Injectable Anesthetics Flashcards
induction of anesthesia is a
transition from a(semi-) conscious state to an unconscious one
priorities during induction
rapidly sercure airways and give oxygen
maintain CV function
induce/maintain anesthesia
why is induction with an inhalational agent via mask not recommended
takes longer to induce and intubate (hold breath) - increased chance for asipration
go through stages 1 and 2 slowly (excitement)
stressful, chance for injury
if you have to do a mask induction which inhalant is better
sevoflurane
which injectable anesthetics are GABA angonists
propofol
thiopental
etomidate
alphaxalone
Ketamine and tiletamine are dissociative anesthetics that act on which receptor?
NMDA antagonists
T/F ketamine may accumulate with repeated doses or CRI
True
T/F Ketamine can cause an catatonic state if used alone
True
always use in combination
does ketamine have an analgesic effect
yes but not as strong as opioids
prevent wind-up and central sensitization - may prevent developement of chronic pain
T/F the anesthetic effect of ketamine is due to its actions on the GABA receptor
False
CV effects of ketamine
direct: negative inotropy
indirect: catecholamine release→increased HR and contractility
T/F the anesthetist can manipulate IC blood volume and therefore can influence ICP
True
dissociative anesthetics increase/decrease ICP
increase
all the other injectables discussed will decrease
factors increasing cerebral blood volume
hypercapnia, hypoxia
hypertension
C+/V+
head down position, jugular vein compression
drugs
main indications for ketamine
hypovolemic shock
asthma
most risk patients tolerate in small doses
chemical immobilzation of aggressive animals
contraindications of ketamine
brain trauma/tumor
perforating eye injury (increase intracorneal pressure)
HCM/ mpst heart diseases
seizures
hepatic/renal insufficiency
what does telazol contain
tiletamine (similar to ketamine)
zelazepam (benzodiazepine)
T/F telazols effect is similar to Ket/Val but is longer acting
True
useful for aggressive small/wild animals
propofol
fast onset, short duration
smooth induction and recovery
no accumulation - ideal for TIVA
no analgesia
IV only
CV effects of propofol
vasodilation - hypotension!
some neg inotropy
no reflex tachycardia
T/F propofol can be used to terminate status epilepticus
True
has antiepileptic effects
why should cats not have repeated administrations of propofol
can cause hemolysis and Heinz-body anemia
propofol is the drug of choice
C-section
when is propofol contraindicated
hemodynamically unstable patients
very sick patients in general
thiopental
fast onset, short duration
withdrawn from USA
thiopental should never be given
extravascularly
if happens - inject 2ml saline or 1% lidocane immediately to each side of the vein
CV effects of thiopental
hypotension - neg inotropy, vasodilation
arrhythmogenic
when is thiopental preferred
good choice for neurosurgery as an induction agent
CV effects of etomidate
almost none!
what is the #1 choice for induction of hemodynamically unstable patients
etomidate
why is etomidate CRI contraindicated
adrenal suppression
propylene glycol accumulation
T/F etomidate can cause V+ even while unconscious
True
combine with fentanyl to decrease etomidate dose and inhibit V+
some cons of etomidate
excitement and twitching possible
pain during injection
hemolysis (propylene glycol)
not an easy to use drug- need experience!
Alfaxalone
rapid onset, short duration
recovery can be rough
no analgesia
CV effects of Alfaxalone
minimal
what drug has the potential to replace etomidate as induction agent for high risk patients
Alfaxalone
when giving Alfaxalone IM for sedation it should be in combination with
midazolam +/- opioids
