CLINICAL PHARMACOLOGY - Induction and Maintenance of Anaesthesia

Question 1

Which three key factors can influence which method of administration you use for the induction of anaesthesia?

Answer 1

Can you establish venous access
Temperament of the animal
Speed of induction required

Question 2

Which three methods of administration can be used to induce anaesthesia?

Answer 2

Intravenous (I.V.) most common
Intramuscular (I.M.)
Inhalational

Question 3

When is intramuscular induction of anaesthesia typically used?

Answer 3

Intramuscular anaesthesia is typically used in animals that are difficult to handle or in animals where you cannot aquire intravenous (I.V.) access

Question 4

Which inhalational anaesthetic is appropriate as an induction drug?

Answer 4

Sevoflurane

Question 5

What is co-induction of anaesthesia?

Answer 5

Co-induction of anaesthesia is the use of two or more drugs to induce anaesthesia

Question 6

What is the main benefit of co-induction of anaesthesia?

Answer 6

Co-induction reduces the doses required which can help to minimise drug side effects

Question 7

Which three methods of administration can be used to maintain anaesthesia?

Answer 7

Inhalational most common
Intravenous (I.V.)
Intramuscular (I.M.)

Question 8

Which three methods of airway management can be used when a patient in under anaesthesia?

Answer 8

Mask
Supraglottic airway
Endotracheal intubation

Question 9

When is a mask particularly useful for airway management?

Answer 9

Is mask is particularly useful for airway management in small patients

Question 10

What are the three disadvantages of using a mask for airway management?

Answer 10

Risks gas leakage
Difficult to hold the mask in place
Does not protect against aspiration

Question 11

What is a supraglottic airway?

Answer 11

A supraglottic airway is an airway management device designed to sit above the glottis and allows for ventilation without the need for tracheal intubation

Question 12

In which species are supraglottic airways popular for airway management?

Answer 12

Rabbits

Question 13

What is the main disadvantage of a supraglottic airway?

Answer 13

Supraglottic airways are easily dislodged

Question 14

What are the three main benefits of endotracheal intubation for airway management?

Answer 14

Maintains a patent airway
Allows the anaesthetist to support ventilation
Protects against aspiration and regurgitated material

Question 15

List five risks/complications due to endotracheal intubation

Answer 15

Laryngospasm
Endobronchial intubation
Kinking the endotracheal tube
Tracheal obstruction
Tracheal rupture

Question 16

How do you choose an appropriate length of endotracheal tube for intubating your patient?

Answer 16

Measure the endotracheal tube from the point of the incisors to the point of the shoulder

Question 17

What can you do to reduce the risk of laryngospasm in cats?

Answer 17

Desensitise the larynx with lidocaine spray
Ensure minimal contact with the larynx

Question 18

Which five methods can you use to confirm an endotracheal tube is in the trachea?

Answer 18

Visual confirmation
Movement of breathing system bag
Condensation in the transparent tubes
Capnography
Palpate for the tube within the trachea

Question 19

How can endotracheal intubation increase anaesthetic risk in cats?

Answer 19

There are more complications associated with endotracheal intubation in cats such as laryngeal spasm due to mechanical manipulation of the larynx, tracheal collapse and pressure necrosis due to overinflation of the cuff

Question 20

Why should you always intubate ruminants if they are put under general anaesthetic?

Answer 20

You should always intubate ruminants going under general anaesthetic due to their high risk of regurgitation

Question 21

In which breeds is oxygenation prior to inducing anaesthesia particularly important?

Answer 21

Brachycephalic breeds

Question 22

What are going to be your main concerns when intubating and anaesthetising brachycepahlic breeds?

Answer 22

• May be challenging to intubate due to their anatomy
• Risk of regurgitation and aspiration so you want to intubate quicky to protect the airway
• You want a rapid recovery so they can regain control of their airway

Question 23

List four things you can you do to reduce the risk of regurgitation and aspiration

Answer 23

Rapid induction
Intubate in sternal recumbency
Cuff the endotracheal tube
If the animal regurgitates, move the head downwards to drain