The action of humidified gas on the pulmonary lining layer. Ultrastructural observations after administration of pure oxygen and of various mixtures of oxygen and carbon dioxide.

The study concerns the action of dehumidified or humidified gas on the pulmonary lining layer. The results of our research suggest that water vapor used in artificial ventilation may be an important determining factor of the respiratory problems reported by clinicians in man. Important modifications of the lining layer of the alveolar epithelium occur, accompanied by more important alterations, including those of the content of the alveolus, all of which contribute to the pulmonary edema observed.