Determinants of pulmonary interstitial fluid accumulation after trauma.

We have sequentially measured the daily extravascular lung water (EVLW) changes in 16 severely traumatized patients to better define the principal etiologic factors causing post-traumatic interstitial fluid accumulation and subsequent respiratory failure. We found that severe hemorrhagic shock (mean initial BP = 40 mm Hg), massive transfusion (12.7 liters of blood), and crystalloid resuscitation with resulting hemodilution of plasma colloid osmotic pressure (PCOP) (PCOP less than or equal to 15 mmHg) do not cause EVLW accumulation. Post-traumatic elevations in EVLW were seen after lung contusion (average EVLW = 15.3 +/- 2.5 ml/kg), sepsis (average EVLW = 17.1 +/- 2.9 ml/kg) and cardiac failure (EVLW = 15.3 +/- 0.3 ml/kg). Severe hemorrhagic shock, massive transfusion, and crystalloid resuscitation with resulting hemodilution of plasma colloid oncotic pressure do not cause EVLW accumulation. Post-traumatic elevations in EVLW are seen after lung contusion, sepsis, and cardiac failure. We conclude that after trauma elevations in capillary hydrostatic pressure and capillary permeability alterations resulting from lung contusion or sepsis are the primary determinants of interstitial fluid accumulation.