Background: Post-operative pain control is one of the greatest concerns for both physicians and patients. In this study, the effect of magnesium sulfate (MgSO4) solution infusion on post-operative pain scores and extubation time in patients undergoing elective coronary artery bypass graft (CABG) surgeries was assessed.

Methods: In a double-blind, randomized, placebo-controlled clinical trial, 218 patients scheduled for elective CABG were selected and randomly assigned to two groups. After matching inclusion and exclusion criteria for the patients, intravenous MgSO4 was administered intraoperatively for one group and placebo to the second group. Except for this, all the cases were similar regarding anesthesia and surgery.

Results: The MgSO4 patients were extubated sooner compared with the placebo group. Pain scores reported by the group who received MgSO4 were less at the 6th, 12th, 18th and 24th hours after the operation; also, they needed less morphine sulfate during this period.

Conclusion: The results demonstrated a significantly shortened post-operative time for extubation and reduced acute post-operative pain scores by intravenous MgSO4 infusion during elective CABG surgery.