Effects of Cardiopulmonary Bypass and Aprotinin on Renal Function in Patients Undergoing Coronary Artery Bypass Grafting

Abstract

BACKGROUND: Perioperative renal dysfunction is a significant complication of coronary artery bypass grafting (CABG), and is associated with major increases in morbidity, mortality, and cost. The risk factors noted in the development of postoperative renal dysfunction include advanced age, preoperative renal dysfunction, preoperative left ventricular dysfunction and cardiopulmonary bypass (CPB). These variables are also considered markers of renal hypoperfusion occurring before, during, or after operation. It is known that aprotinin can reduce bleeding and blood transfusion requirements in patients undergoing cardiac operations. Aprotinin is a small molecule and is freely filtered by the glomeruli and nearly completely absorbed. Thus, many concerns have been raised regarding its possible nephrotoxic effects. Thus, we designed a randomized double‐blind study to assess the effects of aprotinin and CPB on renal function in patients undergoing CABG. METHODS: Fifty‐two stable or unstable angina patients scheduled for elective CABG were allocated randomly into Group O: off‐pump CABG (OPCAB) (n = 20), Group P: CABG with CPB (n = 16) or Group P‐A: CABG with CPB and high‐dose aprotinin (n = 16). Renal function parameters (serum creatinine, blood urea nitrogen) were measured in all patients preoperatively, just after CABG and on postoperative days one and two, respectively. RESULTS: In groups O and P, no significant change of creatinine or blood urea nitrogen (BUN) were noticed perioperatively. In general, postoperative creatinine and BUN levels of group P‐A were higher than those of group O, with statistical significance, but within the normal range. Although postoperative increases of creatinine and BUN were noticed, with statistical significance, in Group P‐A on postoperative day two, they also remained within the normal range. CONCLUSIONS: In spite of mild and transient postoperative elevations of creatinine and BUN, we conclude that renal function does not seem to be adversely affected by CPB or CPB with aprotinin medication in CABG patients. Further study regarding the influence of CPB or CPB with aprotinin medication is needed for patients with risk factors of renal dysfunction. [By kind permission, KoreaMed, Korean Association of Medical Journal Editors.]