Comparison of the effects of intrathecal fentanyl and intrathecal morphine on postoperative pain for inguinal hernia repair

Purpose: The aim of this study was to compare the effects of intrathecal fentanyl and intrathecal morphine combined with spinal anesthesia on postoperative pain control for inguinal hernia repair. Materials and Methods: Fifty patients aged 18-60 years with American Society of Anesthesiologists physical status I-II scheduled for elective inguinal hernia repair surgery were enrolled in this prospective randomized double-blinded study. Patients received spinal anesthesia with either 25 mcg fentanyl plus 12.5 mg heavy bupivacaine intrathecally (group F, n=25) or 0.1 mg morphine plus 12.5 mg heavy bupivacaine intrathecally (group M, n=25). Hemodynamic parameters, time to first analgesic requirement, postoperative pain scores, the number of analgesic requirements and side effects over postoperative 24 h were recorded. Results: Pain scores were significantly lower in group M compared with group F in the postoperative 24 h. The time to first analgesic requirement was higher in group M than group F. Analgesic requirement was higher in group F than group M for postoperative 24 h. Conclusion: We concluded that the addition of 0.1 mg morphine intrathecally to 12.5 mg heavy bupivacaine provides improved postoperative analgesia, especially after postoperative 12 h than 25 mcg fentanyl for inguinal hernia repair under spinal anesthesia.