Bronchiectasis
By Isra
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
Vicious Cycle Model — 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
Etiology (Causes)
Infectious
- Post-infectious (TB, pneumonia, measles, pertussis) → necrotizing infection destroys bronchial walls
Genetic/Structural
- 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-Related
- Immune deficiency (e.g., hypogammaglobulinemia, HIV) → recurrent infections due to poor immune defense
Mechanical/Obstructive
- Airway obstruction (foreign body, tumor, stenosis) → distal stasis + infection
Allergic/Autoimmune
- Allergic Bronchopulmonary Aspergillosis (ABPA) → hypersensitivity to Aspergillus → mucus plugging + inflammation
- Autoimmune/Connective tissue disease (RA, Sjögren’s) → airway inflammation and damage
Clinical Features
General Symptoms
- Chronic cough with copious purulent sputum (often foul-smelling)
- Hemoptysis (due to bronchial artery hypertrophy)
- Recurrent chest infections
- Dyspnea, wheeze
Physical Examination Findings
- 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
Microbiological
- Sputum culture → detect pathogens (Pseudomonas, H. influenzae, Staph aureus)
Laboratory
- Blood tests: immunoglobulin levels, CBC, eosinophils
Imaging
- Chest X-ray: tram-track opacities, ring shadows
- HRCT chest — gold standard (signet ring sign)
Specialized Testing
- CF testing (sweat chloride, genetic testing)
- Ciliary function tests (nasal brush biopsy, electron microscopy)
- Aspergillus-specific IgE/IgG for ABPA
Management
General Measures
- Treat underlying cause (CF, ABPA, immunodeficiency)
- Vaccination (influenza, pneumococcal)
- Smoking cessation
Airway Clearance
- Chest physiotherapy (postural drainage, percussion, oscillatory devices)
- Mucolytics (hypertonic saline, nebulized DNase in CF)
Antibiotic Therapy
- Acute exacerbation → oral/IV depending on severity
- Chronic infection (esp. Pseudomonas) → long-term macrolides (azithromycin) or inhaled antibiotics (tobramycin)
Anti-inflammatory Treatment
- Macrolides have immunomodulatory effect
- Corticosteroids — only in ABPA
Surgical Interventions
- Localized disease not controlled medically → surgical resection
- Massive hemoptysis → bronchial artery embolization
- Advanced diffuse disease → lung transplantation
Good luck