A STUDY ON PERI - OPERATIVE MAGNESIUM SULPHATE ON POST - OPERATIVE PAIN MANAGEMENT IN PATIENTS UNDERGOING PELVIC AND LOWER LIMB SURGERIES

CONTEXT: Post-operative pain is the major morbidity of most of the surgeries. This study aims to find out the analgesic property of MAGNESIUM SULPHATE as it blocks N-Methyl DAspartate receptor. AIMS: To study the effect of Peri-operative IV Magnesium sulphate on Postoperative pain management and to determine the adverse reactions, if any. SETTINGS AND DESIGN: This prospective study is double-blind, randomised, placebo controlled clinical trial among the patients undergoing elective lower limb and pelvic surgery under spinal anaesthesia. METHODS AND MATERIAL: 60 ASA 1 & 2 patients aged between 18 and 50 years was selected and assigned to two groups ‘M’ group for magnesium and ‘S’ group for placebo. ‘M’ group was infused with 500ml normal saline containing Inj. Magnesium sulphate at a dose of 8mg/kg body weight/hour till the end of the surgery. The placebo group ‘S’ also received same amount of normal saline till the end. Post-operative pain analysis was done with VAS scoring system at 3, 6, 12 & 24 hours. STATISTICAL ANALYSIS USED: Data analysis was done with SPSS software. To present the results, mean+SD was used and a ‘P’ value of < 0.05 was considered statistically significant. RESULTS: There existed a statistically significant difference in mean VAS within the groups during the observation period (p-value <0.000). The highest mean VAS in M groups was recorded at 12 hours and in S group at 6 hours. Only 22 patient required morphine for pain relief in M group while all patients in group S required morphine. The total dose of morphine used was higher in the placebo group. But this mean difference was not statistically significant (p-value = 0.43). The total dose of magnesium used and the post-operative morphine requirement showed a strong inverse relation with a p-value of < 0.0001. The rescue analgesic requirement was delayed in M group (p-value of 0.01) CONCLUSIONS: We hypothesis that peri-operative IV Magnesium prolongs the first analgesic requirement with a reduction in total pain scores and the analgesic requirement without any increase in adverse reactions. This signifies the role of magnesium in multimodal preventive analgesia.