[Quality of buprenorphine and morphine as components of combined anesthesia]

Perioperative effects of buprenorphine during and after combined anesthesia for gynecological laparotomies were compared to those of morphine. In a controlled, randomized study two similar groups of patients received flunitrazepam (0.016 mg/kg) and either buprenorphine (0.008 mg/kg) or morphine (0.333 mg/kg); all patients were ventilated with a N2O/O2-mixture. To maintain adequate anesthesia, additional injections of buprenorphine or morphine and a volatile anesthetic agent (enflurane, less than 1.0 vol.%) were administered as needed. In some patients in both groups the injection of thiopental (1-2 mg/kg) became necessary for induction of anesthesia. Hemodynamic parameters showed a slight but not significant increase during intubation and remained stable intraoperatively (Figs. 1 and 2). The frequencies of additional intraoperative injections of buprenorphine or morphine and modalities of enflurane administration were similar in both groups. Based on an awakeness score, recovery from anesthesia was similar in both groups (Fig. 3). All patients were pain-free for a long period postoperatively (pain score 1-2, duration 6-10 h) (Fig. 4). In both groups respiratory depression could be demonstrated by means of ventilatory CO2 response (Figs. 6 and 7). The respiratory depression was of no clinical importance and seems to have been due to the combination of a long-acting benzodiazepine with an opiate. There were no differences in the occurrence of nausea and vomiting in both groups. Buprenorphine seems to be an alternative to morphine in combined anesthesia.