[The influence of buprenorphine and tramadol on the postoperative CO2 response after general anaesthesia (author's transl)].

The degree of respiratory depression caused by buprenorphine and tramadol were studied in two groups of 25 patients each by means of Read's re-breathing technique. The estimations were made during the immediate postoperative stage in order to include potential residual effects of the general anaesthesia. The slope of the CO2 curve as a measure of respiratory depression decreased by 27 per cent after administration of 0.3 mg of buprenorphine, a reduction which equals that produced by potent morphine-type analgesics. The response to 50 mg of tramadol was a non-significant decrease by 3 per cent. At doses mentioned buprenorphine produced reliable pain relief, whereas with tramadol the failure rate was 28 per cent. There was no difference between the two drugs in respect of circulatory reactions and side-effects. Despite its depressing effect on the respiration (an action it shares with all potent analgesics) buprenorphine is a very useful analgesic because it provides excellent pain relief, has no or only minimal addictive properties and is not subject to the Dangerous Drugs Act.