GV4: Cystic Fibrosis Flashcards Preview

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Flashcards in GV4: Cystic Fibrosis Deck (21)
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1
Q

which organ is affected in cystic fibrosis

A

pancreas

CF is a defect in ion transport

2
Q

what is cystic fibrosis

A
impaired function of organs with secretory function (eccrine sweat glands, epididymis & vas deferens, nasal polyps, pancreas (lack of enzyme secretion, reduced insulin))
digestive system (meconium ileus & obstruction; failure to thrive in newborns)
3
Q

how is nutrition managed in cystic fibrosis

A

patients have pancreatic insufficiency (lack of protease, amylase, lipase) and are unable to digest food properly
managed by diet & enzyme supplements like pancreatin (lipase, protease, amylase; in e/c capsules)

4
Q

how does cystic fibrosis lead to lung disease

A

chronic infection, mucus plugging, structural changes, massive neutrophil infiltration in airways, epithelial damage

5
Q

what structural changes occur in lung disease associated with cystic fibrosis

A

bronchial wall thickening, bronchiectasis (abnormal dilation of bronchial tree), pneumothorax

6
Q

what are the consequences of neutrophil infiltration in lung disease associated with cystic fibrosis

A

frustrated phagocytosis, failure to clear bacteria and dying neutrophils, inflammatory damage to airway tissue, decline in lung function

7
Q

what screening takes place in cystic fibrosis

A

immunoreactive trypsinogen, genetic screening, sweat test

8
Q

what is the IRT test for CF

A
immunoreactive trypsinogen (Guthrie test)
all newborns in the UK; trypsinogen made by pancreas and secretion into gut imapired in CF which is elevated in blood
9
Q

what genetic screening takes place in CF

A

IRT positive (and siblings) screened for most common mutations

10
Q

what happens in the sweat test for CF

A

elevated skin Cl- levels
below 30mM means CF unlikely
above 60 mM means CF is likely

11
Q

what does CFTR stand for

A

cystic fibrosis transmembrane conductance regulator

12
Q

what are the consequences of low volume of CFTR

A

sticky viscous mucous, difficult to clear by cilia, provides growth environment for bacteria, partial correction with inhaled hypertonic saline

13
Q

why is DNA found in mucin in CF

A

mostly from dying neutrophils attempting to clear bacteria; so very viscous mucous because of dehydration and large amount of DNA

14
Q

what bacteria can cause a lung infection in CF

A

pseudomonas aeruginosa
staphylococcus aureus
haemophilus influenza
burkholderia cepacia

15
Q

what antibiotics are used in CF

A

prophylactic flucloxacillin in infants for s. aureus
regular swab or sputum cultures
early oral or IV intervention
inhaled antibiotics useful

16
Q

what are the established therapies in CF

A

early recognition using neonatal screening, antibiotics against pathogens, beta-adrenoreceptor agonists, anti-inflammatory, osmotic agens, mucolysis (recombinant DNAase, N-acetyl cysteine)

17
Q

what is the function of recombinant DNAase

A

breaks down very viscous mucous, CF mucous contains large amounts of DNA from inflammatory cells and bacteria

18
Q

what anti-inflammatory therapies are used in CF

A

glucocorticoids, macrolides, high dose NSAIDs

19
Q

how are glucocorticoids used in CF

A

inhaled no proof of a reduction in inflammation

IV prednisolone has some benefit but significant adverse effects (imapired growth and cataracts)

20
Q

how are macrolides used in CF

A

non-antibiotic effect of azithromycin

risk of myobacterium infection

21
Q

how are high dose NSAIDs used in CF

A

e.g. ibuprofen

some slowing of lung function decline