Bronchiectasis

Bronchiectasis is a chronic lung disease characterised by the permanent enlargement of parts of the airways (bronchi). This condition often leads to a chronic productive cough, shortness of breath, chest pain, and frequent lung infections. Wheezing and nail clubbing may also be present.

Bronchiectasis can result from various causes, including infections, cystic fibrosis, and other genetic conditions, although in many cases, the exact cause remains unknown. The disease is classified as an obstructive lung disease and can be confirmed through a CT scan.

Symptoms

Symptoms of bronchiectasis include a chronic cough with green or yellow sputum, difficulty breathing, wheezing, and chest pain. Exacerbations may worsen these symptoms and include systemic effects such as fever, night sweats, fatigue, and weight loss. In some cases, patients may cough up blood without sputum, known as "dry bronchiectasis." Complications can include respiratory failure, lung abscess, empyema, and cor pulmonale.

Causes

Bronchiectasis can be caused by a wide range of factors:

• Infections: Bacterial pneumonia, Mycobacterium infections, and severe viral infections can lead to bronchiectasis.
• Genetic Conditions: Cystic fibrosis, primary ciliary dyskinesia, and other congenital disorders.
• Impaired Host Defences: Conditions like HIV/AIDS, primary immunodeficiency, and the prolonged use of immunosuppressive drugs.
• Autoimmune Diseases: Rheumatoid arthritis, Sjögren syndrome.
• Obstructions: Tumours, foreign body aspiration.
• Hypersensitivity: Allergic bronchopulmonary aspergillosis.
• Other: Chronic aspiration, toxic inhalation, smoking.

The disease often begins with an initial lung injury leading to impaired mucociliary clearance, followed by bacterial colonisation. This triggers a host immune response, resulting in a "vicious cycle" of inflammation and lung tissue destruction. Overactive neutrophil activity, including NETs and elastase, perpetuates this cycle, leading to the progressive dilation of bronchi.

Diagnosis

Diagnosis involves radiographic imaging, laboratory tests, and lung function tests. A CT scan is essential for confirming the diagnosis, revealing airway dilation and bronchial wall thickening. Laboratory tests may include complete blood counts, sputum cultures, tests for genetic disorders, and immunoglobulin levels. Lung function tests assess the degree of obstructive impairment, while flexible bronchoscopy may be performed if an obstructing lesion is suspected.

Prevention

Preventing bronchiectasis involves minimising lung infections and damage. Immunisations against common childhood respiratory infections, avoiding inhalation of foreign objects, and avoiding smoking and toxic fumes are very important preventive measures. Regular vaccinations against pneumonia, influenza, and pertussis are recommended, alongside maintaining a healthy BMI and regular medical check-ups.

Treatment

Airway clearance techniques involve loosening secretions to interrupt the cycle of inflammation and infection. Techniques include the use of hypertonic saline and chest physiotherapy. The active cycle of breathing technique (ACBT) and various devices can be beneficial.

Macrolides and inhaled corticosteroids are the primary anti-inflammatory treatments. Macrolides have immunomodulatory effects, reducing exacerbations and improving symptoms. However, long-term use of inhaled corticosteroids can lead to adverse effects.

Antibiotics are used to eradicate bacterial infections, particularly P. aeruginosa and MRSA. Options include oral non-macrolide antibiotics and inhaled antibiotics like tobramycin and ciprofloxacin.

Inhaled bronchodilators may benefit patients with demonstrated bronchodilator reversibility, improving dyspnea and quality of life.

Surgical intervention may be necessary for localised disease, massive hemoptysis, or airway obstructions. The goal is to manage specific manifestations rather than cure the disease entirely.

Recent clinical trials, such as those with Brensocatib, indicate promising results in reducing exacerbations and prolonging the time to first exacerbation.

Prognosis depends on several factors, including FEV-1, age, chronic infection presence, and disease extent. Bronchiectasis is more common in women and the elderly, with increased prevalence in certain ethnic groups and a notable rise in diagnoses in recent years due to better recognition and imaging techniques.

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Self-assessment MCQs (single best answer)

What characterises bronchiectasis?

Which of the following is NOT a common symptom of bronchiectasis?

What is the "vicious cycle" in the pathophysiology of bronchiectasis?

Which diagnostic method is essential for confirming bronchiectasis?

Which of the following is a preventive measure for bronchiectasis?

Which type of therapy is used to loosen secretions in bronchiectasis patients?

Which class of antibiotics is used for its immunomodulatory effects in bronchiectasis management?

Which of the following is a possible surgical indication in bronchiectasis patients?

What is a common complication of bronchiectasis?

Which factor does NOT directly contribute to the prognosis of bronchiectasis?