Lung diffusion testing

• A
• B
• C
• D
• E
• F
• G
• H
• I
• J
• K
• L
• M
• N
• O
• P
• Q
• R
• S
• T
• U
• V
• W
• X

Lung diffusion testing

Lung diffusion testing is used to determine how well oxygen passes from the air sacs of the lungs into the blood. The test measures the "diffusing capacity of the lung for carbon monoxide" or DLCO.

Diffusing capacity; DLCO test

You breath in (inhale) some gas containing a very small quantity of carbon monoxide, hold your breath for 10 seconds, then rapidly blow it out (exhale). The single exhaled gas is analyzed to determine how much carbon monoxide was absorbed during the breath.

Do not eat a heavy meal before the test. Do not smoke for at least 4 - 6 hours prior to the test. If you use a bronchodilator or inhaler medications, ask your health care provider whether or not you can use them before the test.

The mouth piece fits tightly around your mouth. Clips are put on the nose. 

The test is used to diagnose the presence and extent of certain lung diseases. It may also be used to see how gases move the lungs into the bloodstream.

Review Date: 08/10/2005
Reviewed By: David A. Kaufman, M.D., Assistant Professor, Division of Pulmonary, Critical Care & Sleep Medicine, Mount Sinai School of Medicine, New York, NY. Review provided by VeriMed Healthcare Network.