Bronchiectasis

Definition

Irreversible dilatation of the bronchi and bronchioles, with thickened, inflamed airway walls, usually following an obstruction and subsequent recurrent infection in the distal airway that causes permanent damage. The “vicious cycle” hypothesis: airway distortion impairs mucociliary clearance → persistent bacterial colonisation and airway inflammation → further airway destruction. Lower lobes are most commonly affected.

Aetiology

No definite underlying cause is identified in around half of patients. Recognised causes/associations:

• Childhood pneumonia (the most commonly identified cause)
• Cystic fibrosis, primary ciliary dyskinesia
• Inherited immune deficiency (hypogammaglobulinaemia)
• Rheumatic/autoimmune disease
• Allergic bronchopulmonary aspergillosis
• Prior pulmonary infection (including tuberculosis, non-tuberculous mycobacteria)
• Inhaled foreign body, bronchial carcinoma (localised obstruction)
• Young syndrome
• May coexist with asthma or COPD

Clinical features

Murtagh’s triad: recurrent (≥3 episodes) wet/productive cough, each lasting >4 weeks, ± other features (e.g. exertional dyspnoea) — a useful bedside rule for when to suspect and investigate.

History:

• Chronic cough, characteristically worse on waking
• Mild disease: yellow/green sputum only after infective episodes
• Advanced disease: profuse purulent (often offensive-smelling) sputum, persistent halitosis, recurrent febrile episodes, malaise, weight loss
• Recurrent pneumonia episodes; sputum production related to posture
• Haemoptysis (may occur, occasionally the presenting feature)
• Childhood history of pneumonia/poor living conditions; known lung disease (e.g. cystic fibrosis); tobacco/irritant exposure

Examination: digital clubbing (uncommon, <5%); coarse crackles over affected areas ± localised wheeze ± bronchial breath sounds; slightly reduced chest wall movement; weight loss in advanced disease.

Investigations

Category	Tests
Imaging	Chest X-ray (may be normal — not sufficient to exclude); HRCT chest is the diagnostic gold standard (dilated airways wider than their accompanying vessel, “tram lines”/signet-ring appearance, tree-in-bud pattern — the latter especially suggestive of non-tuberculous mycobacterial infection)
Pathology	FBC, biochemistry, CRP, Aspergillus serology, autoimmune screen, immunoglobulins (IgG/IgA/IgM/IgE)
Microbiology	Sputum microscopy/culture for bacteria (including resistant organisms e.g. Pseudomonas), mycobacteria and non-tuberculous mycobacteria (AFB ×3)
Cytology	To exclude neoplasia where relevant
Function	Spirometry (may be obstructive, restrictive, mixed, or normal) and 6-minute walk test
Selected adults/all children (specialist discussion)	Sweat chloride test + extended CFTR mutation testing — consider in patients with bowel obstruction episodes, heat prostration, pancreatitis, pre-existing liver disease, male infertility, or age <50

Management

Referral

Refer all newly diagnosed patients to a multidisciplinary team (respiratory specialist, physiotherapist, dietitian) — particularly important where an underlying cause (cystic fibrosis, ABPA, autoimmune disease) needs longer-term specialist management, or exacerbations are difficult to control.

Non-pharmacological

• Airway clearance physiotherapy — refer to a respiratory physiotherapist; techniques include the active cycle of breathing, bubble positive expiratory pressure (bubble PEP) devices, and ELTGOL (slow expiration with open glottis in the lateral posture). Regular airway clearance improves sputum expectoration, quality of life and reduces exacerbation frequency, though evidence doesn’t show one technique clearly superior to another or a direct effect on lung function.
• Avoid lung irritants (smoking, vaping, occupational chemical exposure).
• Optimise nutritional status — lower BMI is associated with more frequent exacerbations, chronic Pseudomonas colonisation and worse outcomes.
• Pulmonary rehabilitation — improves exercise capacity and quality of life.
• Treat coexisting asthma/COPD with bronchodilators or ICS as indicated — patients without underlying asthma/COPD don’t need routine inhaled corticosteroids or long-acting bronchodilators for bronchiectasis alone.

Vaccination

Ensure influenza, pneumococcal, and COVID-19 vaccination are up to date for all patients.

Acute exacerbations

Antibiotics are indicated only when all three of the following are present: increased sputum volume/viscosity, increased sputum purulence, and increased cough (± wheeze, breathlessness, haemoptysis).

• Obtain a sputum sample for culture and sensitivity before starting antibiotics where practical.
• Treat for 14 days (can be tailored/narrowed once sensitivities return).
• Without known chronic Pseudomonas: amoxicillin 1 g TDS or doxycycline 100 mg BD.
• With known chronic Pseudomonas aeruginosa: start narrow-spectrum therapy as above; if not improving and P. aeruginosa is confirmed on culture, change to ciprofloxacin 750 mg BD (if susceptible).
• New isolation of P. aeruginosa should prompt consideration of an eradication antibiotic regimen (may run up to 3 months) — aimed at clearing the organism from the airway, with evidence (albeit indirect) for reduced exacerbation frequency and improved quality of life afterward.
• Refer to emergency care if hypoxic or not responding to oral antibiotics (for IV antibiotics ± oxygen support).

Long-term therapies for frequent exacerbators

• Long-term macrolide prophylaxis (azithromycin or erythromycin) — consider in patients with ≥3 exacerbations per year; reduces infective exacerbation frequency and is generally well tolerated.
• Long-term mucolytics (≥3 months) — for patients with poor quality of life and ongoing difficulty expectorating sputum despite standard airway clearance technique.
• Inhaled antibiotics — reduce bacterial load and produce a small but statistically significant reduction in exacerbation frequency in trials (inhaled liposomal ciprofloxacin — ORBIT-3/ORBIT-4; ciprofloxacin dry powder — RESPIRE 1), though without a clearly demonstrated quality-of-life benefit; reserved for specialist-guided use, typically in patients with chronic P. aeruginosa infection and frequent exacerbations.
• A written bronchiectasis action plan helps patients recognise and respond early to exacerbations, similar in concept to a COPD action plan.