Neutrophil Gelatinase-Associated Lipocalin Concentrations Predict Development of Acute Kidney Injury in Neonates and Children after Cardiopulmonary Bypass

Objectives To investigate neutrophil gelatinase-associated lipocalin (NGAL) as an early acute kidney injury (AKI) biomarker after neonatal and pediatric cardiopulmonary bypass (CPB). Study design Serum and urine samples were obtained before and at intervals after CPB from 374 patients. AKI was defined as a serum creatinine (SCr) concentration increase from baseline >= 0.3 mg/dL in neonates and >= 50% in children within 48 hours of CPB. Logistic regression was used to assess predictors and clinical outcomes associated with AKI. Results AKI developed in 30% of patients. Plasma and urine NGAL thresholds significantly increased in patients with AKI at 2 hours after CPB and remained elevated at all points, with 2-hour NGAL the earliest, strongest predictor of AKI. In non-neonates, 2-hour plasma and urine NGAL thresholds strongly correlated with length of hospital stay and severity and duration of AKI. Conclusion Plasma and urine NGAL thresholds are early predictive biomarkers for AKI and its clinical outcomes after CPB. In neonates, we recommend a 2-hour plasma NGAL threshold of 100 ng/mL and 2-hour urine NGAL threshold of 185 ng/mL for diagnosis of AKI. In non-neonates, recommended AKI thresholds are 50 ng/mL for both 2-hour plasma and urine NGAL. (J Pediatr 2011;158:1009-15).