Impact of Initial Central Venous Pressure on Outcomes of Conservative Versus Liberal Fluid Management in Acute Respiratory Distress Syndrome

Objectives: In acute respiratory distress syndrome, conservative fluid management increases ventilator-free days without affecting mortality. Response to fluid management may differ based on patients' initial central venous pressure. We hypothesized that initial central venous pressure would modify the effect of fluid management on outcomes.

Design: Retrospective analysis of the Fluid and Catheter Treatment Trial, a multicenter randomized trial comparing conservative with liberal fluid management in acute respiratory distress syndrome. We examined the relationship between initial central venous pressure, fluid strategy, and 60-day mortality in univariate and multivariable analysis.

Setting: Twenty acute care hospitals.

Patients: Nine hundred thirty-four ventilated acute respiratory distress syndrome patients with a central venous pressure available at enrollment, 609 without baseline shock (for whom fluid balance was managed by the study protocol).

Interventions: None.

Measurements And Main Results: Among patients without baseline shock, those with initial central venous pressure greater than 8 mm Hg experienced similar mortality with conservative and liberal fluid management (18% vs 18%; p = 0.928), whereas those with central venous pressure of 8 mm Hg or less experienced lower mortality with a conservative strategy (17% vs 36%; p = 0.005). Multivariable analysis demonstrated an interaction between initial central venous pressure and the effect of fluid strategy on mortality (p = 0.031). At higher initial central venous pressures, the difference in treatment between arms was predominantly furosemide administration, which was not associated with mortality (p = 0.122). At lower initial central venous pressures, the difference between arms was predominantly fluid administration, with additional fluid associated with increased mortality (p = 0.013).

Conclusions: Conservative fluid management decreases mortality for acute respiratory distress syndrome patients with a low initial central venous pressure. In this population, the administration of IV fluids seems to increase mortality.