Acute Kidney Injury Following Cardiopulmonary Bypass in Children　- Risk Factors and Outcomes.

Background: Acute kidney injury (AKI) is the most common and most serious complication following heart surgery. We aimed to determine the prevalence of, and risk factors for, AKI following pediatric cardiac surgery. Methods and Results: We retrospectively analyzed 135 patients aged <= 18 years who underwent cardiac surgery for congenital heart defects; by RACHS-1 category, 58 patients (43%) had an operative risk score >= 3. AKI was defined and classified using the pediatric pRIFLE criteria (Pediatric Risk, Injury, Failure, Loss, and End-stage Kidney Disease); 19 patients (14.1%) developed AKI: 17 had AKI with a severity classified as risk (R) and 2 had AKI classified as injury (I). Body weight, height, body surface area, and preoperative mechanical ventilation were all independently associated with AKI development (P= 0.038, 0.040, 0.033 and 0.008, respectively). Preoperative ventilation strongly correlated with AKI severity. Higher pRIFLE classification positively correlated with increased incidence of peritoneal dialysis, increased postoperative mechanical ventilation duration, and longer hospital stay (P= 0.009, 0.039 and 0.042, respectively). Conclusions: In this study, we found a low prevalence of postoperative AKI in pediatric patients undergoing severe cardiac surgery. AKI was associated with worse early postoperative outcomes. Early prediction and appropriate treatment of AKI during the postoperative period are emphasized.