Lung Injury from Oxygen in Lambs: The Role of Artificial Ventilation

Eighty to 100 per cent oxygen, breathed by lambs one or two weeks of age, is lethal after two to four days. Artificial ventilation did not aggravate or significantly ameliorate the pulmonary response. Lambs ventilated with air on respirators for comparable periods had no significant pulmonary damage. The cause of death of the oxygen-treated lambs was the pulmonary injury, characterized by edema. Studies of the excised lungs showed that the lesion was spotty, that the normal-appearing portions of the lung were normally distensible, and no significant alterations in pulmonary surfactant occurred. Several methods of assessment of the mechanical derangements are presented.