Oxygen and resolution of lung injury.
We investigated the effects of varying inspired oxygen concentrations on the resolution of oleic acid-induced lung injury in rabbits. Rabbits were injected intravenously with oleic acid and maintained in room air, or exposed to 60, 70, or 80% oxygen for periods of 7 or 10 days. Oleic acid caused hemorrhagic pulmonary edema with hypoxemia. Hypoxemia was more profound in the oxygen-treated animals, a difference that was significant after 7 days' exposure to 60 and 70% oxygen, and after 4 days to 80% oxygen. Mortality was increased in the animals maintained in 80% oxygen. The data suggest that environmental oxygen concentrations greater than 60% interfere with the return to normal lung function following oleic acid injury in rabbits. The hypoxemia may be due to either mismatching of ventilation and perfusion or to a diffusion block resulting from the increased septal width. There was no evidence of massive pulmonary edema as a cause of the hypoxemia. It was not possible to distinguish between injury primarily caused by oxygen and its interference with the healing process.
D000818:Animals; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D000860:Hypoxia / Q000139:chemically induced; D008168:Lung / Q000473:pathology; D008297:Male; D019301:Oleic Acid; D009829:Oleic Acids; D010100:Oxygen / Q000009:adverse effects* / Q000097:blood; D011654:Pulmonary Edema / Q000139:chemically induced; D011659:Pulmonary Gas Exchange; D011817:Rabbits; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000401:mortality / Q000473:pathology*
D009829:Oleic Acids; D002245:Carbon Dioxide; D019301:Oleic Acid; D010100:Oxygen