ANAESTHESIA - Ruminant and Pig Anaesthesia

Question 1

What should you do to prepare for ruminant anaesthesia?

Answer 1

Fast your patient
Establish intravascular access (if possible)

Question 2

How long should you fast calves for prior to anaesthesia?

Answer 2

8 - 12 hours for food, 8 hours for water

Question 3

How long should you fast mature cows for prior to anaesthesia?

Answer 3

12 - 24 hours for food, 12 hours for water

Question 4

How long should you fast mature bulls for prior to anaesthesia?

Answer 4

24 - 36 hours for food, 24 hours for water

Question 5

Which vessels can you use to establish vascular access in ruminants?

Answer 5

Jugular vein
Auricular vein

Question 6

Which procedure will you commonly need to do to gain access the jugular vein in ruminants?

Answer 6

Venous cut down procedure because of their thick skin

Question 7

What is the standard premedication combination for ruminants?

Answer 7

α2 agonist and Butorphanol

Question 8

Which α2 agonists are licensed in ruminants?

Answer 8

Xylazine
Detomidine

Question 9

Which opioid is licensed in ruminants?

Answer 9

Butorphanol

Question 10

Which two risks should you be aware of when administering α2 agonists to ruminants?

Answer 10

Arterial hypoxaemia
Pulmonary oedema

Question 11

What should you always have on hand when administering α2 agonists to ruminants?

Answer 11

Oxygen supplementation just in case they develop arterial hypoxaemia and/or pulmonary oedema

Question 12

What can you do to reduce the risk of arterial hypoxaemia and pulmonary oedema in ruminants following α2 agonist administration?

Answer 12

Administer the α2 agonist IM as there is an increased risk of side effects with IV administration

Question 13

What is the standard intravenous (IV) anaesthetic induction protocol in ruminants?

Answer 13

Ketamine ± Thiopentone

Question 14

Why is thiopentone often combined with ketamine to IV induce ruminants?

Answer 14

Ketamine is a dissociative anaesthetic and thus the swallowing reflex will be maintained which makes intubation very challenging. Thiopentone reduces swallowing reflex making intubation less challenging

Question 15

Why is it so important to properly cuff the endotracheal tube when using thiopentone as an IV induction drug in ruminants?

Answer 15

Thiopentone causes regurgitation in ruminants so it is important to properly cuff the endotracheal tube to protect the airway from aspiration

Question 16

Why should thiopentone only be administered IV?

Answer 16

Thiopentone should only be administered IV as it causes perivascular irritation and tissue necrosis

Question 17

What is the standard intramuscular (IM) anaesthetic induction protocol in ruminants?

Answer 17

α2 agonist and ketamine

Question 18

Which inhalant anaesthetic drug is used for maintenance in ruminants?

Answer 18

Isoflurane

Question 19

Why is endotracheal intubation so important in ruminants?

Answer 19

Endotracheal intubation is so important in ruminants as they are at such a high risk of regurgitation and aspiration of rumenal content and saliva

Question 20

How should you recover ruminants from anaesthesia?

Answer 20

Ruminants should be recovered in sternal recumbency with their head elevated and their endotracheal tube left in (still cuffed) which should not be removed until the patient begins to chew the tube. This all reduces the risk of regurgitation and aspiration

Question 21

What are the two most common complications seen in ruminant anaesthesia?

Answer 21

Regurgitation and aspiration of rumenal content and saliva
Rumenal tympany (rumen bloat)

Question 22

What should you do to prepare for pig anaesthesia?

Answer 22

Fast your patient
Get a patient weight
Establish vascular access (if possible)

Question 23

How long should you generally fast pigs prior to anaesthesia?

Answer 23

8 - 12 hours for food and water

Question 24

How long should you fast pigs due to undergo abdominal surgery?

Answer 24

24 hours for food and water

Question 25

Which vessel can you use to establish vascular access in pigs?

Answer 25

Auricular vein

Question 26

Why do you generally have to use intramuscular (IM) administration in pigs?

Answer 26

It is very challenging to gain intravascular access in pigs so intramuscular (IM) injection is generally more realistic

Question 27

Where should you carry out intramuscular (IM) injections in pigs?

Answer 27

In the neck muscles behind the ears

Question 28

Why should you carry out intramuscular (IM) injections behind the ears in pigs?

Answer 28

Neck muscles behind the ears has the least subcutaneous fat so you reduce the risk of intrafat injections and there is not valuable meat behind the ears that you can risk damaging

Question 29

What are the two most common premedication combinations in pigs?

Answer 29

Azaperone and ketamine Detomidine, butorphanol and ketamine

Question 30

Why is azaperone and ketamine as a premedication often an unrealistic choice?

Answer 30

Azaperone and ketamine require a quiet environment for the pig to become sedated which is often unrealistic on a piggary

Question 31

What is the standard anaesthetic induction protocol in pigs?

Answer 31

Ketamine ± Thiopentone

Question 32

Which inhalant anaesthetic drug is used for maintenance in pigs?

Answer 32

Isoflurane

Question 33

Why is endotracheal intubation important in pigs?

Answer 33

Pigs are prone to regurgitation and aspiration ## Footnote However ET intubation is very challenging in pigs so mask induction is also an option

Question 34

What are the three most common complications seen in pig anaesthesia?

Answer 34

Regurgitation and aspiration Hypothermia Porcine malignant hyperthermia

Question 35

Which two factors can trigger porcine malignant hyperthermia?

Answer 35

Stress Inhalant anaesthetic agents

Question 36

Which three breeds of pig are predisposed to porcine malignant hyperthermia?

Answer 36

Pietrain Landrace Largewhite

Question 37

Explain the pathophysiology of porcine malignant hyperthermia

Answer 37

Porcine malignant hyperthermia is a ryanodine receptor mutation which causes an uncontrolled release of calcium from the sarcoplasmic reticulum causing sustained muscle contraction which causes hyperthermia and increases the metabolic demand of those skeletal muscle cells resulting in increased oxygen consumption, increased carbon dioxide production and an ATP depletion. This ATP depletion leads to a loss in cell membrane integrity resulting in potassium, myoglobin and creatine kinase release into the bloodstream

Question 38

What are the seven clinical signs of porcine malignant hyperthermia?

Answer 38

Generalised muscle rigidity Blotchy skin Severe, sustained hyperthermia Hypercapnia Metabolic acidosis Hyperkalaemia Cardiac arrhythmias

Question 39

Which five methods should you use to treat porcine malignant hyperthermia?

Answer 39

- Stop anaesthesia - Remove the vaporiser and replace the breathing system with an uncontaminated one - Intermittent positive pressure ventilation (IPPV) with 100% oxygen - Cool down patient - Symptomatic treatment of hyperkalaemia, cardiac arrythmias and metabolic acidosis

Question 40

Which three methods can you use to cool down a patient with porcine malignant hyperthermia?

Answer 40

Drench with cold water Cold IV boluses Cold enemas

Question 41

Which sedative drug can reduce the risk of porcine malignant hyperthermia?

Answer 41

Azaperone

Question 42

What is the prognosis for porcine malignant hyperthermia?

Answer 42

Poor prognosis

Question 43

When are benzodiazepines used in ruminants and pigs?

Answer 43

Benzodiazepines are used in research ruminants and pigs