Objective: To determine the incidence and risk factors associated with acute kidney injury (AKI) in patients after cardiac surgery with extracorporeal circulation.
Methods: A retrospective case control study was done in patients who underwent cardiac surgery from 2003 to 2007 in Second Xiangya Hospital, with 340 patients in an AKI group and the other 4 760 patients without AKI as a control group. All variables were analyzed by univariate analysis, Mann-Whitney U test and logistic regression.
Results: AKI occurred in the 340 patients (6.7% incidence). Univariate analysis revealed that age, preoperative serum creatinine, preoperative ejection fraction (EF), preoperative beta2-microglobulin, preoperative blood albumin, preoperative blood uric acid, intraoperative cardiopulmonary bypass time, intraoperative aortic cross-clamp time, and dosage of mannitol were significantly related to AKI following cardiac surgery with extracorporeal circulation. Logistic multivariate regression analysis showed that preoperative serum creatinine (P<0.001), preoperative ejection fraction (EF) (P<0.001), preoperative beta2-microglobulin (P=0.002), preoperative blood uric acid (P=0.015), intraoperative cardiopulmonary bypass time (P<0.001), and intraoperative aortic cross-clamp time (P<0.001) were independent risk factors for AKI.
Conclusion: The incidence of AKI after cardiac surgery with extracorporeal circulation is closely related with a variety of perioperative risk factors. Our data suggest that patients planning to accept cardiac surgery with extracorporeal circulation should be more comprehensively assessed and monitored, thereby preventing the occurrence of AKI.