Double-blind comparison of the postoperative respiratory depressant effects of alfentanil and fentanyl

Abstract

Alfentanil was compared with fentanyl in a double blind study of 90 female patients undergoing laparoscopic sterilizations. The analgesic was combined with droperidol and etomidate for induction and with etomidate, nitrous oxide and occasional increments of succinylcholine for maintenance of anesthesia. Twenty-four percent of the patients required reversal of postoperative respiratory depression after fentanyl compared with 7% after alfentanil (p = 0.042). When the last dose of analgesic had been given more than 10 minutes before the end of the operation, none of the alfentanil patients required reversal of respiratory depression while under the same circumstances 26% of the fentanyl patients required naloxone (p = 0.005). Awakening was delayed in all patients, exceeding a mean time of 20 minutes in both groups. However, 84% of patients were alert on awakening after alfentanil compared with 62% of patients after fentanyl (p = 0.032). Duration and quality of postoperative analgesia were similar in both groups. Cardio-vascular stability was satisfactory in all patients and side effects were minor and infrequent.