Induction Drugs + TIVA

Question 1

Propofol

type, onset/duration, admin

Answer 1

• GABA agonist
• fast onset, short duration
• IV only

Question 2

Propofol CV and respiratory effects

Answer 2

CV: vasodilation (due to hypotension)
- some negative inotropy
Resp: strong depression

Question 3

Propofol in cats

metabolism, recovery, side-effects

Answer 3

• slower metabolism (liver)
• recovery may be delayed after long infusions
• may cause hemolysis and Heinz-body anemia after repeated administration
• pain during IV injection

Question 4

Etomidate

type, onset/duration, metabolism, accumulation

Answer 4

• Imidazole derivative, GABA agonist
• fast onset, short duration
• metabolized by hepatic and plasma esterases
• no accumulation

Question 5

Etomidate effects

Answer 5

• no analgesia
• minimal CV effects
• moderate muscle relaxation
• adrenal suppression
• intracerebral blood volume and ICP decreases, cerebral metabolic O2 consumption decreases

Question 6

Alfaxalone

type, onset/duration, admin

Answer 6

• neurosteroid anesthetic (GABA agonist)
• rapid onset, short duration
• IM and IV

Question 7

Alfaxalone effects

Answer 7

• minimal CV
• muscle relaxation
• no analgesia
• dose-dependent resp depression

Question 8

Thiopental

type, onset/duration, metabolism, redistribution

Answer 8

• barbiturate
• fast onset, short duration
• slow metabolism
• fast redistribution

Question 9

Describe the distribution of Thiopental

Answer 9

1) vessel rich groups (CNS)
2) muscle groups
3) fat groups
Repeated doses will fill up muscle groups

Question 10

Thiopental effects

Answer 10

• hypotension via vasodilation
• arrhythmogenic
• reflex tachycardia
• better muscle relaxation than propofol

Question 11

Ketamine

admin, accumulation, metabolism

Answer 11

• IM, IV
• may accumulate
• metabolized in liver to active metabolite

Question 12

Ketamine effects

Answer 12

• catatonic state
• some analgesic effect (somatic)
• direct: negative inotropy, indirect: positive inotropy
• minimal respiratory depression
• increased ICP
• increased IOP

Question 13

What are the contraindications of ketamine?

Answer 13

• brain trauma or tumor
• perforating eye injury
• heart disease
• seizures
• hepatic and renal insufficiency

Question 14

Is Propofol suitable for TIVA?

Answer 14

Ideal for TIVA because no accumulation

Question 15

Propofol CNS effects

Answer 15

• intracerebral blood volume and ICP decreases
• cerebral metabolic O2 consumption decreases
• antiepileptic
• may cause muscle twitched
• no analgesia

Question 16

Propofol contraindications

Answer 16

• hemodynamically unstable patients

- very sick patients in general

Question 17

What are the ideal features for a TIVA agent?

Answer 17

• short-acting
• stable and short half-life
• does not have active metabolite
• wide therapeutic window
• smooth recovery

Question 18

What is the most common TIVA for small animals?

Answer 18

Propofol - Fentanyl

Question 19

What does the Triple Drip for horses consist of?

Answer 19

• Guaifenesin
• Xylazine
• Ketamine

Question 20

What is the risk with using a Ketamine-based TIVA?

Answer 20

may accumulate after large or repeated doses, causing delayed and rough recovery

Question 21

Which drug is contraindicated in cats and why?

Answer 21

Lidocaine due to cardiogenic toxicity