Two hours of urine output are a reliable parameter for intravenous furosemide adequacy and the need for doubling dose in acute heart failure: a prospective study.

OBJECTIVES

This study compared urine output at 2 and 6 h post-furosemide and explored factors influencing diuretic efficacy in acute heart failure (AHF).

METHODS

A prospective study (June-August 2023) included AHF patients (≥18 years) with NT-proBNP ≥300 pg/mL. Urinary spot sodium and urine output were measured at baseline, 2, and 6 h after 40 mg IV furosemide.

RESULTS

Among 32 patients, 26 (81.25 %) had satisfactory urine output, and 30 (93.75 %) met the target urinary sodium concentration at 2 h. No significant difference in mean urine output was found between the 2 and 6 h intervals (267 ± 189 mL vs. 298 ± 149 mL, p=0.099). Urine output correlated strongly with urinary sodium concentration (p < 0.001, R2=0.683). Serum creatinine was a significant predictor of urine output (p=0.007).

CONCLUSIONS

The comparable urine output at 2 and 6 h suggests that a 2 h assessment may be sufficient to evaluate diuretic response and guide dose adjustments in AHF.