Magnesium and myocardial reperfusion injury - a study in patients undergoing coronary artery bypass surgery

This study examined the effect of various doses of magnesium sulphate on the reperfusion injury in patients subjected to coronary artery bypass surgery. Intravenous magnesium sulphate (0, 2, 4 and 6 g) was administered from the onset of surgery up to the release of the aortic cross-clamp. General haemodynamics, pharmacological support of the circulation, CK-MB fraction and (Q-wave changes were monitored. In addition, the incidence and severity of reperfusion ventricular tachycardia or fibrillation were recorded. A total of 138 patients were successfully randomised into one of the groups. There was no difference in the demographics, general haemodynamics or arrhythmias between groups either before or after surgery. Results of this study do not support the use of magnesium las per our protocol) as an effective method of limiting the reperfusion injury after cardiac surgery.