Poor diuretic response after first furosemide dose predicts KRT need in critically ill ICU patients.

Patients with urine output ≤25 mL/h in 2 h post-furosemide had higher KRT rate than those with >50 mL/h.

Low urine output post-furosemide was linked to AKI progression and higher KDIGO stages.

Even small furosemide doses showed predictive value, supporting its role in ICU risk stratification.

The administration of furosemide can predict the likelihood of clinical deterioration in patients with early-stage acute kidney injury (AKI). This study aimed to evaluate the response to a patient's first furosemide bolus administered during ICU admission in critically ill patients, and to assess the significance of this response in predicting the need for kidney replacement therapy (KRT).

This retrospective cohort study included critically ill adult patients admitted to a tertiary care hospital ICU between 2017 and 2023 who received a first intravenous furosemide bolus with documented urine output. Patients treated with continuous furosemide infusion were excluded. The response to furosemide was assessed at 2 and 6 h after administration. The primary outcome was the initiation of kidney replacement therapy (KRT) within 7 days.

A total of 1527 critically ill patients were included in the analysis. Among patients with urine output ≤25 mL/h during the first 2 h post-furosemide, 23.9 % received KRT within 7 days, compared to 8.8 % in the 25.1–50 mL/h group and 3.6 % in the >50 mL/h group (p < 0.001). Similar patterns were observed for urine output at 6 h. Lower urine output was also associated with greater AKI progression and higher KDIGO stages. In multivariable analysis, lower urine output at 6 h remained a significant predictor of KRT initiation (adjusted OR per 10 mL/h increase: 0.905, 95 % CI: 0.861–0.951).

This study demonstrates that the response to a first furosemide bolus administered during usual clinical care can be a valuable tool for anticipating the future receipt of KRT.

Furosemide Stress Test

KRT

Fluid balance

Urine output

© 2025 The Authors. Published by Elsevier Inc.