Advanced Anaesthesia and Recovery Surgery

Question 1

What is the triad of anaesthesia?

Answer 1

Unconsciousness- loss of awareness and no memory of the procedure

Analgesia - loss of pain sensation

Muscle relaxation

Question 2

List the home office anaesthetic codes.

Answer 2

AA - no anaesthesia

AB - recovery:
- AB(L) - local
- AB(R) - regional
- AB(G) - general

AC - non-recovery

AD - general with neuromuscular blockade

Question 3

List the classes of drugs used for premedication and important examples of each.

Answer 3

1 - Antimuscarinics
- Atropine
- Glycopyrrolate

2 - Phenothiazines
- Acepromazine
- Chlorpromazine
- Promazine

3 - Butyrophenones
- Droperidol
- Fluanisone
- Azaperone

4 - Benzodiazepines
- Midazolam
- Diazepam

5 - Alpha 2 agonists
- Medetomidine
- Dexmedetomidine
- Xylazine

6 - Opioids
- Buprenorphine** (partial mu agonist)
- Butorphanol (kappa agonist, mu antagonist)
- Morphine (full opioid agonist)
- Methadone (full opioid agonist)
- Fentanyl (full opioid agonist)
- Pethidine (full opioid agonist)

Question 4

List the classes of injected anaesthetic drugs and important examples of each.

Answer 4

1 - Steroid anaesthetics
- Alfaxalone

2 - Alkylphenols
- Propofol

3 - Dissociative anaesthetics & related combinations
- Ketamine
- Combined with medetomidine or xylazine (alpha 2 agonists)

4 - Barbiturates
- Pentobarbital
- Thiobarbital
- Methohexital
- Inactin

5 - Neuroleptanalgesic combinations (an opioid + premedicant)
- Hypnorm (fentanyl + fluanisone) **
- Innovar-vet / thalamanaol (fentanyl + droperidol)
- Immobilon SA (etorphine + methotrimeprazine)

Question 5

List the important inhalational anaesthetic drugs.

Answer 5

1 - Isoflurane **

2 - Sevoflurane **

3 - Desflurane

4 - Halothane

5 - Methoxyflurane

Question 6

List the important NSAID drugs.

Answer 6

1 - Paracetamol

2 - Carprofen **

3 - Meloxicam **

4 - Ketoprofen

5 - Flunixin

*No further cards on NSAIDS because nothing special to remember

Question 7

List the important local anaesthetics.

Answer 7

1 - Bupivacaine

2 - Lidocaine

3 - EMLA cream

Question 8

List the important features of antimuscarinics?

Answer 8

Reduce bronchial and salivary secretions

Reduce drug-induced cardiac depression

Question 9

List the important features of phenothiazines.

Answer 9

Produce mild sedation

Potentiate the actions of other opioids and analgesics

Smooths recovery

Question 10

List the important features of butyrophenones

Answer 10

Similar to phenothiazines (mild sedation, potentiate opioids and analgesics, smooths recovery)

Most commonly used in neuroleptanalgesic combinations

Cause mild sedation and have an anaesthetic-sparing effect

Question 11

List the important features of benzodiazepines

Answer 11

Variable tranquilisation

Potentiate anaesthetics and opioids

Induce skeletal muscle relaxation

Question 12

List the important features of alpha 2 agonists.

What are the important side effects?

Answer 12

Potent sedation

Potentiate anaesthetics

Mild-moderate analgesia

Side effects: CV and respiratory depression and vomiting

Question 13

List the important features of opioids

What are the important side effects?

Answer 13

Moderate sedation

Variable analgesia

Anaesthetic-sparing effect

Side effects: respiratory depression and nausea

Question 14

List the important features of alfaxalone

Answer 14

Given IV

5-10 minutes duration

Can have repeated doses / CRI

Smooth induction

May produce moderate hypotension

Licenced in cats, dogs and rabbits only

Question 15

List the important features of propofol.

Answer 15

Given IV

5-15 minutes duration

Transient apnoea after induction with CV depression

Question 16

List the important features of ketamine.

Answer 16

Produces reliable immobility but skeletal muscle increased

Variable analgesia but usually profound

Cataleptic sedation

Potently abolishes corneal reflex - dry eyes

Question 17

List the important features of ketamine-alpha 2 agonist combinations.

Answer 17

As with ketamine but extended anaesthesia to 20-30 minutes

Question 18

List the important features of neuroleptanalgesics such as hypnorm. **

Answer 18

Profound analgesia

15-30 minutes duration

Cause respiratory depression

Poor muscle relaxation

Often combined further with a diazepine (so-called neuroleptanaesthetic combinations - see next card)

Question 19

Give an example of a common neuroleptanaesthetic combination.

Answer 19

Hypnorm + midazolam

Allows massive dose reduction

Good muscle relaxation

20-30 minutes duration

Question 20

List the important features of pentobarbital.

Answer 20

Given IV

Severe respiratory and cardiac depression

Poor analgesia

Prolonged recovery

Generally used instead for euthanasia

Question 21

List the important features of thiopental.

Answer 21

Given IV

Smooth and rapid induction

Transient apnoea after induction

5-15 minutes anaesthesia

Question 22

List the important features of isoflurane. **

Answer 22

Rapid induction and recovery with easy depth change

Minimal metabolism

Moderate respiratory and cardiovascular depression

Can cause breath holding

Question 23

List the important features of sevoflurane.

Answer 23

Faster onset and offset than isoflurane

Less pungent than isoflurane

Minimal excitement on recovery

Question 24

List the important features of desflurane.

Answer 24

Most rapid onset of inhalational anaesthetics

Least metabolism of inhalation anaesthetics

Expensive and not often used in animals

Question 25

List the important features of morphine.

Answer 25

Short duration of 2-4 hours analgesia Powerful analgesia Significant respiratory depression

Question 26

List the important features of pethidine.

Answer 26

Very short duration of action of <2 hours analgesia Spasmolytic

Question 27

List the important features of methadone.

Answer 27

Duration 2-4 hrs rodents and 4-6 in other species Commonly used in cats and dogs

Question 28

List the important features of fentanyl. List 3 similar drugs.

Answer 28

Potent analgesia Very short duration of <30 minutes Commonly used in neuroleptanalgesic combinations Can be given as a patch or gel Similar drugs: alfentanil, sufentanil, remifentanil

Question 29

List the important features of buprenorphine. **

Answer 29

Partial mu agonist Widely used due to long duration of action (6-8 hours) Less potent than morphine

Question 30

List the important features of butorphanol.

Answer 30

Kappa agonist, mu antagonist - mammals have few kappa receptors but birds have more so is effective in birds. Duration 45 minutes - 1 hour Can be used to reverse other drugs