Amnesia: inhalational agents

Question 1

What are the 2 methods of maintaining anaesthesia?

Answer 1

Total IV anaesthesia (propofol infusion)

Inhalational agents

Question 2

When do you start a maintenance amnesia?

Answer 2

Immediately after giving the induction agent

Question 3

Give 3 inhalational agents

Answer 3

Isoflurane
Sevoflurane
Desflurane

Question 4

What is sevoflurane used for?

Answer 4

Inhalational induction and maintenance of GA

Question 5

Give a characteristic of sevoflurane

Answer 5

Sweet smelling

Question 6

What length of operation is desflurane used for?

Answer 6

LONG operations!!

Question 7

Give some properties of desflurane

NB DESFLURANE IS RARELY USED

Answer 7

Low lipid solubility, so more to the brain & less to the fat

Rapid onset and offset

Question 8

What is a property of isoflurane?

Answer 8

Least effect on organ blood flow

Question 9

Give the most appropriate agent for:
- 8 hour finger re-implantation

• organ retrieval from a donor
• fat child, no IV access

Answer 9

• desflurane
• isoflurane
• sevoflurne

Question 10

What is MAC?

Answer 10

Minimum alveolar concentration

i.e. will prevent a reaction to surgical stimulus (pain) in 50% of people

Question 11

What is the MAC of sevoflurane?

Answer 11

2

Question 12

How does sevoflurane affect HR, BP and RR?

Answer 12

Lowers all 3!