What are the typical presentation, differential diagnosis (DDx), investigations (InvX), and management (Mx) of bronchiectasis?

Bronchiectasis: Typical Presentation, Differential Diagnosis, Investigation, and Management

Bronchiectasis is characterized by abnormal and permanent dilatation of the bronchi, presenting with chronic cough, sputum production, and recurrent respiratory infections that require a systematic diagnostic approach and comprehensive management strategy. 1

Typical Presentation (Signs and Symptoms)

Cardinal Features

• Chronic productive cough with persistent mucopurulent or purulent sputum production 1
• Daily sputum expectoration (often purulent)
• Recurrent respiratory infections/exacerbations 1
• Breathlessness (varying severity)

Other Common Symptoms

• Rhinosinusitis 1
• Fatigue
• Hemoptysis
• Thoracic pain
• Fetid breath in severe cases 2

Physical Examination Findings

• Variable degrees of rhonchi and crackles (may be normal)
• Clubbing (in advanced cases)
• Note: Presence or absence of crackles does not reliably correlate with bronchiectasis diagnosis 1

Differential Diagnosis (DDx)

Respiratory Conditions

• Chronic Obstructive Pulmonary Disease (COPD) - particularly with frequent exacerbations and P. aeruginosa colonization 1
• Asthma - especially severe or poorly controlled 1
• Chronic bronchitis
• Lung cancer
• Tuberculosis and non-tuberculous mycobacterial infections
• Allergic bronchopulmonary aspergillosis (ABPA)

Systemic Conditions Associated with Bronchiectasis

• Rheumatoid arthritis and other connective tissue diseases 1
• Inflammatory bowel disease 1
• Primary immunodeficiency syndromes 3
• Alpha-1 antitrypsin deficiency 1
• Primary ciliary dyskinesia 3
• HIV infection 1
• HTLV-1 infection with inflammatory complications 1

Investigation (InvX)

Initial Investigations

1. Chest X-ray - first-line imaging but has limited sensitivity 1, 4

2. High-Resolution CT (HRCT) scan - diagnostic gold standard with sensitivity and specificity exceeding 90% 1, 4

   • Key diagnostic features:
     • Bronchoarterial ratio >1 (signet ring sign)
     • Lack of airway tapering toward periphery
     • Airways visible within 1cm of pleural surface
     • Bronchial wall thickening
     • Mucus impaction
     • Mosaic perfusion/air trapping on expiratory CT 4

3. Sputum culture - to identify pathogens:

   • Common organisms: H. influenzae, S. aureus, S. pneumoniae, P. aeruginosa 1
   • Special cultures for mycobacteria and fungi

4. Blood tests:

   • Complete blood count with differential
   • Immunoglobulin levels (IgG, IgA, IgM, IgE) 3
   • Inflammatory markers (ESR, CRP)

5. Pulmonary function tests:

   • Spirometry (pre- and post-bronchodilator) 3

Additional Investigations (Based on Clinical Suspicion)

• Sweat test or genetic testing for cystic fibrosis
• Testing for alpha-1 antitrypsin deficiency
• Ciliary function tests for primary ciliary dyskinesia
• Bronchoscopy to obtain specimens for microbiological analysis 4
• Immunological workup for immunodeficiencies
• Rheumatological workup if autoimmune disease suspected

Management (Mx)

General Approach

1. Identify and treat underlying causes 5
2. Enhance mucociliary clearance
3. Control infection
4. Prevent and treat complications

Specific Interventions

Airway Clearance

• Airway clearance techniques - daily regimen 3
• Regular exercise and pulmonary rehabilitation 3
• Mucoactive agents:
  • Nebulized hypertonic saline to loosen secretions 3
  • Consider mucolytics 5, 6

Infection Control

• Exacerbation treatment:

  • Oral or intravenous antibiotics based on previous sputum cultures 3
  • Typically 14-day courses

• Preventive strategies:

  • For patients with ≥3 exacerbations annually, consider:
    • Long-term inhaled antibiotics (e.g., colistin, gentamicin) 3
    • Daily oral macrolides (e.g., azithromycin) 3
  • Consider P. aeruginosa eradication if newly isolated 1

Anti-inflammatory Treatment

• Inhaled corticosteroids - indicated primarily when bronchiectasis coexists with asthma or COPD 3
• Bronchodilators (β-agonists and antimuscarinics) - for patients with reversible airflow obstruction or coexisting asthma/COPD 3

Advanced Interventions

• Surgical treatment - consider for localized disease not responding to medical therapy 6
• Lung transplantation - for severe disease with impaired pulmonary function and frequent exacerbations 3

Monitoring and Follow-up

• Regular sputum surveillance cultures
• Pulmonary function monitoring
• Follow-up imaging as clinically indicated (avoid unnecessary radiation exposure) 4

Pitfalls and Caveats

• Bronchiectasis is often underdiagnosed or misdiagnosed as asthma or COPD
• Traction bronchiectasis in fibrotic lung diseases should not be misinterpreted as true bronchiectasis 4
• Radiological bronchiectasis without clinical symptoms may not require treatment 1
• P. aeruginosa colonization is associated with worse outcomes (3-fold increase in mortality risk) 1
• Bronchiectasis may be multifactorial with multiple conditions coexisting 4
• Adult criteria for bronchiectasis diagnosis may be inappropriate for children 4