[Epidural buprenorphine with nitrous oxide-oxygen-enflurane anesthesia].

Epidural buprenorphine (Bn) with nitrous oxide-oxygen-enflurane (GOE) anesthesia was investigated as an anesthetic method in 63 patients who underwent upper abdominal surgery over three hours. The patients were divided randomly into three groups. The first group received only GOE anesthesia (group A, n = 13), the second group was given GOE anesthesia and 0.2 mg epidural Bn every three hours during operation (group B, n = 23) and the third group was administered GOE anesthesia and 0.2 mg epidural Bn every six hours (group C, n = 27). The patients were rated according to intraoperative anesthetic dosage, awakening from anesthesia, postoperative respiratory depression and postoperative analgesia. The administered enflurane concentration declined approximately 0.4% in group B and C as compared that in group A (P less than 0.05). And there was no intra-group difference in the awakening time from anesthesia. Postoperative respiratory depression was noted in group B. The respiratory rate 18.7 +/- 1.0 (mean +/- SE) min-1 in group B was significantly lower compared with the rates 22.8 +/- 1.5 min-1 in group A and 22.1 +/- 1.1 min-1 in group C (P less than 0.05). The PaCO2 value 44.1 +/- 1.0 mmHg in group B was significantly higher compared with the values 39.8 +/- 0.8 mmHg in group A and 41.3 +/- 0.9 mmHg in group C (P less than 0.01). Postoperative analgesia was remarkably prolonged in group B and C; 542 +/- 97 minutes and 504 +/- 97 minutes, respectively, as compared with 55 +/- 20 minutes in group A (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)