Bronchiectasis

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | Important note

Definition

Bronchiectasis is a chronic condition characterised by irreversible dilatation and thickening of the bronchi, associated with recurrent infections, mucus build-up, and impaired mucociliary clearance.

Aetiology

Bronchiectasis can result from various underlying conditions:

  • Infections:
    • Severe or recurrent respiratory infections (e.g., pneumonia, tuberculosis).
    • Childhood infections such as measles or whooping cough (pertussis).
  • Immune Deficiencies: E.g., hypogammaglobulinaemia.
  • Cystic Fibrosis: a common cause in younger patients.
  • Primary Ciliary Dyskinesia: impaired ciliary function leading to mucus retention.
  • Allergic Bronchopulmonary Aspergillosis (ABPA): an allergic reaction to fungal spores.
  • Idiopathic: no identifiable cause in up to 50% of cases.

Pathophysiology

Bronchiectasis develops through a cycle of infection, inflammation, and tissue damage:

  • Infections and inflammation cause damage to the bronchial walls.
  • Mucociliary clearance is impaired, leading to mucus retention.
  • Retained mucus promotes recurrent infections, perpetuating the cycle.

Risk Factors

  • History of severe or recurrent respiratory infections.
  • Underlying lung diseases such as COPD or asthma.
  • Immune deficiencies or autoimmune conditions.
  • Exposure to environmental irritants such as smoke or pollutants.

Signs and Symptoms

Key clinical features include:

  • Chronic Cough: often with large amounts of sputum production.
  • Recurrent Respiratory Infections: frequent exacerbations requiring antibiotics.
  • Haemoptysis: coughing up blood-stained sputum.
  • Breathlessness: worsening over time or during infections.
  • Fatigue: related to chronic inflammation and recurrent infections.

Investigations

Key investigations and expected findings include:

  • Chest x-ray: may show thickened bronchial walls or tramline shadows.
  • High-Resolution CT (HRCT) Scan: the diagnostic gold standard, showing dilated bronchi and mucus plugging.
  • Sputum Culture: identifies pathogens, including Pseudomonas aeruginosa or Haemophilus influenzae.
  • Blood Tests:
    • Full blood count (FBC) to identify anaemia or leucocytosis.
    • Immunoglobulin levels to exclude immune deficiency.
  • Spirometry: may show an obstructive pattern (reduced FEV1/FVC ratio).

Management

1. Non-Pharmacological Management

  • Airway Clearance Techniques: use of physiotherapy, such as postural drainage, to clear mucus.
  • Smoking Cessation: essential to reduce lung damage.

2. Pharmacological Management

  • Antibiotics:
    • Oral antibiotics (e.g., amoxicillin or doxycycline) for acute exacerbations.
    • Prophylactic antibiotics (e.g., azithromycin) for frequent exacerbations.
  • Mucolytics: e.g., carbocisteine to reduce sputum viscosity.
  • Bronchodilators: e.g., salbutamol for associated airway obstruction.

3. Specialist Interventions

  • Long-Term Oxygen Therapy (LTOT): for patients with significant hypoxaemia.
  • Surgery: rarely indicated; considered for localised disease resistant to treatment.

Important note

  • You should refer suspected bronchiectasis to a respiratory physician.
 
RespiratorymypanotesBronchiectasis