Induction of Anaesthesia

Question 1

What size of catheter should be used in a 0.8kg cat?

Answer 1

24 gauge

Question 2

What size catheter should be used in a 1-5kg cat?

Answer 2

22 guage

Question 3

What size catheter should be used in a 5-30kg dog?

Answer 3

20 gauge

Question 4

What size catheter should be used in a dog over 30kg?

Answer 4

18 gauge

Question 5

What size catheter should be used in large animal jugular veins?

Answer 5

10g-16g

Question 6

what is the mechanism of action of propofol?

Answer 6

GABA A agonist

Question 7

Why should cats not be reanaethetised with propofol within 7 days?

Answer 7

They have a mutation in a gene encoding a liver enzyme which makes ir unfunctional. They therefore have more limited metabolism than dogs and infusions result in prolonged recovery. Sighthounds also may have a prolonged recovery due to the p450 mutation in the liver.

Question 8

What is the mechanism of action of Alfaxan

Answer 8

GABA A agonist.

Question 9

What is the mechanism of metabolism of alfaxan?

Answer 9

hepatic

Question 10

how should alfaxon be administered?

Answer 10

IV or IM but IM is more sedation. IV over 45 seconds. Less hypotension than propofol but have post induction apnoea

Question 11

Why is premedication important in animals anaesthatised with alfaxan?

Answer 11

excitement is seen on recoveryin unpremedicated animals, particularly if the animals are udisturbed.

Question 12

How must ketamine hydrochloride be kept?

Answer 12

limited access in locked cabinet

Question 13

What makes ketamine a painful injeciton?

Answer 13

Its low pH

Question 14

How is ketamine metabolised in dogs, horses and how is this different in cats

Answer 14

dogs horses: hepatic. Cats: renal

Question 15

What is the mechanism of action of Ketamine?

Answer 15

NMDA antagonist. Some action at opiod receptors.

Question 16

What other uses can ketamine have?

Answer 16

analgesic, sedative and induction agent.

Question 17

Why is ketamine not used alone at higher doses?

Answer 17

Does not cause muscle relaxation.

Question 18

what is ketamine premeded with?

Answer 18

alpha2 agonists or benzodiazepines (diazepam, midazolam)

Question 19

Is etomidate licensed for use in animals?

Answer 19

No

Question 20

When is etomidate used and why?

Answer 20

In very cardiovascular unstable patients as it does not cause changes in blood pressure or increase cardiac arrhythmias

Question 21

What is the mechanism of action of etomidate?

Answer 21

GABA agonist.

Question 22

Why does etomidate have limited use?

Answer 22

Does not cause good muscle relaxation or analgesia and is unlicensed in animals.