Dose requirements of propofol by infusion during nitrous oxide anaesthesia in man. I: Patients premedicated with morphine sulphate.

The study was performed to determine the ED50 and ED95 of a continuous infusion of the emulsion formulation of propofol during 67% nitrous oxide anaesthesia in 57 patients premedicated with morphine sulphate 0.15 mg kg-1. Anaesthesia was induced with propofol 2 mg kg-1, and maintained before incision with a fixed-rate infusion of propofol to supplement nitrous oxide.