Out-of-proportion dyspnea and exercise intolerance in mild COPD

摘要

Most patients with COPD show only mild airflow limitation on spirometry. Despite FEV1 normalcy, however, dyspnea on exertion is a frequent complaint. Structural and functional investigations in dyspneic patients with mild COPD showed important abnormalities in gas exchange efficiency, caused by a complex interaction among small airway disease, emphysema, and microvascular dysfunction.1 Cardiopulmonary exercise testing is invariably useful to indicate whether patients presenting with out-of-proportion dyspnea can or cannot be ascribed to mild COPD.2