Toxic effects of 100% O2
When humans or other animals breathe 100% O2 for prolonged periods, it is usually detrimental to pulmonary surfactant formation. The latter causes an increase in alveolar surface tension, resulting in increased atelectasis (alveolar collapse) and possibly pulmonary edema, often manifested clinically as a decrease in pulmonary compliance, a reduced vital capacity, an increased A-aO2 gradient, and a decreased pulmonary diffusing capacity. Mucociliary transport in the airway is also slowed. The eyes are particularly sensitive to prolonged exposure to high O2 tensions and can result in Retrolental Fibroplasia. While man may be more resistant to O2 toxicity than mice or dogs, symptoms, such as those listed on the right, may appear within 12 hours after continuous breathing of 100% O2.