Ketamine

Question 1

Pharmacology and presentation of Ketamine?

(Paramedic - Analgesia only)

Answer 1

200mg:2ml

• Analgesic, that predominantly blocks NMDA receptor resulting in inhibition of excitatory neurotransmitters in the brain.
• Low doses = analgesia, larger doses = dissociation, and high doses = sedation

Question 2

Indicators of Ketamine?
CPR, Pain 4xSedate

S.A.C.R.I.D

Answer 2

• Asthma with severe agitation
• Severe pain
• Significant movement during CPR
• RSI
• Inducing dissociation
• Delirium
• Severe pain (in addition to other medicines), particularly musculoskeletal or burn pain that has not been adequately controlled with an opiate.
• Inducing dissociation, for example for cardioversion, joint relocation or limb alignment.
• Agitated delirium causing a severe to immediately life-threatening risk to safety.
• Rapid sequence intubation (RSI).
• Significant movement during CPR that is interfering with resuscitation.
• Asthma with severe agitation that is impairing the ability to safely provide treatment and/or transport.

Question 3

Contraindications of Ketamine?

Answer 3

• Known severe allergy.
• Aged less than one year

Question 4

Cautions of Ketamine?

4x neuro impaired, 3 x Heart

A.C.E.M.U.C.H?

Answer 4

1. A - active psychosis
2. C - concurrent admin of other sedatives
3. E - elderly/frail
4. M - M.I
5. U - Unable to obey
6. C - Clinical conditions made worse by HTN
7. H - HTN

• Unable to obey commands.
• Active psychosis.
• Concurrent administration of sedatives or midazolam.
• Elderly and/or frail.
• Hypertension.
• Clinical conditions that may be made worse by hypertension, for example haemorrhagic stroke.
• Current myocardial ischaemia.

Question 5

Side Effects of Ketamine?
Head down x 6

Answer 5

Head Down Approach
- Sedation.
- Hallucinations.
- Nausea and vomiting.
- Apnoea.
- Tachycardia.
- Transient hypertension.

Question 6

Dosing Regimes of Ketamine?

Answer 6

Ketamine IV Adult >80kgs
- 30mg IV over 15minutes, repeat prn

Ketamine IV Adult 50-80kgs
- 20mg IV over 15minutes, repeat prn

Ketamine IV Paediatrics
- 10kg = 2.5mg
- 20kg = 5mg
- 30kg = 8mg
- 40kg = 10mg

IV Administration
- Dilute 100mg:1ml of Ketamine into a 100ml 5% Glucose bag.
- Adults draw up dose and administer 2mg:2ml every 1-2mins
- Children draw up dose, dilute to 20ml and administer 2ml every 1-2mins

Infusion >40kgs
- Draw up analgesic dose of ketamine, add to 100ml 5% Glucose bag and infuse at 2-3 drops per second. Will give 100mls over 15mins. Then flush set

Ketamine IM or PO
- 0.5mg per kg to a maximum of 50mg if IV access cannot be obtained. Repeat same dose once at 20mins
- PO should be administered undiluted in a liquid like paracetamol syrup or water

Question 7

Onset and duration of Ketamine?

Answer 7

Onset:
- IV: 1-2mins
- IM: 5-1Omins
- PO: 10-20mins

Duration
- 10-60mins