Cystic Fibrosis Flashcards
Explain the pathophysiology of cystic fibrosis
Autosomal recessive condition that occurs in 1 in 2500
Defect in chromosome 7 that encodes the CFTR gene
Respiratory manifestations - nasal polyps, bronchiectasis
GI - malabsorption, meconium ileus, gallstones
Non-erosive arthropathy and infertility
What are the common colonisers in cystic fibrosis?
- Staphylococcus aureus
- Pseudomonas aeruginosa
- Haemophilus influenzae
- Burkholderia cepacia (pseudomonas cepacia)
- Aspergillus
What are the causes of false positive sweat test?
- Malnutrition
- Adrenal insufficiency
- Glycogen storage disease
- Nephrogenic DI
- Hypothyroidism
- Hypoparathyroidism
- G6PD deficiency
- Ectodermal dysplasia
How would you manage cystic fibrosis patient?
- Multidisciplinary approach
Non-Pharmacologic
2. Regular chest physiotherapy and postural drainage
3. Deep breathing exercise
4. High calorie and fat diet
Pharmacologic and Surgical
5. Vitamin supplementation
6. Pancreatic enzyme supplementation taken with meals
7. Prophylactic antibiotics
- Flucoxacillin - staph aureus
- Amoxicillin - haemophilus, streptococcus
- Ciprofloxacin
8. Ivacaftor - CFTR modulator
9. Home NIV
10. Heart and lung transplant
End stage
11. Palliative care
What are the treatment options for chronic pseudomonas infection?
- Nebulised tobramycin, polymyxin or aztreonam
- Bactrim
- Azithromycin prolonged 6 months course
What are the diagnostic investigations for cystic fibrosis?
- Sweat chloride test - abnormally high > 60 mEq/L
(normal < 40 mEq/L) - Genetic testing - DF508 and F542X
- Dried spot test (Guthrie test)
- immunoreactive trypsin activity
Cystic fibrosis is an __ __ affecting multiple epithelial cells.
Chromosome __ encoding __ gene functions as __ in apical (luminal) plasma membranes of epithelial cells, regulates __ and __ of exocrine secretion
Autosomal recessive exocrinopathy
Chromosome 7 endocing CFTR gene, anion channel
Regulates volume and composition of exocrine secretions
Who should undergo screening for cystic fibrosis?
BTS recommends all patients < 40 years old with bronchiectasis to undergo screening for CF
Additional points to consider:
1. Current or childhood steatorrhoea
2. Persistent isolation of Staphylococcus aureus in the sputum
3. Features of malabsorption
4. Male primary infertility
5. Upper lobe bronchiectasis
Screening investigations should include”
- Sweat chloride measurement x2
- CFTR genetic mutation analysis.
