Anesthesia - Advanced Exam

lateral recess stenosis

Lateral recess stenosis causes radicular pain in the nerve above the spinal level. The lateral recess is very posterior in the spinal canal and impinges on nerves leaving the canal at the level above the corresponding vertebral level. For example, lateral recess stenosis of L3-4 will cause radicular pain of the L2 nerve.

Intubation view grades

Lehane-Cormack Laryngeal View (Cook-Yentis Modifications) Grade I Visualization of the entire laryngeal aperture Grade II Posterior third of glottis visible Grade IIa Arytenoids and posterior cords visible Grade IIb Only epiglottic edge and arytenoids visible Grade III No cords visible, only epiglottis visible Grade IIIa Only epiglottic edge visible (epiglottis raised) Grade IIIb Downfolded or floppy epiglottis visible Grade IV No view of any airway structure (including epiglottis)

Transient lab finding in TRALI

Leukopenia - 2/2 massive agglutination of leukocytes in recipient's pulmonary microcirculation in response to donor anti-human leukocyte antigens (HLA) Def: new acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) w/in six hours of blood product administration Hallmark of TRALI: increased permeability of the pulmonary microvasculature -> edema w/ increased protein composition. This results in hypoxemia, pulmonary infiltrates on chest radiography, fever, hypotension, cyanosis, and potentially pink frothy airway secretions.

CRPS lower extremity, TX, AE

Lower extremity complex regional pain syndrome (CRPS) is treated with serial lumbar plexus sympathetic blocks, which can be complicated by ejaculatory problems in males, particularly when bilateral blocks are performed.

MC causes hypophosphatemia in hospitalized patients

MC - Glucose loading (e.g. TPN) -> inc insulin -> intracellular shift of glucose and phosphate. Sepsis and other disorders can cause mild hypophosphatemia. There are a few causes of severe hypophosphatemia. In the critical care setting, these causes are: Refeeding syndrome Diabetic ketoacidosis Large decreases in PCO2 (e.g., hyperventilation during hypercarbic respiratory failure)

Spinal stenosis

Mechanical compression of the nerve roots causes pain in a radicular pattern and neurogenic claudication. Spinal stenosis often caused by spondylosis and degenerative arthritic changes of the spine. Symptoms worsened by extension and improved with spinal flexion. Walking uphill or squatting causes lumbar flexion and improves symptoms. TrueLearn Insight : Lateral recess stenosis causes radicular pain in the nerve above the spinal level. The lateral recess is very posterior in the spinal canal and impinges on nerves leaving the canal at the level above the corresponding vertebral level. For example, lateral recess stenosis of L3-4 will cause radicular pain of the L2 nerve.

Magnesium toxicity levels

NMDA receptor and thus is an option in pain management. It acts at the nicotinic acetylcholine receptor and thus prolongs non-depolarizing neuromuscular blockade. It also acts at the L-type calcium channels causing calcium antagonism.

Alveolar Gas Equation (PAO2)

PAO2= FIO2 (Pb-PH2O) - (PaCO2/RQ) e.g. PAO2= 0.21 (760-47) - (35/0.8)=106mmHg Realize that a change in FiO2, barometric pressure, PaCO2 (dilution), or respiratory quotient will influence the alveolar concentration of O2.

TEE TG Mid SAX blood supply

Posteromedial papillary muscle rupture is more common than anterolateral papillary muscle rupture because of the single blood supply (right coronary artery or left circumflex artery) of the former and the dual blood supply (left anterior descending artery and left circumflex artery) to the latter.

Neurolytic block indication (e.g. lumbar facet arthropathy)

Presence of debilitating pain Presence of well-localized pain (for medial branch blocks, a physical exam with positive provocative maneuvers for loading the facet joint and positive radiographic findings are usually required)) Failure of conservative treatment (oral analgesics, physical therapy, and home exercise programs) Relief of pain 30-80% with diagnostic local anesthetic blocks

Neuraxial fentanyl MOA

Rapid onset of analgesia via activation of mu receptors in the substantia gelatinosa in the dorsal horn of the spinal cord Opioids activate G-protein coupled inhibitory receptors both pre and postsynaptically to inhibit the release of excitatory neurotransmitters (presynaptic) and hyperpolarize postsynaptic neurons to inhibit neuronal transmission. Brain - opioids work in periaqueductal gray matter of the midbrain and rostral ventromedial medulla and modulate descending inhibitory pain pathways. Systemic administration, ascent in the CSF to the brain (hydrophilic opioids such as morphine), and absorption from neuraxial administration (primarily with lipophilic opioids such as fentanyl) activate these descending inhibitory pathways. Neuraxial administration of opioids results in analgesia primarily by action in the dorsal horn of the spinal cord in the substantia gelatinosa where they inhibit the release of excitatory neurotransmitters such as substance P and glutamate and inhibit afferent neural transmission to the brain from incoming peripheral pain neurons.

Respiratory quotient (Respiratory Exchange Ratio, RER)

Ratio between carbon dioxide produced in metabolism versus the amount of oxygen used At rest, the typical value is 0.8

PFTs and response to bronchodilators

Response to bronchodilators as seen on PFTs follows a bell-shaped curve; patients with moderate COPD will benefit most while patients with mild or severe COPD benefit least. If PFTs reveal pneumonectomy may not be tolerated, split-function lung testing using xenon radiospirometry and technetium imaging is the recommended next step in preoperative workup.

Anesthetic management of patients at high risk for (autonomic hyperreflexia) AH

SCI/lesion above T5 Neuraxial anesthesia with LA and/or deep GA. (Opioid-only anesthetics administered intravenously or neuraxially do not reliably prevent AH) Symptoms: profound vasoconstriction below the level of the lesion (e.g. headaches, hypertensive crisis, MI) and vasodilation above the level of the SCI (e.g. diaphoresis of upper body, nasal congestion). Treatment: fast-acting vasodilating agents such as nitroprusside, nitroglycerin, and nicardipine, and stop stimulant cause TrueLearn Insight : Meperidine is an opioid that also has local anesthetic-like properties. Due to these characteristics, epidural anesthesia with meperidine has been described as an acceptable method of anesthesia for patients at risk for AH (rarely performed in the U.S.).

ScvO2 vs SvO2

ScvO2 ~ 5-10% higher than the SvO2 because SvO2 includes includes both upper/lower extremities as well as deoxygenated coronary sinus blood Surviving Sepsis Campaign advocates maintaining SvO2 > 65% and ScvO2 >70% SvO2 = SaO2 - [VO2 / (CO * Hgb * 1.39)] Mixed venous oxygen saturation is directly related to SaO2, CO, and Hgb. It is inversely related to VO2.

Sodium deficit and correction

Sodium deficit = (140 - serum sodium) * total body water Total body water = kilograms of bodyweight * 0.6 Symptomatic patients with serum Na+ < 120 mEq/L should have their serum osmolality corrected by 3% hypertonic saline (HS). Discontinue once symptoms resolve and/or Na+ rises above 120 mEq/L. Central pontine myelinolysis (CPM), a demyelinating CNS lesion, may result from rapid increase in serum osmolality during HS therapy. Typically, 50% of the Na+ deficit is corrected during the first 24 hours, and the rate of hypertonic saline administration should never be higher than 100 mL/hr.

SSEP (somatosensory evoked potential) and MEPs (Motor evoked potentials)

Somatosensory evoked potentials (SSEPs) involve stimulation of the peripheral sensory nerve followed by measurement of that response somewhere along the sensory pathway, most commonly in the cerebral cortex. SSEPs measure the cortical, subcortical, spinal, and peripheral components. The most frequently stimulated peripheral nerves are the median, ulnar, or posterior tibial. SSEPs test primarily the dorsal column of the spinal cord (the posterior segments). Motor evoked potentials (MEPs) are most often used during spinal and vascular surgery; however, they can also be useful in cortical surgery. MEPs have better correlation with postoperative outcome since they are inherently more sensitive to ischemic vascular insults. Electrical stimulation in the motor cortex via electrodes placed on the scalp starts the signal and the response is recorded in the extremities. MEPs monitor the anterior spinal cord pathways which is an earlier predictor of impeding damage to the spinal cord due to the more precarious blood supply (when compared with SSEPs). Electroencephalogram (EEG) monitors the cortex only, thus it cannot provide information about any other pathways. This is why SSEPs may be used during carotid endarterectomy to monitor for subcortical ischemia.

Epiglottis pathogens

Staphylococcus aureus, Streptococcus pyogenes, S. pneumoniae, and nontypeable Haemophilus influenza. Before routine vaccination - Haemophilus influenzae type B 4 Ds: dysphagia, dysphonia, dyspnea, and drooling; high fever, tripoding

muscular dystrophy (MD) considerations

Succ & volatiles - increased risk of rhabdo & hyperK (succ) Increased risk in the perioperative period for hypoventilation due to compromised respiratory musculature, atelectasis, difficulty weaning from mechanical ventilation, congestive heart failure and cardiac arrhythmias. Avoid NMBD if possible. Increased risk of cardiac complications due to the involvement of the cardiac musculature. Preoperative evaluation - important, including ECG and echo. Abnormality -> dobutamine stress test and/or cardiac consultation. High risk for heart failure and potentially fatal dysrhythmias.

Sepsis definition

Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) were published in 2016 and redefined the clinical diagnoses of sepsis and septic shock. Per Sepsis-3 definitions, sepsis is defined as "life-threatening organ dysfunction caused by a dysregulated host response to infection." Organ dysfunction can be clinically diagnosed by an increase of two or more points on the Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score "a subset of sepsis in which underlying circulatory and cellular metabolism abnormalities are profound enough to substantially increase mortality."

Specific medications in anesthesia and how dosage should be calculated

Total body weight: maintenance infusion dose of propofol, succinylcholine Lean body weight: thiopental, induction dose of propofol, fentanyl Ideal body weight: rocuronium, vecuronium Still need more studies: dexmedetomidine, etomidate (although LBW is recommended based on the similar properties to propofol).

Trigger points vs tender points

Trigger points - painful limitation to ROM; taut bands of skeletal muscle; can produce REFERRED pain Active: produce spontaneous pain, & painful on palpation Latent: pain only when palpated Result from prolonged use of muscle, overload or overuse injury, and/or trauma. Tender points - severe tenderness w/out referred pain *Fibromyalgia pain is widespread, where trigger point myofascial pain is more localized.*

NMBD with active NMBD metabolites

Vecuronium - three active metabolites, 3-desacetyl-, 17-desacetyl-, and 3,17-desacetyl vecuronium. 3-desacetyl metabolite has ~ 80% of the activity of vecuronium. Accumulates w/ infusions esp in renal disease (metabolite is renally cleared). e.g. - 81-year-old with renal failure and subclinical chronic cirrhosis remained paralyzed for 13 days following a vecuronium infusion

IV oxytocin info and SE

Very short half-life (approximately six minutes) SE: most common are hypotension, tachycardia, and myocardial ischemia; nausea, hyponatremia Mild vasoconstrictive effect in renal, splanchnic, and skeletal muscle arteries. Powerful vasoconstrictive effect in umbilical arteries and veins and in coronary vessels

Runaway pacemaker

Waving or use of the activated electrocautery tip over the generator may result in a "runaway pacemaker" phenomenon. Runaway pacemaker is a potentially catastrophic pulse generator malfunction characterized by the sudden onset of rapid and unpredictable pacing. Circuitry in modern pacemakers and implantable defibrillators limits the runaway pacing rate to < 210 beats per minute.

Oculocardiac reflex

afferent limb - trigeminal nerve, ophthalmic branch (CN V1), via the ciliary ganglion efferent limb - vagus nerve (CN X), where pressure or traction on the eye can lead to bradycardia and even asystole

Fat Emboli Syndrome (FES)

classic triad of symptoms has been described consisting of petechiae (mostly around the head, neck, and axillae), hypoxemia, and neurologic abnormalities (e.g., altered level of consciousness or seizure) ​

treatment for surgical bleeding prophylaxis in patients with type 1 von Willebrand disease (vWD)

desmopressin/DDAVP - causes release of vWF from endothelial cells to improve plasma vWF concentration and factor VIII function; contraindicated in type 2B vWD as may lead to significant thrombocytopenia Factor VIII-vWF concentrate - tx for significant bleeding, bleeding despite desmopressin therapy, or for bleeding prophylaxis for major surgery in type 1 vWD *Cryoprecipitate contains clinically significant concentrations of vWF and factor VIII, but due to the risk of transfusion-transmitted infection (albeit small), factor VIII-vWF concentrate is preferred

Two factors that DECREASE in pregnancy

factor XI and factor XIII

Fem and Sciatic Nerves

femoral nerve emerges from the lumbar plexus and is formed by L2-L4. Its anterior branch supplies sensation to the anterior and medial aspects of the thigh and further distal it gives rise to the saphenous nerve, which supplies the medial aspect of the leg below the knee-joint. sciatic nerve originates from the sacral plexus and is the combination of nerve roots L4-S3. It courses through the leg along the posterior thigh and then divides into the common peroneal and tibial nerves a little over halfway down the femur. The sciatic nerve and its branches supply sensation to the back of the thigh and knee as well as the entire lower leg, except for the medial portion which is supplied by the saphenous nerve.

Risk factors for multi-drug resistant pathogens causing ventilator-associated pneumonia include:

five or more days of hospitalization at the time of pneumonia onset, prior intravenous antibiotic use within 90 days, septic shock at the time of occurrence, and acute respiratory distress syndrome or acute renal replacement therapy prior to onset. Patients presenting with ventilator-associated pneumonia with any of these risk factors need to be treated empirically with two anti-pseudomonal antibiotics and coverage against MRSA.

Known predictors of postoperative OSA

history of prematurity, age < 3 years, neuromuscular disorders, URI within 4 weeks of surgery, and nasal or craniofacial disorders Also: - Severe OSA on polysomnography - History of prematurity (B) - Age <3 years (A) - Morbid obesity- Mallampati score of 3-4 - Nasal pathology (e.g. deviated septum or enlarged turbinates) - Neuromuscular disorders - Craniofacial disorders and genetic disorders - Enlarged lingual tonsils - Upper respiratory infection (URI) within 4 weeks of surgery (D) - Cor pulmonale - Systemic hypertension - Marked obstruction on inhalational induction (C) - Disordered breathing in the PACU - Difficulty breathing during sleep - Growth impairment resulting from chronic obstructed breathing More than 20% of children undergoing adenotonsillectomy to improve upper airway obstruction experience respiratory compromise in the postoperative period

Common metabolic changes with TPN

hypercarbia (carbs), hyperglycemia, and hypophosphatemia (glucose load shifts phosphate intracellularly) Hepatic steatosis also common with TPN. Glucose calories > caloric requirements; excess sugar stored as fat in the liver. AST & ALT levels can rise (dec w/ TPN adjustments) May also see: Hypokalemia, hypomagnesemia, Hyperinsulinemia, thrombophlebitis

Factors that speed induction with sevoflurane in infants relative to adults

increased minute ventilation relative to FRC (higher FA/FI) as their metabolic rates are higher; similar FRC to adults (30 mL/kg) decreased blood and tissue solubility of sevoflurane in infants increased proportion of CO going to the vessel-rich groups in infants (so faster inh ind, despite higher CI)

transversus abdominal plane (TAP) block nerves

intercostal, subcostal, ilioinguinal, iliohypogastric

path of stimulus to terminal recording of a (lower extremity) motor evoked potential (MEP)

lower limb cortex, internal capsule, brainstem, corticospinal tract, peripheral nerve, and eventually the lower limb muscle

SOFA score

mental status (GCS) respiration (PaO2/FiO2) cardiovascular function (MAP and pressor dose) coagulation (platelet count) liver function (bilirubin) renal function (creatinine and urine output) Each category scored from 0-4

Increased Svo2 (mixed venous sat) causes

mixed venous oxygen saturation can be INCREASED by increasing cardiac output, hemoglobin concentration, and arterial oxygen saturation

Neurogenic claudication (NC), also known as pseudoclaudication

most common symptom of lumbar spinal stenosis (LSS) and describes intermittent leg pain from impingement of the nerves emanating from the spinal cord Walking up a hill or an incline causes a natural flexion of the lumbar spine. The flexion of the spine often improves symptoms in patients with lumbar spinal stenosis. Walking uphill can be strenuous on the lower extremity muscles, which would worsen vascular claudication and can help differentiate these 2 disorders.

Carbamazepine toxicity

neurologic: nystagmus, AMS, delirium, and a paradoxical reduction in the seizure threshold cardiovascular: widening of the QRS complex, prolonged QT interval, ventricular arrhythmias, tachycardia, and hypotension (from direct myocardial depression) anticholinergic: mydriasis, hyperthermia ("atropine fever"), flushing, dry mouth, urinary retention Liver metab w/ active metabolites: Diplopia, ataxia, BLOOD DYSCRASIAS (e.g. AGRANULOCYTOSIS & aplastic anemia); liver toxicity, teratogen, INDUCES CYP450 (inc metab of other drugs); can cause SIADH & STEVENS-JOHNSON syndrome. (Na channel blocker). "dry as a bone, mad as a hatter, blind as a bat, and hot as a hare." Use: Na ch inhibitor. Tx for partial and generalized seizures, trigeminal neuralgia, bipolar disorder, and neuropathic pain syndromes; mood stabilizer.

Treatment of CRPS type II

physical therapy, tricyclic antidepressants, gabapentin, sympathetic blocks, somatic blocks, spinal cord stimulators, and intrathecal medications.

HoTN/Brady with endovascular carotid stenting

pre-treat w/ atropine/glyco; transcutaneous pacing carotid sinus via glossopharyngeal nerve to the medulla, which inhibits the sympathetic neurons -> HoTN nucleus ambiguous and the vagal nucleus are stimulated -> bradycardia Stimulation of carotid sinus -> glossopharyngeal nerve -> inhibits sympathetic tone/stimulates vagal nucleus -> hypotension and bradycardia

risk factors most strongly correlated with post-cardiopulmonary bypass AKI

preoperative Cr > 1.2mg/dL combined valve and bypass procedures emergency surgery preoperative intraaortic balloon pump

Retrobulbal Block Complications

retrobulbar hemorrhage - closing of the upper eyelid, proptosis, and an INCREASE in intraocular pressure, which is often palpable oculocardiac reflex stimulation - Pressure or retraction of the eye leads to ciliary and gasserian ganglia stimulation (trigeminal nerve, afferent limb) followed by vagal stimulation (efferent limb). This can cause significant bradycardia, heart block, and even arrest. central retinal artery occlusion - painless "shade" over eye; may present with concomitant neck or back pain puncture of the posterior globe - immediate ocular pain and restlessness following the block without an increase in intraocular pressure; Myopia (elongation of the globe) major risk factor penetration of the optic nerve - Optic atrophy and permanent loss of vision, peripheral vision loss, or color vision loss Inadvertent brain stem anesthesia - sudden disorientation, amaurosis fugax, aphasia, hemiplegia, and possible respiratory and/or cardiac arrest and epinephrine toxicity

Nitric Oxide

selective pulmonary vasodilator; decreases pulmonary artery pressure and RV afterload, decrease ventilation-perfusion mismatch, and improve systemic oxygenation. When inhaled, it has minimal systemic effects due to rapid inactivation by hemoglobin in erythrocytes within the pulmonary circulation. Potential side effects: formation of higher oxides of nitrogen and methemoglobinemia

sensory level of a spinal anesthetic is primarily affected by

the baricity of the solution, dosage of the local anesthetic (which factors in the volume and concentration), and the patient's position. The patient's height, CSF volume, and CSF density are minor factors with regards to determining the sensory level.

Spinal Cord Stimulator Indications

thoracic and lumbar post-laminectomy syndrome ("failed back syndrome"), post-herpetic neuralgia, phantom limb pain, cauda equina syndrome, CRPS I and II, cardiovascular angina, lower extremity ischemic pain, chronic cervical radiculopathy, and nerve root injury

AFE Phases

two phases: 1) pulmonary hypertension with right ventricular dysfunction, 2) left ventricular failure and coagulopathy. two distinct phases. The first phase occurs when the AFE in the maternal circulation triggers a release of inflammatory mediators. This results in pulmonary artery vasospasm and right ventricular dysfunction, causing hypoxemia and hypotension. There is systemic vasodilation from the inflammatory response. This phase can last up to 30 minutes. The second phase occurs in those who survive the first phase. Here the left ventricle fails due to impaired filling from a dysfunctional right ventricle and a deviated intraventricular septum. The left ventricular failure results in hypotension and elevated pulmonary pressures. The biochemical mediators also trigger coagulopathy resulting in massive hemorrhage

SOFA score (Sepsis-related organ failure assessment)

(SOFA) score of 2 or more points, with each of the values in the following categories scoring 1-4 points (using the worst values in the past 24 hours): PaO2/FiO2 ratio Platelet count Glasgow Coma Scale Bilirubin Mean arterial pressure (MAP) or administration of vasopressors required Creatinine level

Morphine conversion chart

1 mg of intrathecal (IT) morphine = 10 mg of epidural (EP) morphine1 mg of EP morphine = 10 mg of IV morphine 1 mg of IV morphine = 3 mg of PO morphine Morphine is a highly hydrophilic drug, so stays in the IT space and gains access to both spinal and supraspinal opioid receptors. This direct analgesic effect accounts for the low dose requirement for IT morphine compared to an equianalgesic IV morphine. Similarly, morphine administered in the EP space will cross the meninges and binds the spinal receptors although to a smaller extent compared to IT administration because some amount will be diffused into the systemic circulation. The behavior of neuraxial opioids mostly depends on how lipophilic the drug is. In general, a highly lipophilic drug such as fentanyl will exit the neuraxial space faster through diffusion into epidural fat, and ultimately, the systemic circulation. Therefore, the conversion ratio of neuraxial to IV fentanyl is smaller compared to the conversion ratio for morphine. Hydromorphone is between morphine and fentanyl in terms of lipophilicity so the conversion ratio is predicted to fall somewhere in between those of morphine and fentanyl.

AFE Criteria

1) Acute hypotension or cardiac arrest 2) Acute hypoxia (dyspnea, cyanosis, respiratory arrest) 3) Coagulopathy or severe hemorrhage 4) Occurs at the onset of labor, during a cesarean delivery, or within 30 minutes post-partum

Hyperkalemia EKG Progression

1) peaked T wave 2) shortened QT interval 3) lengthened PR interval 4) increased QRS duration 5) absence of P wave with QRS complex becoming a sine wave *EKG changes occur in < 50% of cases. (not sensitive, but specific in clinical setting) * Sx: muscle weakness, paralysis, cardiac conduction abnormalities, arrhythmias

Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) and the intensive care delirium screening checklist (ICDSC)

1. Is there an acute change in mental status or fluctuating course? (yes/no) 2. Is the patient inattentive or easily distracted? (yes/no) 3. Is there an altered level of consciousness or RASS other than zero? (yes/no) 4. Does the patient experience disorganized thinking? (yes/no) If the answers to both questions 1 and 2 are "yes," continue to questions 3 and 4. If the answer to either question 1 or question 2 is "no," the patient does not have delirium per CAM-ICU screen. If the answer to either question 3 or question 4 is yes, then the patient is CAM-ICU positive for delirium. Both questions 1 and 2 must be positive, and either question 3 or question 4 must be positive, for CAM-ICU to be positive for delirium. 10% of inpatients experience delirium 50% to 75% of critically ill patients Delirium -> increased increased morbidity and mortality

5 causes of hypoxemia

1. decreased inspired oxygen 2. hypoventilation 3. alveocapillary diffusion problem 4. v/q mismatch 5. shunting

Peds fluid management

20-40 mL/kg of isotonic solution administered over 2-4 hours - reduces ADH secretion typically elevated in under-resuscitated 4-2-1 rule patients Maintenance rates in the 12 hours immediately post-operatively should be reduced to 2-1-0.5-mL/kg/hr and then only returned to 4-2-1 mL/kg/hr if the patient is not tolerating PO. In populations at risk for hypoglycemia including neonates and infants < 6 months old, malnourished children, and those undergoing cardiac surgery, glucose-containing solutions of 1-2.5% dextrose may be beneficial. It is also recommended to monitor blood glucose levels intraoperatively in this population.

Pacemaker Setting

2011 ASA and Heart Rhythm Society (HRS) practice advisory - "Expert Consensus Statement on the Perioperative Management of Patients with Implantable Defibrillators, Pacemakers, and Arrhythmia Monitors: Facilities and Patient Management."

Max dose lidocaine tumescent liposuction

55 mg/kg 0.05 % lidocaine amount of infiltration solution used is 1 to 2 mL per 1 cm3 of adipose tissue peak plasma lidocaine concentrations occur 12 to 16 hours after initial injection for tumescent liposuction maximum recommended dose of epinephrine is 0.07 mg/kg (1:1,000,000 concentration)

Adenosine indications, contraindications

Adenosine is a nucleotide that transiently blocks the atrioventricular node. Use: diagnose and/or treat SVTs and regular wide-complex tachycardias. Don't use: irregular wide-complex tachycardias (e.g. polymorphic ventricular tachycardia, ventricular fibrillation, and atrial fibrillation with aberrancy or Wolff-Parkinson-White syndrome) since it can result in hemodynamic instability and an increase in the ventricular rate.

Reasons against/for bicarb in cardiac arrest

Against: Bicarbonate produces excess CO2 which can diffuse into cells of the body resulting in an intracellular acidosis. The extracellular alkalosis may inactive catecholamine drugs making them less effective For: tx for hyperkalemic arrest and TCA overdose

VAE (venous air embolism)

Approximately 3-5 mL/kg bolus of air and 10-15 mL/kg bolus of CO2 are sufficient for fatal air lock situation. RV/RA air lock -> increased preload (increased central venous pressure), decreased pulmonary artery pressure, decreased blood in the left heart, and decreased systemic blood pressure air in the pulmonary circulation will cause VQ mismatch,, endothelial damage and inflammation leading to noncardiogenic pulmonary edema, bronchoconstriction, increased dead space, and decreased pulmonary compliance. Arterial air embolisms will cause systemic effects such as hypoxia from direct arterial obstruction of local tissues including coronary artery obstruction leading to myocardial ischemia and cerebrovascular obstruction leading to acute stroke.

Distal vs proximal arterial line waveform

Arterial waveforms will have higher systolic peaks when measured at more distal arterial sites. (e.g. - higher systolic peak radial vs aorta cannulation) due to summation Distal: smoother appearing notch occurring later in the cardiac cycle and is more representative of arterial wall properties and waveform reflections than aortic valve closure. Compared to the proximal aorta, arterial waveforms measured at more distal sites have the following characteristics: higher systolic peak, steeper systolic upstroke, lower diastolic peak, blunted dicrotic notch, delayed dicrotic notch, slightly lower MAP.

Optimal leak pressure uncuffed ETT peds

Between 20-30 cm H2O Leak pressure < 10-20 cm H2O = inadequate seal and may result in an increased risk of aspiration, difficulty providing positive pressure ventilation, and/or inaccurate EtCO2 monitoring. Leak pressure > 30-40 cm H2O = risk for a range of complications due to tracheal ischemia. Short term: increased incidences of sore throat, laryngeal/tracheal edema, and postintubation croup. If too large of an ETT is left in place for an extended period of time, a patient may develop tracheal stenosis, tracheomalacia, and/or tracheal fistulas (e.g. tracheoesophageal, tracheocutaneous).

Steroids in TBI

CONTRAINDICATED Steroid therapy to decrease ICP is effective for space-occupying lesions with surrounding edema. By decreasing the inflammation, ICP will decrease. Ineffective in traumatic injury and can worsen outcomes by increasing hyperglycemia

CPDA-1 blood storage components

CPDA-1 anticoagulant allows PRBC and whole blood storage for up to 35 days - Citrate is the anticoagulant (binds calcium necessary for clot formation) - Phosphate is incorporated for cellular function and ATP production - Dextrose is the nutrition source for glycolysis - Adenine is incorporated for ATP production

10 MCC pregnancy-related deaths in US

Cardiovascular diseases: 15.2% Non-cardiovascular diseases: 14.7% Infection or sepsis: 12.8% Hemorrhage: 11.5% Cardiomyopathy: 10.3% Thrombotic pulmonary embolism: 9.1% Cerebrovascular accidents: 7.4% Hypertensive disorders of pregnancy: 6.8% Amniotic fluid embolism: 5.5% Anesthesia complications: 0.3% Risk factors for maternal mortality include advanced maternal age, maternal obesity, multi-fetal pregnancies, and cesarean delivery

CBF with PCO2

Cerebral blood flow (CBF) decreases approximately 3% from baseline for every 1 mm Hg change in PCO2. Linear relationship between 25 and 65 mm Hg. Further decreases in PCO2 may be detrimental.

Tube feeding considerations

Composition: - Carbs: generate more CO2 than lipids; may worsen ventilator weaning - Excessive proteins: increase in respiratory drive and create a feeling of breathlessness for the patient Diarrhea Risk of sinusitis with larger tubes - maxillofacial CT

Post hemodialysis (HD) labs

Dec potassium Inc prealbumin (Large molecules like proteins can't pass through semipermeable membranes used for ultrafiltration) semipermeable membrane separating the dialysate (customized solution of electrolytes, salts, minerals, etc., in water) from the patient's blood. The membrane has microscopic pores that only permit substances of certain sizes to cross according to their concentration gradients, including water, electrolytes, and some small proteins, such as immune globulins. Larger proteins such as albumin or prealbumin are too large to cross.

MOA hypoxemia/hypercarbia from GA, opioids, benzos

Decreased afferent impulses via the glossopharyngeal nerve (Hering's nerve)to CNS ventilation centers. Hypoxemic and hypercapnic respiratory insufficiency related to opioids, benzodiazepines, and volatile anesthetic administration with a decrease in glossopharyngeal afferent nerve activity due to impairment of the carotid body chemoreceptors CO2 chemoreception - mostly central with a smaller peripheral component PaO2 sensing - purely peripheral; mainly at carotid bodies (at carotid bifurcation) Carotid body chemoreceptors increase ventilation when PaO2 (not PAO2, CaO2, or SaO2) decreases through afferent impulses via the glossopharyngeal nerve to CNS ventilation centers. Their function is impaired by opioids, benzodiazepines, volatile anesthetics (as low as 0.1 MAC), and bilateral carotid endarterectomy. *carotid bodies are chemoreceptors while carotid sinuses are baroreceptors

Septic shock definition

Diagnosis of sepsis with the following, in the absence of hypovolemia: - Vasopressor requirement for MAP > 65 mm Hg, and - Serum lactate > 2 mmol/L

celiac plexus block side effects

Diarrhea is associated with a celiac plexus block (T5-12), which supplies innervation to all the intraabdominal organs, including most of the bowel Complications from celiac plexus blockade include but are not limited to orthostatic hypotension, diarrhea, retroperitoneal hemorrhage, hematuria, venous and arterial injection, aortic dissection, dysesthesia, interscapular back pain, backache, reactive pleurisy, hiccups, loss of bladder function, transient motor paralysis, and paraplegia (disruption of artery of Adamkiewicz or lumbar segmental arteries)

PAOP in good EF & Values

EF > 50% and normal V wall function, CVP ~ PAOP. EF < 40% or WMA, use PA monitoring Normal PAOP - Normal 4 - 12 mmHg - Borderline 13 - 17 mmHg - HF > 18 mmHg

OB Hemorrhage: Therapeutic Management

Ergot alkaloids (ergonovine and methylergonovine): 2 - 4 hr duration; SE: nausea, vomiting, hypertension, myocardial ischemia, and cerebrovascular accidents Prostaglandins (15-methyl prostaglandin F, misoprostol, carboprost) MOA: act by increasing free calcium concentration in the myometrial tissue leading to increased uterine contractions. SE: N/V, fevers, bronchospasm, and increased intrapulmonary shunting *If ineffective: uterine compression sutures, embolization of the uterine arteries by an interventional radiologist, or even cesarean hysterectomy

Acute intermittent porphyria (AIP) anesthetics

Exacerbated by inducers of the P450 system, which leads to an increase in aminolevulinic acid (ALA) concentration. This increase in ALA concentration can precipitate an attack. Avoid: Barbiturates, benzodiazepines, nifedipine, glucocorticoids, and alcohol Most anesthetic agents are considered safe. Keep normothermic and well hydrated. Acute intermittent porphyria is the most common form of porphyria. It is an autosomal dominant condition that results from an error in porphobilinogen deaminase, an enzyme involved in heme synthesis. Symptoms of AIP are often vague and include abdominal pain, diarrhea or constipation, and neurological complaints. Attacks are often precipitated by conditions that increase ALA. Dextrose: used to suppress ALA synthase. Glucose causes negative feedback and inhibits ALA synthase. Glucose administration, hydration, and avoidance of hypothermia are very important when treating patients with porphyria.

TPN, excess glucose, CO2 production and respiratory quotient

Excess glucose can -> increased carbon dioxide production and the respiratory quotient. (e.g.- CO2 production can increase by 20% after the first hour of therapy in patients receiving 5% dextrose intraoperative versus those receiving saline solutions.) Hypophosphatemia w/ TPN can -> decreased muscle strength, diaphragmatic weakness (impaired vent weaning); may lead to reduced 2,3-diphosphoglyceric acid (DPG) and leftward shift of oxygen-hemoglobin dissociation curve may occur

4 unique clinical situations for billing anesthesia services

Extremes of age (patients < 1 year or >70 years) Use of (deliberate) total body hypothermia Use of controlled hypotension Anesthesia complicated by emergency conditions

FeNa levels

FENa = (Urine sodium * Plasma creatinine) / (Urine creatinine * Plasma sodium) FENa < 1% = Prerenal FENa >1% = Intrinsic (e.g., acute tubular necrosis) FENa >4% = Postrenal

Factor VII liver disease

Factor VII becomes deficient in the setting of liver disease because it has a very short half-life (approximately 6 hours). This deficiency serves to prolong the PT.

Factors affecting SvO2

Factors Increasing SvO2: - Decreased oxygen extraction (cyanide poisoning, methemoglobin) - Increased CO (left to right shunt, inotropes) - Blood transfusion - Increased oxyhemoglobin saturation Factors Decreasing SvO2: - Decreased delivery (low CO, hypovolemia, right to left shunt) - Increased extraction (catabolic states, shivering, fever, pain) - Anemia - Decreased arterial oxygen saturation (pneumonia, pulmonary edema)

qSOFA criteria

GCS < 15 SBP < 100 RR > 22 1 pt each A score ≥2 indicates a worse prognosis

Hemophilia A hemorrhage tx refractory to cryo

Hemophilia A patients who do not respond well to exogenous human factor VIII infusion may have developed anti-factor VIII antibodies. The treatment in the case of hemorrhage or surgery in patients with hemophilia A with anti-factor VIII antibodies involves porcine factor VIII, recombinant factor VIIa, or recombinant factor IIa.

C-section vs labor epidural dermatome coverage

Labor - T10-L1 (stage 1) S2-4 (stage 2) Cesarean - T4-S4

moderate to severe carbon monoxide (CO) poisoning findings

Labs: metabolic acidosis (hypoxic lactic acidosis), normal PaO2, falsely elevated SaO2 (calculated; assumes normal Hgb) Vitals: pulse oximetry (SpO2) falsely elevated

pH stat vs alpha stat

Hypothermia plays a major role in reducing cerebral metabolic demands during CPB. There is a natural "alkaline drift" with hypothermia resulting from the increase in gas solubility and reduction of the PaCO2. The 2 methods of managing acid-base balance during CPB have been identified as pH-stat and alpha-stat management. A pH-stat management technique corrects the alkaline drift by maintaining a neutral pH during hypothermia by adding CO2 to the cardiopulmonary bypass circuit., and alpha-stat management allows the natural alkaline drift to occur without correction. During pH-stat management, CO2 is added to the oxygenator, or the CPB "sweep" may be reduced (the sweep mechanism removes CO2 from the CPB circuit). The addition of CO2 to the circuit increases total body CO2 to maintain pH neutrality despite the continuous reduction in core temperature. The advantages of pH-stat management include an increased speed of homogenous cerebral cooling through cerebral vasodilatation, increased cerebral blood flow, and improved oxygen delivery to tissues by counteracting the leftward shift of the oxyhemoglobin curve typical of alkalosis. The disadvantages of pH-stat management include increased delivery of embolic load to the brain as a result of cerebral vasodilatation as well as loss of cerebral autoregulation. Outcome data provide evidence to support the use of pH-stat management during congenital heart surgery as a result of homogeneous brain cooling. Alpha-stat is more commonly used in adults.

Predictors of morbidity and mortality post pneumonectomy

Inability to obtain a maximum oxygen consumption (VO2) of ≥ 15 mL/kg/min is a predictor of increased preoperative morbidity and mortality following pneumonectomy Phase 1: ABG, spirometry; if fails, on to Phase 2 testing Phase 2 criteria that predict increased perioperative morbidity and mortality include: 1) Inability to ascend at least two flights of stairs 2) Predicted postoperative FEV1 < 30% of normal predicted value for the patient (some studies suggest FEV1 < 50%) 3) A combined predicted postoperative FEV1 < 35% and DLCO < 35% of normal predicted value for the patient 4) Right heart catheterization data: mean PAP > 35 mm Hg; PCO2 > 45 mm Hg; PO2 < 60 mm Hg; and the following with exercise: PVR > 190 dynes/sec/cm^5 , decrease in SaO2 > 2-4%, and max VO2 < 15 mL/kg/min Predicted postoperative values are based on split lung function testing. Right heart catheterization criteria which predict increased preoperative morbidity and mortality include: 1) Mean pulmonary artery pressure (PAP) > 35 mm Hg 2) PCO2 > 45 mm Hg 3) PO2 < 60 mm Hg Poor post-pneumonectomy outcomes are associated with the following values obtained with or during exercise: 1) PVR > 190 dynes/sec/cm5 2) Maximum VO2 < 15 mL/kg/min 3) A decrease in arterial oxygen saturation (SaO2) > 2-4%

Effects of PEEP in HFrEF

Increase: CVP, PAP, CI Decrease: LVEDP, PCWP PEEP application raises intrathoracic pressure, right ventricular afterload, decreases preload and can cause hypotension in the normovolemic or hypovolemic patient without heart failure. In patients with systolic heart failure, preload is excessive, thus PEEP preload effects are minimized but afterload is decreased with resultant improvement in cardiac output and a decrease in LVEDP.

Why infants require higher doses NMBD

Infants and small children have larger extracellular fluid volumes by percentage of TBW and therefore require larger weight-based dosing of muscle relaxants Extracellular fluid volume in infants is approximately 40% total body weight. Total body water (TBW) is about 75% in term and 85% in premature infants. Extracellular fluid volume reaches adult levels of 20% (TBW of about 60%) at approximately 18-24 months of age. Larger doses of neuromuscular blockers including succinylcholine (2-2.5 mg/kg vs. 1-1.5 mg/kg) are commonly needed in children for this reason.

Inhaled nitric oxide (NO) affect on P50

Inhaled nitric oxide (NO) can result in methemoglobinemia (Methemoglobin is formed by the nitrosylation of Fe2+ to Fe3+ by NO) resulting in a left shift in the oxyhemoglobin curve and a decrease in the P50 vasodilation through the production of cGMP