Background: 0.5% Bupivacaine used in subarachnoid block provides about 3 hours of analgesia. Opioids morphine and Fentanyl are used as adjuvant to produce extended postoperative analgesia. Nalbuphine is an agonist antagonist and does not require a narcotic license, which is a must for procuring other opiods. This study was carried out to evaluate the efficacy of Nalbuphine versus Fentanyl as intrathecal adjuvant. Material and Methods: Hundred ASA 1­3 patients posted for elective Total Abdominal Hysterectomy were included in this study and were randomly divided into two groups of fifty each. Group FB received 15mg of 0.5% Bupivacaine and 25 mcg of Fentanyl. Group NB received 15mg 0.5% Bupivacaine and 1mg Nalbuphine. Results: The onset of sensory blockade, time to attain peak sensory block and complete motor block was significantly faster in Group FB(p<0.001). The duration of motor block was comparable in both the groups. The time for sensory block to regress by two segments was significantly longer in Group NB, 97.72±9.50 minutes, than in Group FB, 88.88±9.48 minutes. The time to first analgesic requirement in Group NB was 460.78±77.98 minutes compared to 283.44±78.97 minutes in Group FB(p<0.001). No statistical difference was seen in terms of adverse effects. Conclusion: Time for sensory level to regress by two segments and the post operative analgesia time is longer with Nalbuphine. So, Nalbuphine is a good adjuvant in spinal anaesthesia especially in centres without narcotics license.

Keywords: Nalbuphine; Intrathecal Adjuvant; Fentanyl; Bupivacaine; Analgesia.