Duration of postoperative analgesia with Nalbuphine vs Butorphanol as an adjunct to spinal anesthesia for lower limb orthopedic surgeries: A randomized double-blind active control trial

BACKGROUND AND AIMS: Nalbuphine as well as butorphanol as adjuvant to intrathecal bupivacaine have been studied in comparison to bupivacaine alone. Both are kappa receptor agonist and have never been compared for its efficacy in terms of postoperative analgesia. The aim of this study was to evaluate duration of postoperative analgesia as well as intraoperative block characteristics using intrathecal nalbuphine hydrochloride (800 μg) or butorphanol (25 μg) as adjuvant to hyperbaric bupivacaine (12.5 mg) in lower limb fracture femur surgeries as compared to active control, that is, saline and bupivacaine. MATERIAL AND METHODS: This prospective, randomized, double-blind, active control study was conducted on 90 adult patients of either sex belonging to ASA grade I/II, aged 18–70 years, being operated for fracture femur surgeries in tertiary care hospital of North India. Patients were randomly divided into 3 groups (n = 30) Group A: received 0.5% hyperbaric bupivacaine 12.5 mg with 800 μg nalbuphine. Group B: Received 0.5% hyperbaric bupivacaine 12.5 mg with 25 μg butorphanol. Group C: Received 0.5% hyperbaric bupivacaine 12.5 mg with normal saline. Total volume injected was 3.0 ml. Duration of analgesia, mean VAS scores, requirement of rescue analgesia in 24 h along with intraoperative sensory or motor characteristics of block and hemodynamic parameters were studied. Statistical analysis was done using ANOVA with post-hoc Tukey test, Student’s t-test and Chi-Square test. RESULTS: Demographic profile was comparable among all the three groups. Mean duration of postoperative analgesia was 348.33 ± 66.96, 156.17 ± 43.9 and 110.36 ± 29.18 min in group A, B, and C, respectively (P = 0.006). Total doses of rescue analgesia were least in group A (32), followed by group B (42) and group C (64), respectively (P = 0.001). Group A had significantly earlier onset of sensory action (P = 0.03) as compared to group B and C. There was significant difference in sensory (P = 0.08) and motor duration (P = 0.04) among all the three groups. However, onset of motor block, haemodynamic profile and side effects were comparable among groups A, B, and C (P > 0.05). CONCLUSION: Addition of 800 μg nalbuphine and 25 μg butorphanol as adjuvant to intrathecal bupivacaine has better outcome as compared to active placebo group. But intrathecal nalbuphine was more effective compared to intrathecal butorphanol in terms of prolonging postoperative analgesia, reducing rescue analgesic doses and onset of sensory block. However, hemodynamic profile and side effects were comparable among all groups.