Buprenorphine Versus Magnesium Sulphate: Adjuvants to Intrathecal Hyperbaric Bupivacaine for Lower Abdominal Surgeries

Abstract

Aims: An adjuvant to a local anaesthetic can potentiate spinal anesthesia and provide better postoperative analgesia. Our study has been drafted to evaluate and compare the analgesic potency of the adjuvants, buprenorphine and magnesium, to intrathecal 0.5% hyperbaric bupivacaine. Methods: One hundred and fifty patients by inclusion criteria posted for an elective lower abdominal surgery were randomised into three groups of 50 each. They received 3ml of 0.5% hyperbaric bupivacaine with either 1ml of 0.9% Saline or 1ml of buprenorphine (60?g) or 1ml of magnesium sulphate (50mg). Time for first rescue analgesia, onset of sensory and motor blocks, time to two-segment regression and duration of motor block, haemodynamic parameters, and side effects were studied. Data was analyzed with ANOVA, Kruskal-Wallis H, Chi-square and Fischer’s exact tests. Our Study was carried out from January 2020 to April 2020. Results: The time for first analgesic request was 248.70> 186.84> 141.44 minutes (Buprenorphine> magnesium> control), p<0.001. The onset of sensory and motor blocks was faster in buprenorphine group compared to magnesium and control groups. The time to two-segment regression and duration of motor block was significantly prolonged in buprenorphine and magnesium groups compared to control group. Conclusion: The time to first analgesic request was longer with buprenorphine compared to magnesium sulphate with adequate sedation and negligible complications. Hence, addition of adjuvant buprenorphine (60?g) has a better demonstrable role in postoperative analgesia compared to adjuvant magnesium (50mg) or 0.5% hyperbaric bupivacaine alone. Keywords: Spinal Anaesthesia; Intrathecal buprenorphine; Intrathecal magnesium; Analgesic efficacy; Intrathecal adjuvants