Bronchopulmonary dysplasia: new becomes old again!

Despite the many advances in neonatology, bronchopulmonary dysplasia (BPD) continues to be a frustrating disease of prematurity. BPD is a disease which is defined oddly by its treatment rather than its pathophysiology, leading to frequently changing nomenclature which has widespread implications on our ability to both understand and follow the progression of BPD. As various treatment modalities for BPD were developed and a larger number of extremely preterm infants survived, the "old" BPD based on lung injury from oxygen therapy and mechanical ventilation transitioned into a "new" BPD focused more on the interruption of normal development. However, the interruption of normal development does not solely apply to lung development. The effects of prematurity on vascular development cannot be overstated and pulmonary vascular disease has become the new frontier of BPD. As we begin to better understand the complex, multifactorial pathophysiology of BPD, it is necessary to again focus on appropriate, pathology-driven nomenclature that can effectively describe the multiple clinical phenotypes of BPD.