Usefulness of plasma neutrophil gelatinase-associated lipocalin as an early marker of acute kidney injury after cardiopulmonary bypass in Korean cardiac patients: A prospective observational study

Objectives: Development of acute kidney injury (AKI) after cardiopulmonary bypass (CPB) is relatively common and associated with increased mortality. Recently, plasma neutrophil gelatinase-associated lipocalin (NGAL) was used for the prediction of AKI. We evaluated the clinical usefulness of plasma NGAL. Design and methods: One hundred twelve adult patients undergoing cardiovascular surgery with CPB were included. Blood samples were obtained at baseline, at intensive care unit (ICU) admission, and 24 h after ICU admission. The development of AKI, which is defined as an increase in serum creatinine by more than 50% within 3 postoperative days, was monitored. NGAL levels were analyzed by a Biosite Triage meter (Alere Medical, USA). Diagnostic performance of NGAL was analyzed using the area under the receiver operating characteristic curve. Results: In AKI patients (n = 13), plasma NGAL levels at ICU admission were significantly higher than those at baseline [ 177 (122-402) vs. 121 (74-158) ng/mL, median (interquartile range), p = 0.028], whereas serum creatinine showed no significant change. The predictive value of NGAL at ICU admission was 0.812 [95% confidence interval (CI), 0.68 to 0.95] with a cut-off value of 168.5 ng/mL (sensitivity, 61.5%; specificity, 88.9%). After the exclusion of 35 patients with preoperative decreased renal function, the predictive value was increased to 0.911 (95% CI, 0.82 to 1.00). Conclusions: This study showed that plasma NGAL may serve as a useful biomarker for the early detection of AKI in adult patients following CPB. (C) 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.