Bronchopulmonary Dysplasia
Bronchopulmonary Dysplasia Definition
Bronchopulmonary dysplasia involves the abnormal development of lung tissue. It is marked by inflammation and scarring in the lungs. It occurs most often in premature babies, who are born with underdeveloped lungs. "Broncho" is the name of the airways (the bronchial tubes) through which the oxygen we breathe travels into the lungs. "Pulmonary" refers to the lungs' tiny air sacs (alveoli), where carbon dioxide and oxygen are exchanged. "Dysplasia" means abnormal changes in the organization or structure of a group of cells. The cell changes in BPD occur in the smaller airways and lung alveoli, making breathing difficult and causing problems with lung function.
Bronchopulmonary Dysplasia Pathophysiology
The pathogenesis of BPD remains complex and very little is understood. BPD is caused by from a variety of toxic factors that can injure small airways and that can interfere with alveolarization (septation), leading to alveolar simplification with a reduction in the overall surface area for gas exchange. The developing pulmonary microvasculature can also be damaged. Many strongly believe that alveolar and vascular developments are closely related. Damage to the lung during a critical stage of lung growth can lead in clinically significant pulmonary dysfunction. The lungs (alveolar and vascular compartments), heart, and brain are the major organs affected by this disease.
Bronchopulmonary Dysplasia Prevalence
BPD occurs rarely in infants who had a birth weight of more than1250 g and in infants who were born at more than 30 weeks' gestation. Antenatal glucocorticosteroids, early surfactant therapy, and gentle modalities of ventilation have lessened the severity of lung injury, particularly in relatively mature infants. However, improved survival has increased the frequency of BPD, especially in small infants who may have been exposed to in utero infection (eg, chorioamnionitis). Several trials of surfactants showed that incidences of BPD range widely from 17-57%, and no substantial difference between placebo- and surfactant-treated survivors was seen. In 1998, Kresch and Clive performed a meta-analysis of surfactant-replacement therapy for infants weighing less than 2 kg. Infants receiving modified natural surfactant had increased survival, without BPD. In 2001, Van Marter and associates described the wide variation in the frequency of BPD in different NICUs using various ventilatory strategies. This variation has also been seen among sites in the Vermont Oxford Network (VON) and in the NICHD research network, suggesting that different populations and practices may directly affect outcomes. Infants with acute BPD are often extremely immature and had a very low birth weight, though term infants with clinically significant respiratory failure may also be at increased risk.
Bronchopulmonary Dysplasia Symptoms and Signs
Babies affected by this condition are more likely than other infants to have problems in other parts of their bodies that aren't yet fully developed. These include the brain, heart, kidneys, stomach, intestines, and eyes