Kidney-specific proteins in patients receiving aprotinin at high- and low-dose regimens during coronary artery bypass graft with cardiopulmonary bypass

Background and objective: The aim was to determine whether the administration of aprotinin can cause deleterious effects on renal function in cardiac surgery with cardiopulmonary bypass (CPB). Methods: Sixty consecutive patients with normal preoperative renal function undergoing elective coronary artery bypass surgery with CPB using the same anaesthetic; CPB and surgical protocols were randomized into three groups. Patients received placebo (Group 1), low-dose aprotinin (Group 2) or high-dose aprotinin (Group 3). Renal parameters measured were plasma creatinine, alpha(1)-microglobulin and beta-glucosaminidase (P-NAG) excretion. Measurements were performed before surgery, during CPB and 24 and 72 h, and 7 and 40 days postoperatively. Results: In the three groups, alpha(1)-microglobulin and P-NAG excretions significantly increased during CPB, at 24 and 72h, and 7 days postoperatively (P < 0.05) and had returned to preoperative levels at postoperative day 40. Plasma creatinine levels were within normal values at times recorded. In Groups 2 and 3, alpha(1)-microglobulin excretion during CPB was significantly higher than in Group 1 (P < 0.00 1), and 24 h after surgery it still remained significantly higher in Group 3 compared to Groups 1 and 2 (P < 0.05). Conclusions: Aprotinin caused a significant increase in alpha(1)-microglobulin excretion but not in beta-NAG excretion during CPB, which may be interpreted as a greater renal tubular overload without tubular damage. This effect persisted for 24 h after surgery when high-dose aprotinin doses had been administered. Creatinine plasma levels were not sensitive to detect these prolonged renal effects in our study.