Association of plasma neutrophil gelatinase-associated lipocalin with acute kidney injury and clinical outcome in cardiac arrest survivors depends on the time of measurement

Purpose: The optimal timing for measurement of neutrophil gelatinase-associated lipocalin (NGAL) level to predict acute kidney injury (AKI) and prognosis in cardiac arrest (CA) survivors has not been elucidated. We aimed to compare the diagnostic and prognostic performance of NGAL levels after return of spontaneous circulation (ROSC) and at 48h after CA.Methods: We included 231 adult cardiac arrest survivors who underwent targeted temperature management between May 2013 and December 2016. The primary outcome was stage 2 and 3 AKI (high stage AKI), and the secondary outcomes were in-hospital mortality and neurologic outcome. Sixty-one (26.4%) developed high stage AKI, 50 (21.6%) died, and 152 (65.8%) had a poor neurologic outcome.Results: NGAL level at 48h (0.876; 95% confidence interval [CI], 0.826-0.916) had a higher area under receiver operating characteristic curve than NGAL level after ROSC (0.694; 95% CI, 0.631-0.753). Both NGAL levels were independently associated with high stage AKI. NGAL level at 48h (1.001; 95% CI, 1.000-1.002) remained a significant predictor for in-hospital mortality, while neither of the NGAL levels were independently associated with neurologic outcome.Conclusions: NGAL at 48h after CA seems to be a robust predictor for high stage AKI and in-hospital mortality.