Recent research has greatly improved our understanding of the pathophysiology of
pulmonary hypertension. There is increasing recognition that
pulmonary hypertension is an important complication of many childhood
respiratory diseases including
cystic fibrosis,
interstitial lung diseases, upper airways obstruction and disorders of the respiratory muscles and chest wall. Chronic hypoxaemia and, in some cases, destruction of the vascular bed are the key factors. The clinical features of
pulmonary hypertension are often overshadowed by those of the primary respiratory disease but newer imaging techniques allow earlier detection of this complication. This may be important in the future if new specific
therapies for
primary pulmonary hypertension are shown to be beneficial in secondary
pulmonary hypertension. With some conditions, such as airways obstruction due to adenotonsillar
hypertrophy, treating the underlying cause leads to rapid resolution of the
hypertension. However, with most disorders, such as
cystic fibrosis, management is focused on treating the
lung disease intensively and correcting the chronic hypoxaemia with
oxygen therapy, sometimes augmented by nasal mask ventilation. However, although several new selective
therapies are effective in
idiopathic pulmonary arterial hypertension, their role in secondary
pulmonary hypertension remains unclear.