Early diagnosis of adult respiratory distress syndrome: an experimental model of complement-mediated pulmonary injury.

This article presents an experimental model of pulmonary injury resembling subclinical human adult respiratory distress syndrome (ARDS) mediated by leukocytes. The activation of complement was prolonged by an intraperitoneal injection of a suspension of zymosan in paraffin. The first step in the development of the disease was an accumulation of polymorphonuclear leukocytes in the lungs. No significant changes were observed on chest radiographs or computed tomograms and the pathophysiologic changes were only minimal in spite of the characteristic structural changes. The criteria currently used for the diagnosis of ARDS are not sensitive enough to detect the subclinical phase of the disease.