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, alpha1-microglobulin and beta-glucosaminidase (beta-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, alpha1-microglobulin and beta-NAG excretions significantly increased during CPB, at 24 and 72 h, 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, alpha1-microglobulin excretion during CPB was significantly higher than in Group 1 (P < 0.001), and 24h 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 alpha1-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.

Pattern of renal dysfunction associated with myocardial revascularization surgery and cardiopulmonary bypass.

BACKGROUND AND OBJECTIVE: A variable incidence rate of renal dysfunction (3-35%) after cardiac surgery with cardiopulmonary bypass has been reported. The aim was to define the typical pattern of renal dysfunction that follows coronary surgery with cardiopulmonary bypass using albumin, immunoglobulin (IgG), alpha1-microglobulin and beta-glucosaminidase (beta-NAG) excretion as indicators. METHODS: Twenty patients with preoperative normal renal function, defined by plasma creatinine, creatinine clearance, fractional excretion of sodium and renal excretion of proteins, undergoing elective myocardial revascularization surgery with cardiopulmonary bypass, were prospectively studied. Variables recorded were demographic and haemodynamic variables, duration of cardiopulmonary bypass and aortic clamping, intra- and postoperative urine output, plasma creatinine concentration, creatinine clearance and excretion of sodium, albumin, IgG, beta-glucosaminidase (beta-NAG), and alpha1-microglobulin. Measurements were made preoperatively, immediately before and then during and immediately after cardiopulmonary bypass, and again at 1, 24, 72 h, 7 and 40 days following surgery. RESULTS: Albumin and IgG excretion rose significantly during cardiopulmonary bypass (P < 0.05), remaining at these levels at 24 h postoperatively. An increase of alpha1-microglobulin and beta-NAG concentrations was observed during cardiopulmonary bypass (P < 0.05), which were maintained until the seventh postoperative day and remained elevated in some patients at the 40th postoperative day. This correlated with preoperative diabetes mellitus (P < 0.001), low cardiac output after cardiopulmonary bypass (P < 0.001) and the duration of stay in the intensive care unit (P < 0.001). CONCLUSIONS: The pattern of renal dysfunction after cardiopulmonary bypass for myocardial revascularization is characterized by temporary renal dysfunction at both glomerular and tubular levels with an onset within 24 h of surgery and which lasts between 24 h and 40 days, respectively, following surgery.