What is the diffusion capacity of the lungs?
The diffusion capacity of the lungs, as measured by the method of one inhalation of CO (DLco), is the ability of the lungs to diffuse oxygen (O2) to the blood and to drive off carbon dioxide (CO) from the blood to the atmosphere.
How to test this? Is it a difficult test?
The test is very simple and completely painless.
- The patient exhales fully.
- Then he inhales (a harmless gas mixture) deeply until the lungs are completely full.
- Then, he holds his breath for 10 seconds.
- Finally, he fully exhales.
The concentrations of the gas mixture inhaled by the patient are measured before and after the test. The difference between the two measurements indicates the amount of gas that diffuses from the lungs to circulation, and substantially the diffusing capacity of the lungs.