Reduces CBF, CMRO2 and ICP Reduces MAP, therefore variable effect on CPP Increases seizure threshold
Pharmacokinetics
Rapid hepatic metabolised, with extra-hepatic metabolism 2–24 hours, but rapid peripheral distribution Short context sensitive
Advantages
Favourable effects on CBF, CMRO2 and ICP Rapid onset of action Relatively short context sensitive facilitating neurological assessment
Disadvantages and major side effects
Hypotension may worsen CPP High lipid load Associated with elevated liver enzymes & pancreatitis Potential for PRIS, particularly with prolonged, high dose infusions Formulation may support bacterial and fungal growth Contraindicated if allergic to egg or soybeans
Dosage
Induction: 1–2.5 mg/kg, 0.5–1.5 mg/kg in elderly or limited cardiovascular reserve Maintenance of sedation: 1.5–4.5 mg/kg/hour, titrated to desired effect
Other significant facts
Increased risk of PRIS at infusions >4 mg/kg/h for >48 h
Appropriate roles in TBI
Induction agent, caution in hypotension Continuous infusion to provide sedation in TBI Refractory elevated ICP Refractory seizures
