Anaesthetic induction agents

Question 1

what is the dosage for propofol?

why is it so good? (2)

Answer 1

1. 5-2.5 mg/kg
   - decreased incidence of PONV
   - best supporter of airway reflexes

Question 2

what are the unwanted effects of propofol? (2)

Answer 2

• marked DROP in HR and BP

- involuntary movements

Question 3

What is the dose for thiopentone?

what are its benefits and why is one of them particularly useful? (2)

Answer 3

4-5 mg/kg

• faster induction than propofol, so used for Rapid Sequence Induction
• antiepileptic/ protects brain

Question 4

What are the adverse effects of thiopentone? (3)

What is it contra-indicated in? (1)

Answer 4

• Drop in BP and rise in HR
• rash/ bronchospasm
• intra- arterial injection can cause thrombosis/ gangrene
• contraindicated in porphyria

Question 5

What kind of operations would you use thiopentone in?

Answer 5

• emergencies such as intestinal obstruction for Rapid Sequence Induction

Question 6

What is the term used to describe the anaesthesia in ketamine? (1)

what is the dose?

Answer 6

• dissociative anaesthesia: profound analgesia

- 1-1.5 mg/kg

Question 7

what are the adverse effects? (4)

Answer 7

• rise in HR/ BP
• slow onset (90 seconds)
• vivid dreams and hallucinations (emergence phenomenon)
• anterograde amnesia

Question 8

What makes ketamine more suited to asthmatics than thiopentone?

What other patients are likely to benefit from it?

Answer 8

• causes bronchodilation instead of bronchospasm

- patients in severe pain (e.g. burns)

Question 9

What is the dose of etomidate?

what is its positive effects? (3)

Answer 9

• 0.5 mg/kg
• keeps patient haemodynamically stable
• lowest incidence of hypersensitivity reaction
• rapid onset

Question 10

what are the negative effects of etomidate? (3)

what patients would benefit from etomidate?

Answer 10

• adreno-cortico suppression
• high incidence of PONV
• can lead to spontaneous movements
• those in heart failure