Obstructive Airway Diseases Flashcards
Name the three main obstructive airway diseases
- chronic bronchitis
- emphysema
- asthma
What is COPD
chronic bronchitis and emphysema; very rare to have one without the other
What is PEFR
the peak rate of flow in one second that indicates airway obstruction when below 50% of the best value
How can COPD be detected in spirometry
- there is airflow limitation
- PEFR is reduced
- FEV1 is reduced
- FVC may be normal
- FEV1/FVC is less than 70%
What is asthma in terms of inflammation
type 1 inflammation in the airways - mast cell degranulation/histamine/IgE…
What are the main causes of COPD
- smoking
- atmospheric pollution
- occupation (dust)
- emphysema alone; alpha-1-antitrypsin deficiency
How is chronic bronchitis defined clinically
cough with sputum most days in at least three consecutive months for two or more consecutive years
What is complicated chronic bronchitis
bacterial bronchitis/bronchopneumonia is interfering with the chronic bronchitis, making it mucopurulent
What are the effects of chronic bronchitis on larger airways
- mucous gland hyperplasia
- goblet cell hyperplasia
- minor inflammation/fibrosis
What are the effects of chronic bronchitis on smaller airways
- appearance of goblet cells where normally absent
- inflammation and fibrosis in long standing disease
How is emphysema defined pathologically
an increase in the size of the airways distal to the terminal bronchioles due to dilatation or destruction of their walls
What are the three types of emphysema
- centriacinar
- panacinar
- periacinar
What is centriacinar emphysema
- destruction closest to the terminal bronchiole
- most common as here material is deposited due to the change to gaseous diffusion
What part of the lung does centriacinar emphysema affect and why
- the upper lobe
- clearance mechanisms are less effective here because there are less alveolar macrophages due to a smaller blood supply
What is panacinar emphysema
destruction of large areas covering the entire lung