Surfactant treatment in experimental hyaline membrane disease.

Premature newborn rabbits obtained by hysterotomy on day 27 of gestation were ventilated artificially under standardized conditions, serving as experimental model of neonatal hyaline membrane disease. Natural surfactant with a phospholipid concentration of approximately 8 mg/ml was administered as 50-microliter doses after 10 min of ventilation and at subsequent 30-min intervals. Initial values for lung-thorax compliance were significantly improved following two doses of surfactant, whereas compliance levels of non-treated littermates remained unchanged. Treatment with surfactant resulted in increased alveolar air expansion. Bronchiolar epithelial lesions were present in both surfactant-treated animals and controls, but the severity of these lesions was clearly reduced after surfactant treatment. We conclude that surfactant substitution is an effective treatment in experimental hyaline membrane disease, even when given after an initial period of artificial ventilation.