Colloid osmotic and pulmonary wedge pressures in acute respiratory failure following hemorrhage.

Acute respiratory failure evolved in five patients following hypovolemic shock related to trauma or surgical operation, or both. A reduction in colloid osmotic pressure, increases in pulmonary artery wedge pressure and reductions in colloid osmotic pressure-pulmonary artery wedge pressure gradient to levels which are likely to account for pulmonary edema were observed. Accordingly, reduction in the colloid hydrostatic pressure gradient may, in part, explain the development of acute respiratory failure after acute blood loss. In one instance, however, the absence of such reduction in the colloid osmotic pressure-pulmonary artery wedge pressure gradient together with increases in pulmonary vascular resistance showed that colloid osmotic pressure and pulmonary artery wedge pressure are not exclusively operative in the pathogenesis of the clinical syndrome of acute respiratory failure.