Effect of pre-emptive magnesium sulfate infusion on the post-operative pain relief after elective cesarean section

BACKGROUND: The aim of this study was to evaluate the analgesic efficacy of pre-operative single dose of intravenous (I.V.) magnesium sulfate infusion in patients undergoing elective Cesarean section. MATERIALS AND METHODS: Seventy pregnant women who underwent elective Cesarean section were randomly divided into two groups. Before induction of anesthesia, the magnesium group (Group A) received magnesium sulfate 50 mg/kg I.V. in bolus dose. The control group (Group B) received the same volume of isotonic saline. The pain scores at rest and also upon movement were evaluated up to 24 h post-operatively and analgesic requirement was recorded during the first 24 h after operation. RESULTS: Cumulative analgesic consumption (24 h after operation was 11.2 ± 6.3 mg in group A vs. 13.9 ± 3.9 mg in group B). Post-operative pain scores (24 h after operation was 1.8 ± 2.1 in group A vs. 2.9 ± 1.2 in group B) and shivering incidents (8.57 in group A vs. 14.28 in group B) were significantly lower in Group A (P < 0.05). Mean arterial pressure just after intubation and during the immediate post-operative period was significantly lower in Group A (P < 0.05). CONCLUSION: Pre-operative intravenous magnesium sulfate infusion decrease post-operation pain and requirement of analgesia in Cesarean section.