ObjectiveTo investigate the risk factors of death in patients undergoing continuous renal replacement therapy (CRRT) after cardiac surgery. MethodsWe retrospectively analyzed records of 66 adult patients without history of chronic renal failure suffering acute kidney injury (AKI) following cardiac surgery and undergoing CRRT in our hospital between July 2007 and June 2014. There were 38 males and 28 females with mean age of 59.11±12.62 years. They were divided into a survival group and a non-survival group according to prognosis at discharge. All perioperative data were collected and analyzed by univariate analysis and multivariate logistic regression analysis. ResultsIn sixty-six adult patients, eighteen patients survived with a mortality rate of 72.7%. Through univariate analysis and multivariate logistic regression, risk factors of death in the post-operative AKI patients requiring CRRT included hypotension on postoperative day 1 (B=2.897, OR=18.127, P=0.001), duration of oliguria until hemofiltration (B=0.168, OR=1.183, P=0.024), and blood platelet on postoperative day 1 (B=-0.026, OR=0.974, P=0.001). ConclusionHypotension on postoperative day 1 (POD1) is the predominant risk factor of death in patients requiring CRRT after cardiac surgery, while blood platelet on POD1 is a protective factor. If CRRT is required, the sooner the better.