Postoperative Analgesia with Intrathecal Nalbuphine versus Intrathecal Fentanyl in Cesarean Section: A Double-Blind Randomized Comparative Study.

Background: Nalbuphine when used as adjuvant to hyperbaric bupivacaine has improved the quality of perioperative analgesia with fewer side effects. Fentanyl is a lipophilic opioid with a rapid onset following intrathecal injection. It does not cause respiratory depression and improves duration of sensory anesthesia without producing significant side effects.

Objective: This study aims to compare the postoperative analgesia of intrathecal nalbuphine and fentanyl as adjuvants to bupivacaine in cesarean section.

Methods: A prospective, randomized, double-blind, and comparative study was conducted on 150 parturients of American Society of Anesthesiologists (ASA) physical status I and II of age group 20-45 years with normal coagulation profile undergoing cesarean section under spinal anesthesia. These patients were randomized into three groups with fifty patients in each group. Group I received 2 ml of 0.5% hyperbaric bupivacaine (10 mg) plus 0.4 ml nalbuphine (0.8 mg), Group II received 2 ml of 0.5% hyperbaric bupivacaine (10 mg) plus 0.4 ml fentanyl (20 μg), and Group III received 2 ml of 0.5% hyperbaric bupivacaine (10 mg) plus 0.4 ml of normal saline.

Results: The mean duration of effective analgesia was 259.20 ± 23.23 min in Group I, 232.70 ± 13.15 min in Group II, and 168.28 ± 7.55 min in Group III. The mean number of rescue analgesics required was significantly lower (P < 0.001) in Group I as compared to Group II and III.

Conclusions: Both intrathecal nalbuphine 0.8 mg and fentanyl 20 μg are effective adjuvants to 0.5% hyperbaric bupivacaine in subarachnoid block. However, intrathecal nalbuphine prolongs postoperative analgesia maximally and may be used as an alternative to intrathecal fentanyl in cesarean section.