[Clinical and pathologic comparison of adult respiratory distress syndrome and infant respiratory distress syndrome].

The authors compared the clinical and pathological findings between adult respiratory distress syndrome (ARDS), and infant respiratory distress syndrome (IRDS). In ARDS, the most common causes were injury, infection, shock and acidosis. The clinical course was longer. The weight of the lungs increased markedly, the hyaline membrane formation in the alveoli was late in the clinical course, and the degree of edema in the interstitium of the lungs and microthrombosis within the blood vessels was more serious. The pathogenesis of ARDS was related to the activation of the complements and neutrophils by inflammation in which proteinase, oxygen radical, thromboxane, leukotriene and prostaglandin were released. Thus the endothelial cells of the blood vessels and capillary-alveoli membrane were damaged by these mediators. On the other hand, the main contributory factors of IRDS were suffocation of premature fetus by various reasons in the uterus and aspiration of meconium during delivery by the infant. The clinical course was shorter, alveolar hemorrhage and collapse were severe and hyaline membrane in alveoli was formed in early stage of the clinical course. Insufficiency of surfactant in premature fetus, damage of the surfactant system by hypoxia, aspiration of foreign materials and defect of the epithelial cells of infant were the pathogenic factors of IRDS, they resulted in increase of permeability of fluid and, as a result, led to pulmonary edema and atelectasis.