Fentanyl versus magnesium sulphate as adjuvants to low-dose bupivacaine in spinal anesthesia in transurethral resection of prostate surgery

Background Recent progress in the use of intrathecal (IT) adjuvants has led to faster recovery and improved pain management following transurethral resection of the prostate (TURP). Promising outcomes have been achieved with the use of IT magnesium. This study investigated the consequences of adding fentanyl or magnesium sulphate (MgSO 4 ) to low-dose IT bupivacaine in patients undergoing TURP using subarachnoid block. Patients and methods Seventy adult males with American Society of Anesthesiologists physical status classification I or II, scheduled for TURP under spinal anesthesia, were enrolled in this prospective randomized, double-blind study. They were randomly allocated into two groups: group F: received 25 µg (0.5 ml) of fentanyl diluted in 1 ml of normal saline added to 1.5 ml of hyperbaric bupivacaine 0.5% to form a total volume of 3.0 ml. Group M: received 100 mg (1 ml) of MgSO 4 diluted in 0.5 ml of normal saline and added to 1.5 ml of hyperbaric bupivacaine 0.5% to form a total volume of 3.0 ml. Hemodynamic parameters, sensory and motor block levels, and pain scores were recorded and compared across the two studied groups. Results A total of 70 patients were included in this study, with 35 patients per group. There was no statistically significant difference in terms of heart rate, oxygen saturation, mean blood pressure, duration of surgery, and postoperative complications ( P >0.05). The two groups showed no significant differences in terms of onset and duration of either sensory or motor blocks after spinal anesthesia ( P >0.05). Additionally, no significant difference was noted in pain scores, time to first analgesic requirements, or total analgesic consumption among the two studied groups ( P >0.05). Conclusion MgSO 4 might be as effective as fentanyl when added to low-dose IT bupivacaine in patients undergoing TURP.