Zinc and copper metabolism during open-heart surgery

Zinc and copper changes were studied in plasma, whole blood, urine and myocardium in 15 patients undergoing valve replacement in hypothermic cardiopulmonary bypass with hemodilution. During the cardiopulmonary bypass, a fall in plasma copper and zinc concentration was related to hemodilution. The zinc concentration also decreased in whole blood, but remained unchanged intracellularly. The urinary concentration of both cations, but not the output, decreased at the end of the operation in relation to the baseline values. The myocardial copper and zinc concentrations increased during the aortic cross-clamping period. The possible causes and significance of these changes are considered.