Pulmonary hypertension in bronchopulmonary dysplasia.

Pulmonary hypertension is common in bronchopulmonary dysplasia and is associated with increased mortality and morbidity. This pulmonary hypertension is due to abnormal microvascular development and pulmonary vascular remodeling resulting in reduced cross-sectional area of pulmonary vasculature. The epidemiology, etiology, clinical features, diagnosis, suggested management, and outcomes of pulmonary hypertension in the setting of bronchopulmonary dysplasia are reviewed. In summary, pulmonary hypertension is noted in a fifth of extremely low birth weight infants, primarily those with moderate or severe bronchopulmonary dysplasia, and persists to discharge in many infants. Diagnosis is generally by echocardiography, and some infants require cardiac catheterization to identify associated anatomic cardiac lesions or systemic-pulmonary collaterals, pulmonary venous obstruction or myocardial dysfunction. Serial echocardiography and B-type natriuretic peptide measurement may be useful for following the course of pulmonary hypertension. Currently, there is not much evidence to indicate optimal management approaches, but many clinicians maintain oxygen saturation in the range of 91 to 95%, avoiding hypoxia and hyperoxia, and often provide inhaled nitric oxide, sometimes combined with sildenafil, prostacyclin, or its analogs, and occasionally endothelin-receptor antagonists.