Anaesthesia and analgesia Flashcards
Define nociception
lack of awareness of painful inputs
Why do we give a premed ?
-reduce dose of inducing agent
-reduce dose of maintenance agent
-pre-emptive analgesia
-smooth recovery
List pre med drugs
acepromazine ACP
alpha 2 agonist -medetomidine
benzodiazepine - midazolam
alfaxalone
opiod
Describe the use of ACP as a pre med
-usually with opiod
-sedation
-cause vasodilation - not good for sick animals
-SC,IM,IV and oral
What alpha 2 agonists do we use for small animals ?
medetomidine or dexmedetomidine
What alpha 2 agonists do we use for horses ? ( fast-slowest to kick in )
xylazine - fastest
detomidine - middle
romifidine - slowest
What alpha 2 agonists are used in cattle ?
xylazine
detomidine
Describe alpha 2 agonist as a pre med
-cardiovascular effects
-analgesia
-increase urine production - no blocked cats
-effects glucose - diabetic patients
-not in sick patients
-has reversal agent ( atipamezole )
List examples of benzodiazepines
midazolam
diazepam
Describe the action of benzodiazepines as pre meds
-no analgesia
-ASA 3 - can use in sick animals
-wide therapuetic index
-avoid in excitable animals
-works on GABA
-reversal ( flumazenil )
- usually combined opiod, ketamine or alfaxalone
Describe the action of alfaxalone
-IV and IM
-usually combined opiod
-minimal cardiovascular effects
-painful in large animals IM - large amount
List some examples of opiods
methadone (dog , cat , horse )
fentanyl ( dog, cat )
butorphanol ( used lot in equine )
buprenorphine ( horse , dog , cat )
Describe the action of opiods as pre med
-analgesia
-limited cardiovascular effects
TRUE/FALSE ASA 5 is a healthy animal
false
TRUE/FALSE no alpha 2 agonists in sick patients
true
List some induction agents
propofol
alfaxalone
ketamine
TRUE/FALSE volatile agents are mainly used for maintenance
true
What does propofol target ?
GABA receptors
State disadvantages and advantages of propofol
-rapid uptake
-rapid smooth recovery
-resp and cardiovascular depression - Good to have IPPV breathing system
-no analgesia
What does alfaxalone target ?
-GABA receptors
Advantages and disadvantages of alfaxalone as a induction agent
-rapid onset of action
-rapid and smooth recovery
-licensed for rabbits too
-resp and cardiovascular depression
-no analgesia
What does ketamine target ?
-NMDA receptor antagonist
Advantages and disadvantages of ketamine as an inducing agent
-analgesia
-licnesed ruminants,rodents,rabbits ,primates and horses as well as cat and dog
-poor muscle relaxation ( combine with alpha 2 or BZD)
-schedule 2