Obstructive Lung Disease Flashcards
How does an obstructive lung disease affect FEV1/FVC
Airflow is limited so FEV1 decreases
FVC may also be decreased depending on the level of obstruction
FEV1/FVC drops below 70% norm.
What is PEFR?
Peak Expiratory Flow Rate
The air exhaled in a minute
What are PEFR values like for someone with an obstructive lung disease?
Normal is between 400-600L
A normal reading would be between 80-100% of the best values
A moderate fall would be 50-80%
A marked fall would be <50% of the best value
Name the common obstructive ariway diseases?
Asthma
Chronic Bronchitis
Emphysema
What is COPD?
An amalgamation of chronic bronchitis and emphysema
Is asthma reversible?
The bronchial smooth muscle contraction and inflammation can be reversed spontaneously or with drugs
What kind of irritants can cause COPD?
Smoking is the most imporant cause
Also atmospheric pollution and occupational irriants like dusts
What other things can cause Emphysema without bronchitis?
An enzyme deficiency can cause COPD. E.g. Alpha-1-antitrypsin (antiprotease) deficiency can cause emphysema
What people are most likely to develop COPD?
The old
Men more than women. (Falling as men do less of the dirty jobs)
People in developing countries (as smoking rises there)
Is damage done by smoking reversible?
Damage to the FEV1 isnt reversible.
Define chronic bronchitis?
’ Cough productive of sputum most days in atleast 3 consecutive months for 2 or more consecutive years.’
What happens when acute bronchial pneumonia occurs as a complication of chronic bronchitis?
Infection so sputum turns yellow/green
Mucuous & pus produced (acute infective exacerbation) and FEV1 falls.
During chronic bronchitis what morphological changes occur in the large airways?
- Mucous gland hyperplasia
- Goblet cell hyperplasia
- Inflammation & fibrosis (minorly)
During chornic bronchitis what morphological changes occur in the small airways?
- Goblet cells appear
- Imflammation & fibrosis when its long standing disease
Define Emphysema?
“An increase beyond the normal size of airspaces distal to the terminal bronchiole arising either from dilatation or destruction of alveolar walls and without obvious fibrosis”
Whats the structure of bronchioles/alveolar?
Terminal bronchiole is last conduction airway sub 1mm in size and fully lined by respiratory epithelium.
Respiraotry bronchioles are part respiratory epithelium part alveolar wall
Then alveolar ducts are all alveolar wall