Pulmonary hypertension in chronic respiratory diseases

Pulmonary hypertension is a well-known complication of chronic respiratory diseases with an adverse influence on prognosis. While hypoxaemia has been traditionally viewed as the main cause of pulmonary vasoconstriction with a subsequent increase of pulmonary arterial pressure, the importance of pulmonary vasculature remodelling is being increasingly realized. Patients with chronic lung diseases who are suspected of having pulmonary hypertension should be screened by transthoracic echocardiography. A diagnosis of pulmonary hypertension should be verified by right heart catheterization, before a specific therapy is started. Patients newly diagnosed with pulmonary hypertension should undergo spirometry, body plethysmography, arterial blood gas analysis at rest and during exercise as well as a pulmonary CT scan with regard to an underlying disease of the respiratory system. Sleep-related disorders of breathing should be excluded by polysomnography. Long-term oxygen treatment in order to maintain sufficient oxygenation is the key therapy in patients with parenchymal lung disease and pulmonary hypertension. Given the lack of evidence of a beneficial effect, pulmonary vasodilators cannot be recommended for these patients.