Nalbuphine and Althesin anaesthesia. A controlled double-blind comparison for cystoscopy.

In a double-blind, randomized study of 52 unpremedicated outpatients undergoing cytoscopy, either nalbuphine 20 mg or saline 2 ml was given intravenously immediately before induction of anaesthesia with Althesin 0.05 ml/kg. Increments of Althesin 0.5 ml were used to maintain anaesthesia. The patients received nalbuphine required less Althesin than those who received saline (p less than 0.001) for a similar duration of surgery, and there was less movement during anaesthesia (p less than 0.001). During surgery hyperventilation was observed in the patients who received saline; those who received nalbuphine had lower respiratory rates and higher peak expired CO2 levels (p less than 0.001), and also a smaller increase in pulse rate (p less than 0.05). Recovery after surgery was faster in the patients who received nalbuphine than those who did not (p less than 0.05) and both patients (p less and anaesthetists (p less than 0.001) graded Althesin anaesthesia as better after nalbuphine than after saline. Intravenous nalbuphine 20 mg improved Althesin anaesthesia for cystoscopy without apparent disadvantages.