Abstract
Serial measurements of the urinary NAG excretion were done in 16 patients who underwent open heart surgery, in order to detect the renal damage prior to the deterioration of the renal function. The excretion of NAG was measured before, during, and after the cardiac surgery with cardio-pulmonary bypass (CPB), and was found to have its peak about 3 hours after the end of CPB. The NAG excretion increased as CPB time prolonged, and returned to normal range on the first postoperative day. There was a good correlation between the total CPB time and the total amount of NAG excretion. The excretion pattern of β2-microglobulin, a sensitive indicator of the reabsorptive function of the kidney, was similar to that of NAG, but its peak was delayed several hours. The study of the urinary excretion of NAG may be of value in predicting postperfusion renal failure.
