Comparison of magnesium sulfate with opioid and NSAIDs on postoperative pain management after coronary artery bypass surgery.

OBJECTIVE This study measured the effectiveness of magnesium sulfate during and after coronary artery bypass grafting (CABG) on postoperative pain and respiratory functions, and compared it with 2 other well-known and widely used analgesic agents: codeine and diclofenac, a nonsteroidal anti-inflammatory drug (NSAID). DESIGN Prospective unblinded study. SETTING Single institution. PARTICIPANTS Patients undergoing CABG. INTERVENTIONS Patients were divided into 3 groups. In group A (n = 50), intraoperative magnesium sulfate, 2 g/70 kg, was infused intravenously and was continued during the first 3 days postoperatively. In group B (n = 50), codeine, 60 mg/70 kg, was given orally 4 times a day for 3 days. In group C (n = 50), diclofenac sodium, 75 mg, was given orally twice a day for 3 days. MAIN RESULTS On the first postoperative day the visual analog scale (VAS) score was greater than 5 in all groups. On the second day the VAS score was greater than 5 in groups B and C, and was less than 5 in group A. On the third day the VAS score was less than 5 in all groups. During the first 2 postoperative days the need for morphine was significantly less in group A than in the other 2 groups. Preoperative respiratory function tests (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], and FEV1/FVC) were similar in each group. The FEV1, FVC, and FEV1/FVC values on the postoperative first, second, and third days were significantly higher in group A. CONCLUSIONS Magnesium sulfate can be a beneficial adjuvant therapy for pain after CABG. In this respect, especially in patients with respiratory problems or intolerance to NSAIDs, magnesium sulfate can be a better choice than NSAIDs and opioids.