Sedation in Traumatic Brain Injury

Table 7

Ketamine
Group	Phencyclidine derivative
Mechanism of Action/Pharmacodynamics	Competitive NMDA receptor antagonist; Interaction with opioid and muscarinic receptors; Na^+ Channel
Effect on ICP	None or decrease
Neuroprotective effects	Decreased glutamate
Pharmacokinetics	20% Bioavailability; 40% protein bound; Distribution 𝑡1/2 10 minutes; Hepatic metabolism; Elimination 𝑡1/2 2.5 h
Advantages	Preserves MAP and CPP
Disadvantages and major side effects	Early studies ↑ICP, ?epileptogenic; Hallucinations/Emergence phenomena
Dosage	Induction: 2 mg/kg; Maintenance: 50 mcg/kg/min
Other significant facts
Appropriate uses in TBI	Haemodynamic instability