Last edited 06/2020
Chronic bronchitis is defined clinically as cough productive of sputum for at least three months in each year for three consecutive years.
It is characterised by intermittent dyspnoea with acute exacerbations. The patient produces profuse, mucopurulent sputum. As airflow becomes chronically obstructed, cor pulmonale and polycythaemia become common.
On chest radiography there are normal peripheral vessels. The arterial CO2 is raised, with alveolar gas transfer normal. Nocturnal hypoxaemia is profound, especially in REM sleep, and associated with pulmonary hypertension.
Chronic bronchitis frequently co-exists with emphysema, the two disease processes acting together to produce the final clinical picture of chronic obstructive airways disease.