Early administration of lactated Ringer's solution and mortality in critically ill patients with heart failure: A retrospective cohort study.

BACKGROUND

Effective fluid management in critically ill patients with heart failure (HF) remains challenging. Lactate, beyond its traditional perception as a metabolic waste product, has emerged as an important myocardial energy substrate and modulator of cardiac function. This study evaluated whether early lactated Ringer's solution (LR) administration is associated with short-term and long-term outcomes in critically ill patients with HF.

METHODS

This retrospective cohort study included 12,354 HF patients admitted to intensive care units, derived from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients were categorized based on early (≤24h) LR administration. Propensity Score Matching (PSM) and Inverse Probability of Treatment Weighting (IPTW) analyses were employed to balance baseline covariates between groups. Primary outcomes were in-hospital, 28-day, and 1-year mortality, evaluated using logistic regression and Cox proportional hazards models.

RESULTS

A total of 4138 patients received early LR infusion, and 8216 did not. After PSM, LR infusion was associated with lower in-hospital mortality (OR, 0.66 [95 %CI, 0.56-0.78]; P < 0.001), as well as lower 28-day (HR, 0.74 [95 %CI, 0.65-0.83]; P < 0.001) and 1-year mortality (HR, 0.77 [95 %CI, 0.70-0.84]; P < 0.001). IPTW analyses produced concordant estimates. Subgroup analyses showed broadly consistent associations across prespecified strata.

CONCLUSION

Early administration of LR was associated with lower short-term and long-term mortality among fluid-eligible ICU patients with HF in a mixed-fluid setting. These observational findings suggest further evaluation of fluid composition in this population. Randomized trials are warranted to confirm these associations and guide practice.