Comparison of Intrathecal Nalbuphine Hydrochloride and Clonidine Hydrochloride as an Adjuvant to Hyperbaric Bupivacaine in Abdominal Hysterectomy

BACKGROUND: Various adjuvants for prolongation of intraoperative and postoperative analgesia have been clinically studied in the literature. AIM: This study was done to evaluate and compare the effects of nalbuphine and clonidine as an adjuvant to bupivacaine in spinal anesthesia. METHODS: In this prospective, randomized, placebo control, double-blind, and comparative study, a total of ninety patients of American Society of Anesthesiologists physical status Classes I and II undergoing abdominal hysterectomy under subarachnoid block were randomly divided into three groups. In addition to 15 mg of 0.5% hyperbaric bupivacaine administered, patients of groups BS, BN, and BC received 0.9% normal saline, 1.6 mg nalbuphine, and 30 μg clonidine, respectively. The total volume of drugs administered intrathecally was made up to 3.5 ml by addition of sterile isotonic normal saline in all. The onset time and duration of sensory and motor block, duration of analgesia, and total dose of postoperative analgesic requirement in the first 24 h were compared among groups. Hemodynamic changes and side effects were also recorded. RESULTS: Addition of study adjuvants brought significantly faster onset of sensory and motor block. Patients in clonidine group showed significantly longer mean time two segment sensory block regression (P < 0.05) lowest seen in control group. The regression time of motor block to modified Bromage Grade I was significantly longer in clonidine group and comparable in the other groups. Adjuvants have significantly increased the mean duration of analgesia, highest in clonidine group (P < 0.05). CONCLUSION: Intrathecal clonidine is associated with prolonged motor and sensory block, better hemodynamic stability, and less postoperative analgesic requirement as compared to nalbuphine.