Identification of risk factors for renal failure after cardiac surgery by RFILE classification.

OBJECTIVE Acute kidney injury (AKI) is a major complication after cardiovascular surgery. The unclear etiology of this highly complex event challenges definition, diagnosis and prediction of AKI, and hence hampers adequate patient management. Identification of associated risk factors have the potential to overcome this limitation. METHODS This retrospective study comprised 3574 patients who underwent cardiac surgery in a hospital in Germany. The patient cohort was interrogated for risk factors for AKI. RESULTS The analysis identified risk factors for AKI development, such as type of surgery (particularly bypass surgery) (P = 0.02), previous coronary surgeries (P < 0.01), the application of intra-aortic balloon pump in surgery (P < 0.01), and blood loss during surgery (P < 0.01). In addition, old age, duration of surgery as well as ischemia, perfusion and reperfusion times contributed to AKI development (P < 0.01). Further, perioperative hypothermia also appeared as putative risk factor in the analysis (P < 0.01). CONCLUSIONS This study identified several risk factors for the development of AKI after cardiac surgery. Further validation of these risk factors could allow the implementation of adequate patient management, and the appropriate implementation of risk-adverse interventions in cardiovascular surgery.