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Flashcards in Cystic Fibrosis Deck (63):
1

How many live births does cystic fibrosis affect

1 in 2500

2

How is cystic fibrosis inherited

in an autosomal recessive manner

3

How much of the population are carriers for the disease

1 in 25

4

Where is the mutational defect that causes cystic fibrosis

On the long arm of chromosome 7 that codes for (CFTR)

5

What does CFTR stand for

Cystic Fibrosis Transmembrane conductance regulator

6

What is the most common mutation

Deletion of three base pairs of the gene results in the loss of phenylalanine at position 508

7

What is the primary physiological defect in cystic fibrosis

Reduced chloride conductance at epthelial embranes

8

What is a characteristic of the disease

Chloride and sodium in the sweat (salty sweat)

9

How many classes of mutations of the CFTR gene are there

5

10

Mutations in classes 1-3 result in what

No CFTR function at the cell membrane

11

What is more severe? classes 1-3 or classes 4-5

Classes 1-3

12

What does reduced chloride secretion and increased sodium reabsorption result in in the bronchial mucosa

Secretions of abnormal viscosity with reduced water content of the airway surface liquid and reduced depth of the periciliary fluid

13

What inactivates defensins

The high salt content of the airway surface

14

What inactivates defensins

The high salt content of the airway surface

15

What are defensins

Naturally occurring antimicrobial peptides on the epithelial surface

16

Why does bacteria adhere to the mucosa and proliferate in patients with cystic fibrosis

These patients have abnormal mucus glycoproteins that act as binding sites for the bacteria

17

In what organ is there abdnormal ion transport resulting in plugging and obstruction of ductules with pregressive destruction of the gland

Pancreas

18

Why does malabsorption occur in patients with cystic fibrosis

Pancreatic enzymes fail to reach the small intestine which results in malabsorption off fats with steathorrhoea and failure to gain weight

19

What might cause diabetes in a patient with cystic fibrosis

Progressive destruciton of the endocrine pancreas

20

Why do patients with cystic fibrosis have an increased incidence of fallstones and biliary cirrhosis

Abnormalities of bile secretion and absorption

21

10% of children with cystic fibrosis present with what at birth

Meconium ileus

22

What is meconium ileus

A form of intestinal obstruction caused by inspissated viscid faecal material resulting from lack of pancreatic enzymes and from reduced intestinal water secretion

23

What are other symptoms of cystic fibrosis

obvious malabsorption by the age of 6 month (50%0
failure to thrive
abdominal distension
copious offensive stools from steatorrhoea
Rectal prolapse occasionally occurs

24

What is the most prominent feature of cystic fibrosis

Recurrent respiratory infections with cough, sputum production and wheeze

25

What is the most prominent feature of cystic fibrosis

Recurrent respiratory infections with cough, sputum production and wheeze

26

What are the typical organisms isolated in sputum cultures

Staph Aureus
Haemophilus influenzae
Streptococcus pneumoniae

27

By the teenage years, many patients will have become infected with what?

Mucoid strains of pseudomonas aerginosa

28

What organism causes onion rot

Burkholderia cepacia complex

29

How can burkholderia cepacia complex spread

From person to person in close social contact (those with CF)

30

What type of Burkholderia cepacia is associated with the worst prognosis

Type 3

31

Why is social contact between patients with CF discouraged

Because of the potential for transmission of infection between patients

32

What happens as the cycle of infection and inflammation progress

Lung damage worsens with deteriorating airways obstruction, destruction of lung parenchyma, impairment of gas exchange and the development of hypoxaemia, hypercapnia and cor pulmonale

33

What provokes hypertrophy of the bronchial arteries and what does this result in

Persistent pulmonary inflammation
Haemoptysis

34

What are some of the GI complications that patients with CF can develop

Fatty liver
gallstones
focal biliary fibrosis
multinodular cirrhosis and hepatosplenomegaly
portal hypertension
oesophageal varices
liver failure

35

What is the equivalent of meconium ileus

Distal intestinal obstruction syndrome

36

Where is there often a palpable mass (GI) in patients with CF

Right ileac fossa

37

What is the treatment to prevent recurrence of GI symptoms

Pancreatic enzyme supplements, avoidance of dehydration and possible use of laxatives

38

What specifically causes almost all male CF patients to be infertile

The congenital bilateral absence of the vas deferens

39

What are CF patients at risk of developing in hot weather and why

Heat prostration
As a result of excess loss of salt in sweat

40

How is the diagnosis of CF based upon

The demonstration of elevated sweat chloride concentrations on a sweat test in association with characteristic clinical features such as recurrent respiratory infections or pancreatic insufficiency

41

What are the two known cystic fibrosis mutations on DNA analysis

Delta F508 and G542X

42

What is sweating induced by

Pilocarpine iontophoresis

43

How is the sweat test carried out

Pilocarpine is placed on the skin of the forearm and a small electrical current is passed across it to enhance its penetration of the skin and stimulation of the sweat ducts.

44

What have the sweat chloride levels got to be above for a high suspicion of CF

over 60mmol/L

45

What is used to detect carrier status

Genotyping

46

What do infants with CF have

Elevated serum immunoreactive trypsin activity

47

How is newborn screening for CF carried out

Measured on a single dried blood spot obtained on a Guthrie card as part of the newborn screening programme for diseases such as PKU and hypothyroidism

48

What are the 4 basic elements to treatment for CF

Chest physio - to clear the bronchial secretions
Antibiotics to treat the pulmonary infection
Pancreatic enzyme supplements to correct the nutritional deficits
Dietary support

49

At what stage of the disease is chest physiotherapy important

All stages

50

What 3 techniques are used during chest physio

Postural drainage
Chest percussion
Positive expiratory pressure devices

51

What is given long term from early childhood?

Flucloxacillin

52

What is the usual antibiotic used to treat exacerbations

Amoxicillin

53

Some patients have a reversible component to their airways obstruction and benefit from what

Bronchodilator drugs (salbutamol) and inhaled steroids (beclametasone)

54

How is mucolytic medication administered

By nebulisation and improves the lung function and reduces the number of exacerbations in some patients

55

How is mannitol administered

A dry powder inhalor

56

How does mannitol work

It is an osmotic agent that also increases the warter content of the airway surface liquid with improved mucociliary clearance

57

What might be useful in reducing lung injury by inhibiting the migration and activation of neutrophils

High dose ibuprofen

58

When are pancreatic enzyme supplements taken

With each meal and with snacks containing fat

59

Patients with CF required how much of the recommended daily calorie intake for individuals without CF

120-150%

60

An FEV1 of less than 30% of the predicted value is associated with what kind of mortality rate

50% 2 year mortality rate

61

What is the main option to be considered in patients with advanced disease

Lung transplantation

62

What is the median survival for CF patients nowadays

38 years

63

What social factors are also affected through the illness

Reduced life expectancy
Insurance
choice of career
relationships
marriage
pregnancy
fertility