[Study of total magnesium concentration in the blood of patients after surgery with extracorporeal circulation].

In 30 patients with acquired and 14 with congenital heart diseases operated on under extracorporeal circulation a significant decrease in the blood Mg level was noted, its amount never returning to the preoperative one within the first week. Therapy with Mg salts helped to prevent these disorders and to maintain the plasma and erythrocytes Mg levels within the normal limits throughout the whole period of therapy.