Structural Changes of Lung Tissues in the Dynamics of Inhalation Poisoning with Carbonic Acid Dichlorohydride

A study of structural changes in lung tissue during the formation of organ edema due to inhalation of a lipotropic poison, carbonic acid dichloride, showed the peculiarities of the formation of acute respiratory distress syndrome. The point of application of the poison is the distal bronchioles, whose epithelium is subject to dystrophic and necrotic changes followed by goblet metaplasia. The absorbed poison causes pronounced changes in blood microcirculation, steroid-resistant NO-mediated endothelial dysfunction with blood deposition in dilated capillaries, aggregation, and lysis of erythrocytes. Changes in the vascular bed in the interalveolar septa precede the formation of an acute inflammatory reaction with the accumulation of alveolar effusion and dystrophic changes in the alveolar epithelium with cell desquamation. Among the cells of the alveolar lining, type II alveolocytes are the most vulnerable. Plasma permeation of the connective tissue of the interalveolar septa interstitium is accompanied by their infiltration with polymorphonuclear leukocytes and activation of macrophages. Desquamation of epithelial cells of the distal bronchioles leads to obstruction of their lumens and, through the valve mechanism, contributes to overextension of the alveoli with the formation of emphysema and reduction of capillary blood circulation in the alveolar septa. The observed changes determined the directions for improving the treatment of poisoning by asphyxiating poisons.