Propofol

Propofol is an IV anaesthetic induction agent that has rapidly become popular as a sedative drug in the critically ill. Its major advantages are that it has a rapid onset of action and a rapid recovery even after prolonged infusion. Propofol 1% (10 mg/ml) and 2% (20 mg/ml) are formulated in intralipid. If the patient is receiving other IV lipid concurrently, a reduction in quantity should be made to account for the amount of lipid infused as propofol: 1 ml propofol 1% contains 0.1 g fat and 1 kcal.

Cremer OL, et al. (The Lancet 2001; 357: 117–18) have suggested an association between long-term (>2 days) high-dose (>5 mg/kg/h) propofol infusion used for sedation and cardiac failure in adult patients with head injuries. All the seven patients who died developed metabolic acidosis, hyperkalaemia or rhabdomyolysis. Reports of similar suspected reactions, including hyperlipidaemia and hepatomegaly,were previously reported in children given propofol infusion for sedation in intensive care units, some
with fatal outcome (MCA/CSM Current Problems in Pharmacovigilance 1992; 34).

Uses
Sedation, especially for weaning from other sedative agents
Status epilepticus

Contraindications
As an analgesic
Hypersensitivity to propofol, soybean oil or egg phosphatide (egg yolk)
Sedation of ventilated children aged 16 years or younger receiving intensive care

Administration
• IV bolus: 10–20mg PRN
• IV infusion: up to 4 mg/kg/h

Titrate to desired level of sedation – assess daily
Measure serum triglycerides regularly
Contains no preservatives – discard after 12 h

How not to use propofol
Do not give in the same line as blood or blood products
Do not exceed recommended dose range for sedation (up to 4 mg/kg/h)

Adverse effects
Hypotension
Bradycardia
Apnoea
Pain on injection (minimised by mixing with lignocaine 1 mg for every 10 mg propofol)
Fat overload
Convulsions and myoclonic movements

Cautions
Epilepsy
Lipid disorders (risk of fat overload)
Egg allergy (most patients are allergic to the egg albumin – not egg yolk)

Organ failure
CNS: sedative effects increased
Cardiac: exaggerated hypotension