Cystic fibrosis Flashcards
CF inheritance type
autosomal recessive
What is the most common mutation that causes CF and that causes the strongest phenotype?
delta F508
Which gene is mutated in CF?
CFTR
(CF transmembrane conductance regulator)
Describe the ions involved in CF and what this leads to
increased sodium absorption and abnormal chloride secretion in the epithelial cells lining the airways
leads to thicker mucus which impairs the function of cilia
Neonatal features of CF
meconium ileus
rectal prolapse
failure to thrive
Respiratory features of CF
chronic sinusitis
nasal polyps
cough
wheeze
haemoptysis
recurrent LRTIs
bronchiectasis
pneumothorax
cor pulmonale
respiratory failure
GI features of CF
pancreatic insufficiency (causing steatorrhea + diabetes mellitus)
cirrhosis
portal hypertension
gallstones
distal intestinal obstruction syndrome
What can CF cause in men?
infertility due to absent vas deferens
- can reproduce via IVF as sperm are still produced
MSK features of CF?
clubbing
osteoporosis (due to reduced absorption of fat-soluble vitamins (A, D, E, K) and therefore impaired calcium homeostasis)
arthritis
hypertrophic pulmonary osteoarthropathy
How is CF diagnosed?
heel prick test
sweat test = Na + Cl >60mmol/L
faecal elastase = can show abnormal pancreatic exocrine function
genetic screening = detect CF mutations
How is airway clearance aided in CF?
physiotherapy
mucolytics
How should infections be treated in CF?
early + aggressively
appropriate antibiotics (dose and duration likely to be higher/longer)
Which tests should be regularly done for CF patients?
cough swabs
sputum samples
lung function from 5-6 years old
radiology only when necessary
What conservative management is important for CF patients?
education
fertility + genetic counselling
dietician
psychosocial counselling
chest physiotherapy (postural drainage + active cycle breathing techniques)
screening for potential complications eg. osteoporosis, diabetes mellitus
What are the aims of treatment in CF?
prevent or delay serious lung problems
maintain lung function and clinical stability for long periods
CF exacerbation due to infection symptoms
increased frequency/duration of cough
increased sputum production
change in appearance of sputum
increased shortness of breath
decreased exercise tolerance
decreased appetite
feeling of increased congestion in the chest
CF exacerbation due to infection signs
increased respiratory rate
use of accessory muscles for breathing
intercostal retractions
change in results of auscultatory examination of chest
decline in measures of pulmonary function consistent with the presence of obstructive airway disease
fever
leukocytosis
weight loss
new infiltrate on chest radiograph
How is lung function monitored?
FEV1 trend
How is aspergillus infection treated in CF patients and what should you be aware of?
acute infection = antifungals
be aware of allergic bronchopulmonary aspergillosis (ABPA) - needs steroids + antifungals
Infection with which bacteria excludes CF patients from being considered for a lung transplant?
Mycobacterium Abscessus
Which organisms are known to be transmissible in CF?
Burkholderia family
MRSA
Non-tuberculous mycobacteria
What precautions are taken to prevent cross-infection between CF patients?
hand washing
aprons
gloves
no shared toilets/waiting areas
no shared equipment, filters for spirometers
How does hypertonic saline help CF patients?
expectorant
increases thickness of airway surface layer (ASL)
promotes coughing
?enhanced mucin secretion
improves mucociliary clearance
What order should CF patients take their inhaled medicines?
bronchodilator
mucolytics
airway clearance
inhaled antibiotics
What are the aims of nutritional management in CF?
ensure sufficient energy and protein for normal growth
ensure optimal absorption of nutrients from the gut
prevention of micronutrient deficiencies
Which vitamins are fat soluble?
A, D, E, K
How does creon help CF patients?
pancreatic enzymes to aid digestion and absorption of nutrients
