[Postoperative pain relief by preanesthetic administration of buprenorphine suppository in elective mastectomy]

Seventy female patients scheduled for elective mastectomy were divided into three groups: Buprenorphine suppository (BPS) 0.4 mg group (n = 29); BPS 0.2 mg (n = 23) group; and control (scopolia extract and tannic acid suppository) group (n = 18). Suppositories were administered rectally to patients of each group one hour before induction of anesthesia. Plasma buprenorphine concentrations, sedation scores at entering the operating room, postoperative pain scores and side effects were evaluated. There were no significant differences in sedation effects of suppository among the three groups. Although there were significant differences in pain scores except at the time when patients left the operating room between BPS 0.2 mg group and the control group, postoperative pain relief in BPS 0.2 mg group was judged not enough. However, postoperative pain relief was more satisfactory in the BPS 0.4 mg group. Plasma concentrations of the BPS 0.4 mg group were higher than those of the BPS 0.2 mg group. Although nausea and vomiting were observed in 5 patients (17.2%) of the BPS 0.4 mg group and 4 patients (17.4%) of the BPS 0.2 mg group, respiratory depression and changes in blood pressure and heart rate were not observed in all groups. In conclusion, preanesthetic administration of the BPS 0.4 mg seemed to be useful for postoperative pain relief after elective mastectomy.