Comparison of methohexitone and propofol ('Diprivan') for induction of enflurane anaesthesia in outpatients.

In 73 unpremedicated patients scheduled for minor outpatient oral surgery or restorative dentistry, enflurane anaesthesia was induced either with an emulsion formulation of propofol (2.5 mg/kg) or with methohexitone (2 mg/kg). Sensations at the site of the injection were more common when the drugs were injected into a vein in the dorsum of the hand (58% for propofol and 28% for methohexitone) when compared to a vein in the forearm or antecubital area (7 to 8% with sensations). After induction of anaesthesia intravenous suxamethonium was given, and endotracheal intubation carried out. Anaesthesia was subsequently maintained using nitrous oxide, oxygen and enflurane. One minute after intubation a similar decrease in mean systolic arterial pressure was noted in both groups but the increase in mean heart rate observed in the methohexitone group (22 beats/min) was significantly (P less than 0.01) greater than that seen in the propofol group (11 beats/min). Excitatory side effects were observed in only one patient in the propofol group and in 12 patients in the methohexitone group (P less than 0.01 between groups). Walking and perceptual speed tests of recovery showed transient impairment of psychomotor skills for 30 to 60 min after both anaesthetic regimens. The incidence of nausea or vomiting was similar (27 to 33%) in both groups. It is concluded that both propofol in emulsion form and methohexitone are satisfactory induction agents in outpatient dentistry. Propofol provided a smoother induction of anaesthesia and recovery was as rapid as after anaesthesia induced with methohexitone.