bronchopulmonary dysplasia BPD can lead to airway obstruction

This patient's symptoms and radiographic changes are most likely a sequela of bronchopulmonary dysplasia (BPD). BPD is defined as the need for oxygen for at least 28 days after birth. BPD develops in approximately 20% of all infants born weighing <1,500 g and is most common in infants born prematurely, before 28 weeks’ gestation. The pathogenesis of BPD is likely a combination of disrupted normal pulmonary development along with perinatal insults and environmental stresses. Prevalence of BPD has not changed despite the use of surfactant and conservative ventilation strategies, in part due to a higher survival rate. Duration of oxygen dependence does not accurately predict long-term respiratory outcome, and late respiratory symptoms have been reported in patients who did not require prolonged oxygen treatment.

Studies of children born with BPD have demonstrated increased respiratory symptoms, and reduced FEV1 and FEV1/FVC ratio, when compared with age-matched controls. Airflow limitation may be a result of dysanaptic growth whereby the length and diameter of the airways grows less rapidly than the lung parenchyma. Compared with term-born patients with asthma, children with a history of BPD more often have fixed airway obstruction.

In general, adult survivors of BPD report more respiratory symptoms, including wheezing and shortness of breath, than do full-term control subjects. In a large Dutch survey study of close to 700 19-year-olds born at a gestational age below 32 weeks and/or with a birth weight less than 1,500 g, women with a history of BPD reported a higher prevalence of shortness of breath during exercise compared with control subjects. This correlates with an exercise study of patients born prematurely showing mean Dlco values during exercise did not increase above preexercise levels compared with control subjects. In a systematic review, adult survivors of BPD were more likely to demonstrate evidence of reduced lung function, although others suggest normalization of lung function over time, pointing to the need for longitudinal studies in this population. Airflow obstruction and airway hyperresponsiveness is also noted in adulthood compared with full-term control subjects, as is the diagnosis of asthma, though some are likely misdiagnosed as the two conditions can have similar characteristics and may be difficult to distinguish. It is unknown if survivors may be at risk for developing COPD. Radiographic abnormalities on CT are frequently noted and include evidence of air trapping, bronchial wall thickening, and multifocal emphysema as well as reticular opacities.

Alpha-1 antitrypsin deficiency is an autosomal codominant inherited disorder leading to early onset COPD, commonly when individuals are in their 40s. Bullous changes are often present, are symmetric, and are noted at the lung bases. Acute chest syndrome can occur in individual’s who have sickle cell disease, not sickle cell trait. It is defined by respiratory symptoms and a new opacity on chest x-ray. Exercise-induced asthma would be reasonable to consider but would not cause emphysematous changes on imaging. 1

Footnotes

  1. SEEK Questionnaires ↩