A comparison between intrathecal nalbuphine versus fentanyl as an adjuvant with 0.5% hyperbaric bupivacaine for postoperative analgesia in parturients undergoing lower segment cesarean section

Background: Nalbuphine when used as an adjuvant to hyperbaric bupivacaine has improved the quality of perioperative analgesia. Fentanyl is a lipophilic opioid with a rapid onset and does not cause respiratory depression and improves duration of sensory anesthesia without producing significant side effects. The aim of this study was to compare intrathecal nalbuphine and fentanyl as adjuvants to hyperbaric bupivacaine for postoperative analgesia in lower segment cesarean section. Methods: A total of 100 American Society of Anesthesiologists (ASA) Physical Status (PS) I and II parturients were enrolled for lower segment cesarean section. Parturients were randomly allocated into 2 groups - Group F (n = 50) received bupivacaine 0.5% (heavy) 1.6 ml (8 mg) + fentanyl 20 μg (0.4 ml) and Group N (n = 50) received bupivacaine 0.5% (heavy) 1.6 ml (8 mg) + nalbuphine 0.4 mg (0.4 ml) under subarachnoid block (total volume = 2 ml). Time of onset and duration of sensory and motor block, Visual Analog Scale (VAS) score, duration of analgesia, sedation, rescue analgesic consumption, APGAR score, hemodynamic changes and adverse effects were noted. Results: Onset of sensory and motor block were significantly faster in Group F while duration of sensory block was significantly longer in Group N (P < 0.05). Duration of analgesia was also significantly longer in Group N (214.34 ± 9.31 min) compared to Group F (195.00 ± 9.18 min) (P < 0.001). No significant hemodynamic changes and adverse effects were noted in both groups (P > 0.05). Conclusion: Both of these drugs can be effectively used as an adjuvant to hyperbaric 0.5% bupivacaine in subarachnoid block for parturients undergoing lower segment cesarean section.