Anaesthetics

Question 1

4 main induction agents

Answer 1

Propofol
Etomidate
Thiopentone (barbiturate)
Ketamine

Question 2

+ve and -ves of Etomidate

Answer 2

+ve - rapid onset, haemodynamic stability, less hypersensitivity reactions

• ve - adrenal suppression - so Post-op BP low
• muscle movement (myoclonus)

Question 3

+ves and -ves of Propofol

Answer 3

+ve - good airway reflex suppression, reduced PONV

-ve - resp depression, drops BP and HR

Question 4

+ves and -ves of Thiopentone

Answer 4

+ve - RSI, good if not fasted, antiepileptic effects

-ve - bronchospasm and rash, cough, CI in porphyria

Question 5

+ves and -ves of Ketamine

Answer 5

+ve - profound analgesia, muscle relaxant

-ve - vivid hallucinations, anterograde/dissociative amnesia

Question 6

4 main inhalational agents

Answer 6

Sevoflurane, Desflurane, Isoflurane, Enflurane

Question 7

MoA of Inhalational agents

Answer 7

Work on glutamate mediated NMDA receptors and GABA

Question 8

What is a MAC

Answer 8

Minimum Alveolar Concentration - required to prevent reaction to surgical incision in 50% of people

Question 9

S/E profile of inhalational agents

Answer 9

dose dependent reduction in CO and BP

PONV

Question 10

3 Local anaesthetics we need to know + MoA

Answer 10

Lignocaine / Lidocaine
Bupivacaine / Levobupivacaine
Prilocaine

Block Na+ influx - preventing action potentials

Question 11

LA doses

Answer 11

Lignocaine - 3mg/Kg / 7 (+ adrenaline)

Bupivacaine - 2mg/Kg / 2 (+ adrenaline)

Prilocaine - 6mg/Kg / 8 (+ adrenaline)

Question 12

Calculation of a LA dose for a 70kg person, e.g. Lignocaine 1%

Answer 12

70 x 3mg/Kg = 210mg/Kg

1% x 10mls = 10ml/mg

210 / 10 = 21mls of Lignocaine 1%

Question 13

2 classes of Akinesis agents

Answer 13

Suxamethonium

Curium’s = Atracurium, mivacurium, pancuronium

Question 14

SE of Suxamethonium

Answer 14

Muscle pain and fasciculations
Hyperkalaemia
Rise in ICP and IOP
!! Malignant hyperthermia

Question 15

Signs of malignant hyperthermia

Answer 15

Increased Exp CO2
Tachycardia
Tachypnoea
Acidosis
Muscle Spasm

Hyperthermia - late

Question 16

Treatment for Malignant Hyperthermia

Answer 16

Discontinue agent
Dantrolene - 2.5mg/Kg IV Bolus
Sodium Bicarbonate for Acidosis/Hyperkalaemia
Cooling Procedure
Hyperventilate with FiO2 100%

Question 17

Doses of Propofol?

Answer 17

1.5 - 2.5 mg/Kg

Question 18

Dose of Thiopentone?

Answer 18

4 - 5 mg/Kg

Question 19

Dose of Etomidate?

Answer 19

0.3 mg/Kg

Question 20

Dose of Ketamine?

Answer 20

1 - 1.5 mg/Kg