Bronchopulmonary Dysplasia: Chronic Lung Disease of Infancy and Long-Term Pulmonary Outcomes

Abstract

Bronchopulmonary dysplasia (BPD) is a chronic lung disease most commonly seen in premature infants who required mechanical ventilation and oxygen therapy for acute respiratory distress. While advances in neonatal care have resulted in improved survival rates of premature infants, limited progress has been made in reducing rates of BPD. Lack of progress may in part be attributed to the limited therapeutic options available for prevention and treatment of BPD. Several lung-protective strategies have been shown to reduce risks, including use of non-invasive support, as well as early extubation and volume ventilation when intubation is required. These approaches, along with optimal nutrition and medical therapy, decrease risk of BPD; however, impacts on long-term outcomes are poorly defined. Characterization of late outcomes remain a challenge as rapid advances in medical management result in current adult BPD survivors representing outdated neonatal care. While pulmonary disease improves with growth, long-term follow-up studies raise concerns for persistent pulmonary dysfunction; asthma-like symptoms and exercise intolerance in young adults after BPD. Abnormal ventilatory responses and pulmonary hypertension can further complicate disease. These pulmonary morbidities, combined with environmental and infectious exposures, may result in significant long-term pulmonary sequalae and represent a growing burden on health systems. Additional longitudinal studies are needed to determine outcomes beyond the second decade, and define risk factors and optimal treatment for late sequalae of disease.

Keywords: bronchopulmonary dysplasia; chronic lung disease of prematurity; long-term outcomes; neonatal lung injury.

Figure 1

Stages of Lung Development, Potentially Damaging Factors, and Types of Lung Injury. In premature newborns, the lungs are often exposed to several sources of injury, both before and after birth. These exposures, along with genetic susceptibility to problematic lung development, can cause direct airway and parenchymal damage and induce a deviation from the normal developmental path. Depending on the timing and extent of the exposures, lung injury may range from early developmental arrest (new bronchopulmonary dysplasia) to structural damage of a relatively immature lung (old bronchopulmonary dysplasia). Premature infants born at a gestational age of 23 to 30 weeks (shaded region)—during the canalicular and saccular stages of lung development—are at the greatest risk for bronchopulmonary dysplasia. From Eugenio Baraldi, M.D.; Marco Filippone, M.D. Chronic Lung Disease after Premature Birth. N. Engl. J. Med. 2007, 357, 1946–1955. Copyright © 2007 Massachusetts Medical Society. Reprinted with permission from Massachusetts Medical Society.