The evolution of neonatal respiratory distress syndrome into chronic lung disease.

Bronchopulmonary dysplasia (BPD) is a distortion of postnatal lung development induced by ventilator treatment for respiratory distress syndrome or other forms of respiratory failure in the newborn. This paper reviews established and proposed mechanisms involved in the pathogenesis of BPD including severe surfactant deficiency, ventilation with high insufflation pressure and high oxygen concentrations, protein leakage and low levels of antioxidants in the immature lung, and a protease-antiprotease imbalance interfering with the layout of elastin and leading to growth without proper alveolarisation. Since the primary insult occurs during the first few days after birth, prophylaxis is highly important. Promising attempts have been made to prevent, or curb, the evolution of BPD by administration of antioxidants, corticosteroids, or exogenous surfactant.