the amount of air that can be forcibly breathed out from your lungs after taking the deepest breath possible
The ratio can be caculated which can help in diagnosis the obstructive or restrictive diseases
A restrictive disease is the one in which you have problem in either gas exchange in your lungs (intrapulmonary) or problems with your chest movement (extrapulmonary).
An obstructive condition is where you have narrowing of the airways.
Interpretation of the ratio
Normal or increased ratio
Normal person
Everything normal
Restrictive disease
both the parameters are decreased
Decreased ratio
Obstructive pattern
Asthma
Shows reversibility with increase in FEV1 by 12% and 200ml
COPD
No reversibility less than what happens in asthma
will also show decrease in DLCO as the area available for gas exchange decreases due to the destruction of small airways.
We can also check FVC at the end
Normal or increased FVC generally means obstructive disease
Whereas if the FVC decreased it means a mixed obstructive and restrictive pattern such as a patient with Asthma and Kyphosis
DLCO
measurement of the gas exchange between lungs and blood
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