Nature of Pulmonary Damage Produced by High Oxygen Pressures

¹ From the Department of Physiology and Pharmacology, Duke University School of Medicine, Durham, North Carolina

When one bronchus is cannulated and the other blocked prior to exposure of an animal to oxygen at high pressure, the obstructed portion of the lung shows massive congestion and complete atelectasis. The gross appearance is not unlike that usually seen in the lungs of laboratory animals exposed for long periods to oxygen at high pressure. They respond, however, as do lungs damaged by high oxygen pressure, to tracheal insufflation by dramatically regaining their original pink healthy color and consistency. Reasons are presented for believing that a major cause of the pulmonary damage produced by high oxygen pressures is simple atelectasis resulting from blockade of the smaller airways, with resultant absorption of the gases peripheral to the obstruction, and the process is reversible as can be shown by forcibly inflating the collapsed alveolar areas. It is further believed that the hormonal influences on pulmonary damage in high oxygen pressures are mediated through an influence on the patency of the distal airways.