Urinary Biomarkers Can Predict Weaning From Acute Dialysis Therapy in Critically Ill Patients

Abstract

Context.-Critically ill patients with acute kidney injury (AKI) requiring renal replacement therapy (RRT) have a poor prognosis. Several urinary AKI biomarkers have been proposed to predict renal recovery, but with limited discriminatory ability. Objective.-To validate the predictive performances of novel biomarkers to identify which critical patients with AKI may successfully wean from RRT. Design.-We prospectively recorded and analyzed clinical variables at several time points: (1) before starting RRT, (2) at the time of weaning off RRT, and (3) 24 hours after stopping RRT. A total of 140 critically ill patients who received RRT at a multicenter referral hospital from August 2016 to January 2019 were enrolled. The outcomes of interest were the ability to wean from RRT and 90-day mortality. Results.-The 90-day mortality rate was 13.6% (19 of 140), and 47.9% (67 of 140) of the patients were successfully weaned from RRT. Cluster analysis showed that the following biomarkers were correlated with estimated glomerular filtration rate at the time of weaning off RRT: urinary neutrophil gelatinase-associated lipocalin, kidney injury molecule 1, hemojuvelin, C-C motif chemokine ligand 14, interleukin 18, and liver-type fatty acid- binding protein (L-FABP). Among these, urinary L-FABP/ creatinine (uL-FABP/Cr) at the time of weaning off RRT showed the best predictive performance for mortality (area under the receiver operating characteristic curve = 0.79). Taking mortality as a competing risk, Cox proportional hazards analysis indicated that a low uL-FABP/Cr (log) level was an independent prognostic factor for weaning from RRT (subdistribution hazard ratio, 0.35; P = .01). Conclusions.-uL-FABP/Cr at the time of weaning off RRT could predict weaning from RRT and 90-day mortality.