pre medication

Question 1

what is premedication and why do we do it

Answer 1

the provision of sedation and anxiolysis before induction of anaesthesia

Question 2

what are the benefits of premedication

Answer 2

• reduction of dose of induction agent
• reduction of dose of maintenance agent
• provide pre-emptive analgesia and preventative analgesia
• ensure a smooth recovery
• prevent side effects associated with other anaesthetic drugs
• premedication/sedation can start at home

Question 3

acepromazine is used in which species?
Which species is it never used in

Answer 3

used in dogs, cats and horses
never farm animals

Question 4

what is the mechanism of action of acepromazine

Answer 4

works by inhibiting central dopaminergic receptors. It also has muscarinic action and blocks norepinephrine and adrenergic receptors

Question 5

does acepromazine provide analgesia

Answer 5

no - often given with an opioid

Question 6

what are the side effects of acepromazine

Answer 6

reduce blood pressure and does reduce oxygen delivery to tissues

Question 7

can you reverse acepromazine

Answer 7

no

Question 8

how is acepromazine given

Answer 8

Sc, IM, IV and oral

Question 9

give examples of alpha 2 agonists in small animals, horses and cattle

Answer 9

small animals: medetomidine and dexmedetomidine
horses: xylazine, detomidine and romifidine
cattle: xylazine and detomidine

Question 10

what are the side effects of alpha 2 agonists

Answer 10

• profound cardiovascular effects (dose dependent) and reduction in cardiac output
• increase urine production
• miosis, intraocular pressure,
• vomiting

Question 11

can oyu reverse alpha 2 agonists

Answer 11

yes - with atipamezole

Question 12

which animals should not be given alpha 2 agonists

Answer 12

animals with heart disease and blocked cats

Question 13

give examples of benzodiazepines

Answer 13

• midazolam
• diazepam
• zolazepam
• alprazolam

Question 14

which receptor does benzodiazepines work on

Answer 14

GABA receptors

Question 15

what do benzodiazepines do

Answer 15

• anxiolytic
• muscle relaxation
• CVS stability
• NOT analgesia

Question 16

is it a good idea to give diazepam IM

Answer 16

not really - dissolved in propylene glycol so painful IM

Question 17

which animals should benzodiazepines be avoided in

Answer 17

• healthy animals as will cause a lot of excitment
• best for sick, elderly or very relaxed patients

Question 18

can you reverse benzodiazepines

Answer 18

yes - with flumazenil

Question 19

what is the mechanism of action of alfaxalone

Answer 19

Works on GABA receptors

Question 20

how can alfaxalone be given

Answer 20

licensed for IV but can be given IM

Question 21

why might you use alfaxalone instead of an alpha 2 agonist

Answer 21

alfaxalone causes minimal effects on the cardiovascular system

Question 22

list opioids, the species they are licensed in, the route of administration, receptors and side effects

Answer 22

Question 23

under whatcircumstances might you give an antihistamine as part of premed

Answer 23

MCT sx

Question 24

what pre medication combo should be given to an ASA 1 dog/cat

Answer 24

acepromazine or alpha 2 agonist and opioids

Question 25

what premedication combo can be given to ASA 2 dogs and cats

Answer 25

- depends on disease - low dose ACP/alpha 2 and opioid usually tolerated - care with ACP in liver disease - care with Alpha 2 agonists in CVS disease (mitral valve disease), ACP might be better option - Alpha 2 agonists may be of use in HCM (low dose)

Question 26

what pre-medication combo can be given to ASA 3-5 dogs and cats

Answer 26

- avoid the alpha 2 agonists in compromised animals - very low doses of alpha 2 agonists may be used if animal very distressed - opioid alone may be sufficient to sedate patient - fentanyl and midazolam IV useful - ketamine and midazolam (IM or IV) in cats - alfaxalone and opioids is an option, can add BZD too if necessary

Question 27

what pre-medication combos can be given to fear agressive patients

Answer 27

- alpha 2 agonists alone (even high doses) often insufficient to sedate these animals - alpha 2 and ketamine and opioid (+/-) ACP combination IM - if possible dispense meds to be given at home (gaba/taz) - minimize handling, safe environment, equipment, route, pheremones