Bronchiectasis and Cystic fibrosis Flashcards
What is bronchiectasis?
Persistent or progressive condition characterised by dilated thick-walled proximal and medium sized airways. It is a pathological end point of a number of different disease processes.
What is the pathology of bronchiectasis?
Failure of mucociliary clearance and impaired immune function
–> continued insult to bronchial wall, through the recruitment inflammatory cells and uncontrolled neutrophilic inflammation.
Bronchitis—> Bronchiectasis—> Fibrosis
What are causes of bronchiectasis?
Cystic fibrosis and post infective are the most common causes.
Many cases are idiopathic
Rarer causes: immunodeficiency, congenital ciliary defect and airways obstruction.
Symptoms and Signs of bronchiectasis?
History of productive cough and recurrent chest infections
In severe cases production of thick foul smelling green sputum.
Haemoptysis, breathlessness, wheeze, finger clubbing,
Upon examination- coarse crackles may be heard when listening to the effected area
investigations for bronchiectasis?
Chest Xray - may be normal or show dilated bronchi with thickened bronchial walls.
High res CT needed for diagnosis
Sputum culture- needed for infective exacerbations, common bacterial causes:
Staph aureus, Haemophilus influenzae, pseudomonas aeruginosa.
What techniques are used to improve mucous clearance?
Chest physio
Mucolytics
What medical treatment is advised?
Frequent sputum culture
Prompt use antibiotics with extended course (10-14 days)
Long term therapy needed for Pseudomonas aeruginosa
Inhaled steroids may slow rate of disease progression
Bronchodilators can provide symptom relief.
What are common complications of bronchiectasis?
Haemoptysis, Pneumonia, Empyema (puss in pleural cavity), metastatic cerebral abscess, pneumothorax and respiratory failure.
Describe the aetiology of CF?
Autosommal recessive disease
Caused by mutations to the cystic fibrosis transmembrane conductance regulator gene on chromosome 7.
∆F508 most common mutation causing CF
90% within a panel of 70 mutations
What is the CFTR protein?
CFTR is a chloride channel found in cell membranes in the lungs, pancreas, GI tract, and reproductive tract.
What pathology occurs as a result of CFTR disfunction?
Abnormal CFTR protein leads to disregulated epithelial fluid transport
Leads to thickened secretions in a number of organs.
What is usually the presenting feature of CF?
What progressive features occur because of this?
Respiratory infections occur frequently in childhood—> presenting feature.
Resultant inflammatory response damages the airway. —> progressive bronchiectasis, airflow limitation and eventually respiratory failure.
What extra pulmonary features also develop?
Finger clubbing
Sinusitis and nasal polyps often present
in new born thick intestinal secretions can cause small bowel obstruction—> early manifestation
May cause pancreatic insufficiency leading to diabetes and steatorrhoea (excess fat in faeces)
Males are infertile due to failure vas deferens to develop.
Children have impaired growth and delayed puberty.
What diagnostic tests are undertaken for CF?
Sweat sodium test: results over 60mmol/L are diagnostic
(lower results that are still above the norm still require DNA analysis)
Blood DNA analysis of gene defect.
Serum immunoreactive trypsinogen
Why is raised serum immunoreactive trypsinogen a marker for CF?
pancreatic ducts are blocked causing insufficient drainage of enzyme meaning its blood concentration is higher
