Pathophysiology
Vicious cycle: mucociliary impairment -> chronic bacterial infection (H. influenzae, P. aeruginosa) -> neutrophilic airway inflammation -> further airway damage. Causes: post-infectious (TB, pertussis), CF, primary ciliary dyskinesia, ABPA, immunodeficiency, alpha-1 antitrypsin deficiency, connective tissue disease.
Sources: ERS Bronchiectasis Adult Guideline (Eur Respir J 2017;50:1700629); BTS Bronchiectasis Guideline (Thorax 2019;74:Suppl 1); NEJM Nontuberculous Mycobacterial Lung Disease (2022;387:1614)
Clinical presentation
Chronic productive cough (large volumes of purulent sputum), haemoptysis, digital clubbing, coarse crackles, and recurrent exacerbations. Fatigue and quality-of-life decline are common.
Diagnosis
High-resolution CT chest: bronchoarterial ratio >1, lack of airway tapering, mucus plugging, signet-ring sign. Etiologic workup: sweat chloride, immunoglobulins, ANCA, IgE/aspergillus precipitins, sputum culture (bacteria + AFB + fungi).
Management
Airway clearance (nebulised saline + physiotherapy), macrolide (azithromycin 3x/week) reduces exacerbations, inhaled tobramycin for chronic Pseudomonas, treat exacerbations with 14-day culture-directed antibiotics, and manage underlying cause. Vaccinate against influenza and pneumococcus.
Complications
Massive haemoptysis (bronchial artery embolisation), respiratory failure, cor pulmonale, and nontuberculous mycobacterial infection.
