Comparison of Efficacy of Intrathecal Isobaric Ropivacaine-Fentanyl and Ropivacaine-Nalbuphine for Post-Operative Analgesia in Lower Limb Orthopaedic Surgery

Abstract Background: Spinal anesthesia is a common widely used technique in lower limb orthopedic surgeries for effective pain relief. Adding intrathecal adjuvants like opioids can prolong the effects of analgesia. This study is done to compare the efficacy of fentanyl citrate and nalbuphine hydrochloride as adjuvants for spinal anesthesia. Methods: The present study included 100 patients undergoing elective lower limb orthopedic surgeries under spinal anesthesia. We randomized the patients into two groups: Group RF (fentanyl 25mcg + ropivacaine 22.5mg) and Group RN (nalbuphine 1mg + ropivacaine 22.5mg). The factors for assessment were Intraoperative hemodynamics, onset and duration of sensory and motor block, analgesia duration, and post-operative pain scores (VAS). Results: We observed that the Group RF had a statistically significant faster onset of sensory and motor block as compared to the Group RN (p < 0.05). Sensory block and motor block durations were shorter in Group RF compared to group RN (254.22 ± 7.89 mins vs. 296.98 ± 8.31 mins) and (153.18 ± 4.76 mins vs. 190.2 ± 5.82 mins) respectively. Longer post-operative analgesia was observed in Group RN (299.7 ± 7.72 mins) than in Group RF (274.38 ± 9.79 mins) (p < 0.0001) which was statistically significant. Conclusions: Both fentanyl and nalbuphine, combined with ropivacaine for spinal anesthesia, provided effective pain relief. Nalbuphine offered longer analgesia, while fentanyl had a quicker onset and shorter motor block. Nalbuphine may be preferred for prolonged analgesia, while fentanyl is better for faster motor recovery.