What is Bronchiectasis?
Bronchiectasis is a chronic inflammatory lung disease characterized by permanent, irreversible dilation of the bronchi on chest CT scan, accompanied by clinical symptoms of chronic cough, sputum production, and recurrent respiratory infections 1.
Radiologic Definition
The diagnosis requires CT imaging demonstrating bronchial dilation, specifically 1, 2:
- Bronchial diameter exceeding the adjacent pulmonary artery (bronchoarterial ratio >1)
- Lack of normal bronchial tapering
- Airways visible within 1 cm of the costal pleural surface or touching mediastinal pleura
Clinical Presentation
Patients typically present with 1, 3:
- Chronic productive cough (most days)
- Mucopurulent or purulent sputum production
- Recurrent respiratory infections/exacerbations
- Hemoptysis (in some cases)
- Progressive dyspnea and fatigue
Pathophysiology: The "Vicious Vortex"
The disease operates through four interrelated components that drive progressive lung damage 1:
- Airway inflammation - chronic inflammatory infiltrate of lymphocytes and macrophages
- Impaired mucociliary clearance - inability to clear secretions
- Chronic airway infection - bacterial colonization (often Pseudomonas aeruginosa)
- Structural lung damage - permanent bronchial wall destruction
These components create a self-perpetuating cycle where each element worsens the others, leading to progressive disease.
Etiology
Bronchiectasis has diverse underlying causes 1:
- Post-infectious (tuberculosis, severe pneumonia, whooping cough, measles)
- Autoimmune disorders (rheumatoid arthritis, inflammatory bowel disease)
- Allergic conditions (allergic bronchopulmonary aspergillosis)
- Genetic disorders (primary ciliary dyskinesia, immunodeficiency)
- Idiopathic - approximately 40% have no identifiable cause 1
Important caveat: Cystic fibrosis-related bronchiectasis is managed separately with distinct guidelines 1.
Management Goals
Treatment aims to 1:
- Improve quality of life and reduce symptoms
- Prevent exacerbations
- Prevent disease progression and preserve lung function
Management targets the four pathophysiologic components through airway clearance techniques, antibiotics (for infection), anti-inflammatory therapies, and mucoactive drugs 1.
Clinical Significance
Bronchiectasis is increasingly recognized as a common condition affecting approximately 1 in 200 adults 4, with rising prevalence, hospitalization rates, and mortality. It imposes substantial symptom burden and healthcare costs, primarily driven by acute exacerbations 4.