17. Cystic Fibrosis

Question 1

What is Cystic Fibrosis

Answer 1

• also called mucoviscidosis
• congenital disease/generalized hereditary disorder associated with widespread dysfunction of the exocrine gland system (everything that sweats)
• destroys pancreas; lungs full of cysts, fibrosis, pus

Question 2

Abnormal CFTR

Answer 2

pathophysiology which bring progressive lung disease is due to impact of abnormal CFTR function on airway surface liquid (ASL)

Question 3

Cystic Fibrosis - Genetics

Answer 3

autosomal recessive disorder caused by mutations in a single gene on the long arm of chromosome 7 that encodes the CTFR protein

• variation is due to CFTR function expression
• most common variant: Delta-508

Question 4

Colour of mucus

Answer 4

indicates severity and length that mucus has been in airway

Question 5

Types of Gene Mutations in CF

Answer 5

1. Door-Jamming Mutation/G551D (3%)
2. Common Delta F508mutation (90%) - CFTR protein is made, but it just floats around inside the cell without reaching the surface

Question 6

Main descriptor of CF

Answer 6

• exocrine gland disorder (everything that sweats is affected)

Question 7

Classical Clinical Features: Chronic Sinopulmonary disease

Answer 7

• Persistent colonization/infection

- Chronic sinus disease: nasal polyps (growth inside nose), radiographic changes

Question 8

Classic Clinical features: Endobronchial disease

Answer 8

• cough and sputum production
• wheeze and air trapping in the lungs (like COPD at 5 years old)
• Radiographic abnormalities
• Digital clubbing due to right-sided heart failure

Question 9

Classic Clinical features: obstructive or restrictive

Answer 9

Obstructive pulmonary disease of PFTs

• become obstructive and restrictive

Question 10

Clinical features: growth

Answer 10

failure to thrive due to protein-caloric malnutrition (PEM)

• failure to grow and maintain muscle mass

Question 11

Clinical features: GI/nutritional abnormalities in infants

Answer 11

1. Meconium ileus: so thick in infants with CF that they’re unable to have bowel movement due to lack of digestive enzymes
2. Steatoorrhea (fatty stools that float). Fat soluble enzyme deficiencies (A, D, E, K)

Question 12

Clinical Features: GI/pancreas (youth)

Answer 12

• recurrent pancreatitis/exocrine pancreatic insufficiency
• Distal intestinal obstruction syndrome (require digestive enzymes)
• Rectal prolapse (extreme: during end stage or skinny babies > malnourished > no muscle mass > rectum pops out due to large stool and no muscle mass)

Question 13

Clinical Features: Azoospermia

Answer 13

Obstructive Azoospermia in males (cannot produce sperm, exocrine gland)

Question 14

Clinical Features: salt

Answer 14

• acute salt depletion

- chronic metabolic acidosis

Question 15

Clinical Features: vitamins

Answer 15

• fat soluble enzyme deficiency (A, D, E, K)
• Cannot absorb vitamin D results in osteoporosis and random joint inflammation
• lack of vitamin K: coughing out blood
• Delayed growth and puberty

Question 16

Clinical features: diabetes

Answer 16

due to pancreas being affected

- women more affected by having diabetes

Question 17

Clinical features: bony pathology

Answer 17

• vertebral compression and rib fractures
• increased thoracic kyphosis
• pressure on spine with coughing (easy to fracture with a cough)
• reduced lean muscle mass

Question 18

Clinical features: CXR

Answer 18

• bronchiectasis
• hyperinflation
• RUL lesion
• Barrel Chest
• Bull eyes or pockets of cysts in the lungs (pus)

Question 19

Diagnosing CF (newborns, sweat, fecal, CTFR, vitamins, bones, CT)

Answer 19

• all newborns tested in Alberta for gene (immunoreactive trypsogin)
• Sweat chloride test (normal rage 1-50)
• Fecal fat test (72 hour stool collection)
• CTFR dysfunction test
• General lab work for vitamin levels
• CT scan for chest and pancreas
• Bone density

Question 20

When can we do coughing/suction in CF

Answer 20

only when hemoptysis stops

Question 21

Trademark feature in the nose

Answer 21

sinus polyps

- chronic snoring

Question 22

Pulmonary Manifestations: newborns

Answer 22

• lungs and mucosal glands appear normal at birth
• gradual increase in mucosal glands suggesting early mucus plugging precedes evidence of inflammation or infection
• soon after birth, infection + bacterial pathogens commences with intense neutrophilic response, over time the airway becomes dilated and bronchiectatic

Question 23

Pulmonary manifestations: late stage

Answer 23

• lung parenchyma becomes affected by atelectasis, pneumonia, and encroachment by enlarging airways
• bronchiectasis causes hypertrophy of bronchial circulation and bronchial cysts

Question 24

Common respiratory symptoms

Answer 24

respiratory symptoms show at less than 6 months of age with:

• tachypnea
• wheezing
• increased WOB
• hyperinflation
• productive cough
• clubbed fingers

Question 25

sputum color

Answer 25

increases in volume and becomes yellow –> green –> tan

Question 26

hemoptysis

Answer 26

frequent in later stages of disease

• chronic cough irritates blood vessels due to amount of coughing
• do not continue coughing/suction until hemoptysis stops