Effects of Intrathecal Nalbuphine as an Adjuvant for Postoperative Analgesia: A Randomized, Double Blind, Control Study

Context: Opioids as adjuvants have been frequently used to prolong the neuraxial blockade for postoperative analgesia and are known to cause adverse effects. Nalbuphine, as an opioid with minimal adverse effects was tried for its effectiveness. Aims: Research was done to evaluate the effects of intrathecal Nalbuphine on the speed of onset of sensory and motor blockade, duration of analgesia and its side effects. Materials and Methods: Randomized clinical trial with a sample size of 60 adults in two groups of 30 each scheduled for lower abdominal and orthopaedic surgeries were included. Group 1 received 3 ml of hyperbaric bupivacaine 0.5% + 0.8 ml nalbuphine (0.8 mg) intrathecally, whereas group 2 received 3 ml of hyperbaric bupivacaine 0.5% + 0.8 ml of normal saline intrathecally. The onset of sensory and motor blockade, regression time of sensory blockade, duration of motor blockade, and analgesia, visual analogue scale (VAS) pain score and side effects were compared between the groups. Statistical Analysis Used: All the data was analyzed statistically and the significance was measured as probability of occurrence by the Student’s t‑test and Mann–Whitney U test. The values were expressed as mean ± the standard deviation and a P value less than 0.05 was considered statistically significant. Results: The onset of sensory blockade was slower with increased duration of analgesia. Regression time of sensory blockade and duration of effective analgesia was prolonged in the study group with no significant side effects. Conclusions: Improvement in the duration of sensory and motor blockade with minimal side effects was observed, thus proving that it is an effective intrathecal adjuvant for postoperative analgesia.