A Comparative Study of Intrathecal Fentanyl and Nalbuphine as an Adjuvant to Hyperbaric Bupivacaine for Spinal Anesthesia in Lower Limb Orthopedic Surgeries: A Prospective, Double-Blind, Randomized Controlled Study

Background: Spinal anaesthesia is the most commonly used technique for lower limb orthopaedic surgeries as it is economical and easy to administer. Opioids as adjuvants to local anaesthetics during spinal anaesthesia have played a vital role in reducing post-operative pain qualitatively and effectively. Methods: This prospective randomised study was conducted on 100 patients divided into two groups scheduled for lower limb orthopaedic surgeries. Group bupivacaine fentanyl (BF) received 25 mcg of fentanyl with 15 mg of bupivacaine and Group bupivacaine nalbuphine (BN) received 1 mg of nalbuphine and 15 mg of 0.5% bupivacaine. The aim of the study was to compare the analgesic efficacy of intrathecal fentanyl and nalbuphine as an adjuvant to hyperbaric bupivacaine for spinal anaesthesia. Duration of effective analgesia, haemodynamic parameters, onset and duration of sensory and motor block, adverse effects, and visual analogue scale (VAS) score were assessed. Results: Duration of effective analgesia was 388 +/- 24.88 minutes in the BN group and was higher (p-value <0.001) in comparison to the BF group, which was 304.70 +/- 15.76 minutes. Conclusion: Nalbuphine was more effective than fentanyl in providing post-operative analgesia when used as an adjuvant to hyperbaric bupivacaine.