Inhalation of varying concentrations of oxygen in the treatment of severe pulmonary insufficiency.

Acute pulmonary insufficiency in chronic pulmonary disease is a medical emergency. Its therapy is difficult, and the mortality is great. A number of approaches to the problem have been employed, including the use of antibiotics, corticosteroids, oxygen, tracheotomy, and various mechanical devices to improve respiration. The physiologic derangement seen in this condition is relatively constant although it may occur in a wide variety of diseases. There is severe arterial hypoxia and hypercapnia. Associated with the persistent hypercapnia is a decreased sensitivity of the respiratory center to the stimulus of carbon dioxide. The sole remaining stimulus to respiration is the hypoxia. When the arterial oxygen is increased above physiologic levels, such as occurs during breathing of 100 per cent oxygen, this stimulus is lost, alveolar ventilation decreases, arterial hypercapnia increases, the pH of the arterial blood decreases, and death ensues.