Cystic Fibrosis Flashcards
What type of condition is cystic fibrosis?
Autosomal recessive
What does cystic fibrosis result in?
Increased viscosity of secretions (e.g. lungs and pancreas).
Which organs are classically affected in someone with CF?
Pancreas and lungs
What is cystic fibrosis due to?
A defect in the cystic fibrosis transmembrane conductance regulator gene (CFTR), which codes a cAMP-regulated chloride channel
What does the CFTR gene code for?
A cAMP-regulated chloride channel
What are 80% of the cases of CF in the UK due to?
Delta F508 on the long arm of chromosome 7
How many people are carriers of the CF gene?
1 in 25
How many people have cystic fibrosis?
1 in 2500
How does CF typically present in neonates?
Meconium ileus
Failure to thrive
Rectal prolapse
What is meconium ileus?
Not passing meconium within 48 hours, abdominal distention and vomiting.
(meconium blocks the last part of the baby’s small intestine (ileum). Above the blockage, the small intestine becomes enlarged as it fills with everything the baby swallows.)
How can CF present in older children/ adults?
- Recurrent chest infections
- Malabsorption- steatorrhoea, failure to thrive
How is CF screened in new borns?
Bloodspot test
When is the newborn bloodspot test done?
Day 5-9
What is the gold standard for diagnosing CF?
Sweat test
How can CF present in later childhood and early adulthood?
- short stature
- diabetes mellitus
- delayed puberty
- rectal prolapse
- nasal polyps
- male infertility, female subfertility
Why can patients with CF get rectal prolapse?
Due to bulky stool
What is abnormal about a patient with CF’s sweat?
Abnormally high sweat chloride
What level of chloride is normal in a patients sweat?
- normal value < 40 mEq/l,
What level of chloride would you expect in a patient with CF?
> 60 mEq/l
Which organisms may colonise a patient with CF?
- Staphylococcus aureus
- Pseudomonas aeruginosa
- Burkholderia cepacia*
- Aspergillus
What is the main management of CF?
Chest physiotherapy and postural drainage (2x day)
What diet is recommended for patients with CF?
High calorie diet, including high fat intake
What should patients with CF try to minimise?
Contact with other CF patients to prevent cross infection
What are patients with Cf at risk of cross infection of?
Burkholderia cepacia complex and Pseudomonas aeruginosa
What do CF patients take long term prophylaxis for?
Staph Aureus infection (take flucloxicillin)
What enzyme supplementation might patients with CF need to take?
Pancreatic enzyme supplementation (CREON)
What enzyme supplementation might patients with CF need to take?
Pancreatic enzyme supplementation
How can Pseudomonas aeruginosa be treated?
Nebulised antibiotics such as tobramycin
How often do patients with CF need to be followed up?
Every 6 months
What does the mutation on chromosome 7 result in?
Increased sodium absorption and abnormal chloride secretion in the epithelial cells lining the airways.
What are the 3 main neonatal features of cystic fibrosis?
Failure to thrive
Meconium Ileus
Rectal prolapse
What are the respiratory features of CF?
Nasal polyps
Recurrent chest infections
chronic sinusitis
What does pancreatic insufficiency commonly result in?
Diabetes mellitus
Steatorrhea
What bedside tests would you carry out in someone with CF?
Glucose tolerance test
Spirometry
What type of pattern would spirometry show in someone with CF?
Obstructive
What liver disease might occur in someone with CF?
Cirrhosis
Portal hypertension
What is a possible MSK complication of CF?
Osteoporosis
What is the management of pancreatic insufficiency?
Insulin replacement regime
Exocrine enzymatic replacement (Creon)
Vitamin A, D, E, K
What is the management of liver dysfunction in someone with CF?
Ursodeoxycholic acid
What is the management of worsening progressive lung disease in CF?
Oxygen
Non invasive ventilation
Diuretics if signs of cor pulmonale
What might be you able to see on a chest x-ray of someone with CF?
Hyperinflation
Bronchiectasis
What might you be able to see on an USS of someone with CF?
Distal Intestinal Obstruction
Liver cirrhosis
Chronic pancreatitis
