Alteration of plasma trace elements in patients undergoing open heart surgery

Trace elements may contribute to myocardial dysfunction and susceptibility of the phospholipid cell membrane to free-radical damage and oxidative changes. We studied the concentration of trace elements copper, zinc, and magnesium in cardiac surgery. Fifty-four consecutive patients for elective coronary artery bypass grafting (n = 30) and valve replacement (n = 24) were studied. Blood samples were collected every 30 min (T1-T5) during cardiopulmonary bypass and postoperatively (T6-T9). Plasma concentrations of copper, zinc, and magnesium were measured with flame atomic absorption spectrophotometry. The concentrations of copper, zinc, and magnesium were significantly different during and after cardiopulmonary bypass (p < 0.01). The zinc concentration at T7 and T8 (p < 0.01) and the copper concentration at T1, T9 (p < 0.05) were significantly different between two groups. However, the magnesium concentration had no significant differences between the two groups (p > 0.05). In patients undergoing valve replacement or coronary artery bypass grafting, the concentrations of copper and zinc decreased significantly during cardiopulmonary bypass. Our study suggests that the current cardiopulmonary bypass protocol is adequate in the maintenance of c magnesium. However, the low copper and zinc concentrations found in the present study may suggest that in the future, supplementation particularly of copper and zinc may become a necessary procedure in cardiac surgery with cardiopulmonary bypass.