The official blog of the Lung Institute.
Nitrogen Lung Washout
When pulmonologists believe someone has lung disease, there are several types of breathing tests done to determine the patient’s diagnosis. These tests will help pulmonologists figure out if it’s chronic obstructive pulmonary disease (COPD), pneumoconiosis, pulmonary fibrosis, or some other condition. One of the most common tests conducted is the nitrogen lung washout.
What is a Nitrogen Lung Washout?
A nitrogen lung washout is a test to determine the state of your lung capacity and airflow. Specifically, it tests the amount of unused air normally in your lungs, known as functional residual capacity. Pulmonologists look for the amount of dead space – the volume of air that doesn’t take part the gas exchange – due to nonfunctioning capillaries in the small air sacks of the lungs. The gas exchange is the process of converting oxygen from your lungs, delivering it to your bloodstream, and extracting carbon dioxide from your bloodstream to your lungs so it can be exhaled. A large amount of dead space in the lungs results in lower lung function, which makes it harder to breathe.
During the test, the person breathes into a machine that fills the lungs with pure oxygen, then exhales for as long as possible. The amount of nitrogen exhaled is measured. The air in the Earth’s atmosphere is 78 percent nitrogen. Since nitrogen will not be part of the air breathed in, it will build up and sit in the lungs until exhaled. So if the air exhaled consists of more than 78 percent nitrogen, the difference determines how much nitrogen remains in the lungs.
The pulmonologist may ask the patient to continue to breathe pure oxygen in a normal breathing pattern for a few minutes after the test. This will measure how long it takes to breathe out the oxygen in your lungs. The test normally takes about seven minutes to complete if the patient is healthy, but it takes closer to 15 minutes for someone suffering from lung disease.
The nitrogen washout test is considered a safe test, with minor dizziness or shortness of breath being the only side effects. Other lung volume tests include the helium dilution test and the body box test.
In a helium dilution test, the patient breathes a mixture of helium and oxygen. In a body box test, the patient sits in an enclosed chamber and performs some small panted breaths. Although the body box test is the most accurate test, it is the most difficult to perform because it requires specially-trained technicians to operate the equipment.
If you or a loved one has been diagnosed with a lung disease and interested in learning about cellular therapy treatment options, please contact us at the Lung Institute to learn more or call (800) 729-3065.