Does Early Initiation of Renal Replacement Therapy Have an Impact on 28-day mortality in Critically Ill Patients with Acute Kidney Injury with Positive Furosemide Stress Test?: a Multicenter Randomized Controlled Trial

Abstract

Background: The timing of initiation of renal replacement therapy (RRT) in severe acute kidney injury (AKI) remains controversial, with early initiation resulting in unnecessary therapy for some patients while expectant therapy may delay RRT for other patients. The furosemide stress test (FST) has been shown to predict the need for RRT and therefore could be used to exclude low-risk patients from enrollment in trials of RRT timing. Methods: FST was performed using intravenous furosemide (1 mg/kg in furosemide-naive patients or 1.5 mg/kg in previous furosemide users). FST-nonresponsive patients (urine output less than 200 mL in 2 h) were then randomized to early (initiation within 6 h) or standard (initiation by urgent indication) RRT. The primary outcome is 28-day difference in mortality rates between early and standard RRT. Results: FST was completed in 162 patients. Only 6/44 (13.6%) FST-responsive patients ultimately received RRT. Among 118 FST-nonresponsive patients, 98.3% in the early RRT arm and 75% in the standard RRT arm received RRT. We observed no differences in 28-day mortality (62.1 versus 58.3%, p = 0.68), 7-day fluid balance, or RRT dependence at day 28. Conclusion: The furosemide stress test appears to be feasible and effective in identifying patients for randomization to different RRT initiation times. There was no difference between 28-day mortality rates between furosemide-nonresponsive patients who were randomized to early or standard RRT initiation.