BACKGROUND: We evaluated the effect of single intravenous bolus of MgSO4 on pain intensity in patients undergoing surgery for lower abdomen.

Methods: The Magnesium group (n =25) and the control group (n=25) received MgSO4 and isotonic saline, respectively, over 30 min before the induction of anesthesia. Intra operatively PR, SBP & DBP were noted.  Postoperative pain (VAS) at rest was noted  

Results: Demographicdata, Mean baseline PR, SBP & DBP were comparable in both the groups. Mean duration of analgesia was longer in MgSO4 group. Mean total dose of analgesic requested and VAS score was lesser in MgSO4 group. MgSO4 group was more sedated. Side effects like nausea & vomiting were more in control group.  

Conclusion: Patients receiving MgSO4 during preop period have better pain relief, more sedation and fewer analgesic requirements of rescue analgesics without any major side effects.