Predictors of 90-Day Restart of Renal Replacement Therapy after Discontinuation of Continuous Renal Replacement Therapy, a Prospective Multicenter Study.

Background: Restart of renal replacement therapy (RRT) after initial discontinuation of continuous RRT (CRRT) is frequently needed. The aim of the present study was to evaluate whether renal markers after discontinuation of CRRT can predict restart of RRT within 90 days.

Methods: Prospective multicenter observational study in 90 patients, alive, still on the intensive care unit at day 2 after discontinuation of CRRT for expected recovery with urinary neutrophil gelatinase-associated lipocalin (NGAL) available. The endpoint was restart of RRT within 90 days. Baseline and renal characteristics were compared between outcome groups no restart or restart of RRT. Logistic regression and receiver operator characteristic curve analysis were performed to determine the best predictive and discriminative variables.

Results: Restart of RRT was needed in 32/90 (36%) patients. Compared to patients not restarting, patients restarting RRT demonstrated a higher day 2 urinary NGAL, lower day 2 urine output, and higher incremental creatinine ratio (day 2/0). In multivariate analysis, only incremental creatinine ratio (day 2/0) remained independently associated with restart of RRT (OR 5.28, 95% CI 1.45-19.31, p = 0.012). The area under curve for incremental creatinine ratio to discriminate for restart of RRT was 0.76 (95% CI 0.64-0.88). The optimal cutoff was 1.49 (95% CI 1.44-1.62).

Conclusion: In this prospective multicenter study, incremental creatinine ratio (day 2/0) was the best predictor for restart of RRT. Patients with an incremental creatinine ratio at day 2 of 1.5 times creatinine at discontinuation are likely to need RRT within 90 days. These patients might benefit from nephrological follow-up.