[Epidural buprenorphine under nitrous oxide-oxygen-enflurane anesthesia in elderly patients]

The effects of epidural buprenorphine (Bn) under nitrous oxide-oxygen-enflurane (E) anesthesia in elderly patients were examined. The subjects were older than 65 years (n = 82) and scheduled for abdominal surgery. They were divided randomly into two groups according to epidural drugs used. The first group received epidural Bn 0.1-0.2 mg (group B, n = 41). The second group received epidural Bn 0.1-0.2mg + 1% lidocaine (group BL, n = 41). The enflurane concentration was 1.13% in group B, and it was significantly higher than 0.78% of group BL (P < 0.01). There was no intra-group difference in the highest systolic blood pressure during operation. The lowest systolic blood pressure during operation was 92.0 +/- 2.1 mmHg in group BL and it was significantly lower than 100.2 +/- 2.9 mmHg of group B (P < 0.05). The percentage of patients who needed vasoconstrictor drugs was 12% in group B, and it was significantly smaller than 42% of group BL (P < 0.01). On the other hand the percentage of patients who needed vasodilator drugs was 39% in group B, and it was significantly larger than 17% of group BL (P < 0.05). There was no intra-group difference in arousing time from anesthesia. Concerning the postoperative respiratory state, there was no intra-group difference in the respiratory rate, tidal volume and PaO2. But the PaCO2 value was 44.7 +/- 0.8 (mean +/- SE) mmHg in group BL, and it was significantly higher than 40.7 +/- 0.7 mmHg of group B (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)