Background: Acute renal injury increases risk of death after cardiac surgery. The objective of the study was to evaluate the ability of the pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease (pRIFLE) criteria to characterize the development of postoperative renal damage in children after cardiopulmonary bypass (CPB) and to evaluate the relationship between the severity of kidney injury and mortality, pediatric intensive care unit (PICU) length of stay, and the duration of mechanical ventilation (MV).
Methods: In this retrospective study including children undergoing CPB surgery during a 3-year period in the PICU of a tertiary hospital, demographic, clinical, surgery-related, and postoperative clinical data were collected. Kidney damage was assessed with pRIFLE criteria.
Results: Four hundred and nine patients were included. Early acute kidney injury (AKI) was found in 82 patients (achieving categories Risk 44; Injury 16; Failure 22). Early AKI was associated with younger age (P = 0.010), longer CPB, deep hypothermic circulatory arrest (DHCA) use, ICU stay >12 days, MV >4 days, and death (P < 0.001). Controlling the effect of age, CPB, DHCA use, previous cardiac surgeries, and Risk Adjustment in Congenital Heart Surgery Surgical Severity Score (RACHS-1), early AKI development proved to predict ICU stay >12 days [odds ratio (OR) 3.5; 95% confidence interval (CI) 1.9-6.5, P < 0.001)] and need of MV >4 days (OR 5.1; 95% CI 2.6-10.2, P < 0.001).
Conclusions: Early AKI when evaluated with the pRIFLE criteria can predict prolonged ICU stay, need of prolonged MV, and mortality.