Pathophysiology
The pathogenesis of bronchopulmonary dysplasia remains complex and poorly understood. Bronchopulmonary dysplasia results from various factors that can injure small airways and that can interfere with alveolarization (alveolar septation), leading to alveolar simplification with a reduction in the overall surface area for gas exchange. The developing pulmonary microvasculature can also be injured. Alveolar and lung vascular development are intimately related, and injury to one may impair development of the other. Damage to the lung during a critical stage of lung growth can result in clinically significant pulmonary dysfunction.
Premature birth and subsequent events (eg, exposure to oxygen, mechanical ventilation, inflammatory agents, infection) likely shifts the balance from lung development consisting of lung alveolar and vascular growth to one of premature maturation, which is associated with an arrest in development and a loss of future gas exchange area; however, alveolar maturation might facilitate gas exchange in the short-term.[9]