A Prospective randomized single Blinded controlled study to evaluate the effect of single dose of magnesium sulphate on Postoperative analgesia in abdominal Surgeries patients receiving balanced general anaesthesia

Abstract

Background: Post-operative pain is the major morbidity of most of the surgeries. This prospective singleblind, randomized, placebo controlled clinical trial was designed to evaluate the effect of Pre-operative IV Magnesium sulphate on Intraoperative and Postoperative pain management and to determine the adverse reactions, as it blocks N-Methyl D Aspartate receptor, among the patients undergoing elective abdominal surgeries under general anaesthesia. Patients and Methods: This study included 80 adult male and female patients, ASA physical status I and II, undergoing various abdominal surgeries under general anesthesia. Patients were randomly allocated into 2 equal groups. Patients in group M and C each group comprising of 40 patients each. Group M (MAGNESIUM): Subjects were given Magnesium sulphate 40 mg/kg 100 ml of.9% normal saline over 15 minutes prior to induction GROUP C (CONTROL): Subjects were given 100ml of.9% normal saline plain over 15 minutes prior to induction.

Unravelling the analgesic effects of perioperative magnesium in general abdominal surgery: a systematic review and meta-analysis of randomized controlled trials

“…Ultimately, 31 studies with 1762 participants (800 patients in the MgSO 4 group and 802 patients in the control group) met the inclusion criteria and were included in the analysis ( Figure 1 ). 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 Participants in the included trials underwent various general abdominal surgeries under General Anesthesia (GA) and received either magnesium sulfate or a control perioperatively. Supplementary Table S2 summarizes the data on the baseline patient characteristics.…”

“…Twenty-seven trials, consisting of 1525 patients, contributed to the analysis of early (up to 6 hours) postoperative pain scores, indicating a significantly lower mean score in the magnesium group (n = 762, 3.1 ± 2.5) compared to the control group (n = 763, 4.1 ± 2.8) (MD = -1.04; 95% CI: -1.52, -0.55; p < 0.0001; I 2 = 94%) ( Figure 3 A). 10 , 11 , 12 , 14 , 15 , 16 , 17 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 33 , 34 , 36 , 37 , 38 , 39 , 40 Publication bias was investigated using a funnel plot ( Figure 4 ), Begg's test ( p = 0.774), Egger's test ( p = 0.646), and fail-safe N-test (1991) for each parameter, which was not significant ( Figure 4 ). The funnel plot identified six studies as the major outliers contributing to the heterogeneity.…”

“…Seventeen trials, consisting of 916 patients, contributed to the analysis of early (up to 6 hours) postoperative opioid consumption, demonstrating a significantly lower mean measurement in the magnesium group (n = 459, 9.7 ± 7.7 MME) compared to the control group (n = 457, 12.4 ± 8.4 MME) (MD = -2.75; 95% CI: -4.20, -1.29; p = 0.0002; I 2 = 99%) ( Figure 5 ). 10 , 11 , 12 , 15 , 17 , 18 , 19 , 20 , 21 , 22 , 25 , 26 , 28 , 30 , 32 , 34 , 38

Figure 5 Meta-analysis of early (6 h) and late (24 h) postoperative opioid consumption in magnesium and control group patients undergoing surgery. The mean difference of each included study is plotted.

…”

“… 3 Most trials in our review employed a 40–50 mg.kg −1 bolus dose of magnesium. 13 , 14 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 30 , 33 , 34 , 37 , 38 , 39 , 40 Interestingly, two trials in our review utilized much lower magnesium doses, with Kocman et al prescribing one group at 5 mg.kg −1 and another at 7.5 mg.kg −1 for laparoscopic cholecystectomy, and Dautaj et al prescribing 3 mg.kg −1 for open cholecystectomy. 31 , 36 Even at lower doses, both trials found that the magnesium groups exhibited significantly better postoperative pain control with no difference in side effects compared to the control group.…”