Pathology of Obstructive Lung Disease Flashcards
What are not primarily obstructive diseases?
- Lung cancer
- Lung tumours
- Inhaled foreign bodies
- Chronic scarring diseases ( bronchiectasis, secondary TB)
What are obstructive airway diseases?
- Chronic Bronchitis
- Emphysema
- Asthma
What is similar about chronic bronchitis, emphysema and asthma?
Airway obstruction
What is different about chronic bronchitis, emphysema and asthma?
The mechanism for obstruction
What are chronic bronchitis and emphysema better known as?
- COPD Chronic Obstructive Pulmonary Disease
- COLD Chronic Obstructive Lung Disease
- COAD Chronic Obstructive Airways Disease
FEV1
Forced Expiratoy Volume of air exiting your lungs in the first second a maximum expiration
FVC
Total amount expires
What are the normal for the FEV1:FVC ration?
- FEV1 is usually 70-80% of FVC
- Normal FEV1 is about 3.5-4 litres
- Normal FVC is about 5 litres
- Normal ratio FEV1:FVC is 0.7-0.8
What is predicted FVC based on?
Age, sex and height
What does spirometry test?
Test of airflow obstruction
What test is commonly used by asthmatics in the home?
Peak Expiratory Flow Rate
What are the ranges for peak flow?
- Normal is 400-600 litres
- Normal range is 80-100% of best value
- 50-80% of best is moderate fall
- <50% best is marked fall
What results would you expect to see in obstructive lung disease?
- There is airflow limitation
- Peak expiratory flow rate is reduced
- FEV1 is reduced
- FVC may be reduced
- FEV1 is less than 70% of FVC
How does the curve of an FEV:FVC graph differ from normal in obstructive lung disease?
The slope is flatter and may have a lower end point
What is bronchial asthma caused by?
Type I hypersensitivity in the airways
What contributes to inflammation and therefore bronchial constriction in the smooth muscle of the airways?
- Degranulation of mast cells
- Mediators and chemotactic factors
- Spasmogens
Why is bronchial asthma considered reversible?
Airway obstruction can be reversed either spontaneously or as a result of medical intervention
What can drugs modify in asthma?
Bronchial smooth muscle contraction and inflammation
What causes COPD?
- Smoking
- Pollution from the atmosphere
- Occupational dust
What is an extremely rare cause of emphysema?
Alpha-1-antiprotease (antitrypsin) deficiency
What leads to a natural decline in FEV1?
Age
For someone to become clinically symptomatic what must happen?
There must be a large drop in FEV1
What happens to someone’s FEV1 curve when the stop smoking?
- Damage is not reversible
- Their curve will continue to decline but at the same rate as someone who had never smoked
How chronic bronchitis defined clinically?
Cough productive of sputum most days in at least 3 consecutive months for 2 or more consecutive years
When is chronic bronchitis complicated?
When mucopurulent or FEV1 falls
What morphological changes do the large airways undergo?
- Mucous gland hyperplasia
- Goblet cell hyperplasia
- Inflammation and fibrosis is a minor component
What morphological changed do the small airways undergo?
- Goblet cells appear
- Inflammation and fibrosis in long standing disease