Propofol ('Diprivan') as a supplement to nitrous oxide-oxygen for the maintenance of anaesthesia

Incremental doses of propofol (10-20 mg) have been used to supplement nitrous oxide in oxygen anaesthesia for patients undergoing body surface surgery. After premedication with morphine 0.15 mg/kg, anaesthesia was successfully induced in 21 patients with 2.5 mg/kg propofol. One patient with labile hypertension suffered a pronounced cardiovascular response to the induction of anaesthesia, but without operative sequelae. The mean maintenance rate of propofol was 73.4 micrograms/kg/min. When compared with 10 patients receiving incremental doses of Althesin, recovery to giving correct date of birth was significantly faster in patients receiving propofol (P less than 0.01); when compared with 11 patients receiving an induction of thiopentone 5 mg/kg and nitrous oxide/oxygen/halothane, more patients receiving propofol had recovered to giving correct date of birth by 10 min after the end of anaesthesia (P less than 0.001). However, use of propofol was associated with pain on injection in 9 out of 20 patients, and apnoea of greater than 30 s in 8 patients.