A comparison of the 2% and 1% formulations of propofol during anaesthesia for craniotomy.

This study investigated the pharmacodynamic and pharmacokinetic equivalence of 1% and 2% propofol emulsions when used for total intravenous anaesthesia for intracranial surgery. The same infusion rate (6.7 mg.kg-1 x h-1) of the two preparations was administered. Induction doses, recovery times, and haemodynamic profiles were identical. Similar propofol concentration profiles were produced and total body clearance of propofol was identical. Both preparations were associated with a similar incidence of injection pain but neither resulted in venous thrombosis or thrombophlebitis at 24 h. Plasma triglyceride concentrations were significantly higher with the 1% solution, but there were no differences in cholesterol concentrations. The 1% and 2% emulsions appeared to be pharmacologically equivalent with similar minor effects on arterial blood pressure and heart rate. Two percent propofol may be preferable to the 1% solution for maintenance of anaesthesia in patients in whom a large lipid load might be considered undesirable.