If you’re having shortness of breath, wheezing and trouble taking in enough oxygen your doctor might request you have a pulmonary function test. A Pulmonary function test, or PFT, is a group of tests that measures how well the lungs take in and release air and how they move oxygen into the blood.
Why the test is performed
Pulmonary function tests are done to:
1. Diagnose certain types of lung disease, especially asthma, bronchitis, and emphysema.
2. Find the cause of shortness of breath.
3. Measure whether exposure to contaminants at work affects lung function.
4. Assess the effect of certain medications.
5. Measure progress in disease.
Lung volume measures the amount of air in the lungs without forcibly blowing out. Some lung diseases (such as emphysema and chronic bronchitis) can make the lungs contain too much air. Other lung diseases (such as fibrosis of the lungs and asbestosis) make the lungs scarred and smaller so that they contain too little air. Testing the capacity allows doctors to estimate how well the lungs move oxygen from the air into the bloodstream.
How is the test performed?
Also known as a PFT, spirometry, spirogram or lung function test, in the spirometry test, you breathe into a mouthpiece that is connected to an instrument called a spirometer, like the Nellcor Puritan-Bennett Renaissance II Spirometry Pulmonary Function Test. The spirometer records the amount and the rate of air that you breathe in and out over a period of time.
The tests can be performed one of two ways; you can breathe normally and quietly or forced inhalation or exhalation after a deep breath.
Lung volume measurement can be performed two ways:
- The most accurate way, sit in a sealed, clear box, like the Morgan Body Box 5000 Series Pulmonary Function Test, while breathing in and out into a mouthpiece. Changes in pressure in the box help to determine the lung volume.
- Or, breathe nitrogen or helium gas through a tube for a predetermined period of time. The concentration of the gas in a chamber attached to the tube is measured to estimate the lung volume.
Results
Normal values are based upon your age, height, ethnicity and sex. Normal results are expressed as percentage. A test is considered abnormal if it is less than 80% of the predicated value. Abnormal results can mean that the patient has some chest of lung disease. For your facilities pulmonary function test equipment review The Physician's Resource state-of-the art selection.