Cystic Fibrosis & Bronchiectasis Flashcards
What is Bronchiectasis?
A chronic obstructive lung disease Characterised by the abnormal, localized irreversible dilatation of the bronchi/bronchial tree. It is divided into CF and Non-CF bronchiectasis.
What are the causes of Bronchiectasis?
- old age
*Recurrent aspiration pneumonia - Tuberculosis, Measles and Pertussis
- Immunoglobulin deficiency
- Idiopathic
- RA and ABPA
- Alpha-1 antitrypsin deficiency
- Genetic causes:Primary ciliary dyskinesia, Kartageners syndrome, Youngs syndrome.
What are the signs and symptoms of Bronchiectasis?
*Chronic productive cough
*Coarse crepitations in affected regions
* ± Wheeze and Clubbing
* Recurrent lower respiratory tract
infections
*Intermittent Haemoptysis
What are the imaging studies in Bronchiectasis ?
- CXR to rule out Kartageners syndrome or cavitary lesions of TB
- HRCT may show abnormally widened and thickened airway with an irregular wall.
What are the blood works in Bronchiectasis ?
*IgE and RAST to rule out ABPA
* Immunoglobulins: to look for < IgG, IgA and IgM.
* Mannose binding lectin level to rule out immune deficiency.
* Pertussis and Measils serology
* Sputum culture to detect MRSA and other Drug resistant organisms.
*Mantoux test for TB
What are the principles of bronchiectasis management ?
*Treat symptoms
* Treat infections early and aggressively & prevent colonisation of difficult pathogens
* Optimise lung function
* Optimise weight & nutrition
* Smoking cessation
* Vaccination against COVID-19, influenza and pneumococcus
What is the management of acute bronchiectasis exacerbation?
- Respiratory support: O2, NIV, ICU referral may be needed.
- Antimicrobial therapy after sensitivity testing for 10 to 14 days with gram negative and positive cover.
- Airway clearance: PT, SABA, and Mucolytics: DNAase (pulmozyme), hypertonic saline (7%).
What is the abx for Pseudomonas aeruginosa and Burkholderia cepacia?
ceftazidime or Tazocin
What is the abx for MRSA cover ?
Linazolid and vancomycin.
In severe resistant cases: aztreonam or meropenem
What is the long term management of bronchiectasis ?
- Portable oxygen if desaturating on exertion
- +/- Non-invasive ventilation at night
- Physiotherapy
- Short-acting bronchodilators
- Mucolytics: DNAase (pulmozyme), hypertonic saline (7%)
- Airway clearance devices
- Inhaled antibiotics for Pseudomonas colonisation e.g. Tobramycin, Colomycin, Aztreonam, Levofloxacin
- Oral macrolides used as anti-inflammatory to minimise exacerbations e.g. Azithromycin
what are the Complications of Bronchiectasis?
- Recurrent infections with resistant organisms
- Hypoxia
- Respiratory failure
- Massive haemoptysis
What is cystic fibrosis ?
The most common life-shortening autosomal recessive disease in Western Caucasian populations due to to a mutation in the CF Transmembrane Conductance Regulator (CFTR) gene, causing dysfunction of a complex chloride channel found in all exocrine tissues.This chloride channel defect results in reduced volume and hyperviscosity of mucosal
secretions leading to end –organ damage causing muti-system disfunction.
What is the CF gene mutation frequency and epidemiology ?
- 1:35 Continental Europe
- 1:25 U.K. Anglo Saxon descent
- 1:19 Irish/ Celtic descent are “carriers” of a mutated CFTR gene.
Ireland has the highest incidence of the disease, with 1 in 19 people being carriers of a mutated CFTR gene.
What is the most common CF mutation in Ireland ?
Delta F508 in the homozygous state [ 2 copies of this mutation ] which accounts for 56% of Irish people living with CF.
* Since 2011 neonatal heel-prick screens for CF [newborn screening programme]
What is the pathophysiology of cystic fibrosis ?
CFTR gene mutation on chromosome 7 causes chloride channel dysfunction in exocrine tissues. This causes abnormal sodium and chloride transport leading to thick mucus in bronchi, the biliary tree, pancreas, intestines and the reproductive tract. This result in Defective mucociliary clearance, Bacterial colonization, Neutrophilic inflammation, and end organ damage for instance Panbronchiectasis.
What are the most common CFTR mutations in Irish population ?
> 1000 CFTR gene mutations
Irish Population:
delta F508 (92%)
G551D (15.5%)
R117H (5.9%)
All other mutations < 4% of CF population