The Impact of Diuretics on Mortality in Acute Kidney Injury With or Without Fluid Accumulation in Intensive Care—A Retrospective Cohort Study
Sofie Bay Nøsted, Frederikke Stenner Falkvist, Martin Schønemann‐Lund, Morten Bestle, Sine WichmannABSTRACT
Background
Acute kidney injury (AKI) is common in the intensive care unit (ICU) and associated with increased mortality. While diuretics are widely used to manage fluid accumulation, their impact on survival in established AKI remains uncertain.
Methods
This retrospective cohort study included adult ICU patients with AKI present on or within 48 h of ICU admission in the Capital Region of Denmark, 2022–2024. Early diuretic exposure was defined as systemic diuretic administration within 24 h after AKI onset. Primary outcome was 30‐day mortality, analyzed using 24‐h landmark Cox regression adjusted for sex, Simplified Acute Physiology Score 3 (SAPS 3), baseline creatinine, and AKI stage. Pre‐specified subgroup analyses by AKI stage and post hoc sensitivity analyses were performed. Secondary outcomes included fluid accumulation (> 5% ideal body weight) and Major Adverse Kidney Events within 30 days (MAKE30).
Results
Of 4430 patients with AKI, 58% received early diuretics. In the primary adjusted analysis, early diuretics were not associated with 30‐day mortality (hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.98–1.26, p = 0.113). In a post hoc time‐dependent sensitivity analysis, diuretic use was associated with higher mortality (HR 1.27, 95% CI 1.08–1.49, p = 0.004). In the pre‐specified AKI stage 3 subgroup, early diuretic use was associated with a higher risk of mortality (HR 1.42, 95% CI 1.16–1.73, p < 0.001). Diuretics were associated with a lower risk of fluid accumulation (odds ratio (OR) 0.58, p < 0.001) but a higher risk of MAKE30 (OR 1.23, p = 0.004).
Conclusion
Early diuretic treatment was frequent but not associated with improved survival in the primary analysis. Given the observational design, causal relationships cannot be inferred from these findings. These results do not support routine early diuretic use in unselected AKI patients; prospective studies are needed to clarify the role of targeted diuretic therapy in patients with fluid accumulation.
Editorial Comment
This retrospective cohort analysis analyzes associations between acute renal injury development in intensive care unit patients and early diuretic use, along with fluid balance. Early diuretic use was not associated with improved survival in this cohort, where treatments were uncontrolled. Risks are described by renal injury severity subgroups and renal outcomes after ICU.