[Pulmonary toxicity of oxygen]

Recent progress in artificial ventilation procedures sheds doubt on the toxicity of oxygen in the lung. Histological studies of the lung by light and electron microscopy were made in rats exposed to 100% oxygen at 1 ATA in spontaneous ventilation. The results are compared with the lesions observed in 19 human patients suffering from acute respiratory distress syndrome and with the data on retinopathy of prematurity. This study suggests to keep in mind that oxygen may, as well as infections or baro-traumatic factors, be involved in causing or aggravating lung fibrosis. The complexity of the mechanisms of this action is emphasized. The production of highly reactive free radicals is one of the essential factors of this aggression. These elements illustrate the value of further studies on ways of preventing these changes, especially using appropriate antioxidant molecules.