Ketamine

Question 1

What is the presentation?

Answer 1

Intravenous/intraosseous administration:

200mg in 2mL

Question 2

What does it do?

Answer 2

Rapid acting dissociative anaesthetic

Question 3

What is the onset?

Answer 3

IM onset: 5-10 minutes

IV onset: 1 minute

Question 4

What are the indications?

Answer 4

IV: Second line agent for severe pain of traumatic origin post IV Fentanyl administration. ASMA consult needed if IV Fentanyl minimum dose (age dependent as per CPG) has not been given prior to IV Ketamine administration.
IM: First line agent for severe pain of traumatic origin should other means of administering pain medication not be available
Actively disturbed patients requiring sedation where midazolam has already been utilised
Combative Traumatic Brain Injury

Question 5

What are the contraindications?

Answer 5

Hypersensitivity
Active cardiovascular disease including cardiac chest pain, heart failure, severe or poorly controlled hypertension
Active psychiatric condition (unless pre- treatment with midazolam)
IM/IV/IO: Patients under extended care (e.g. ‘ramped’ patients)
IM/IV/IO: Non traumatic pain
IM/IV/IO: Age <12 months
Oral wafer: Age <12 years

Question 6

What are the precautions?

Answer 6

Used with caution in patients with stable psychiatric disorders such as Schizophrenia (unless pre-treatment with midazolam)
Use with caution in patients with hyperthyroidism or receiving thyroid replacement due to increased risk of hypertension and tachycardia.
IV Fentanyl minimum dose (age dependant as per CPG) should be given prior to IV Ketamine administration
Wafer can be administered to patients experiencing non-traumatic pain where methoxyflurane has proven to be ineffective or cannot be administered.
Prior to administration of the Ketamine Wafer, patients should be encouraged to rinse mouth with water and swallow completely.
Wafer should be placed posterior towards the base of the tongue and medially on either side of the frenulum in the sublingual space.

Question 7

What is the adult dose for pain relief?

Answer 7

IM (pre-hospital only):
Initial does: 1 mg/kg;
Subsequent doses at 5 minute intervals – 0.5mg/kg;
Concentration: 200mg/2ml = 100mg/ml
IV/IO (pre-hospital only):
Initial dose: 10-20mg (1-2ml)
Subsequent doses at 5 minute intervals – 10mg (1ml)

Question 8

What is the paed dose for pain relief?

Answer 8

IM (pre-hospital only):
Initial does: 1 mg/kg;
Subsequent doses at 5 minute intervals – 0.5mg/kg;
Concentration: 200mg/2ml = 100mg/ml
IV/IO (pre-hospital only):
0.1mg/kg administered slowly titrated to effect
Repeated at 5 minute intervals as required

Question 9

What is the dose for sedation?

Answer 9

IM (pre-hospital only):
Initial does: 1 mg/kg;
Subsequent doses at 5 minute intervals – 0.5mg/kg;
Concentration: 200mg/2ml = 100mg/ml
IV/IO (pre-hospital only):
0.1mg/kg administered slowly titrated to effect
Repeated at 5 minute intervals as required

Question 10

Special considerations/side effects?

Answer 10

Blood pressure and pulse frequently elevated
Random purposeless movements, muscle twitching and rash are common
Hypersalivation
Emergence reactions (10%)
Transient laryngospasm
Transient apnoea or respiratory depression

Discarding unused medication must be witnessed and countersigned by attendant and credible witness.