PFT LAB

What are pulmonary function tests?
Pulmonary function tests - often referred to as “spirometry” are a group of tests that measure how well the lungs take in and release air and how well they move gases such as oxygen from the atmosphere into the body's circulation.


Why would I need a pulmonary function test?
Pulmonary function tests are done to:

• Diagnose certain types of lung disease (such as asthma, bronchitis, and emphysema)
• Find the cause of shortness of breath
• Measure whether exposure to chemicals at work affects lung function
• Check lung function before someone has surgery

They also can be done to:

• Assess the effect of medication
• Measure progress in disease treatment

How are the tests performed?
Spirometry measures airflow. By measuring how much air you exhale, and how quickly, spirometry can evaluate a broad range of lung diseases. In a spirometry test, while you are sitting, you breathe into a mouthpiece that is connected to an instrument called a spirometer. The spirometer records the amount and the rate of air that you breathe in and out over a period of time. For some of the test measurements, you can breathe normally and quietly. Other tests require forced inhalation or exhalation after a deep breath. Sometimes you will be asked to inhale the substance or a medicine to see how it changes your test results.

Lung volume measurement can be done in two ways:

1. The most accurate way is to sit in a sealed, clear box that looks like a telephone booth (body plethysmograph) while breathing in and out into a mouthpiece. Changes in pressure inside the box help determine the lung volume.
2. Lung volume can also be measured when you breathe nitrogen or helium gas through a tube for a certain period of time. The concentration of the gas in a chamber attached to the tube is measured to estimate the lung volume.

To measure diffusion capacity, you breathe a harmless gas, called a tracer gas, for a very short time, often for only one breath. The concentration of the gas in the air you breathe out is measured. The difference in the amount of gas inhaled and exhaled measures how effectively gas travels from the lungs into the blood. This test allows the doctor to estimate how well the lungs move oxygen from the air into the bloodstream.


How will the test feel?
Since the test involves some forced breathing and rapid breathing, you may have some temporary shortness of breath or lightheadedness. You breathe through a tight-fitting mouthpiece, and you'll have nose clips.


Do I need a referral for these tests?
Most insurances require a referral from your primary care physician to have a pulmonary function test done.  Please call our office if you have questions regarding referrals and appointments at 719-227-7800.


Reference: US National Library of Medicine