ABSTRACT
Bronchopulmonary dysplasia (BPD) is a chronic lung disease primarily affecting preterm infants needing respiratory support after birth. In the post-surfactant era, BPD is even more important because of increased survival of very preterm infants. Furthermore, the spectrum of BPD has changed since Northway et al. (1) published their classic description in 1967. BPD follows abnormal repair processes after inflammatory lung injury, leading to remodeling of the lung (2). Inflammation may be initiated by many stimuli including mechanical ventilation, oxidative stress, and infection. Neutrophil chemotaxis and degranulation release enzymes that may cause proteolysis of lung extracellular matrix. Abnormal healing with remodeling leads to poorly compliant lungs with reduced capacity for gas exchange.
