Propofol, Ketamine, NSAIDs, & ERAS Flashcards
What class of drug is propofol?
A sedative/hypnotic
What is the induction dose of propofol?
1.5-2.5 mg/kg IV
How long does an induction dose of propofol take to render the patient unconscious?
30 seconds
Is phase II of consciousness desirable or undesirable? How does propofol interact with phase II?
Undesirable; it is the excitatory phase; propofol allows the induction of anesthesia with very little time spent in phase II.
What is a major advantage of propofol over other induction agents regarding recovery?
It allows for rapid awakening with minimal CNS effects
Describe the solution in which propofol is administered.
A 1% solution in soybean oil, glycerol, and egg lecithin (a long-chain triglyceride) which supports bacterial growth and can transiently increase plasma triglyceride levels.
Which preservative does Diprivan have?
Disodium edetate and NaOH
Which preservative does generic propofol have?
Metabisulfite
True or false? Different propofol preservatives have the same pH.
False
Why is mixing propofol and lidocaine not recommended?
Can cause pulmonary emboli through coalesced oil
What is the problem with Ampofol?
Even more severe injection site pain compared to Diprivan.
What is the problem with Aquavan?
While it causes less injection site pain than propofol, it will cause genital burning!!
With which receptor does propofol interact and how?
Propofol is a GABA-A receptor agonist (inhibitory neurotransmitter)
What effect does the stimulation of GABA-A have?
Hyperpolarization of cell membranes
Into what organs is propofol taken up during the first pass effect?
Lungs and liver
Abnormalities with which liver enzyme can alter the metabolism of propofol?
Cytochrome P-450
What is the elimination half time for propofol?
0.5-1.5 hours
What are the context sensitive half times for propofol (time to 50% drop in blood level after infusion is stopped) after less than 3 hours? Greater than 3 hours? Greater than 8 hours?
10 minutes; 25 minutes; 40 minutes
Minimal for most surgical times
In ____, most of propofol goes back into circulation after 1st pass effect.
Lungs
Propofol is metabolized by the ____ and excreted mostly through the _______, however _____ and/or _____ disease does NOT impair elimination.
liver; kidneys; liver; renal
How does propofol’s clearance impact cumulation? Placenta? CP bypass?
Rapid clearance –> no cumulation
Crosses placenta but rapidly cleared from neonatal circulation
Unpredictable with CP bypass
Is propofol a good drug for OB? Why or why not?
As long as mom is hemodynamically stable, yes! Because while it does cross the placenta, it is rapidly cleared from neonatal circulation.
What is the induction dose of propofol?
1.5-2.5 mg/kg IV
Pediatrics require _______ doses of propofol due to _______ volume of distribution and ________ clearance.
increased; larger; faster
Elderly patients require _______ doses of propofol due to _______ volume of distribution and ______ clearance.
decreased; smaller; slower
What is the sedation infusion dose range of propofol?
25-100 mcg/kg/min
Propofol provides good _______ but no ________.
amnesia; analgesia
What is GA maintenance infusion dose range for propofol?
100-300 mcg/kg/min (less with opioids and volatile)
What is an antiemetic dose of propofol?
10-15 mg
What is an antipruritic dose of propofol?
10 mg
What is an anticonvulsant dose of propofol?
Greater than 1 mg/kg; does NOT decrease the therapeutic effectiveness of ECTs
Which preservative in generic propofol can cause bronchoconstriction?
Metabisulfite (use with caution in asthma, smokers)
Propofol has better analgesia for _________ pain than for ________ pain.
neuropathic; nociceptive
What are the neurologic systemic effects of propofol?
Decreased CMRO2, cerebral blood flow, and ICP
Autoregulation with PaCO2 NOT impacted (GOOD :)
Allows robust SSEPs and MEPs without N2O or volatile
No evidence of tolerance
What are the cardiovascular effects of propofol?
Decreased HR, SVR, CO; can be offset by laryngoscopy/intubation/LMA
Extreme drop in BP with hypovolemia, LV dysfunction, elderly
Does NOT have SA or AV node effects or QTc prolongation
What are the characteristics of propofol related bradycardia?
Causes increased incidence of oculocardiac reflex (“5 and dime reflex”) especially in peds
You should pretreat/treat with anticholinergic, however profound bradycardia/asystole may persist; increased doses do not attenuate.
May require epinephrine (direct beta agonist)
What are the respiratory effects of propofol?
Dose-dependent respiratory depression (both rate and TV)
Enhanced by opioids but offset by surgical stimulation
Causes downward shift of hypoxic response curve BUT HPV maintained
While _____ and ______ are usually not effected by propofol, prolonged infusions can cause ______ injury and _______ _________ ________.
liver; kidneys; liver; propofol infusion syndrome
What causes benign green urine with propofol with no renal dysfunction?
Phenol
What causes benign cloudy urine with propofol?
Uric acid
What effect does propofol have on intraocular pressure?
Decreases
What effect does propofol have on coagulation?
NO change in coagulation factors or platelet function BUT inhibits platelet aggregation
What side effects are related to propofol’s lipid profile?
Risk of infection, injection site pain, hypertriglyceridemia, pulmonary embolus
What ingredient of propofol can cause anaphylaxis?
Phenol (often after first exposure with neuromuscular blockers)
What is an adverse respiratory allergic effect of propofol?
Bronchoconstriction
Propofol Infusion Syndrome is seen after doses of >__ mcg/kg/min for >__ hours
75; 24
Propofol Infusion Syndrome is most often seen in which population?
Children
What are signs and symptoms of Propofol Infusion Syndrome?
Lactic (metabolic) acidosis, profound refractory (lethal) bradycardia in peds
Tachycardia is an EARLY sign of PIS and usually reverses when infusion is stopped.
What are differential diagnoses for Propofol Infusion Syndrome?
Hyperchloremic metabolic acidosis (NS) and increased organic acids (DKA, tourniquet release)
What alarming but benign symptom can occur upon propofol injection?
Myoclonus (NOT cortical epileptic in origin; NO contraindications in epileptic patients/EEG)
Propofol accounts for __% of known substance abuse in anesthesia practitioners.
40
Describe the antioxidant effect of propofol.
It scavenges free radicals (similarly to Vitamin E) and attenuates reperfusion injury from oxygen free radicals (post-MI, CP bypass, cross-clamping, tourniquets)
Unused propofol should be discarded in _ hours due to supporting _ ___ and ________ growth.
6; E. coli; Pseudomonas
Propofol does/does not trigger MH?
Does not
Which is safe for porphyria? (propofol/thiopental)
Propofol
Which causes adrenocortical suppression? (propofol/etomidate)
Etomidate
How is ketamine classified?
PCP derivative for dissociative anesthesia