 = OMM (top to bottom of face) oh max man
What does the glossopharyngeal nerve innervate?
sensory to soft palate, oropharynx, tonsils, posterior 1/3 of tongue, VALLECULA, ANTERIOR side of the epiglottis, afferent limb of the GAG reflex Think trigeminal in the front, glossopharyngeal in the back
who is at risk for DIC
sepsis OB - preeclampsia, placenta abruption, AFE malignancy - adenocarcinoma leukemia and lymphoma
What is a tet spell?
severe hypoxia due to almost total occlusion of the RV outflow tract Presents as hypoxemia and cyanosis Stress increases myocardial contarcitly and may cause spasm of the intravalvular region of the RVOT
why give albuterol to treat hyperkalemia?
shifts K+ into the cells
Describe West zone 3
shunt Arterial pressure > venous pressure > Alveolar pressure
When V/Q = zero, this area of the lung is called ______
shunt You cannot divide by zero (Q is on the bottom) PerFUSHi0n without ventilation The smaller the number, the more shunt Shunt = perfusion without ventilation
Cushing's Triad
sign of intracranial HTN HTN, bradycardia, irregular respirations Increased ICP reduces CPP... in an effort to preserve cerebral perfusion, HTN occurs, activated baroreceptor reflex = bradycardia, compression of medulla = irregular respiration
what do A alpha fibers mediate?
skeletal muscle motor propioception
what are signs and symptoms of hypokalemia?
skm cramps weakness paralysis worsen digoxin toxicity short PR interval long QT interval flat t wave u wave
what are signs and symptoms of hypomagnesemia?
skm weakness arrhythmias (torsades) long QT
how does acidosis affect Hoffman elimination?
slows it down
how does hypothermia affect Hoffman elimination?
slows it down
how does alkalosis affect Hoffman elimination?
speeds it up
how does hyperthermia affect Hoffman elimination?
speeds it up
cranial nerve XI
spinal accessory motor - shoulder shrug
give 3 examples of K+ sparing diuretics
spironolactone, amiloride, triamterene
what is the OB risks associated with maternal cocaine abuse
spontaneous abortion premature labor placental abruption low apgar score
Anticholinesterases not only inhibit the enzyme that metabolizes ACh, but it also ......
stimulates the presynaptic receptor to cause even more ACh release
DDAVP
stimulates vWF tissue release
Excretion
substance is removed from the body in the urine
PTX signs and symptoms
sudden hypoxia increased airway pressures absent breath sounds on the affected side tracheal shift away from infected side asymmetric CW movement tachycardia hypotension extreme anxiety if awake agitation
All opioid receptors (mu,delta,kappa) cause which two effects and/or side effects?
supraspinal and spinal analgesia Respiratory depression
what situations will increase the concentration of alpha 1 acid glycoprotein?
surgical stress MI chronic pain RA advanced age
what drugs does pseudocholinesterase metabolize?
sux mivacurium ester LA - procaine, tetracaine, chloroprocaine, cocaine (+hepatic)
which neuromuscular blocker most commonly causes anaphylaxis
sux> atracurium > cisatracurium > rocuronium > vecuronium
Prostaglandin I2
synthesized by endothelial cells; vasodilator, inhibits platelet aggregation Prostaglandin I2 inhibits vWF adherence, TxA2 activation, and release of storage granules
once the clot is degraded, the body turns off the fibrinolytic process. how does the body do this?
tPA inhibitor inhibits the conversion of plasminogen to plasmin Alpha 2 antiplasmin inhibits the action of plasmin and fibrin
tPA inhibitor
tPA inhibitor inhibits the conversion of plasminogen to plasmin prevents bleeding by preventing clot break down this is how Amicar works
tPA must be given within how many hours of the onset of sytmpoms?
tPA must be given within THREE hours of the onset of symptoms tPA has 3 letters....3 hrs
CV risks with cocaine abuse
tachycardia, arrhythmia, MI Chronic use is associated with thrombocytopenia
What structures make up the diencephalon?
thalamus and hypothalamus
What is renal autoregulation? what are the limits of renal autoregulation?
the ability of the nephrons to adjust their own blood flow and GFR without external (nervous or hormonal) control When renal perfusion is too low, RBF is increased by reducing renal vascular resistance and vice versa Renal autoregulation occurs between 50 and 180 mmhg
what is the minimum effective concentration (Cm) of a local anesthetic? what does it mean when fibers have a lower Cm? higher?
the concentration of local anesthetic that is required to block conduction (analogous to ED50) Fibers that are more EASILY blocked have a LOWER Cm Fibers that are more RESISTANT to LA blockade have a HIGHER Cm
what parts of the airway comprise the "conducting zone"?
the conducting zone is the part of the airway that is anatomic dead space it extends from the mouth to the terminal bronchioles
the cords of the brachial plexus are named according to their relationship to the ___________ artery
the cords are named according to their relationship to the axillary artery
what does the external brach of the SLN innervate?
the cricothyroid muscle (motor)
Efficacy
the intrinsic ability of a drug to elicit a given clinical effect y axis of dose response curve
What is closing capacity?
the lung volume above residual volume where the small airways begin to collapse during expiration it is the sum of the closing volume and residual volume When Closing capacity is > FRC VQ mismatch occurs
hydrostatic pressure
the pressure within a blood vessel that tends to push water out of the vessel
what parts of the airway comprise the "respiratory zone"?
the respiratory zone is the part of the airway that participates in gas exchange it extends from the respiratory bronchioles to the alveoli
Secretion
the substance is transferred from the peritubular capillaries to the tubule
Reabsorption
the substance is transferred from the tubule to the peritubular capillaries
Boiling point
the temperature at which VP = atm pressure increased atm pressure increases boiling point
what intrinsic muscles of the airway shorten (relaxes) the vocal ligament?
the vocalis and the thyroarytenoids VocaLis = Vocal cords reLax ThyroARytenoid = they adduct and relax
Chlorthalidone
thiazide diuretic
what are signs and symptoms of hypernatremia?
thirst mental status changes seizures coma cerebral dehydration (cell shrinkage)
why should you NOT oil a cylinder valve?
this increases the chances of fire
why does a kid with a TET spell squat?
this kinks the arteries in the groin and in turn increases SVR, reduces right to left shunt, and improves oxygenation
what can cause LEFT sided RLN injury?
thoracic tumor PDA ligation LA enlargement (MS) aortic arch aneurysm
what is the Vt/Vd ratio? what is its numeric value?
tidal volume/dead space ratio is the fraction of the tidal volume that contributes to dead space 150/450 = 0.33
What converts plasminogen to plasmin?
tissue plasminogen activator (tPA)
where is the usual location of gastrochisis?
to the right of the umbilicus
what do A beta fibers mediate?
touch pressure
what are the side effects associated with using glycine for TURP procedure?
transient blindness Increased ammonia → decreased LOC
Re 2000-4000
transitional flow
what is triple H therapy
treatment for vasospasm hemodilution to 30 hct, hypervolemia, HTN Liberal hydration supports BP Hemodilution reduces blood viscosity and SVR Increased BP + decreased viscosity improves cerebral blood flow
what is the treatment for Conn's syndrome?
tumor removal aldosterone antagonist like spironolactone K supplements and sodium restriction
Re > 4000
turbulent flow
what drugs can be hepatotoxic?
tylenol, amio, tetracycline, abx - PCN, sulfa
when the fetus is transitioning to extrauterine life, what causes the ductus venosus to close?
umbilical cord clamping
Hypoplastic Left Heart Syndrome
underdevelopment of the left side of the heart, usually resulting in an absent or nonfunctional left ventricle and hypoplasia of the ascending aorta Single ventricle lesion Requires Fontan procedure for correction
how does a unilateral RLN injury present? bilateral?
unilateral RLN injury results in paralysis of the ipsilateral vocal cord ABductors. this does not cause respiratory distress bilateral RLB injury results in bilateral paralysis of the vocal cords and causes stridor and respiratory distress ** chronic injury is well tolerated Preventing injury of the RLN is Really IMPORTANT!
what are contraindications to TTJV?
upper airway obstruction laryngeal injury
what is the primary metabolite of protein metabolism?
urea
what is the rule of 15s when it comes to LMA use with laparoscopy?
use < 15 degree tilt < 15 cm H2O intraabdominal pressure less than 15 min insufflation
Methergine what is the dose? in whom should it be avoided?
used in postpartum to prevent hemorrhage (may cause HTN) 0.2 mg IM IV administration results in severe HTN, esp in the with preeclampsia Uterotonic - increases contractility -Second line
APGAR score what does 1 and 5 min scores correlate with? what is normal score, moderate distress and impending demise? what is assessed?
used to assess newborn and guide resuscitation The score at 1 minute correlates with fetal acid base status The score at 5 minutes score may be predictive of neuro outcomes Normal is 8-10 Mod distress = 4-7 Impending demise = 0-3 Think of test scores** 0,1, or 2 points for 5 things → HR, RR, muscle tone, reflexes, color Perfect score = HR greater than 100, normal crying, active motion, cough, sneeze, cry, completely pink
what is the most common cause of post partum hemorrhage?
uterine atony
what are causes of post partum hemorrhage?
uterine atony retained placenta DIC uterine inversion coagulopathy
which cranial nerve is responsible for 75% of all of the parasympathetic nervous system activity?
vagus
the plasma concentration of local anesthetic is the net balance between what 2 things? what factors influence this?
vascular uptake relative to redistribution and metabolism Plasma protein binding helps limit the peak plasma concentration increased/faster metabolism decreases plasma concentration A vasoconstrictor decreases systemic absorption by up to ⅓ and also prolongs the duration of action
what is the leading cause of morbidity and mortality after a subarachnoid hemorrhage?
vasospasm
What is dead space? how does dead space affect alveolar ventilation?
ventilation without perfusion gas that does not participate in gas exchange Anything that increases dead space decreases alveolar ventilation
what agents impair hypoxic pulmonary vasoconstriction?
volatile anesthetics vasodilators PDE inhibitors dobutamine CCB Vasoconstrictive drugs may constrict well oxygenated vessels and increase shunt flow Hypervolemia and increase CO may distend constricted vessels and also increase shunt flow Excessive PEEP or high tidal volumes will increase dead space (zone 1) and reduce optimal VQ matching
Factors that affect the spread of epidural anesthesia
volume
What is alveolar ventilation? what is the relationship to CO2 production and PaCO2?
volume of air that reaches the respiratory zone (tidal volume - dead space) x RR Directly proportional to CO2 production, inversely proportional to PaCO2
What is drug clearance?
volume of plasma cleared of drug per unit time
frontal lobe of brain
voluntary muscle control and storage of those memories To Front is an action
what are causes of hypokalemia?
vomiting diarrhea NG suction kayexalate diuretics metabolic alkalosis beta 2 agonists insulin alkalosis
Describe West zone 2
waterfall Arterial pressure > Alveolar pressure > venous pressure
Pharmacokinetics
what the body does to the drug study of relationship between drug dose and plasma concentration
Pharmacodynamics
what the drug does to the body study of relationship between effect site concentration and clinical effect
when comparing the bronchial blocker and the DLT: which can prevent contamination? which can be used to suction secretions from the isolated lung? provide ventilation to an isolated lung? provide lung separation for kids less than 8 years old? provide lung separation for nasal intubation? allow oxygen insufflation into the isolated lung?
which can prevent contamination --> DLT which can be used to suction secretions from the isolated lung --> DLT provide ventilation to an isolated lung --> DLT provide lung separation for kids less than 8 years old -> BB provide lung separation for nasal intubation --> BB allow oxygen insufflation into the isolated lung --> both DLT and BB
how long does it take angiotensin II and aldosterone to take effect?
while the sodium retaining effect of angiotensin II is almost immediate, there is a 1-2 hr delay from aldosterone release to physiologic effect
in the pt attached to the anesthesia machine, dead space ends at the _________
y piece