Analgesic efficacy of dexmedetomidine versus fentanyl as an adjunct to thoracic epidural in patients undergoing upper abdominal surgery: a randomized controlled trial

Background: This randomised, double-blind study was designed to assess the analgesic efficacy of dexmedetomidine as compared with fentanyl as an adjunct to local anaesthetic in thoracic epidural for upper abdominal surgeries.Methods: Forty adult patients of American Society of Anesthesiologists grade I-II undergoing upper abdominal surgery were randomly allocated into two groups to receive 50g fentanyl or 50g dexmedetomidine as an adjunct to 10ml 0.125% bupivacaine via thoracic epidural. Anaesthesia was induced with morphine, propofol and vecuronium and maintained by isoflurane with 60% nitrous oxide in oxygen. In the postoperative period patient-controlled analgesic pumps were used to deliver similar types of mixtures via the epidural catheter. Patients were evaluated for rescue analgesic requirements, haemodynamic stability, postoperative pain, sedation and any adverse events.Results: The groups were comparable regarding intraoperative analgesic requirements, recovery times and postoperative pain scores. The total consumption of rescue analgesia was significantly less in the dexmedetomidine group as compared with the fentanyl group (p = 0.049). Two patients in the fentanyl group had vomiting and one had pruritus. None of the patients had bradycardia, hypotension, excessive sedation or respiratory depression. Patients receiving epidural dexmedetomidine were more satisfied with the technique than those receiving fentanyl (p < 0.001).Conclusion: It was concluded that the addition of dexmedetomidine with 0.125% bupivacaine in thoracic epidural provides effective perioperative analgesia with greater patient satisfaction compared with fentanyl.