Development of Hyaline Membranes and Atelectases in Experimental Chronic Respiratory Acidosis. ∗

Abstract

Summary

Guinea pigs exposed to 1.5%, 3% and 15% CO₂ for prolonged periods developed, under 3% and 15% CO₂, hyaline membranes associated with atelectases which were predominantly located in subpleural areas. Simultaneous blood pH and pCO₂ measurements indicated that these pulmonary lesions were related to a nonspecific acidosis effect rather than to a specific CO₂ effect. Incidence of hyaline membranes declined from 100% during the uncompensated phase of respiratory acidosis induced by 1-2 days of exposure to 15% CO₂ to 0% during 14-93 days of exposure to 15% CO₂. Under the latter condition blood pH was compensated but blood pCO₂ was elevated to a level twice normal. Rats did not exhibit hyaline membranes during prolonged exposure to 1.5% CO₂ and 3% CO₂.