Lecture 15- Bronchiectasis and Cystic fibrosis Flashcards
define bronchiectasis
- chronic IRREVERSIBLE dilatation of one or more bronchi- pathological condition can be caused by many diseases or be idiopathic-resulting in abnormally enlagred bronchi
deformed bronchi in bronchiectasis exhibit
poor mucous clearance
- predisposition to recurrent or chronic bacterial infections
aetiology of bronchiectasis
Variety of underlying causes, with a common underlying emchanism of chronic inflammation
chronic inflammation and bronchiectasis
- Inflammaiton causes destruction of elastic and muscular components of the bronchial wall and peribronchial fibrosis
- Used to primarily be caused by pertussis and TB
- Some part of the world still primary cause
- Ask where they grew up/ have been
- Underlying congenital conditions primary triggering cause in UK/ europe/ USA
radiological findings of bronchiectasis: CXR
- Usually abnormal
- May be normal in early disease
- Inadequate in diagnosis or quantification of bronchiectasis/ bronchial dilatation
- Classic abnormality: dilated bronchi with thickened walls (tram-track signs)
radiological findings of bronchiectasis: CT
gold standard
- Demonstrates bronchial dilation biggeer than the adjacent blood vessel, bronchial wall thickening
- signet ring sign
Gross pathologic lung specimen from a patient with bronchiectasis
notice te small pulmonary artery abutting the much larged dilated bronchus (arrow) both of which are seen on cross-section
bronchiectasis causative organisms
- H.influenza
- pseudomonas aeruginosa
- moraxella catarrhalis
- fungi- aspergillus, candidida
- Mycobacteria tuberculosis
- less common: S. aureus
bronchiectasis viscious cycle
bronchial dilation leads to mucus accumulation, impaired ciliary fucntion and increased risk of infection
infection leads to inflammation na dloss of bronchial elastic fibres and smooth muscle– more dilatation
Clinical symptoms (not very specific) of bronchiectasis
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Very common
- Chronic cough
- Daily mucopurulent sputum production- can vary in quantity, colour and consistency- can smell
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Common
- Breathlessness on exertion
- Intermittent haemoptysis (coughing up blood)
- Nasal symptoms
- Chest pain
- Fatigue
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Less common
- Wheeze
Clinical signs of bronchiectasis
- Hypoxaemia in advanced case of bronchiectasis (pulse oximetry)
- Fever relativeky common
- Haemoptysis – 50% of pt-s usually mild
- Fine crackles (rales)
- High pitches inspiratory squeaks
- Rhonchi
- Sometimes can hear both crackles and wheezing- lung sounds from CF pts w/bronchiectasis
- Clubbing of digits
- Systemic signs- weight loss
causes of bronchiectasis
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Post infective
- Whooping cough (pertussis) and TB
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Immune deficiency
- Hypogammaglobulinemia
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Mucociliary clearance defects
- CF, primary ciliary dyskinesia, Youngs syndrome (triad of bronchiectasis, sinusitis and reduced fertility), Kartagener syndrome (triad of bronchiectasis, sinusitis and situs inversus)
- Alpha-1 antitrypsin deficiency
- Obstruction–> foreign body, tumour, extrinsic lymph node
- Toxic insult –>gastric aspiration (post lung transplant), inhalation of toxic chemicals/ gases
- Allergic bronchopulmonary aspergillosis
- Secondary immune deficiency’s- HIV, malignancy
- Rheumatoid arthritis
- Idiopathic
- Associations- IBD, yellow nail syndrome
Early diagnosis and treatment- ask yourself ‘does this pt have bronchiectasis’
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- Treatment of predisposing underlying disorders may slow disease progression
- History of asthma but new spirometry shows no reversibility with bronchodilator – enquire more about history and think about bronchiectasis
- History of COPD but diminished breath sounds, characterising COPD, but not found and different risk factors
- History of
- Severe chest infection earlier in life
- Lifelong chest infections? Genetic cause?
- Recurrent chest infections? Immunodeficiency
- Recurrent sinus infections since childhoods? Ciliary dysfunction
- Sputum culture positive for common organisms such as
- Haemophilus or pseudomonas and atypical mycobacterium
- IBD, RA also associated with bronchiectasis
bronchiectasis is an
obstructive airway disease
reduced FEV1/FVC ratio <70% (late finding)
bronchiectasis pulmonary function tests
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Obstructive airways disease
- Reduced FEV1/FVC ratio of <70% (late finding)
- Full PFT may show elevation of Residual Volume/Total Lung Capacity ratio consistent with air trapping
- DLCO may be reduced in severe disease (when inflammation spread to alveolar)
differentiating between bronchiectasis and chronic bronchitis
Chronic bronchitis (mucous gland hyperplasia) is not the same as bronchiectasis (airway dilation, scarring).
Management of bronchiectasis
- Physio/airway clearance
- Daily airway clearance is essential for treatment success
- Sputum sampling- routine culture and non tuberculosis mycoplasma (NTM)
- Exclude immunodeficiency/treat identifiable causes
- Consider longer-term therapies at future visits
- Annual flu and routine vaccinations against Influenzaw and Streptococcus pneumoniae
- An established MDT is key
Acute exacerbation of bronchiectasis
A person with bronchiectasis with deterioration in 3 or more key symptoms for at least 48 hours
what is the most common identifiable cause of bronchiectasis in the western world
CF
life expectancy of someone with CF
- In 1950s median life expectancy was a few months
- In 1990s- late teens
- Today- 40 y/o
CF is an ……. …….. disroder
- Autosomal recessive disorder
- 1 in 2,500
- Most common within northern European ancestry
- Predominant mutation in those with CF is the
Phe508del – deletion of phenylalanine at position 508 of the polypeptide chain
where is the mutation found and what abnormal function does it lead to
- Caused by mutation of gene located on long arm chromosome 7 that leads to abnormal function of epithelial chloride channel- Cystic fibrosis transmembrane conductance regulation (CFTR)
Sweat test
An increased sweat chloride concentration >60mmol/l- sweat test- very salty
- hypertonic sweat dye to dysfunctional NaCl absorption due to defect in CTFR
(in normal sweat gland NaCl we be reasborbed along the duct)
