Mod 1 - Injectable Induction Agents 8/17 Flashcards
why do we use induction agents?
to induce unconsciousness + muscle relaxation + SNS stabilization
what are the 3 ways animals should be maintained after induction of anesthesia?
- inhalant agents
- total IV anesthesia - TIVA (repeated boluses or infusion of injectable agents)
- partial IV anesthesia - PIVA (inhalant + injectable infusion)
T/F - there is an injectable induction agent that produces all the components of general anesthesia.
False!
what are 3 possible ways induction agents may cause an effect?
- alter cell membranes
- interact with NTM, esp. GABA
- act at receptor sites
T/F - the higher the therapeutic ratio number, the safer the drug.
True
Therapeutic ration = ? / ?
lethal dose50 / effective dose50
Etomidate’s therapeutic ratio is 16. What does this mean?
you must give 16x the effective dose to kill a patient
barbiturates are 1 depressants that are dose-dependent. They have an 2 effect but no 3.
- CNS
- anticonvulsant
- analgesia
what barbiturate has a duration that is:
1. long (8-10hr)?
2. short (45-90min)?
3. ultrashort (5-20min)? (2)
- phenobarbital
- pentobarbital
- thiopental, thiamylal
T/F - thiopental is available for use in the US.
false
how are barbiturate effects terminated? (3)
- physical redistribution away from CNS
- hepatic metabolism
- renal excretion
what receptor does propofol act on?
GABA-A
T/F - if you accidentally inject some propofol outside of the vein into the surrounding tissue, it will cause tissue damage.
False - thiopental will, NOT propofol
T/F - propofol rapidly crosses the BBB and placenta.
true
propofol undergoes rapid biotransformation in the 1. Glucuronide conjugation of propofol turns it into inactive metabolites that are excreted mostly by the 2. Propofol also undergoes 3 metabolism (in the 4).
- liver
- kidneys
- extra-hepatic
- lungs
T/F - it’s okay to give cats propofol consecutively over a few days.
False - they don’t have UGP-glucuronosyltransferase
T/F - administrating propofol over 30-60 secs will help reduce side effects, and its onset of action occurs within 1min.
true
what is the main side effect of propofol?
apnea - very predictable & repeatable!
T/F - propofol does not provide analgesia.
True
what type of anesthetic is alfaxalone?
neurosteroid anesthesic
alfaxalone binds to the 1 receptor in the 2.
- GABA-A
- CNS
what is dissociative anesthesia?
interruption of ascending transmission from the unconscious to the conscious parts of the brain
what state does dissociative anesthesia put the patient in?
cataleptoid - you put the patient in a position and they stay that way
ketamine can be given in what 2 routes?
IM or IV
T/F - ketamine has good analgesia effects. when given at low doses at a CRI, these analgesia effects improve.
true
what is a common side effect that ketamine produces, esp. if used alone?
muscle rigidity
what is ketamine?
what is the MOA of ketamine? (3)
non-competitive NMDA receptor antagonist
- prevents central sensitization in dorsal horn neurons
- thalamoneocortical system depressed
- limbic system activated
ketamine has a ? effect, which prevents the reuptake of endogenous catecholamines.
sympathomimetic
etomidate seems like the perfect drug - there is no depression of the 1 or 2 systems. however, a single dose results in 3 suppression for at least 24hrs and there is poor induction without appropriate 4.
- cardiovascular
- respiratory
- adrenal
- sedation
what is neuroleptanalgesia?
a combo effect of a tranquilizer and an opioid
- usu. benzodiazepine + hydromorphone (or fentanyl or methadone)
MSU uses co-induction agents. why? (3)
- prolongs and potentiates anesthesia
- muscle relaxation
- poor sedation if single drug in healthy animals
