pathology of obstructive lung disease Flashcards
what is COPD?
Chronic bronchitis and emphysema are better known as COPD (very rare to have a patient with only CB or emphysema).
what are the 3 main obstructive airways diseases?
chronic bronchitis, emphysema, and asthma
All these conditions, airway obstruction, and the mechanism of obstruction is different in all these conditions. Depending on the mechanism of the obstruction, if the patient can be treated or not
what is the normal FEV1?
3.5 - 4 litres (70-80% of FVC(amount squeezed out after the FEV1))
Which ways can we demonstrate obstructive lung disease?
spirometry and peak expiratory flow rate (PEFR)
normal PEFR is between 400 - 600L/min (look over these graphs and how they work)
what happens to FEV1, FVC, and PEFR in obstructive lung disease?
FEV1 is reduced, less than 70% of FVC
FVC MAY be reduced, FEV1 is most greatly impacted
PEFR is reduced
what causes bronchial asthma?
Type 1 hypersensitivity reaction, caused when mast cells in airways degrade, releases chemical factors which lead to inflammation by attracting cells which inflame, causing oedema and also those which directly cause bronchial smooth muscle to constrict
what is a rare cause of emphysema?
antitrypsin deficiency (inherited condition)
what is the clinical definition of chronic bronchitis and what is complicated chronic bronchitis?
cough productive of sputum for most days, in at least 3 consecutive months, for 2 or more consecutive years
often confused with chronic bronchial asthma clinically
complicated when sputum turns mucopurulent (acute infective exacerbation) or FEV1 falls
what is the definition of emphysema?
EMPHYSEMA is the increase beyond normal size of airspaces distal to the terminal bronchiole (acinus, region of the lung supplied with air from one of the terminal bronchioles) arising from dilation or from destruction of their walls WITHOUT FIBROSIS, SIMPLY the loss of those alveolar walls.
what are centriacinar, panacinar, and periacinar emphysema and where do they occur?
CENTRIACINAR emphysema is when it occurs in the centre of the acinus, generally found in the apical parts of the upper and lower lobes of the lung.
PANACINAR tends to take out a singular big region in the lungs in the lower parts of the lungs, and usually happens from antitrypsin deficiency.
PERIACINAR happens in the edges of the acinar, specifically pleura of lung and is dangerous as if it pops, can leak air into the pleural space and can result in spontaneous pneumothorax