Bronchiolar epithelial lesions induced in the premature rabbit neonate by short periods of artificial ventilation.

Premature newborn rabbits were ventilated with standardized tidal volume (10 ml/kg) or standardized insufflation pressure (35 cm H2O) for 1--30 min. The lungs of the experimental fetuses were fixed by perfusion of the pulmonary artery and examined by light and electron microscopy, with particular reference to the prevalence and ultrastructure of bronchiolar epithelial lesions. Necrosis and desquamation of bronchiolar epithelium were constant findings in fetuses ventilated for 5 min. or more, and were also present in some of the fetuses ventilated for only 1 min. Since the light microscopic and ultrastructural appearance of these bronchiolar lesions is similar to early stages of human neonatal hyaline membrane disease, we conclude that artificially ventilated pre-term newborn rabbits might serve as a useful model of this disease.