Basic principles

Question 1

‘Anaesthesia’ definition

Answer 1

Elimination of sensation by the controlled reversible suppression of nervous function with drugs (+ monitoring that goes with it)

Question 2

‘Analgesia’ definition

Answer 2

State in which there is no sensibility to pain

Question 3

‘Pain’ definition

Answer 3

Conscious appreciation of unpleasant stimuli

Question 4

Purposes of anaesthesia (6)

Answer 4

Perform surgery
Restrain and examine
Control pain
Facilitate intensive care
Control seizures
Euthanasia

Question 5

Describe CNS sensitivity to anaesthesia

Answer 5

Anaesthetics enter brain rapidly because they are highly lipophilic molecules, and the brain is v. vascular, so brain/blood equilibrium established quickly.
“Higher” regions of brain more sensitive to anaesthetics as more sensitivity and blood supply.

Question 6

Types of anaesthesia

Answer 6

1. Local anaesthesia (peripheral nn)
2. Extradural local anaesthesia (spinal nn)
3. General anaesthesia (brain): deep general, supported deep general, balanced

Question 7

Describe the main features of a deep general anaesthetic

Answer 7

High doses of drugs
Profound depression of vital function
eg. injecting a dog with propofol and leaving it

Question 8

Describe the main features of a supported deep general anaesthetic

Answer 8

High doses of drugs

Compensation for adverse affects by anaesthetist eg. by intubation, monitoring

Question 9

Described the main features of a balanced general anaesthetic

Answer 9

Use anaesthetics, and ADJUNCT DRUGS: muscle relaxants and analgesics.
Lower dose of anaesthetic needed so vital centre activity = preserved

Question 10

List the stages of the ‘anaesthetic period’

Answer 10

1. Pre-anaesthetic examination
2. Pre-op prep
3. Pre-anaesthetic medication
4. Induction
5. Maintenance
6. Recovery
7. Convalescence

Question 11

What are the functions of anaesthetic machines?

Answer 11

1. Deliver safe concs of IAA
2. Deliver oxygen
3. Mobile ICU: provide PPV during apnoea/cardiopulm arrest