Acute kidney injury in congenital cardiac surgery: Pediatric risk-injury-failure-loss-end-stage renal disease and Acute Kidney Injury Network

Background: Acute kidney injury (AKI) is associated with an increased risk of mortality, especially in pediatric intensive care units. The aim of this study was to determine the risk factors of AKI in children undergoing cardiac surgery for congenital heart disease and to compare two different classification systems: pediatric risk-injury-failure-loss-end-stage renal disease (pRIFLE) and Acute Kidney Injury Network (AKIN). Methods: We retrospectively analyzed 145 patients undergoing pediatric congenital heart surgery who were between 1 month and 18 years of years, and treated at a cardiovascular surgery department from January 2009 to October 2011. Results: One hundred and thirty-seven patients (mean age, 36.6 +/- 43.3 months) were enrolled: 84 (61.3%) developed AKI according to the pRIFLE criteria (25.5%, risk; 20.4%, injury; 15.3%, failure); and 65 patients (47.4%) developed AKI according to the AKIN criteria (15.3%, stage I; 18.2%, stage II; and 13.9%, stage III). Children younger than 11 months were more likely to develop AKI (P < 0.005). Longer cardiopulmonary bypass time was associated with an increased risk of AKI (P < 0.05). pRIFLE identified AKI more frequently than AKIN (P < 0.0005). pRIFLE may help in the early identification of patient at risk for AKI and seems to be more sensitive in pediatric patients (P < 0.05). Any degree of AKI in both classifications was associated with increased mortality (pRIFLE: OR, 15.1; AKIN: OR, 11.2; P = 0.007). Conclusion: pRIFLE identified AKI more frequently than the AKIN criteria. pRIFLE identified patients at risk for AKI earlier, and was more sensitive in pediatric patients. Any degree of AKI in both classifications was associated with increased mortality. Both sets of criteria had the same association with mortality.