Case 5 - COPD, asthma, Emphysema And Chronic Bronchitis

Question 1

What factors are associated with getting COPD?

Answer 1

Exposure to toxins from... 
1) Smoking - MOST LIKELY CAUSE 
2) occupational particles (dust, silica etc) 
Genetic ** 
Alpha-trypsin deficiency 
Nutrition ** 
Low vitamin C and E

Question 2

What is chronic bronchitis?

Answer 2

Long term inflammatory condition when sufferers cough and produce sputum most days

Question 3

What is the pathophysiology of chronic bronchitis?

Answer 3

1) smoke and noxious chemicals damage CILIA
2) direct damage to epithelium
3) Inhibits leukocyte removal of bacteria and other pathogens
4) hypertrophy of mucous glands and goblet cells

Question 4

Chronic bronchitis leads to increased mucus secretion and retention. What are the consequences?

Answer 4

1) inability to clear mucous
2) retained mucus more likely to become infected
3) increased airway inflammation and bronchial wall thickening

Question 5

What is the pathophysiology of emphysema?

Answer 5

1) toxins activate alveolar macrophages
2) leads to the release of MMP-12 which activates the epithelium where cytokines are released (IL-8)
3) neutrophils are recruited and they release neutrOphil elastase which degrades ECM
4) ELASTIN DEGRADED

Question 6

What does the degradation of elastin lead to in emphysema?

Answer 6

1) Hyperinflation of alveoli
2) alveolar wall destruction and capillary walls
3) loss of lung elasticity

Question 7

What is asthma?

Answer 7

1) Chronic inflammatory condition of the airways… characterised by airway obstruction, airway hyperresponsiveness, bronchial obstruction.

Question 8

What happens to the lungs histologically in asthma?

Answer 8

1) smooth muscle and mucous gland hyperplasia
2) basement membrane thickening
3) mucosal sloughing of epithelium
4) tissue oedema

Question 9

What are the symptoms of asthma?

Answer 9

1) breathlessness
2) wheezing
3) chest tightness
4) coughing esp. At night

Question 10

What are the causes of asthma?

Answer 10

1) Genetic
- ( increased incidence in primary relatives)
- ADAM 33 gene (associated with airway hyperresponsiveness)

2) Non atopic asthma
- viral infections of respiratory tract (lowers threshold for subepithelial vagal receptors)
- inhaled air pollutants
- nitrogen dioxide

Question 11

The arterial blood gas of a patient comes back and the results are as follows; 
pH 7.1, PCO2 4.8 KPa, HCO3 13
Na 135, Cl 88
What is the abnormality?
What is the likely cause?

Answer 11

• check case 5 week 2 lecture on respiratory failure*

Question 12

What causes COPD?

Answer 12

1) long term exposure to Toxins (e.g. From cigarette smoke, air pollution)
2) cause release of cytokines from macrophages - more mucus production
3) narrowing of lumen
4) increasing resistance and reducing air flow