【COPD英文PPT课件】 Restrictive and Obstructive Diseases.ppt

Restrictive and Obstructive Diseases-Pulmonary Pathology Lab 3-
Robert Allan, MD
Restrictive and Obstructive Lung Pathology- Background
What is the fundamental problem in restrictive lung disease?
You can’t get air in the lungs
What is the fundamental problem in obstructive lung disease?
You can’t get air out of the lungs
Name two major disease categories that are obstructive lung diseases?
Chronic obstructive pulmonary disease (COPD) which includes emphysema and chronic bronchitis
Asthma
Restrictive and Obstructive Lung Pathology- Background
What happens to the total lung capacity (TLC) in restrictive lung disease?
It goes down. You have less total lung capacity. You can’t get air in.
What happens to the total lung capacity (TLC) in obstructive disease?
The total lung capacity (TLC) in obstructive lung diseases is INCREASED.
The reason this happens is that patients with obstructive diseases trap air in their lungs (they can’t get air out) and as a result the TLC in their lungs is actually increased.
In order to measure the lung function pulmonologists do something called spirometry (hopefully you covered this in physiology). In simplified terms– you measure the amount that the person can puff out at 1 second (Forced expiratory volume-1, FEV1) compared to the total amount they can puff out (Forced vital capacity- FVC).
This is often expressed as the ratio of FEV1/ FVC.
Restrictive and Obstructive Lung Pathology- Background
What do you think happens to the FEV1/FVC ratio in obstructive lung diseases, in restrictive lung disease? (yes I know this wasn’t in lecture– if you can figure this out yourself you will remember it)
In OBSTRUCTIVE disease (remember can’t get air out)- the amount that you can get out of your lungs at one second will be diminished. As a result the proportion of the amount you can breath out at one second will be diminished relative to the total amount that you can breath out (forced vital capacity). The FEV1/FVC will be reduce