What physiological change occurs in preterm infants that may lead to bronchopulmonary dysplasia?

In very premature infants, one of the critical factors that can lead to bronchopulmonary dysplasia (BPD) is inadequate surfactant production. Surfactant is a substance composed mainly of lipids and proteins that reduces surface tension within the alveoli in the lungs. Inadequate surfactant results in increased surface tension, making it more difficult for the alveoli to expand during inhalation. This can lead to atelectasis, where parts of the lung collapse, trapping air and impairing gas exchange. The lack of proper lung function increases the risk of injury from mechanical ventilation and supplemental oxygen, both of which can contribute to the development of BPD in preterm infants.

Surfactant deficiency is a hallmark of preterm birth, as surfactant production typically increases significantly in the later weeks of gestation. Thus, understanding the importance of surfactant is crucial in managing and preventing complications like BPD in this vulnerable population.