Bronchopulmonary dysplasia-associated pulmonary hypertension
Chronic respiratory sequelae are a major health problem in surviving premature infants. Despite immense improvement in the care of premature infants, the rate of bronchopulmonary dysplasia (BPD) and pulmonary morbidities have remained the same or even slightly increased over the past decades. BPD results from the impairment of lung development following premature birth, and the resultant dysregulated pulmonary vasculature leads to chronic pulmonary hypertension (PH). It is seen more commonly in the setting of moderate to severe BPD. A high index of suspicion is necessary to diagnose PH in BPD. Diagnosis is most commonly done by echocardiogram, but cardiac catheterization may be required to delineate the cardiac structure, cardio-pulmonary vasculature and myocardial function. Once the diagnosis is made, a multidisciplinary approach for management of these patients is suggested, aiming to optimize management of BPD and use of various pulmonary vasodilators. The various therapeutic agents available help reduce pulmonary vascular resistance by acting on the nitric oxide (NO), prostacyclin and/or endothelin pathways. Serial echocardiograms and measurement of biomarkers are used to evaluate the response to therapy. Currently there is not much evidence to support optimal management approaches, but the recent guidelines published by the Pediatric Pulmonary Hypertension Network (PPHNet) provide practical recommendations for screening and management of these infants.