General Anaesthetics

Question 1

What does MAC stand for?

Answer 1

Minimum Alveolar Concentration

Question 2

What is the MAC?

Answer 2

Minimum concentration of drug in the lung that will cause 50% of the population to remain unconscious when the surgeon begins the operation

Question 3

How does the MAC relate to potency?

Answer 3

High MAC –> low potency

Question 4

How does lipid solubility relate to potency?

Answer 4

The more lipid soluble the drug, the more potent it will be

Question 5

Give 3 examples of IV induction agents

Answer 5

Propofol
Thiopentone
Etomidate

Question 6

What is the mechanism of action of ketamine?

Answer 6

Antagonise NMDA receptors

Question 7

Which drug causes stone bladder?

Answer 7

Ketamine

Question 8

Name 4 inhalation anaesthetics

Answer 8

Nitrous oxide
Isoflurane
Sevoflurane
Desflurane

Question 9

Which drug is used for inhalation induction of children?

Answer 9

Sevoflurance

Question 10

Name two inhalation agents that are irritable to the airway therefore not used for induction

Answer 10

Isoflurane

Desflurane

Question 11

What is entonox?

Answer 11

50:50 oxygen and nitrous oxide

Question 12

What is the link between blood solubility of a drug and onset?

Answer 12

The more soluble, the slower the onset

We want drugs to be less soluble as they need to exert a partial pressure in the blood, not become dissolved in it

Question 13

Which receptors do anaesthetics act upon?

Answer 13

GABA

Question 14

How do anaesthetics affect respiration?

Answer 14

IV - fall in rate

Inhalation - fall in tidal volume

Question 15

Which anaesthetic relatively stable?

Answer 15

Etomidate

Question 16

How does ketamine affect physiology parameters?

Answer 16

Increases

Question 17

What is the effect of most anaesthetics on physiological parameters?

Answer 17

Decrease BP, CO, HR, SVR, RR, ICP