Comparison of Intrathecal Nalbuphine vs Intrathecal Clonidine as Adjuvant with Hyperbaric Bupivacaine in Pelvic and Lower Limb Orthopaedic Surgeries: A Randomised Clinical Study

Introduction: Addition of an adjuvants to local anaesthetic like bupivacaine, helps to make sensory and motor blockade better compare to bupivacaine alone. In this study, comparison was done amongst nalbuphine—a mixed opioid with high efficacy as an agonist of kappa receptors—and clonidine, a selective alpha-2 adreno receptor agonist. Aim: To determine the effects of intrathecal nalbuphine and clonidine as adjuvant with hyperbaric bupivacaine 0.5% on onset and duration of sensory and motor block with duration of total postoperative analgesia in pelvic and lower limb orthopaedic surgeries. Materials and Methods: This randomised clinical study was done on 50 patients aged between 18 and 65 years with American Society of Anaesthesiologists (ASA) Grade I or II, of either gender. They were randomly divided 25 in each group as Group BCL (clonidine), containing hyperbaric 0.5% bupivacaine 3.4 mL + 30 µg clonidine (total 3.6 mL) and Group BN (nalbuphine) containing hyperbaric 0.5% bupivacaine 3.4 mL + 1 mg nalbuphine (total 3.6 mL). Parameters studied were motor and sensory block characteristic like time of onset, duration of sensory and motor block, two-segment regression time, total duration of postoperative analgesia and side-effects. Haemodynamic changes were also noted. Statistical analysis done by using Student’s t-test and Chi-square test. Tests were considered statistically significant if p-value was <0.05. Results: Demographic data, including age, gender, weight, ASA grading and duration of surgery for both the groups, were comparable and statistically non significant. BCL group (4.15±0.57 minutes) had significantly faster onset for motor block than BN (5.06±0.42 minutes) (p-value <0.0001). Group BCL has significantly longer motor block duration (335.2±23.69 minutes) than BN (285.2±23.21 minutes), with significantly longer sensory block duration in group BCL (400.6±30.29 minutes) than BN (357.8±29.51 minutes) (p-value <0.0001). The duration of postoperative analgesia was significantly extended in the BCL group (445.8±33.87 minutes) than BN (410.8±26.56 minutes) (p-value ≤0.0002). Conclusion: Present study concluded that addition of clonidine 30 µg with hyperbaric bupivacaine 0.5% in spinal anaesthesia, compared to nalbuphine 1 mg, shortens the onset time of motor block and prolongs the duration of both sensory and motor block, while also increasing total postoperative analgesia period, all with haemodynamic stability and minimal side-effects.