The Effect of Lidocaine and Magnesium Sulfate on Prevention of Ventricular Fibrillation in Coronary Artery Bypass Grafting Surgery

One of the most common events, after the release of aortic cross-clamp in patients undergoing coronary artery bypass grafting surgery is reperfusion induced ventricular fibrillation, which occurs in 74% of 96% of patients. Regarding the controversies over the use of lidocaine or magnesium sulfate for the prevention of ventricular fibrillation following the release of aortic cross-clamp, this study was designed to compare the effectiveness of magnesium sulfate and lidocaine to suppress ventricular fibrillation. In a double blind, prospective, randomized, controlled trial study, 76 patients who were candidates for elective coronary artery bypass grafting surgery were divided into three groups including Group A (lidocaine, n=26), group B (magnesium sulfate, n=25), and group C (normal saline, n=26). Lidocaine (1.5 mg/Kg), magnesium sulfate (30 mg/Kg) and normal saline were administered 5 minutes before the release of aortic cross clamp. The incidence of ventricular fibrillation significantly decreased in patients receiving magnesium sulfate (12% vs. 26.9% and 44% in patients who received lidocaine and normal saline, respectively) There was no statistically significant difference between the groups with respect to age, ejection fraction (L/ min), anesthetic time (min), cross-clamping time (min), PH, HCT (%), and serum K+ level (meq). The administration of lidocaine and magnesium sulfate before the release of aortic cross-clamp reduces the incidence of postoperative ventricular fibrillation in adult patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass. In our study, magnesium sulfate was more efficient in prevention of ventricular fibrillation than lidocaine. Administration of magnesium sulfate (30 mg/kg) caused no toxic effect and wais safe for patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass.