Cystic Fibrosis Flashcards
What is cystic fibrosis?
Autosomal recessive conditions which causes increased viscosity in secretions in the lungs, pancreas and digestive tract. This is as a result of defects in the CF transmembrane conductance regulator gene (CFTR) which encodes a cAMP-regulated chloride channel.
What are the clinical features of cystic fibrosis?
Meconium ileus Prolonged jaundice Recurrent chest infections Wet hacking cough Clubbing Malabsorption – steatorrhea and failure to thrive Failure to thrive and delayed growth
What are the complications that can occur as a result of cystic fibrosis?
Cor pulmonale Diabetes mellitus Delayed puberty Rectal prolapse (bulk stools) Nasal polyps Male infertility and female subfertility Haemoptysis Pneumothorax Cirrhosis Cholesterol gallstones
How is cystic fibrosis diagnosed and investigated?
Sweat test <40 is normal >60 is indicative of CF
False positives occur due to: skin oedema (most common), malnutrition, adrenal insufficiency, glycogen storage diseases, nephrogenic diabetes insipidus, hypothyroidism, hypoparathyroidism, G6PD and ectodermal dysplasia.
CXR should be performed – hyperinflammation, increased antero-posterior diameter, bronchial dilatation, cysts, linear shadows and infiltrates.
How is cystic fibrosis screened for?
Screening – all children screen with the heel prick test looking at raised levels of immunoreactive trypsinogen on the Guthrie card
How is cystic fibrosis managed?
Chest physiotherapy to help move secretions and postural drainage (parents taught this)
Older children will learn force expiration techniques
High calorie diet including high fat intake
Minimise contact with other CF patients to prevent cross infection
Pancreatic enzymes (omeprazole increases absorption by increasing duodenal pH) Heart and lung transplants if required
If homogenous for the F508 mutations, then can treat with Orkambi (Lumacaftor/Ivacaftor). Lumacaftor increases number of CFTR proteins that arrive at the membranes and Ivacaftor increases the number of defective channels that open to allow chloride to pass.
What infections are cystic fibrosis patients vulnerable to in the lungs
CF patients are vulnerable to respiratory infections. The most common organisms are:
Staphylococcus Aureus
Pseudomonas Aeruginosa (eventually 90% will be chronically infected)
Burkholderia Cepacia
Aspergillus
If respiratory decline, then treat early with Ticarcillin and gentamicin or ceftazidime.
What are cystic fibrosis patients energy requirements?
Energy requirements are raised by 130% due to malabsorption and lung inflammation
Vitamin supplementation
How often are cystic fibrosis patients screened for diabetes?
Yearly screen of blood glucose with OGTT
What is meconium ileus?
Meconium ileus – no meconium passed due to meconium plug. Will see dilated bowl loops on AXR. Occurs in 15-20% of CF babies or 1 in 5000 normal births.
How does meconium ileus present?
Presents with abdominal distension and bilious vomiting typically within 24-48 hours
How is meconium ileus managed?
Manage with surgical decompression with NG drainage and washout enema or excision of the gut containing the most meconium.
