Spirometry Q & A

Q. What is Spirometry?

This is the most common of the Pulmonary Function Tests (PFTs), measuring lung function, specifically the measurement of the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. Spirometry is an important tool used for assessing conditions such as asthma, cystic fibrosis, and COPD.  The spirometry test is performed using a device called a spirometer, which comes in several different varieties. The most commonly used guidelines for spirometric testing and interpretation are set by the American Thoracic Society (ATS) and the European Respiratory Society (ERS).

Q. What to expect at your visit?

You will be asked to take the deepest breath you can, and then exhale into the sensor as hard as possible, for as long as possible. It is sometimes directly followed by a rapid inhalation (inspiration), in particular when assessing possible upper airway obstruction. Sometimes, the test will be preceded by a period of quiet breathing in and out from the sensor (tidal volume), or the rapid breath in (forced inspiratory part) will come before the forced exhalation. During the test, a soft nose clips will be used to prevent air escaping through your nose. Filter mouthpieces will be used to prevent the spread of microorganisms, particularly for inspiratory maneuvers.

The test involves having you blast out at least 3 acceptable spirometry maneuvers. Then, administering a bronchodilator (inhaler) before performing another round of tests for comparison. This is commonly referred to as a reversibility test, or a post bronchodilator test (Post BD), and is an important part in diagnosing asthma versus COPD.

Q. How long does this test take?

The test usually takes 45 minutes, which includes pre and post bronchodilator maneuvers.