Fluids in ARDS: from onset through recovery.

Abstract

Early acute respiratory distress syndrome (ARDS) is characterized by protein-rich inflammatory lung edema often associated with a hydrostatic component. Mechanical ventilation with positive intrathoracic pressure further induces salt and water retention, while impairing the pathways designed for edema clearance. In this framework, we will review the recent findings on fluid strategy and edema clearance in ARDS. Consistently, conservative strategies lead to better oxygenation and reduce the length of mechanical ventilation. A possible drawback associated with conservative strategy is the impaired cognitive function. Echography may be used for safer use of furosemide or hemofiltration therapy during edema clearance. Albumin and furosemide techniques may accelerate edema clearance, particularly when pulmonary capillary permeability is restored. Beta-2 agonist therapy does not accelerate edema clearance and is potentially dangerous. Lung edema is likely the single pathogenic factor more relevant for ARDS severity and outcome. Fluid overload must be avoided. Several monitoring techniques are available to reach this target. No specific studies are available to recommend a given fluid composition in ARDS. In our opinion, the general recommendations for fluid composition suggested for severe sepsis and septic shock should be applied to ARDS that may be considered an organ-confined sepsis.