Urine neutrophil gelatinase-associated lipocalin and urine output as predictors of the successful discontinuation of continuous renal replacement therapy in critically ill patients with acute kidney injury

Abstract

Background: Continuous renal replacement therapy (CCRT) is a frequently used modality for the support of intensive care patients with acute kidney injury (AKI). Nevertheless, there are no objective criteria for the discontinuation of CRRT. The purpose of this study was to investigate whether urine neutrophil gelatinase-associated lipocalin (uNGAL) alone or in combination with urine output could be used as a diagnostic test for renal function recovery in ICU patients on CRRT. Methods: This was a single-centre prospective observational study including patients with acute kidney failure needing CRRT. Sixty-nine patients were enrolled, and 54 completed the study. Of the 54 patients, 22 recovered renal function (REC), defined as dialysis independency at 72 h from discontinuation, while 32 patients did not (NREC). Urine NGAL was measured at 0, 6, 12, and 24 h after CRRT discontinuation. The cumulated urine output was measured for 24 h prior to discontinuation and at 6, 12, and 24 h after discontinuation. Missing uNGAL values were calculated by interpolation. The Youden's index was used to calculate cutoff values in order to define uNGAL and urine output single variable and 2-variable diagnostic tests with the optimum prediction of successful CRRT discontinuation. Results: Baseline characteristics at CRRT initiation were similar between groups. Compared to the NREC group, the REC group had significantly higher urine output (p < 0.0001) and lower uNGAL (p < 0.001) at all time points, except for uNGAL at 24 h (p < 0.24). The best uNGAL predictor for successful CRRT discontinuation was uNGAL at 6 h after discontinuation (predictive value 80%). The best single predictor was cumulated urine output 24 h before discontinuation (predictive value 85%). The combinations of uNGAL at 6 h (cut-off 1650 μg/L) with cumulated urine output 24 h prior to discontinuation (cut-off 210 ml) proved to be the superior tests (using either "or" or "and"), with predictive values of 93% (successful CRRT discontinuation) and 92% (dialysis dependency). Conclusions: With a predictive value of 93%, the combination of uNGAL at 6 h after and the cumulated urine output 24 h prior to CRRT cessation proved to be the best diagnostic test for successful CRRT discontinuation in ICU patients.

Analysis of urinary C–C motif chemokine ligand 14 (CCL14) and first-generation urinary biomarkers for predicting renal recovery from acute kidney injury: a prospective exploratory study

“…Urine NGAL has been proven to have good utility for predicting short-term and long-term kidney function reversal [32][33][34]. Yet, no significant difference in urine NGAL levels existed between the recovery and nonrecovery groups in the present study (Fig.…”

Current Approach to Successful Liberation from Renal Replacement Therapy in Critically Ill Patients with Severe Acute Kidney Injury: The Quest for Biomarkers Continues

“…Twenty-two of the 54 patients recovered renal function defined as dialysis independency at 72 h, while 32 did not. With a predictive value of 93% the combination of urine NGAL at 6 h after CRRT cessation and the 24-h UO prior to CRRT cessation proved to be the best diagnostic test for CRRT liberation [ 38 ].…”

Urinary neutrophil gelatinase-associated lipocalin and plasma IL-6 in discontinuation of continuous venovenous hemodiafiltration for severe acute kidney injury: a multicenter prospective observational study

“…We observed here a similar result in urinary NGAL. Stads et al and Thomsen et al also demonstrated the predictive value of urinary NGAL on CVVHDF discontinuation [ 29 , 30 ]. The former study included 92 patients and reported that urinary NGAL was higher in the unsuccessful group.…”