Peri-Anesthetic Agents Flashcards
what is general anesthesia characterized by?
muscle relaxation
unconsciousness
amnesia
analgesia
what is responsiveness like with deep sedation/analgesia?
purposeful response following repeated or painful stimulation
why should you perform pre-oxygenation before induction?
delays time to deoxygenation/desaturation: gives time to figure it out
how is acepromazine excreted?
in urine, both conjugated and unconjugated
how is acepromazine metabolized?
hepatic
what are the general effects of acepromazine?
muscle relaxation
sedative (anxiolysis)
when can you use acepromazine?
premedication: young, healthy dogs, horses
postoperative sedation: cardiovascular stable dogs, cats, horses
what are the general effects of alpha2 adrenergic agonists?
analgesia
muscle relaxation
sedation
what is the cardiovascular response to alpha2 adrenergic agonists like?
biphasic: peripheral and then central
decrease cardiac output
do alpha2 adrenergic agonists cause a decrease in coronary artery perfusion or myocardial oxygenation?
no
what are the gastrointestinal effects of alpha2 adrenergic agonists?
decrease motility, ruminal contractions, gastric emptying
salivation, emesis, reflux
what is sedation like with alpha2 adrenergic agonists as the sole agent?
very rousable sedation
what is the mechanism of action of benzodiazepines?
enhance GABAa receptor affinity for GABA
increased chloride conduction and hyperpolarization of postsynaptic cell
when can you use benzodiazepines for premedication?
neonatal or geriatric
unstable, critical
combined with 2+ other sedatives
what is buprenorphine useful for?
mild to moderate pain, long-acting
post-op analgesia in stable patients
good post-op choice for cats
can airway intervention be required for deep sedation?
may be required
is cardiovascular function usually maintained under deep sedation?
yes
what are the sedatives/tranquilizers/analgesics?
phenothiazines
alpha2-agonists
benzodiazepines
opioids
what is a phenothiazine?
acepromazine
which drug should you not use the labeled dose on the bottle of?
acepromazine
what is the duration of acepromazine?
4-6 hours dogs/cats
2-4 hours horses
does acepromazine provide analgesia?
no
can you reverse acepromazine?
no
what are the cardiovascular effects of acepromazine?
vasodilation
decreases stroke volume and cardiac output and high doses, may increase heart rate
antiarrhythmic
how does acepromazine affect the CNS?
does not affect electrical activity
thermoregulation impacted
is acepromazine MAC sparing?
yes
when should you avoid acepromazine?
hepatic disease or shunt
unstable animals
prior to laparoscopic procedure
stallions
low doses on large floppy dog breeds
euro boxers
what is phase 1 of alpha2 agonist cardiac effects like?
peripheral vasoconstriction lead to baroreceptor-mediated reflex bradycardia
what is phase 2 of alpha2 agonist cardiac effects like?
central alpha 2a receptor acitvation
decreases sympathetic outflow and increases parasympathetic tone
what are the respiratory effects of alpha2 agonists?
decreases respiratory rate but increases tidal volume: maintains minute ventilation
what are the gastrointestinal effects of alpha2 agonists?
decreased motility, ruminal contractions, gastric emptying
salivation, emesis, reflux
what are the genitourinary effects of alpha2 agonists?
inhibition of antidiuretic hormone release
increased myometrial tone and intrauterine pressure
decreased oxygen delivery
what are the alpha2 adrenergic agonists?
xylazine
detomidine
romifidine
medetomidine/dexmedetomidine
what is the duration of dexmedetomidine?
60-90 minutes
dose dependent
when should you avoid alpa2 agonists?
neonates
hemodynamically unstable patients
diabetic animals?
urinary obstruction
cardiovascular disease
species sensitivity
what are the general effects of benzodiazepines?
anticonvulsant
muscle relaxation
amnesia
sedation/anxiolysis
which animals sedate well on benzodiazepines alone?
ferrets
rabbits
birds
pigs
are benzodiazepines MAC sparing?
minimal
which benzodiazepine has pain on injection and poor bioavailability when given IM or SQ?
diazepam
when should you avoid benzodiazepines?
young, excited dogs/cats
hepatic disease, hypoproteinemia
what are the cardiovascular effects of opioids?
bradycardia
what are the genitourinary effects of opioids?
increased urethral sphincter tone
what is buprenorphine not useful for?
sedation
severe pain
unstable patients- poorly reversible
