NGAL Usefulness in the Intensive Care Unit Three Hours after Cardiac Surgery

Objective. Neutrophil gelatinase-associated lipocalin (NGAL) measured by a research ELISA is described as an early marker of acute kidney injury (AKI). The aim of this study is to define the usefulness of plasma NGAL (pNGAL) and urine NGAL (uNGAL) measured with platform analysers to detect AKI 3 hours after cardiac surgery in fifty adult patients. Methods and Main Results. pNGAL and uNGAL were measured before and 3 hours after cardiac surgery. AKI, defined following the acute kidney injury network definition, was observed in 17 patients. pNGAL was >149 ng/mL in 8 patients with AKI, two of them died in the follow-up. We also observed elevated pNGAL in 8 patients without AKI. Only one uNGAL was >132 ng/mL among the 15 AKI patients. Sensitivity of pNGAL for prediction of AKI is 47% and specificity is 75.7%. The positive likelihood ratio (LR+) is 1.9 and negative likelihood ratio (LR-) is 0.7. uNGAL performance is slightly improved when reported to urinary creatinine. Following this study, a ratio >62 ng/mg assure a sensitivity of 66.6% and a specificity of 78.5%. LR+ is 3 and a LR- is, 0.42. Conclusions. Three hours after cardiac surgery, pNGAL predicts AKI with a low sensitivity and specificity.