CA-2 year/ITE 2022 [1557] by John_Yousef
2/2-uteroplacental issues. 1.) If hypotensive give fluid bolus/pressors 2.) Place in lateral position or hands/knees 3.) D/C utrerotonics 4.)Tocolytics +/- -if all fail-->c-section.
Late decel management:
>10. -If too high, give calcium chloride or clacium gluonate.
Levels above what can cause arrythmias and mycocardial depression?
Increased pre-synaptic Ca2+ = a more than normal increase in ACH release (temporary) = antagonize the roc on the post-synaptic receptors.
MOA of Post-tetanic twitch?
Magnesium sulfate is administered in preeclamptic patients in order to prevent seizure activity through NMDA antagonism within the CNS
MOA of magensium for pre-E patients?
irreversibly oxidize the cobalt atom of vitamin B12 to an inactive state. This inhibits methionine synthetase and prevents the conversion of methyltetrahydrofolate to tetrahydrofolate, which is required for DNA synthesis
MOA of nitrous causing decrease DNA synthesis?
-competes with calcium, preventing the actin-myosin cross-linking. -decreases NO & PGI2 in endothelial cells.
Mechanism by which magnesium decreases BP in OB pt. who is pre-eclamptic?
Meperidine has structural similarities to atropine and some weak local anesthetic effects.
Meperidine works on Kappa receptors. Besides opioid properties, what other drugs does it represent?
Esophagus ends in a blind proximal pouch with the distal end of the esophagus connected to the trachea (usually posteriorly) just above the carina.
Most common form of a Tracheal-Esophageal Fistula?
: Common side effects of ondansetron include QTc prolongation (20%, very rarely clinically significant), headache (11%), transient AST/ALT increases (5%), constipation (4%), rash (1%), flushing/warmth (< 1%), and dizziness (< 1%). Recommended to keep IV max dose <16 mg.
Most common side-effects from Zofran and what is the recommended maximum single IV dose?
n presenting signs are fetal bradycardia, followed by change in uterine contraction pattern (often with complete loss of a tocometer tracing), and pain.
Most common sign of uterine rupture?
NHFTA = Patient Antibodies attacking donor WBC = cytokine release. Acute Hemolytic Anemia = Pt. antibodies attack A or B antibody. Coombs test. TRALI = Donor antibodies against patient's leucocytes = inflammatory response in the lungs. Decreased by restricting child-bearing females from donating plasma.
Non-hemolytic febrile transfusion reactions MOA? Acute Hemolytic Anemia MOA? TRALI
1.) back up power supply. 2.) Recommended for the ansesthesiologist to be present in the intra-op period. 3.) Prior to discharge, patients must be evaluated. 4.) sufficent staff trained in ACLS and PALS must be avaible. 5.) protocol for transfer to another facility in the event that it's needed.
Office-based anesthesia has a higher complication rate than ambulatory surgical center. What are some requirements that the ASA mandates for office-based anesthesia?
-median-9 o'clock position, antero-lateral. -radial-6'oclock position, most posterior and located closest to the humurus. -ulnar nerve-3'oclock position, antero-medial. -muskoskeletal nerve is outside the seath and missed during an axillary nerve block.
Orientation of the axillary sheath for an axillary nerve block? -median -radial -ulnar
First-T10-L1 dermatomes. | Afferents travel with the sympathetic fibers to the spinal cord. Paracervical, Hypogastric Plexus Second stage-S2-S4 dermatomes. | Pudendal Nerve
Pain in first stage of labor? Second stage of labor?
CO causes a decrease in 2,3DPG production from RBC and binds to HG tighter than oxygen, causing a left-ward shift. It's elimination is dependent on MV. Usually a half-life fo 6 hours, which can be decreased to an hour with exercise.
Physiology of CO in smoking on the curve?
placenta previa has a 3%, 11%, 40%, 61%, and 67% risk of placenta accreta for first, second, third, fourth, and fifth or more repeat cesarean deliveries, respectively
Placenta previa requires C-section. What would previa and c-section result in an increase in?
Clinically significant vasospasm occurs most frequently between days 3 and 15 while rebleeding occurs within the first 48 hours after SAH. -Can be seen in 1/3rd of SAH patients. -Dx: Clinical, CTA.
Potential MOA of cerebral spasm s/p SAH and how long is usual onset of time? How is it Dx?
Optic nerve -->Oculomotor nerve. efferent nerve fibers from the eye receiving the stimulus cross to the contralateral Edinger-Westphal nucleus, so results in constriction of both eyes.
Pupillary light reflex pathway?
DBS = 2 bursts x 3, 0.75 seconds apart. Felt as two busts however. If second burst is felt after the first, then = 0.3 TOF. Tetanic = 5 s at 50 hz = 4/4 = 0.7 TOF.
Quality-wise, what explain what DBS and Tetanic do?
Nalbuphine works as a kappa-agonist/mu-antagonist analgesic.
Receptors of Nalbuphine?
Sweat gland secretion is increased as part of both the adrenergic (apocrine) and cholinergic (eccrine) responses via alpha-1 and muscarinic receptors respectively
Receptors responsible for apocrine gland function vs. eccrine gland function?
-Increase: IRV, TV, IRV. -Decrease: ERV, RV, FRC, TLC -Unchanged: VC 2/2 increased IRV + TV, but decrease ERV.
Respiratory changes in Pregnancy: -Increases -Decreases -Unchanged and why?
PO2 = increased to >100 mmhg. Most pronounced in first trimester. Minute Ventilation = increased due to TV > Respiratory rate. 2/2 progestrone. Bicarb = 20-21 Base excess falls by 2-3.
Respiratory changes in pregnancy to: pO2? Minute ventilation? bicarb ? Base excess?
between a febrile and hemolytic transfusion reaction a direct antiglobulin test can be performed.
Test to determine the difference between febrile and hemolytic reactions?
The therapeutic range (for treatment of preeclampsia) for magnesium sulfate therapy is 5-9 mg/dL
Therapuetic range for magensium for pre-E?
Children.
Theta waves are commonly seen in which population?
1.) Placenta accreta vera occurs when the placenta is adherent to the myometrium without a decidual line of separation. 2.) placenta increta occurs when the placenta grows into the myometrium. 3.) placenta percreta occurs with placental growth through the uterus into surrounding structures.
Three forms of accreta?
nitrous oxide, desflurane, and sevoflurane, the time constant is about 2 minutes. Equilbrium is reached after 3 time constants considering they're first order kinetics. 2 x 3 = 6 minutes.
Time constant of nitrous oxide, desflurane, and sevoflurane? How long will they reach eqilirbium at?
Electromagnetic induction and "antenna" effect are the two main mechanisms for thermal injury in the MRI suite.
Two main mechanisms of MRI burns?
VACTERL association (vertebral abnormalities, imperforate anus, congenital heart disease, tracheoesophageal fistula, renal abnormalities and limb abnormalities (typically radial atresia) An echocardiogram should be performed prior to any surgical intervention
VACTERL association
mid-esophageal ascending aortic long axis view. It is obtained at about 100-110 degrees.
View on ECHO that is good at assessing the aortic root and the ascending aorta?
Other non-iatrogenic causes include hemolysis, diabetic ketoacidosis, adrenal insufficiency, and hyperparathyroidism.
What are some pathologic causes of hypermagensiumia?
Decrease amplitude and latency, especially if less than hg 10.
What does anemia do to neuromonitoring?
Relaxes it.
What does cAMP do to smooth muscle?
Portal pressure depends primarily on the degree of constriction or dilatation of the mesenteric and splanchnic arterioles and on intrahepatic resistance.
What does portal pressure rely on?
Testestrone
What hormone can be diminished with intrathecal morphine?
Hurler disease-a Severe autosomal recessive disease where glycosaminoglycans accumulate due to by deficiency of α-L-iduronidase. Increased risk for macroglossia and difficult airway.
What is Hurler Disease and why is it pertient for anesthesia to know about it?
Burst suppression = isoelectric activity that is interupted with periods of electrical EEG bursts. This is desirable during barbituate coma because it ensures that the patient continues to have brain function.
What is burst suppression and why is desired in anestheisa vs. Isoelectric activity?
Decreased amplitude by 50% and latency by 10%.
What is clinically significant decrease in amplitude & latancy in neuromonitoring?
De-iododination from T4 to T3 via 5-Iodoninase enzyme. Can be blocked by PTU.
What is the mechanism by which most of the T3 is produced in the body?
Normeperidine
What is the metabolite of Meperidine that is most proconvulsant?
Ulnar Nerve Injury: -most common -obese & thin patients. -male -older -hyperflexed elbows. -Nerve conduction studies are beneficial in evaluating both motor and sensory deficits. (not EMG which is at the level of muscle).
What is the most common nerve injured in OR positioning? Risk factors?
Density of the fluid. 1 mmhg = 1.36 cmh20.
What is the primary determinant of the height of the fluid rising when exposed to a given pressure when doing column momentary?
TOF > 0.9.
What is the quantitiy gold standard to ensure that there is aqeuate reversal of a patient?
Delection on X7 and are often small & elf-like. Have a supravalvular aortic stenosis which can lead to myocardia ischemia, especially if patient is fluid down.
What is williams syndrome and are is knowing a patient has it significant for anesthesia?
>7 mg/dl
What magensium level does hypotension, bradycardia occur at?
Spinal anesthesia has a more rapid onset and shorter duration of action in infants than older children and adults because: - infants have a relatively higher cardiac output - highly vascular pia matter - loose myelination that provides little barrier to drug diffusion across the spinal cord.
What makes Subarachnoid anesthesia more rapid onset in infants > adults?
Peds-used for lower abdominal & lower extremity surgeries in neonates & pre-mature babies especially, to reduce respiratory depression & post-op apnea. Adults-used in pain management to access the lumbar space when hardware exists.
When are caudal epidurals used in pediatric patients vs. adults?
FRC. = lowest PVR PVR Highest at : why? TLC-distended alveoli block small vessels. RV-small vessels become kinked & decrease in large vessel radius.
When is Pulmonary Vascular Resistance lowest?
When F8 is <50%. Should be treated with desmopressin. There is tachyphalyxsis to it, so if patients dont respond, you can give a F8 and desmopressin concentrate like-, Humate-P or Alphanate can be used which is a concentrate of factor VIII and vWF
When should Type I vWF disease be treated and how should it during pregnancy?
end of the spinal cord being at L3 until 2 years of age and the dural sac ending at S3 instead of S2.
Where does the dural sac and spinal cord end in kids <2 year old?
Interscalene block, causing 25% reduction in pulmonary function. It effects the roots and trunks of the brachial plexuas. It has been demonstrated that forced vital capacity is decreased nearly 27%, FEV1 is decreased 26%, and peak expiratory flow rate decreased by 15%
Which block causes a 100% ipsilateral phrenic nerve palsy?
Complement system activation.
Which immune system portion is responsible for ABO incompatability reactions?
Unlike other benzos, ativan is metabolized by glucoradiation in the liver to an inactive metabolite. Other benzos are metabolized by CYP enzymes causing drug-drug interactions.
Why does ativan have minimal drug-drug interactions?
Short & intermediate acting LA are hydrophillic and less protein bound, so they will leave the tissue where it needs to stay to provide analagesia, as oppose to drugs like marcaine which are already lipophiilic and will remain in the tissue longer.
Why does epi result in longer duration of LA in short/intermediate acting > long acting?
Right tip getting caught on the right posterior arytenoid. Decreased by using a parker tube which has the tip in the middle.
Why does the ETT get stuck when advancing into the glottis in a fiberoptic intubation?
succinylcholine and volatile anesthetics are avoided in Duchenne muscular dystrophy because of the risk of rhabdomyolysis, not because of an increased susceptibility to MH.
Why should sux and violatile anesthestics be avoided in Duchenne's?
decrease CMRO2, act as free-radical scavengers, stabilize liposomal membranes, and exhibit excitatory amino acid receptor blockade.
barbiturates exhibit neuroprotective properties how?
biaval view
what is this view?
Mu 1-analgesic and physical dependence properties Mu 2-respiratory depression, miosis, euphoria, decreased gastrointestinal motility, and physical dependence.
3 Mu receptors and their function?
three muscle diseases which confer increased susceptibility to MH, namely: - central core disease, - multiminicore disease, -and King-Denborough syndrome
3 muscle disorders which increase risk of MH?
Patients with coronary heart disease, significant arrhythmia, peripheral arterial disease, cerebrovascular disease, or other significant structural heart disease who are undergoing elevated-risk surgery.
According to the 2014 guidelines, it is reasonable to perform a preoperative ECG ?
Macroglossa make them difficult to intubate. Also have abdominal wall defects due to large organs and hypoglycemic.
Anesthestic significance of Beckwith-Wideman Syndrome?
S4-S5.
At what level is the sacral hiatus?
vecuronium and pancuronium have active metabolites that may accumulate in renal failure and result in prolongation of neuromuscular blockade.
Besides pancuronium, what other neuromuscular blocking agent has the ability to build up as an active metabolite in renal patients?
heromas, dissection, and aneurysms of the ascending aorta can be seen. Also, can confirm placement of a PA cath.
Besides seeing the aortic root and ascending aorta, what other advantages can be seen on ascending aortic long axis view?
The quality and density of the block may be augmented by local vasoconstriction as well as the intrinsic analgesic effects of epinephrine, which hinge on its alpha2-adrenergic agonist activity.
Besides vasoconstriction, what other way does epi work with LA to prolong its effects?
Graft vs. Host diease.
Blood given to immunocompromised patients and blood from first degree relatives should be irradiated to inactivate donor lymphocytes. This decreases what?
Cardiac myxomas are actually predominantly found in the left atrium (70%) and interatrial septum, rather than the right atrium (30%). Mostly in females.
Cardiac myxomas are commonly found where?
one of a few mutations described in the voltage-dependent L-type calcium channel gene.
Commonly the MH dysfunction gene is in the ryanodine receptor gene. What other malfunction in a gene can potentially trigger MH?
five subunits (two alpha, one beta, one delta, and one epsilon). The alpha subunits possess the binding site for ACh
Composition of the ACH and which protein activates it?
Time constant = capacity of circuite / FGF. First-order kinetics-63%, 84%, 95%, and 99% of equilibrium will be reached after 1, 2, 3, and 4 time constants, respectively. In order to reach equilbrium, it would take at least 3 time constants. Example: Iso time constant = 3-4 minutes. Equilbrium is reached at 12 minutes.
Concept of time constant of violatile agents?
Muscle weakness, and hypoventilation (reflecting diaphragm weakness) occur at magnesium levels of 7-12 mg/dL.
Deep tendon are lost at what level of magensium?
Type II or β error = incorrectly accepting Ho (false negative). Power will help you correctly reject the null hypothesis (Ho) when the alternative hypothesis (Ha) is actually true.
Define type II Error? How is it prevented?
Rupture-Uterine rupture can be a catastrophic event in which the integrity of the entire thickness of the myometrial wall is compromised. Ubruption-placental seperation from the wall of the uterus.
Define uterine rupture vs. abruption?
Delta waves are associated with deep coma, encephalopathy, and deep anesthesia
Delta waves on EEG?
A high frequency, low amplitude pattern is present during wakefulness and arousal.
EEG of wakefulness shows what type of pattern on EEG?
Hypermagnesemia can lead to depressed cardiac conduction, widened QRS, and prolonged PR intervals on ECG at levels of >5-10 mg/dL
EKG changes can be seen with magensium at what level and what is seen?
-Placing: Wait 4 hours -Removing: Wait 4 hours since last dose. -Restarting Heparin after epidural cath removed: Can be restarted immediately. Waiting 4 hours doesn't have to happen if patient has normal PTT.
Epidural cath guidlines for BID/TID 5000 unit heparin SQ? -Placing -Removing -Restarting heparin?
ferromagnetic metals include nickel, iron, and cobalt. Aluminum is not considered ferromagnetic. Some weakly magnetic metals are allowed in the MRI, such as a gold, silver, or platinum wedding band/ring.
Example of Ferromagnetic metals which can pose a risk in MRI?
Zone I-is the public area with free access Zone II- is the intermediate area between the public and the MRI suite Zone III-is where the introduction of ferromagnetic materials may pose a risk. Must be screened before entering into Zone III and beyond. Zone IV is the scanner room itself
Four safety zones of the MRI?
Malignant hyperthermia (MH) is mostly inherited as an autosomal dominant condition with incomplete penetrance. Incomplete penetrance refers to the fact that individuals with the susceptibility gene will not alway develop the clinical MH
Genetic inheritance of MH?
Potassium binder, takes 7 hours to work via GI losses. Other agent thats more effective sodium zirconium cyclosilicate that has potassium lowering capabilities in one hour
How fast does Patiromer work? What is it?
nicotinic acetylcholine receptor (nAChR), either two acetylcholine (ACh) molecules or one succinylcholine molecule must bind.
How many sux molcules are required to activate the Ach receptor?
Q24-48 hours. Looks at the Flow velocity of MCA and internal carotid. Generally, vasospasm is considered if the FVMCA >120 cm/s or the FVMCA:FVICA ratio is larger than 3
How often should a Transcranial Doppler be done to r/o Cerebral Vasospasm?
Awake or inhaled induction
How should intubation be done in a TFE?
Calcium Chloride. insulin +/- dextrose (hold if >250)-shifts cells intracellulary. Albuterol (not as effective) Loop diuretics if patient can produce urine. | Patiromer if they can't produce urine.
Hyoerkalemia tx protocol:
Intra-arterial: sudden seizure. Intra-thecal: produce a total spinal that would cause loss of consciousness and respiratory insufficiency or apnea. Pupils may not be responsive to light. Decreased by moving the needle caudal.
Intra-arterial vs. Intrathecal injection of an interscalene block?
Decreased pain, decrease SNS, and decrease RR.
If BP is maintained, how would neuroaxial anesthesia allow for increase utero blood flow?
-Cerebral angiogram-gold standard. no blood flow past carotid bifurcation. -Transcranial doppler -MRA -CTA -Radionuclide brain imaging -EEG-recommended in younger patients. A flat EEG will be present which is called electrocerebral silence. There will be no nonartifactual electrical potentials > 2 μvolts within a 30-minute recording period.
If apnea test can't be done, what are comfirmatory exams which can be completed to determine brain death?
-Lumbar paravertebral blocks are an alternative to neuraxial anesthesia for stage one of labor. Works well in patients with harrington rods. Also less risk of bleeding than Neuraxial anesthesia. -Para-cervical blocks-high rate of fetal bradycardia and injection.
If patient doesn't want neuroaxial anesthesia, but wants to be covered for the first stage of labor, what procedure is needed?
If there is a shortened period of time as it is recommended to observe for six hours or has COPD and is a chronic CO2 retainer.
In brain death exam, when is an apnea test not valid for clinical decision making?
Etomidate-likely secondary to the propylene glycol solution considering it is poorly water soluable, making it hyperosmolar. Tx with nsaids & stockings.
Induction medication with highest rate of thrombophlebitis? Why? Treament?
