Resp - Bronchiectasis Flashcards
What is bronchiectasis? What are the 2 main types?
- Permanent DILATION and THICKENING of the bronchi (may be diffuse or focal).
- 2 main types:
- Airway widening + wall collapse (saccular) - Increased risk of infection
- Airway widening + traction (e.g. fibrosis)
Describe the pathophysiology of bronchiectasis.
Chronic inflammation of airways destroys their elastic and muscular structure… easily collapse… impairment of airflow and drainage of secretions… accumulation of large amounts of mucus… mucus colonised by bacteria - predisposition to frequent and often severe LRTIs.
What are the common causes of airway inflammation in bronchiectasis?
- Post-infective (most common): childhood resp. viral infections (measles, influenza), whooping cough, pneumonia, TB
- CF (2nd most common)
- Other genetic/mucociliary clearance defects: primary ciliary dyskinesia, Young’s syndrome (triad of bronchiectasis, sinusitis and reduced fertility), Kartagener syndrome (triad of bronchiectasis, sinusitis and situs inversus)
- Connective tissue disease (3-6%): RA, Sjogern’s syndrome, systemic sclerosis, SLE, EDS, Marfan’s
- Immune deficiency: hypogammaglobulinaemia, HIV, malignancy
- Obstruction: foreign body, tumour, extrinsic LN
- Toxic insult: gastric aspiration, inhalation of toxic chemicals/gases
- Allergic bronchopulmonary aspergillosis
What are the common pathogens seen in sputum of pts with bronchiectasis?
i. Haemophilus influenzae
ii. Pseudomonas aeruginosa
iii. Moraxella catarrhalis
iv. Fungi: aspergillus, candida
What symptoms are usually present in pts with bronchiectasis?
- chronic cough
- excessive sputum production
- recurrent acute infections
- may be associated non-specific Sx inc. SOB, chest pain and haemoptysis
What signs are usually present in pts with bronchiectasis?
- coarse crackles (70%) heard in early inspiration and often in lower zones
- large airway rhonchi (44%)
- wheeze (34%)
- clubbing (rare)
Which investigations allow confirmation of a Dx of bronchiectasis?
- High-resolution CT thorax (v. high sensitivity and specificity).
Features:
- bronchial dilation - internal lumen diameter greater than accompanying pulmonary artery, or lack of tapering
- bronchial wall thickening - CXR: baseline CXR should be done in all pts to exclude other causes of Sx. Abnormal in 90%, e.g. ring or tubular opacities, tramlines and fluid levels, but non-specific.
Which investigations would you perform on a bronchiectasis pt to determine cause?
- Immune function tests
- serum immunoglobulins (IgG, IgA, IgM): ?immune deficiency as cause
- serum IgE testing to Aspergillus fumigatus and aspergillosis precipitins: ?allergic bronchopulmonary aspergillosis as cause
- baseline specific antibody levels against tetanus toxoid and capsular polysaccharies of S. pneumoniae and H. influenzae - CT testing in all children and adults <40 yo
- 2 measurements of sweat chloride
- CFTR genetic mutation analysis - Ciliary investigations if no other causes found or appropriate risk factors
Describe the management of a pt with bronchiectasis.
- Treat underlying cause
- Yearly follow-up with FEV1, FVC and PEF measurements
- Assessment of suptum microbiology every 6 mths to determine likely pathogens during infections
- Antibiotics according to sputum cultures/sensitivities for acute exacerbations +/- long-term suppression (e.g. azithromycin (macrolide))
- Supportive: physiotherapy and nebulised saline for mucus clearance, healthy diet and exercise, flu vaccine, bronchodilators if required
Name possible complications of bronchiectasis
- acute infective exacerbations
- empyema or lung abscess
- pneumothorax from repeated coughing
- life-threatening haemoptysis
- respiratory failure
- cor pulmonale
- Increased risk of neutrophilic asthma
(reduction in life expectancy, although much better outcome with aggressive therapy)
