Propofol. A review of its pharmacodynamic and pharmacokinetic properties and use as an intravenous anaesthetic.

Propofol is an intravenous anaesthetic which is chemically unrelated to other anaesthetics. Induction of anaesthesia with propofol is rapid, and maintenance can be achieved by either continuous infusion or intermittent bolus injections, with either nitrous oxide or opioids used to provide analgesia. Comparative studies have shown propofol to be at least as effective as thiopentone, methohexitone or etomidate for anaesthesia during general surgery. The incidence of excitatory effects is lower with propofol than with methohexitone, but apnoea on induction occurs more frequently with propofol than with other anaesthetics. Additionally, a small number of studies of induction and maintenance of anaesthesia have found propofol to be a suitable alternative to induction with thiopentone and maintenance with halothane, isoflurane or enflurane. Propofol is particularly suitable for outpatient surgery since it provides superior operating conditions to methohexitone (particularly less movement), and rapid recovery in the postoperative period associated with a low incidence of nausea and vomiting. When used in combination with fentanyl or alfentanil, propofol is suitable for the provision of total intravenous anaesthesia, and comparative studies found it to be superior to methohexitone or etomidate in this setting. Infusions of subanaesthetic doses of propofol have been used to sedate patients for surgery under regional anaesthesia, and also to provide sedation of patients in intensive care. In the latter situation it is particularly encouraging that propofol did not suppress adrenal responsiveness during short term studies. If this is confirmed during longer term administration this would offer an important advantage over etomidate. Thus, propofol is clearly an effective addition to the limited range of intravenous anaesthetics. While certain areas of its use need further study, as would be expected at this stage of its development, propofol should find a useful role in anaesthetic practice.