[Changes in blood zinc and copper and their clinical significance in patients undergoing open-heart surgery]

The levels of zinc and copper in the serum, plasma, erythrocyte and urine were determined in 17 cases undergoing open-heart surgery. Samples were taken daily before, during, and after cardiopulmonary bypass operations for 9 days. Mean plasma zinc dropped significantly 30 minutes after perfusion and reached its lowest level on the first postoperative day and remained lower than the preoperative level until the seventh postoperative day. Mean urinary zinc excretion was high on the day of operation and showed a peak value 2 hours after operation. A transient decrease of plasma copper occurred after 30 minutes of perfusion. However, it returned to the preoperative level by the first or second postoperative day followed by a persistent rise to a level significantly higher than preoperative levels from the third to the ninth day. Urinary copper excretion presented the same trend as urinary zinc excretion. The results suggest that a severe loss of zinc and copper occurs in the patients undergoing open-heart surgery and a rational supply of zinc and copper is necessary.