Cystic fibrosis

Question 1

CF inheritance type

Answer 1

autosomal recessive

Question 2

What is the most common mutation that causes CF and that causes the strongest phenotype?

Answer 2

delta F508

Question 3

Which gene is mutated in CF?

Answer 3

CFTR
(CF transmembrane conductance regulator)

Question 4

Describe the ions involved in CF and what this leads to

Answer 4

increased sodium absorption and abnormal chloride secretion in the epithelial cells lining the airways

leads to thicker mucus which impairs the function of cilia

Question 5

Neonatal features of CF

Answer 5

meconium ileus
rectal prolapse
failure to thrive

Question 6

Respiratory features of CF

Answer 6

chronic sinusitis
nasal polyps
cough
wheeze
haemoptysis
recurrent LRTIs
bronchiectasis
pneumothorax
cor pulmonale
respiratory failure

Question 7

GI features of CF

Answer 7

pancreatic insufficiency (causing steatorrhea + diabetes mellitus)
cirrhosis
portal hypertension
gallstones
distal intestinal obstruction syndrome

Question 8

What can CF cause in men?

Answer 8

infertility due to absent vas deferens
- can reproduce via IVF as sperm are still produced

Question 9

MSK features of CF?

Answer 9

clubbing
osteoporosis (due to reduced absorption of fat-soluble vitamins (A, D, E, K) and therefore impaired calcium homeostasis)
arthritis
hypertrophic pulmonary osteoarthropathy

Question 10

How is CF diagnosed?

Answer 10

heel prick test
sweat test = Na + Cl >60mmol/L
faecal elastase = can show abnormal pancreatic exocrine function
genetic screening = detect CF mutations

Question 11

How is airway clearance aided in CF?

Answer 11

physiotherapy
mucolytics

Question 12

How should infections be treated in CF?

Answer 12

early + aggressively
appropriate antibiotics (dose and duration likely to be higher/longer)

Question 13

Which tests should be regularly done for CF patients?

Answer 13

cough swabs
sputum samples
lung function from 5-6 years old
radiology only when necessary

Question 14

What conservative management is important for CF patients?

Answer 14

education
fertility + genetic counselling
dietician
psychosocial counselling
chest physiotherapy (postural drainage + active cycle breathing techniques)
screening for potential complications eg. osteoporosis, diabetes mellitus

Question 15

What are the aims of treatment in CF?

Answer 15

prevent or delay serious lung problems
maintain lung function and clinical stability for long periods

Question 16

CF exacerbation due to infection symptoms

Answer 16

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

Question 17

CF exacerbation due to infection signs

Answer 17

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

Question 18

How is lung function monitored?

Answer 18

FEV1 trend

Question 19

How is aspergillus infection treated in CF patients and what should you be aware of?

Answer 19

acute infection = antifungals

be aware of allergic bronchopulmonary aspergillosis (ABPA) - needs steroids + antifungals

Question 20

Infection with which bacteria excludes CF patients from being considered for a lung transplant?

Answer 20

Mycobacterium Abscessus

Question 21

Which organisms are known to be transmissible in CF?

Answer 21

Burkholderia family
MRSA
Non-tuberculous mycobacteria

Question 22

What precautions are taken to prevent cross-infection between CF patients?

Answer 22

hand washing
aprons
gloves
no shared toilets/waiting areas
no shared equipment, filters for spirometers

Question 23

How does hypertonic saline help CF patients?

Answer 23

expectorant
increases thickness of airway surface layer (ASL)
promotes coughing
?enhanced mucin secretion
improves mucociliary clearance

Question 24

What order should CF patients take their inhaled medicines?

Answer 24

bronchodilator
mucolytics
airway clearance
inhaled antibiotics

Question 25

What are the aims of nutritional management in CF?

Answer 25

ensure sufficient energy and protein for normal growth
ensure optimal absorption of nutrients from the gut
prevention of micronutrient deficiencies

Question 26

Which vitamins are fat soluble?

Answer 26

A, D, E, K

Question 27

How does creon help CF patients?

Answer 27

pancreatic enzymes to aid digestion and absorption of nutrients