**Week 2 - Exam 1 - Intravenous Induction Agents Ch 9 in Nagelhout Questions and Answers Expert Verified

Propofol CNS effects: - ANSWER-- reductions in: - cerebral blood flow - cerebral metabolic rate of oxygen consumption - intracranial pressure - cerebral perfusion pressure Propofol CNS effects caused by: - ANSWER-- decreased mean arterial pressure - depressed metabolic rate - cerebral vasoconstriction Predictors of hypotension in propofol administration - ANSWER-- age greater than 50 - baseline mean arterial pressure less than 70 mmHg - coadministration of high doses of fentanyl - hypotension usually occurs within 10mins after induction and is more prevalent in the second half of the 0-10min interval Primary reasons for propofol induced hypotension - ANSWER-- decreased sympathetic tone - vasodilation Respiratory effects of propofol - ANSWER-- transient respiratory depression - decrease in tidal volume - apnea - frequency and duration depression depend on dose, speed of injection, patient characteristics, and presence other meds Two most effective interventions to reduce pain on injection of propofol - ANSWER-- use of antecubital vein - pretreat with lidocaine 20-40mg in conjunction with venous occlusion with the hand vein was chosen - intraarterial injection of propofol does not cause vascular injury Propofol obstetric use - ANSWER-- passes easily through parental barrier - sedative effects occur in neonate when used for C section Contraindications for propofol use - ANSWER-- allergy - propofol infusion syndrome (with long term high dose infusions) - this is various metabolic derangements and organ failures Risk factors for propofol infusion syndrome - ANSWER-- young age - dose greater than 4-5mg/kg/hr - duration greater than 48hrs - critical illness - high fat - low carb intake - inborn errors of mitochondrial fatty acid oxidation - concomitant catecholamine infusion - steroid administration - acute inflammatory disease - acute neurologic disease Cardiac clinical features of Propofol Infusion Syndrome (PRIS) - ANSWER-- hypotension - widening of QRS complex - bradycardia - v tach or fib - systole Respiratory clinical features of PRIS - ANSWER-- hypoxia (preexisting) Renal clinical features of PRIS - ANSWER-- acute kidney injury - hyperkalemia Musculoskeletal features of PRIS - ANSWER-- rhabdomyolysis Metabolic features of PRIS - ANSWER-- hyperthermia - metabolic acidosis Hepatic features of PRIS - ANSWER-- hepatomegaly - transaminitis - steatosis - hypertriglyceridemia - lipidemia Induction dose of propofol - ANSWER-1-2mg/kg followed by maintenance infusion of 100-200mcg/kg/min Conscious sedation dose of propofol - ANSWER-25-75 mpg/kg/min Etomidate - ANSWER-alternative to propofol with little - no cardioresp effects - side effects = pain on injection, myoclonic, N/V, and adrenocortical suppression. lower acceptance of use of drug - lipid soluble - supplied as a lipid emulsion - has less pain on injection - extremely short duration of action bc of rapid redistribution Pharmacokinetics of etomidate - ANSWER-- rapidly metabolized in liver by hepatic microsomal enzymes and plasma esterases - hydrolyzed to form inactive carboxylic acid metabolites - 10% found in bile, 13% in feces, and remainder eliminated through kidney - awakening happens 5-15 mins after bolus admin. - 76% protein bound to albumin CNS effects of etomidate - ANSWER-- produces dose dependent CNS depression with one arm brain circulation - duration of action is dose dependent - decreases cerebral blood flow - decreases cerebral metabolic rate of O2 consumption (CMRO2) - decreases intraocular pressure