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The following is a summary of “Spontaneous diuresis in combination with furosemide stress test (SD-FST) as predictor for successful liberation from kidney replacement therapy: a prospective observational study,” published in the May 2025 issue of Critical Care by Weidhase et al. 

Researchers conducted a retrospective study in the field of nephrology to assess the effectiveness of the furosemide stress test (FST) in determining the optimal timing for discontinuing kidney replacement therapy (KRT) in acute kidney injury (AKI). 

They performed the FST in patients who developed spontaneous diuresis during ongoing KRT with urine output of at least 400 ml in 24 hours (h) without diuretic use. A positive test was defined as urine output exceeding 200 ml within 2 h after intravenous furosemide administration. Follow-up lasted 7 days (d), with daily evaluation of the need to resume KRT.  

The results showed that out of 100 enrolled patients, 98 met eligibility for evaluation. Among these, 76 were positive for the FST, and 22 were negative for the FST. The KRT was resumed within 7 d in 14.5% of patients with FST-positive compared to 72.7% of FST-negative (P< 0.001). Additionally, urine output following FST was strongly linked to successful discontinuation of KRT, with an area under the curve (AUC) of 0.87 (P< 0.001).  

Investigators concluded that patients with critical illness and with spontaneous diuresis over 400 ml per day during KRT, the FST effectively identified those likely to be successfully weaned from therapy by assessing tubular reserve and predicting short-term kidney recovery after AKI. 

Source: ccforum.biomedcentral.com/articles/10.1186/s13054-025-05452-1