ObjectiveTo retrospectively evaluate the risk factors of mortality in postoperative acute kidney injury (AKI) patients undergoing continuous renal replacement therapy (CRRT) after cardiopulmonary bypass (CPB). MethodsWe retrospectively analyzed the clinical data of 66 patients (38 males and 28 females with mean age of 59.11±12.62 years) underwent CRRT after cardiovascular surgery in our hospital between May 2009 and June 2014. The patients were divided into a survival group (18 patients) and a death group (48 patients) according to treatment outcome at discharge. Univariate analysis for risk factors of death was carried out for preoperative characteristics and lab results among study population. Significant univariate factors were then further analyzed by multivariable logistic regression models. ResultsSignificant predictors of death included blood transfusion volume during operation, peak level of blood sugar and lactate during operation, the total bilirubin level and platelet count on the first day after operation, hypotension on the first day after operation, pulmonary infection, multiple organ dysfunction syndrome (MODS) and the interval time of oliguria and CRRT (P<0.05). Logistic regression showed that there were statistical differencs in hypotension on the first day after operation, postoperative platelet count, and interval time of oliguria and CRRT respectively (P<0.05). ConclusionImproving intraoperative management, reducing bleeding and blood transfusion, controlling blood sugar level, dealing with complications such as hypotension, pulmonary infection and MODS more aggressively, starting CRRT when needed may be helpful to reduce mortality. Monitoring of the blood pressure and platelet count on the first day after operation is useful for prognosis estimation.