Positive Fluid Balance Worsens Clinical Outcomes in Hospitalized Pneumonia Patients

Objective: To evaluate the impact of fluid balance on the outcomes of patients admitted for pneumonia and to describe the clinical risk factors associated with these outcomes in hospitalized pneumonia patients.

Methods: This is a subgroup analysis using data from a multicenter, observational cohort (LIPS1 study). Adult ED patients presenting with pneumonia were enrolled from March through August in 2009. Fluid balance was categorized as ≤1, 1-2, 2-3, and >3 liters within the first 6 hours of care. Outcomes were defined as a composite of acute respiratory failure (ARF) requiring invasive or non-invasive mechanical ventilation (MV) or in-hospital mortality. Multivariate logistic regression analysis incorporating covariates with biological effect and significant differences in univariate analysis was performed to determine the adjusted odds ratios for the fluid balance categories and composite outcome.

Results: Univariate analysis of 896 ED patients showed an increasing rate of combined ARF requiring MV and hospital mortality with incremental positive fluid balance (p < 0.001). The covariates of shock index, admission source, and aspiration had a significant effect in univariate analysis. Multivariate regression modeling continued to show a statistically significant difference between categories of fluid balance ≤1 liter vs. >3 liters with respect to our composite outcome (odds ratio 2.14; 95% confidence interval, 1.12 to 4.08).

Conclusion: For pneumonia patients, we found a significant association between positive fluid balance within the first six hours and the composite outcomes of ARF requiring MV and hospital mortality. This finding is consistent with similar observations for other critically ill patients.

Keywords: Pneumonia, Fluid Balance, Respiratory Failure.