What is the definition of bronchiectasis?
- Recurrent episodes of chronic wet cough
- Recurrent is >=3 episodes per year
- Chronic cough is >4 weeks of cough
- Radiographic features on HRCT
What is the definition of protracted bacterial bronchitis?
- Chronic wet cough (>4 weeks)
- Absence of specific signs and symptoms (no cough pointers = nothing pointing to a specific diagnosis)
- Resolution within 2-4 weeks with an appropriate oral antibiotic (typically amox-clav). For the majority of children, there is resolution within 2 weeks of antibiotic. (This is why we typically treat a CF exacerbation with 2 weeks of antibiotics)
What is the spectrum of suppurative lung disease? What differentiates bronchiectasis from chronic suppurative lung disease?
- PBB–>chronic suppurative lung disease–>bronchiectasis
- Bronchiectasis is differentiated by the HRCT finding of irreversible bronchial dilatation
When should you worry about patients having bronchiectasis?
- > =3 episodes of chronic wet cough per year
- persistent wet cough that doesn’t respond to >4 weeks of antibiotics
- persistent CXR abnormality after >4 weeks of antibiotics
What are the airway and vascular changes that happen in bronchiectasis?
- eventually, the airway’s elastic tissue, muscle and cartilage is destroyed and there is just scar tissue–>loose bag of scar tissue (mucous filled saccular airway)
- increased bronchial artery blood flow, can get anastomoses between bronchial and pulmonary circulation
- hypoxia–>pulmonary hypertension
How do you interpret nasal nitric oxide for the purpose of diagnosing PCD?
● Role of nasal nitric oxide in diagnosis
● Low nasal nitric (<77 nL/min) is quite consistent in PCD, though other things can also result in low nasal nitric oxide (viral illness, sinusitis, cystic fibrosis)
● Low nasal NO is relatively sensitive (90% range) and specific (90% range) for PCD
● But nasal NO is not well studies in children <5 years of age
● Recommendation: in a child >=5 years of age with a clinical phenotype of PCD and CF excluded, low NO on 2 separate occasions can make a presumptive diagnosis of PCD
○ Key point: 2 separate occasions
What are the subtypes of subtypes?
- ultrastructural defect - most common is outer dynein arm defect
- other types:
- dynein arm defect
- radial spoke defect
- microtubular transposition defect
- functional defect
Draw the structure of cilia
See PCD chapter
Management of PCD?
- Regular airway clearance
- Consider antibiotics during pulmonary exacerbations, regular sputum cultures
- Ensure appropriate nutrition and growth
- Immunizations–>influenza, routine, pneumovax
- Avoid smoking
- ENT: audiology assessment, ?hearing aids, referral to ENT physician
- Genetic testing and counselling
- Sibling screening
(from OSCE discussion)
What are the bare minimum investigations for bronchiectasis?
- CT chest (so that bronchiectasis can be diagnosed)
- CBC
- IgG, A, M, E
- vaccine titres
- sweat chloride
Differential diagnosis for bronchiectasis?
- idiopathic (most common)
- impaired host defences
- cystic fibrosis (CF) (most common cause in children)
- primary ciliary dyskinesia, e.g. Kartagener syndrome, Young syndrome
- primary immunodeficiency disorder, e.g. common variable immunodeficiency, hypogammaglobulinaemia, chronic granulomatous disease
- HIV/AIDS 15,16
- postinfective (most common known non-CF cause in adults)
- bacterial pneumonia and bronchitis, e.g S. aureus, H. influenzae, B. pertussis
- mycobacterial infection, e.g. tuberculosis, Mycobacterium avium-intracellulare complex
- allergic and autoimmune
- allergic bronchopulmonary aspergillosis (ABPA)
- connective tissue disease, e.g. rheumatoid arthritis 6, Sjögren syndrome, systemic lupus erythematosus (SLE) 7
- inflammatory bowel disease
- obstruction
- severe obstructive lung disease: asthma or chronic obstructive pulmonary disease (COPD)
- neoplasm, e.g. bronchial carcinoid, bronchogenic carcinoma
- inhaled foreign bodies
- congenital
- bronchial tree malformations, e.g. Mounier-Kuhn syndrome, Williams-Campbell syndrome, pulmonary sequestration, bronchial atresia
- alpha-1-antitrypsin deficiency
- others
- chronic aspiration
- traction bronchiectasis due to diffuse lung disease, e.g. pulmonary fibrosis
- radiation-induced lung disease
- post-transplantation
CXR findings in bronchiectasis
- Tram track opacities in cylindrical bronchiectasis
- Air fluid levels in cystic bronchiectasis
- Ring shadows (from seeing bronchi end on)
- Increased bronchovascular markings
CT findings for bronchiectasis
- bronchus visualised within 1 cm of pleural surface
- especially true of lung adjacent to costal pleura
- most helpful sign for early cylindrical change
- lack of tapering
- increased bronchoarterial ratio
- bronchial wall thickening: normally wall of bronchus should be less than half the width of the accompanying pulmonary artery branch
- mucoid impaction
- air-trapping and mosaic perfusion
Signs described on CT include: - tram-track sign
- signet ring sign
For what bronchoarterial ratio do you consider a diagnosis of bronchiectasis?
> 1-1.5 in adults
review differential diagnosis of bronchiectasis as based on location
See note on Bronchiectasis (Radiology)
