A Comparative Study of Nalbuphine and Fentanyl as Adjuvants to Bupivacaine in Spinal Anesthesia in Lower Limb Orthopedic Surgeries

Abstract

Background: Subarachnoid block is the most common technique employed for lower limb orthopedic surgeries. Adjuvants such as fentanyl and nalbuphine are added to increase the duration of post-operative analgesia. This study aimed to compare the efficacy of nalbuphine and fentanyl as adjuvants to bupivacaine in providing intra-operative anesthesia and post-operative analgesia in lower limb orthopedic surgeries. Objectives: The aim of this article is to compare the characteristics of sensory and motor block, hemodynamic parameter, time of first rescue analgesia, and adverse effects between the two groups. Materials and Methods: In this clinical trial, 80 patients undergoing elective lower limb orthopedic surgeries under spinal anesthesia were randomly allocated into two groups. In group BN, the patients received 0.5% 3 mL (H) bupivacaine + 800 mcg nalbuphine. In group BF, the patients received 0.5% 3 mL (H) bupivacaine + 25 mcg fentanyl. In both the groups, characteristics of sensory and motor block and time for first rescue analgesia were compared. Results: The onset of motor block, the maximum level of the block, and time to reach the peak level of the block were significantly faster in the BF group. Duration of motor block and time for first rescue analgesia were significantly prolonged in the BN group. However, there was no significant difference in time for two-segment regression [P = 0.157 (NS)] and hemodynamic changes. Conclusion: We conclude that combination of fentanyl as adjuvant to bupivacaine provides higher segmental level sensory blockage and faster sensory and motor blockage than nalbuphine. But nalbuphine gives longer time of post-operative analgesia than fentanyl did.