Bronchiectasis

Bronchiectatic lung contains permanently dilated subsegmental airways that are inflamed, tortuous, and often partially or totally obstructed with secretions. It arises as a result of the combination of an infectious insult with associated impaired clearance mechanisms: local obstruction and infection distal to the obstruction are both required. Causes include developmental defects, immune deficiency, mucociliary clearance defects and mechanical obstruction, but in many cases (40–60%) the cause is unknown.

Clinical features—bronchiectasis should be suspected when there is a history of persistent cough productive of mucopurulent or purulent sputum throughout the year. About 80% of patients have upper respiratory tract symptoms (postnasal drip, chronic sinus sepsis, recurrent ear infections). Clinical examination is often normal, although ‘classical’ severe cases show finger clubbing and widespread coarse crackles.

Investigation—the ‘gold standard’ for diagnosis is high-resolution CT of the chest, which reveals abnormal thick-walled and dilated bronchi. The chest radiograph is normal in at least 50% of cases, but abnormal thickened and dilated bronchi may produce tramline opacities and ring shadows. Investigations to determine the underlying cause will be determined by clinical suspicion but may include testing for cystic fibrosis, immunoglobulins, bronchoscopy, nasal nitric oxide, nasal brushing/biopsy, and tests for allergic bronchopulmonary aspergillosis. Disease status is assessed by high-resolution CT, lung function tests, sputum culture, and measurement of inflammatory markers.

Management—involves the treatment of the specific underlying cause (when possible) and treatment of the bronchiectasis itself, with the most important elements being sputum clearance by physiotherapy and antimicrobials, which need to be given in high dose, often by the nebulized or parenteral routes, and with careful assessment of response in each individual patient. Surgery can be a curative for patients with single lobe, focal bronchiectasis secondary to bronchial obstruction, and lobar resection may also be indicated for otherwise uncontrollable bleeding, or if it is felt that a particular lobe is acting as a ‘sump’ of infection which prevents good control of symptoms with medical therapy. Lung transplantation may be appropriate in carefully selected cases.