anesthetics Flashcards
5 general benefits/uses of anesthesia drugs?
Sedation and reduced anxiety Lack of awareness and amnesia Skeletal muscle relaxation Suppression of undesirable reflexes Analgesia
can one drug do all five benefits/uses of anesthesia drugs?
NO, generally combine IV and inhaled to maximize effects and avoid ADRs
which is cheaper and easier to use? IV or inhaled anesthetics?
IV
what do IV anesthetics do? what are they used for? (used alone, vs adjunct, vs continual infusions)
rapid induction of anesthetic effect
- alone: short procedures, anesthesia
- continual infusions: longer procedures
- adjuncts: to inhaled
what is the one IV barbituate anesthetic agent?
methohexital (brevital)
what is the MOA of methohexital (brevital)?
binds barbiatuate site on GABAa receptor
–> enhance Cl- channel opening to increase GABA inhibitory effect on the receptor.
how long does it take methohexital (brevital) to work?
fast, 30 sec. rapid induction of sleep
2 ADRs of methohexital?
- respiratory depression
2. hypotension (from VasoDilation)
what is the MOA of IV propofol and IV Etomidate, ?
binds beta subunit on GABAa receptor
–> enhance GABA inhibitory effect
what is the major benefit of IV propofol over IV methohexital ?
kinetics: rapid on, rapid off receptor.
- Recovery is better- less N/V
what are the kinetics of IV propofol?
rapid!
onset- 30sec, rapid metabolism, short 1/2 life (30-60min)
3 ADRs of IV propofol? (maybe weeds)
Apnea, decrease cardiac output, hypotension
drug of choice for shorter ambulatory procedures in the OR? what is used prior to admin of other anesthesias?
short in OR: IV propofol
prior: IV ketamine
when would you choose to use IV etomidate? (over propofol)
if BP low before surgery – agent has minimal cardiac and respiratory depression
only Side Effects:
Nausea/vomiting on emergence from anesthesia
what is the 2 part MOA of IV ketamine?
- blocks NMDA glutamate (excitatory) receptor in CNS = rapid hypnotic state
- mu opiod agonist - analgesic effects
which IV drug Produces rapid hypnotic state (dissociative anesthesia) where patient exhibit analgesia, are unresponsive to commands, have amnesia, their eyes may open and limbs move involuntarily?
IV ketamine
what are the two major advantages of IV ketamine over other anesthetics?
1 . No risk for hypotension or bronchospasm
(increases HR, BP & cardiac output)
2. Pediatric procedures: @ low doses in combo with others (propofol &/or midazolam)
what would you use for a short painful procedure on a kid (like burn dressing change)?
IV ketamine
ADRs of IV ketamine?
illusions
increases HR, BP and CO
major MOA of inhaled anesthetics?
bind beta subunit on GABAa (inhibitory) receptor
same as IV propofol and Etomidate
what are the 3 other MOAs of inhaled anesthetics? what do they all lead to?
- inhibit NMDA receptors
- activates K+ channels
- inhibits nicotinic (excitatory) receptor- activated cation channels
- -> hyperpolarization and reduced membrane excitability
onset and duration of inhaled anesthetics? (maybe weeds)
onset: 2-3min
duration: <2hrs
5 ADRs of inhaled anesthetics?
shivering blurry vision weak for a few days following after administration *Rare: hepatotox *Rare: malignant hyperthermia
two types of inhaled anesthetics
- inhaled gas - nitrous oxide
2. volatile agents (liquid turns to gas)- “-fluranes”
