Bronchiectasis
By Isra
© MAYO FOUNDATION FOR MEDICAL EDUCATION AND RESEARCH ALL RIGHTS RESERVED.
Definition
- Bronchiectasis is a chronic condition characterized by permanent, abnormal dilatation of the bronchi due to destruction of the bronchial wall from chronic infection and inflammation.
Pathophysiology
- Cycle of infection and inflammation:
- Initial insult → impaired mucociliary clearance.
- Mucus stasis → bacterial colonization.
- Persistent infection → neutrophilic inflammation.
- Release of proteases, elastases, ROS → destruction of bronchial wall (cartilage, muscle, elastic tissue).
- Structural damage → irreversible dilation → worsens clearance → cycle continues (“vicious cycle” model).
Causes
- Post-infectious (TB, pneumonia, measles, pertussis) → necrotizing infection destroys bronchial walls.
- Cystic Fibrosis (CF) → defective CFTR protein → thick mucus → obstruction + chronic Pseudomonas infection.
- Primary Ciliary Dyskinesia (e.g., Kartagener’s syndrome) → defective ciliary motility → impaired clearance.
- Immune deficiency (e.g., hypogammaglobulinemia, HIV) → recurrent infections due to poor immune defense.
Causes
- Airway obstruction (foreign body, tumor, stenosis) → distal stasis + infection.
- Allergic Bronchopulmonary Aspergillosis (ABPA) → hypersensitivity to Aspergillus → mucus plugging + inflammation.
- Autoimmune/Connective tissue disease (RA, Sjögren’s) → airway inflammation and damage
Clinical Features
General:
- Chronic cough with copious purulent sputum (often foul-smelling).
- Hemoptysis (due to bronchial artery hypertrophy).
- Recurrent chest infections.
- Dyspnea, wheeze.
On examination:
- Coarse inspiratory crepitations (crackles), especially at lung bases.
- Wheeze, rhonchi.
- Digital clubbing (in advanced disease).
Cause-specific associations
- CF → young age, pancreatic insufficiency, malabsorption.
- Kartagener’s → sinusitis + situs inversus.
- ABPA → asthma, eosinophilia.
- Immunodeficiency → recurrent bacterial infections
Investigations
- Sputum culture → detect pathogens (Pseudomonas, H. influenzae, Staph aureus).
- Blood tests: immunoglobulin levels, CBC, eosinophils.
- Radiology: Chest X-ray (tram-track opacities, ring shadows). HRCT chest is gold standard (signet ring sign).
- Special tests: CF testing (sweat chloride, genetic testing).
- Ciliary function tests (nasal brush biopsy, electron microscopy).
- Aspergillus-specific IgE/IgG for ABPA
Management
a. General
- Treat underlying cause (CF, ABPA, immunodeficiency).
- Vaccination (influenza, pneumococcal).
- Smoking cessation.
b. Airway clearance
- Chest physiotherapy (postural drainage, percussion, oscillatory devices).
- Mucolytics (hypertonic saline, nebulized DNase in CF).
Management
c. Antibiotics
- Acute exacerbation → oral/IV depending on severity.
- Chronic infection (esp. Pseudomonas) → long-term macrolides (azithromycin) or inhaled antibiotics (tobramycin).
d. Anti-inflammatory
- Macrolides have immunomodulatory effect.
- Corticosteroids only in ABPA.
Management
e. Surgery
- Localized disease not controlled medically → surgical resection.
- Massive hemoptysis → bronchial artery embolization.
- Advanced diffuse disease → lung transplantation.