Obstructuve VS restrictive Flashcards
Which structures are involved in obstructive lung disease?
The actual breathing tubes:
- bronchi
- terminal bronchioles
Which structures are involved in restrictive lung disease?
Lung parenchyma: sites of gas exchange
- alveoli
- respiratory bronchioles
Chest wall
What is obstructive lung disease?
Problem with the airways (breathing tubes) that make it harder to get air in and out of the lungs
Takes a long time to inhale/exhale, but the volume of air inhaled/exhaled is normal
What is restrictive lung disease?
Problems in the lung that restrict lung expansion
Reduced volume of air inhaled/exhaled, but no problem with the time it takes to inhale/exhale
What will FEV1 values look like in obstructive and restrictive lung disease?
Obstructive:
Low because obstruction of airways means air cannot be exhaled quickly
Restrictive:
Low because volume of air in lungs is less than it should be
What will FVC values look like in obstructive and restrictive lung disease?
Obstructive:
Normal as there is no reduction in chest volume
Restrictive:
Low because there is less air in the lungs due to restriction of lung expansion
What type of breaths will you see in obstructive and restrictive lung disease?
Obstructive:
Long, wheezy breaths
Restrictive:
Short breaths, hardly any air going in or out
Draw a graph of volume/time of a patient with:
- Obstructive lung disease
- Restrictive lung disease
http://almostadoctor.co.uk/node/48/revisions/7303/view
What will the FEV1/FVC ratio look like in a patient with obstructive lung disease?
It will be lower than 0.7
Because FEV1 is lower, but volume remains pretty normal
What will the FEV1/FVC ratio look like in a patient with restrictive lung disease?
It will be higher than 0.7
Because FEV1 and FVC are equally reduced since lung volumes are reduced.
What are the causes of obstructive lung disease?
Problem with breathing tubes
COPD
Asthma
Bronchiectasis
Cystic fibrosis
What are the causes of restrictive lung disease?
Problem with lung parenchyma, scarring.
Pulmonary fibrosis
Sarcoidosis
Asbestosis
TB
What is the transfer coefficient?
A measure of the ability of oxygen to diffuse across the alveolar membrane
What will transfer coefficient values look like in obstructive and restrictive lung disease?
Obstructive: normal
Restrictive: reduced
What conditions cause low transfer coefficient?
Fibrosis of alveoli
Anaemia
Severe emphysema
Pulmonary vasculitis
