RANDOMIZED CONTROLLED TRIAL TO COMPARE EFFECTS OF INTRAVENOUS BOLUS VERSUS BOLUS FOLLOWED BY INFUSION OF MAGNESIUM SULPHATE FOR POSTOPERATIVE PAIN FOLLOWING ABDOMINAL HYSTERECTOMY UNDER GENERAL ANAESTHESIA

Abstract

Introduction: Postoperative pain in abdominal hysterectomy is moderate to severe. Magnesium sulphate has been used as an adjuvant for postoperative pain. Review of literature did not reveal any study showing comparison of magnesium sulphate given
either as bolus or bolus followed by infusion. Therefore, this study was planned with primary aim to compare the effects of magnesium sulphate given either as intravenous bolus or bolus followed infusion for post operative pain.
Methods: Randomized, double-blind study was undertaken in Female Patients, 18-60 years of age undergoing open abdominal hysterectomy. GROUP MB (n=20) received magnesium sulphate 50mg/kg bodyweight in 100 ml normal saline solution i.v. as
bolus followed by infusion of i.v. normal saline. GROUP MBI (n=20) received magnesium sulphate 50mg/kg in 100ml normal saline solution i.v. as bolus followed by i.v. infusion of magnesium sulphate 10mg/kg/hr. Pain was assessed by Visual Analogue Scale (VAS) score. Between group comparison was done by repeated measure ANOVA followed by Tukey’s test.
Results: Postoperative Pain score was less in group MBI as compared to group MB at 2nd, 5th, 9th hours after surgery. At rest of the time points VAS score was comparable in both groups. Duration of analgesia was significantly higher in Group MBI as compared
to Group MB.
Conclusions: We recommend that magnesium sulphate 50mg/kg bodyweight in 100ml normal saline solution i.v. as bolus before induction of anaesthesia followed by i.v. infusion of magnesium sulphate 10mg/kg/hr in 50ml/hr saline may provide adequate analgesia