Induction Injectable Anesthetics Part I Flashcards
what are the main sedative/hypnotics?
propofol
alfaxalone
what do propofol and alfaxalone cause in the CNS?
decreased cerebral blood flow, intracranial pressure, and VO2
dose-dependent depression of CNS
modulates GABAa receptor
what is the lipid emulsion of propofol?
soybean oil
egg lecithin
does recovery from propofol depend on liver function?
no
where does propofol cause depression?
respiratory
cardiovascular
does propofol provide analgesia?
no
how does propofol cause respiratory depression?
decreased responsiveness to elevations in CO2 and hypoxemia
how does propofol cause cardiovascular depression?
decreased MAP due to decrease in cardiac output and peripheral vascular resistance
who should you avoid using propofol in due to its cardiovascular effects?
hypovolemic, hypotensive patients
is there reflex tachycardia with propofol?
no
propofol undergoes rapid oxidative metabolism by _____________________________
cytochrome P450 enzymes
hepatic and extra-hepatic
do disease and obesity significantly affect recovery from propofol?
no
why does propofol cause methemoglobinemia in cats?
phenolic ring
what can cause myoclonus and seizure-like activity?
propofol
what are the doses of propofol for dogs?
with premed: 2-4 mg/kg
without: 4-6 mg/kg
what is alfaxalone registered for?
induction and maintenance of anesthesia in dogs and cats
does alfaxalone cause analgesia?
no
how can alfaxalone be administered?
IM
IV
what systems does alfaxalone cause depression in?
cardiovascular
respiratory
is the therapeutic index of propofol or alfaxalone higher?
alfaxalone: harder to ovedose
what are the metabolic pathways for alfaxalone?
similar to endogenous steroids
rapidly redistributed and metabolized
when can alfaxalone result in very rapid and uncontrolled recoveries?
if not well premedicated
what is the duration of action of alfaxalone after full induction dose?
dogs: 10 minutes
cats: 25 minutes
both not premedicated
what are the induction dose rates of alfaxalone for cats?
without premedication: 4 mg/kg
with: 2-3 mg/kg
what are the dissociatives?
ketamine and benzodiazepine
tiletamine and zolazepam
what are dissociatives useful for?
IV induction of anesthesia in all mammalian species
IM chemical restraint difficult animals
what do dissociatives require to act?
functional cortex
how do dissociatives work?
NMDA receptor antagonist
depression of thalamocortical system but spares RAS and limbic system
does ketamine provide analgesia?
yes
what are the cardiovascular impacts of ketamine?
indirect: increases HR, SV, CO, MAP, PAP
direct: decreases SV and CO
overall: increases HR, BP, CO
what does ketamine cause in the respiratory system?
bronchodilation
apneustic breathing
what does ketamine cause in the CNS?
stimulation: avoid if history of seizures
increases CSF and intraocular pressures if used alone
what are the metabolites of ketamine like in cats?
active
how is ketamine metabolized?
rapidly distributed and redistributed
liver metabolism and renal excretion
is there a reversal agent for ketamine?
no
does ketamine cause good muscle relaxation?
no
what analgesia does ketamine provide?
some visceral
excellent somatic
can you use tiletamine and zolazepam in rabbits?
no
is ketamine or tiletamine and zolazepam more potent?
tiletamine and zolazepam
who should you avoid using tiletamine and zolazepam in?
cats with renal disease or hypertrophic cardiomyopathy
animals getting a C-section
animals with liver disease
animals with seizure history
rabbits
what do tiletamine and zolazepam cause in rabbits?
nephrotoxicity
