Ketamine

Question 1

What is the mechanism of action of Ketamine?

Answer 1

●Blocks N-methyl-d-aspartate (NMDA) receptors preventing excitation of neurotransmitters in the brain.
●Low doses cause analgesia.
●Larger doses cause amnesia and dissociation.
●High doses cause anaesthesia.

Question 2

What are the indications for Ketamine?

Answer 2

●Severe pain not controlled with opiates.
●Dissociation.
●Acute behavioural disturbance causing a severe to immediately life-threatening risk to safety.
●Asthma with severe agitation that is impairing the ability to safely provide treatment or transport.
●RSI.
●Significant movement during CPR causing disruption of CPR.

Question 3

What are the contraindications of Ketamine?

Answer 3

●Known severe allergy.
●Less than 1 year old.

Question 4

What are the cautions for Ketamine? (5)

Answer 4

●ALOC (can reduce LOC).
●Signs of shock (May worsen shock).
●Myocardial Ischaemia (may increase 02 demand).
●Concurrent administration with opiates or Midazolam (will prolong/increase effects).
●75 years old or older (will prolong/increase effects).

Question 5

What are the adverse effects of Ketamine?

Answer 5

●Hypertension
●Tachycardia
●Apnoea
●Sedation
●Hallucinations
●Nausea and vomiting

Question 6

What is the adult IV dose of Ketamine for analgesia?

Answer 6

0.25mg/kg up to 25mg administered over 15 minutes.
Can be repeated as required.

Question 7

What is the adult IM and oral dose of Ketamine?

Answer 7

0.5mg/kg up to 50mg.
Can be repeated once after 20 minutes.

Question 8

What is the onset time of Ketamine IV?

Answer 8

1-2 minutes

Question 9

What is the IM duration of effect of Ketamine?

Answer 9

5-10 minutes.

Question 10

What is the oral onset of effect of Ketamine?

Answer 10

10-20 minutes.

Question 11

What is the preparation of Ketamine?

Answer 11

Ampoule containing 200mg/2ml.