A prospective, randomized, single-blind investigation was undertaken into the value of midazolam as an agent for the induction of anaesthesia. Sixty patients undergoing orthopaedic surgery of short duration were allocated randomly to receive either midazolam 0.2 mg kg-1 or thiopentone 3 mg kg-1. The induction time (measured as the time until loss of eyelash reflex) in the thiopentone group was significantly shorter than in the midazolam group. No differences were observed between the two drugs as regards time to onset of apnoea, or changes in heart rate and arterial pressure.

The CO2-production and degree of relaxation after increasing doses of suxamethonium were measured in seven patients undergoing alloplastic surgery of the hip. The study indicates that the CO2-production rises following the injection of increasing doses of suxamethonium. Another group of patients received diazepam 0.1 mg kg-1 before the injection of suxamethonium 1 mg kg-1. CO2-production was significantly reduced compared to CO2 production when suxamethonium was not preceded by diazepam. It is suggested that diazepam in doses larger than 0.1 mg kg-1 might be effective in preventing fasciculations and postoperative muscle pains before the injection of suxamethonium in a dose of 0.5 mg kg-1.