Cystic fibrosis (CF)

Question 1

1) What kind of inheritance is CF?
2) What does this genetic mutation affect?

Answer 1

1) Autosomal recessive
2) Mucous glands

Question 2

What are the 3 major consequences of CF?

Answer 2

• Thick pancreatic and biliary secretions that cause blockage of the ducts
• Low volume thick airway secretions that reduce airway clearance, resulting in bacterial colonisation and susceptibility to airway infections
• Congenital bilateral absence of the vas deferens in males resulting in infertility

Question 3

How is CF screened for at birth?

Answer 3

Newborn blood spot test

Question 4

How does CF often present in newborns?

Answer 4

Meconium ileus

Question 5

1) What is meconium ileus?
2) How does it present?

Answer 5

1) Thick and sticky meconium which causes it to get stuck and obstruct the bowel
2) Not passing meconium within 24 hours, abdominal distention and vomiting

Question 6

Name 2 symptoms of CF

Answer 6

• Chronic cough
• Thick sputum production
• Recurrent respiratory tract infections
• Loose, greasy stools
• Abdominal pain and bloating
• Parents may report the child tastes particularly salty when they kiss them, due to the concentrated salt in the sweat
• Poor weight and height gain (failure to thrive)

Question 7

Name 2 signs of CF

Answer 7

• Low weight or height on growth charts
• Nasal polyps
• Finger clubbing
• Crackles and wheezes on auscultation
• Abdominal distention

Question 8

As well as newborn blood spot test, what are the 2 other ways CF can be diagnosed?

Answer 8

• Sweat test is the gold standard for diagnosis
• Genetic testing for CFTR gene can be performed during pregnancy by amniocentesis or chorionic villous sampling, or as a blood test after birth

Question 9

1) What is the sweat test?
2) When is a diagnosis of CF made from the sweat test?

Answer 9

1) Measurement of chloride concentration in sweat
2) Chloride concentration of more than 60mmol/l.

Question 10

Name 2 common colonisers of the airways in CF

Answer 10

• Staphylococcus aureus *
• Haemophilus influenzae
• Klebsiella pneumoniae
• Escherichia coli
• Burkhodheria cepacia
• Pseudomonas aeruginosa *

Question 11

Colonisation with which of these colonisers significantly increases mortality and morbidity?

Answer 11

Pseudomonas Aeruginosa

Question 12

1) What drug do patients with CF take long term for the prophylaxis of an infection with staph aureus?
2) Name another medication that might be given in a patient with CF

Answer 12

1) Flucloxacillin
2) Bronchodilators (salbutamol), mucolytics (Nebulised DNase - dornase alfa, and nebulised hypertonic saline)

Question 13

Name 2 other aspects of the treatment of CF

Answer 13

• Chest physiotherapy several times a day is essential to clear mucus and reduce the risk of infection and colonisation
• Exercise improves respiratory function and reserve, and helps clear sputum
• High calorie diet is required for malabsorption, increased respiratory effort, coughing, infections and physiotherapy
• CREON tablets to digest fats in patients with pancreatic insufficiency (these replace the missing lipase enzymes)
• Treat chest infections when they occur
• Vaccinations including pneumococcal, influenza and varicella

Question 14

Name 2 things patients with CF need monitoring on

Answer 14

• Diabetes
• Osteoporosis
• Vitamin D deficiency
• Liver failure.