Comparison between Intrathecal Hyperbaric Bupivacaine with Nalbuphine and Hyperbaric Bupivacaine with Fentanyl in Infraumbilical Surgeries: A Randomised Clinical Trial

Introduction: Intrathecal adjuvants to local anaesthetics have been introduced to enhance clinical efficacy and prolong the duration of analgesia following infraumbilical surgical procedures, as spinal anaesthesia alone often provides inadequate postoperative pain relief. The addition of intrathecal opioids has been shown to effectively extend postoperative analgesia. Aim: To compare the efficacy of intrathecal nalbuphine (0.4 mg) vs fentanyl (25 μg) as adjuvants to hyperbaric bupivacaine in infraumbilical surgeries. Materials and Methods: The present triple-blinded randomised, clinical study was conducted at Dhiraj General Hospital, Vadodara, Gujarat, India, from February 2025 to June 2025. Sixty American Society of Anaesthesiologists (ASA) I-II patients undergoing elective infraumbilical surgeries were randomly allocated into two groups (n=30 each). Group A received bupivacaine (15 mg) with fentanyl (25 μg) and group B received bupivacaine (15 mg) with nalbuphine (0.4 mg) intrathecally. Primary outcomes included onset and duration of sensory/ motor blockade and duration of analgesia. Secondary outcomes included haemodynamic parameters, sedation scores, and side-effects. Data were analysed using Statistical Package for Social Sciences (SPSS) version 20.0. Independent Student’s t-test was used for continuous variables and Chi-square test for categorical variables. The p<0.05 was considered significant. Results: Both groups had comparable demographic characteristics with no significant differences in age, weight, gender distribution, ASA grading, or surgery duration (p>0.05). Onset of sensory (4.07±1.12 vs 6.67±1.01 min, p<0.001) and motor blockade (6.73±1.00 vs 7.87±1.20 min, p=0.009) was faster in group A. Duration of analgesia was significantly longer in group B (404.76±25.23 vs 291.91±31.87 min, p<0.001). Group B required fewer rescue analgesics (2.03±0.95 vs 3.57±0.88, p<0.001). Pruritus occurred only in group A (13.3%), while bradycardia (23.3%) and hypotension (26.7%) were higher in group B. Conclusion: Nalbuphine (0.4 mg) provides superior postoperative analgesia compared to fentanyl (25 μg) as an intrathecal adjuvant, making it an effective alternative for infraumbilical surgeries requiring prolonged pain relief.