Acute kidney injury following cardiopulmonary bypass in children

Abstract

Introduction. Acute kidney injury (AKI) is the most common and most serious complication following heart surgery. Aim of the study. To determine the prevalence of, and risk factors for, AKI following pediatric cardiac surgery. Materials and methods. We retrospectively analyzed 203 patients aged ≤18 years who underwent cardiac surgery for congenital heart defects; by RACHS-1 category, 41 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). Results. 58 patients (28.6%) developed AKI: 40 had AKI with a severity classified as risk (R), 14 had AKI classified as injury (I) and 4 had AKI classified as injury (F). RACHS-1 (Risk- Adjusted classification for Congenital Heart Surgery) category, fluid administration as well as fluid overload were compared between patients with and without AKI. Longer cardiopulmonary bypass (CPB) time (P=0.03) and vasoactive-inotropic score (P=0.0002) were independent risk factors for AKI. Fluid overload and intraoperative lactate level was not a significant predictor for AKI. Higher pRIFLE classification positively correlated with increased postoperative mechanical ventilation duration, and longer ICU stay (P=0.01). Conclusions. In this study, we found a higher 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.