Bronchiectasis and Cystic fibrosis Flashcards
Define bronchiectasis
Persistent or progressive dilatation of thick-walled bronchi
Resulting in poor mucus clearance that predisposes to recurrent/chronic infection
Describe the pathogenesis of bronchiectasis
Vicious cycle of:
- Neutrophilic inflammation: impairs immunity
- Recurrent infection
- Airway damage: further impairs mucociliary clearance
List three causes of bronchiectasis
- Cystic fibrosis
-
Previous severe LRTI
- eg. pneumonia; pertussis; TB; mycoplasma; influenza
- Gastric or foreign body aspiration
- Mucociliary clearance disorders; immunodeficiency
- Endobronchial tumours
- Allergic bronchopulmonary aspergillosis
- RA; UC
What is primary ciliary dyskinesia
A rare autosomal recessive condition featuring chronic infections of the sinuses, middle ear, and lungs.
Associated syndromes:
- Young: Bronchiectasis + sinusitis + azoospermia
- Kartagener: Bronchiectasis + sinusitis + situs inversus
Name two common organisms in bronchiectasis
- Haemophilus influenzae
- Pseudomonas aeruginosa
- Moraxella catarrhalis
What causative agent is particularly associated with bronchiectasis?
Pseudomonas aeruginosa
Worse prognosis due to limited oral abx available for gram -ve bacteria, and biofilm formation
Ciprofloxacin is first-line for P. aeruginosa, but commonly causes GI upsets and photo-sensitivity.
Give three presenting features of bronchiectasis
- Persistent productive cough
- Daily expectoration of large volumes of purulent sputum
- Dyspnoea
- Haemoptysis: usually sign of infection
- Chest pain between exacerbations: typically non-pleuritic
- Associated nasal symptoms
- Absence of smoking history
List three signs of bronchiectasis
- Coarse crackles: esp in lower zones
- Large airway rhonchi: low-pitched wheeze
- On inspiration and expiration, due to secretions
- Wheeze: high-pitched wheeze heard
- On expiration, due to bronchospasm or obstruction
- Clubbing (infrequent): cystic fibrosis
Name three complications of bronchiectasis
- Infective exacerbations; chronic bacterial colonisation
- Haemoptysis: may be lift-threatening
- Respiratory failure; congestive heart failure
- Coughing:
- Pneumothorax; rib fractures
- Urinary incontinence; sexual problems
- Reduced QoL; anxiety; depression
- Chronic fatigue
- Nutritional deficiency
Request four investigations for suspected bronchiectasis
- High-resolution CT: Gold-standard
- Spirometry: assess airway obstruction
- CXR: exclude other causes
- Sputum culture: focused antibiotic treatment
- Establish cause:
- Sweat test: cystic fibrosis
- Aspergillus skin test
- Nasal NO: primary ciliary dyskinesia
- Gross antibody deficiency screening
- Bronchoscopy
What radiological findings are indicative of bronchiectasis?
- Signet ring sign:
- bronchus >1.5x size of accompanying pulmonary artery
- Lack of tapering
- Bronchi visible within 1cm of pleural surface
- CXR: Tram-lines (parallel line shadows)
Outline the management of bronchiectasis
- Treat underlying cause if known
- Influenzae vaccine
- Chest physiotherapy: mucus clearance techniques
- Pulmonary rehab if MRC dyspnoea score 3 or more
- Salbutamol for wheeze/dyspnoea
- Consider hypertonic saline
- Abx for 2/52
- Unknown organism: use previous cultures as guide
- Empirical: Amoxicillin
- Ciprofloxacin: first-line if P. aeruginosa
Describe the pathogenesis of cystic fibrosis
- Autosomal recessive
- Mutations of CFTR gene: abnormal CFTR chloride channel
- Impaired chloride movement alters fluid movement
- Dehydration and thickening of secretions
Outline the diagnostic criteria for cystic fibrosis
At least one of:
- Typical clinical features
- History of CF in a sibling
- Positive newborn heel prick test
Plus, one of:
- Sweat test: sweat NaCl >60mmol/L
- Genotyping: two CFTR mutations
List five presenting features of cystic fibrosis in adults
Pancreatic dysfunction:
- Intestinal malabsorption (>90%); low BMI
- CF-related diabetes
- Steatorrhoea
Lung disease:
- Recurrent respiratory infections
- Chronic daily cough and sputum production
- Bronchiectasis
Gastrointestinal (non-pancreatic):
- Distal intestinal obstruction syndrome
- CF-related liver disease (20%) and cirrhosis (2%)
- Gallstones
- Increased risk of GI malignancy
Other: Male infertility, osteoporosis, arthropathy
