B7-097 CNS Anesthetics Flashcards
which stage of anesthesia is from regular respiration to respiratory arrest
stage 3
stages of anesthesia are based on the effects of
Ether
the less soluble, the […] induction and emergence
faster
concentration of anesthetic in the inspired air at equilibrium when there is no response to skin incision in 50% of patients
minimum alveolar concentration (MAC)
lower MAC = […] potent
more
actual relative potency depends on the anesthetic’s partial pressure in the
brain
has analgesic activity but is insufficient potency for surgical anesthesia
nitric oxide
-ane
what class?
volatile (inhaled) anesthetics
desflurane, isoflurane, sevoflurane
most widely used inhaled anesthetic
isoflurane
MOA of the inhaled anesthetic agents
depress spontaneous and evoked neuronal activity
why must patients be monitored under anesthesia?
causes medullary depression of respiratory and CV function
complete CNS depressants (can lead to coma/death)
adverse reaction to inhaled anesthetics that occurs in individuals with ryanodine receptor mutations
malignant hyperthermia
malignant hyperthermia can be treated with
dantrolene
which inhalable anesthetic depresses the myocardium?
nitrous oxide
also desflurane, minimally
which inhalable anesthetics cause vasodilation and tachycardia? [2]
isoflurane
desflurane
which inhalable anesthetic causes vasodilation without tachycardia?
sevoflurane
rate of induction of nitrous oxide
rapid
rate of induction of isoflurane
medium
rate of induction of sevoflurane
rapid
rate of induction of desflurane
rapid
list the inhaled anesthetics from least potent to most potent (MAC) [4]
nitrous oxide
desflurane
sevoflurane
isoflurane
barbituates used as IV anesthetics [2]
thiopental
methohexital
long DOA due to accumulation in adipose
no analgesia, in fact causes hyperalgesia
IV barbiturates
thiopental, methohexital
cause a profound decrease in respiration at anesthetic doses
IV barbituates
IV anesthetic that redistributes to other tissues
can accumulate in adipose leading to long duration of action
thiopental
propofol acts at […] receptors
GABA-a
similar effects as barbituates, but there is a more rapid recovery due to 10x faster hepatic metabolism
propofol
often used for maintenance of anesthesia, as well as induction
propofol
most popular fixed anesthetic
often used for OP prodcedures
propofol
used for induction, especially in patients at risk of hypotension
etomidate
no analgesia
does etomidate have analgesic activity?
no
used for induction in patients with hypotension
dissociative anesthesia
causes catatonia, analgesia, and amnesia without loss of consciousness
ketamine
ketamine blocks the […] receptor
NMDA
IV anesthetic that provides excellent analgesia and amnesia
ketamine
associated with “emergence phenomenon” of hallucinations and disorientation
ketamine
(can be decreased by benzos, kids tolerate this better)
anesthetic use mainly limited to small children
ketamine
IV anesthetic that causes cardiac stimulation via increased SNS outflow
ketamine
IV benzodiazepines used for anesthetic [2]
midazolam
remimazolam
short-acting 2-4 hours
which IV benzodiazepine is faster and shorter acting, allowing it to be used for induction?
remimazolam
can be used for maintenance of anesthesia with other agents or for conscious sedation
IV benzodiazepines
IV benzodiazepines have good […] effect
amnestic
antagonist […] can accelerate recovery when using IV benzodiazepines
flumazenil
can achieve anesthesia with sufficient dose
provides excellent post-op analgesia
fentanyl
useful in patients with compromised CV function
nomenclature of ___cur___ indicates they belong to what class?
competitive nicotinic antagonists
competitive nicotinic antagonists [4]
d-tubocurarine
atracurium
rocuronium
parcuronium
depolarizing nicotinic agonist
succinylcholine
depolarizing nicotinic agonist with very short duration of action
less than 8 min
succinylcholine
competitive neuromuscular blocking agents are nicotinic […]
antagonists
depolarizing neuromuscular blocking agents are nicotinic […]
agonists
[competitive/depolarizing] neuromuscular blocking agents cause partial persistent depolarization
depolarizing
[competitive/depolarizing] neuromuscular blocking agents cause fasiculations
depolarizing
[competitive/depolarizing] neostigmine causes reversal of the block
competitive
many paralytics cause […] release, leading to hypotension and bronchospasm
histamine
(esp. d-tubocurarine)
paralytic that can cause muscle pain due to fasciculations
succinylcholine
reversal agents for neuromuscular blocking agents [2]
neostigmine (cholinesterase inhibitor)
sugammadex (SRBA)
encapsulates rocuronium and renders it unavailable for binding at NMJ
sugammadex
increase the potency and duration of competitive antagonist neuromuscular blocking agents [2]
antibiotics
inhalable anesthetics
produce readily reversible anesthesia
inhaled anesthetics
do fixed or inhaled anesthetics produce rapid, smooth induction?
fixed
however, slow elimination
produces a relatively slow induction and emergence and is hepatotoxic
no longer used in USA
halothane
etomidate is a […] anesthetic
fixed
not sufficiently potent to produce surgical anesthesia or muscle relaxation,
hematoxic
nitrous oxide
inhaled anesthetic that produces rapid induction and emergence, good muscle relaxation, and has potential renal toxicity
sevoflurane
medium rate of induction and emergence, has no known organ toxicities, and produces moderate skeletal muscle relaxation
isoflurane
definition of MAC
percentage of anesthetic in the inspired air when there is no response to a skin incision in 50% of patients
MAC is […] proportional to potency
inversely
hallucinations and other emergence phenomena are associated with
ketamine
(disturbing to adults, but don’t bother small children)
thiopental accumulates in […] tissue
adipose
causes long duration of action
non-competitive antagonist at NMDA receptor
ketamine
inhaled anesthetic that can cause myocardial depression
nitrous oxide
also desflurane, minimally
primarily used for induction and balanced anesthesia in patients at risk for hypotension
etomidate
no analgesia
barbiturate that is less lipophilic and does not penetrate the BBB rapidly enough to be used for induction
phenobarbital
widely used because its hepatic metabolism is roughly 10x faster than IV barbiturates, leading to a more rapid recovery and lower likelihood of accumulation in adipose
propofol
which barbiturate is most likely to be used as an induction agent
thiopental
often used as a carrier gas
nitrous oxide
the lower the MAC, the […] the agent
more potent
has the greatest influence on induction and emergence
oswald coefficient
(blood:gas partition coefficient)
the less soluble the agent in blood, the […] the rate of induction
more rapid
(blood:gas partition coefficient)
oswald coefficient
the potency and duration of […] is increased when used in combination with inhaled anesthetics
nicotinic antagonists
causes fasciculations because it is a nicotinic agonist
succinylcholine
short duration of action (less than 8 min) makes it suitable for short procedures like ECT
succinylcholine
reversal agent for nicotinic antagonists
neostigmine
reversal agent for rocuronium
sugammadex
hypotension and brochospasm are most likely due to […] release
histamine
(atracurium and morphine cause histamine release)
are mixed anesthetics used to maintain anesthesia?
no, make it difficult to control
