Cystic Fibrosis

Question 1

What causes CF?

Answer 1

• Faulty CFTR gene on chromosome 7

Question 2

Describe its inheritance pattern.

Answer 2

Autosomal recessive

Question 3

How do we screen for CF?

Answer 3

Heel-prick at birth

- Screens for immunoreactive trypsinogen

Question 4

What other tests are there for CF?

Answer 4

Sweat test

• Normal NaCl is less than 40
• NaCl of 60+ is diagnostic

Faecal elastase
- Exocrine function of the pancreas

Question 5

What symptoms can they have as babies/toddlers?

Answer 5

• Won’t pass meconium in 48hrs (meconium ileus)
• Failure to thrive (grow)
• Steatorrhoea
• Recurrent pneumonia’s

Question 6

What causes their failure to thrive and steatorrhoea?

Answer 6

Cannot produce fat soluble vitamins (ADEK)

Question 7

What signs are there on examination?

Answer 7

• Wheeze

- Cough

Question 8

What bloods should you do?

Answer 8

• ABG (hypoxia)
• Serum vitamins (low ADEK)
• LFTs (liver function- can cause cirrhosis)

Question 9

What might and AXR show?

Answer 9

Dilated loops of bowel (obstruction)

Question 10

What could a CXR show in older Pts?

Answer 10

• Barrel chest

- Flattened diaphragm

Question 11

What special tests are vital?

Answer 11

Spirometry/Lung Function Tests

• Obstructive pattern
• Reduced FEV1/FVC ratio

Question 12

What conservative treatments are there?

Answer 12

• Counselling and education
• Physio- younger = postural draining
  - older= forced expiration
• MDT involvement and input (inc. dietician, resp, GP, psych)

Question 13

What two screenings should CF Pts have?

Answer 13

Diabetes (Annual)
- Oral glucose tolerance test of 11.1mmol/mol or less

Osteoporosis (5 yearly)
- DEXA Scan

Question 14

How would you treat meconium ileus?

Answer 14

• NG

- Enema/laxatives

Question 15

What antibiotic regimens should they be on?

Answer 15

• Long term prophylaxis

- Additional ABx for exacerbations

Question 16

What other drugs are useful for airway clearance and breathing?

Answer 16

• Mucolytics
• Bronchodilators
• Exogenous amylase and ADEK vitamins (PO)

Question 17

What is short gut/bowel syndrome?

Answer 17

• Meconium ileus may need surgery to cut out the meconium dense bowel
• This can lead to malabsorption due to inadequate length of small bowel
• Requires stoma/NG feed

Question 18

Name the respiratory complications of CF.

Answer 18

• Pneumonia
• Pneumothorax
• Pleural effusion
• Bronchiectasis

Question 19

Name five other complications of CF:

• Cardiovascular
• Endocrine
• MSK
• Reproductive
• GI

Answer 19

• Cor pulmonale
• Diabetes (blocked pancreatic duct)
• Osteoporosis (vit D deficiency so Ca2+ absorption impaired)
• Blocked vas deferens (infertility)
• Cirrhosis of the liver