Plasma neutrophil gelatinase-associated lipocalin measured in consecutive patients after congenital heart surgery using point-of-care technology.

Neutrophil gelatinase-associated lipocalin (NGAL) is an early predictive biomarker of acute kidney injury. Plasma NGAL was measured in 218 consecutive patients aged three days to 21.1 years after admission to the intensive care unit after cardiopulmonary bypass surgery using a commercially available point-of-care test to evaluate its diagnostic value in daily practice. Plasma NGAL was between 60 and 644 ng/ml in all patients [median 134 (interquartile range 94-194) ng/ml]. In 31% of patients, serum creatinine increased more than 50% within three days after surgery, but no patient needed renal replacement therapy. In the early neonatal period, NGAL was positively correlated to baseline serum creatinine (r=0.47; P=0.02). In patients aged more than 10 days, plasma NGAL was correlated to peak serum creatinine in the postoperative course (r=0.21; P=0.003), and to the severity of acute kidney injury (r=0.15; P=0.032). However, NGAL values were substantially scattered. Plasma NGAL levels early after congenital heart surgery are correlated to acute kidney injury, but the severity of kidney injury cannot be deduced from an individual NGAL value. Therefore, the value of one single plasma NGAL measurement performed early after cardiac bypass surgery for congenital heart disease is limited.