Spirometry is a pulmonary function test that measures how quickly the lungs can move air in and out as well as how much air the lungs can displace. While other methods can be used to test lung function, including gas diffusion tests, residual volume measurement, body plethysmography, inhalation challenge tests and exercise stress tests, spirometry is most routinely used. When a patient has an abnormal spirometry test result, other more complex and expensive tests may be used to follow up.
Who should be tested?
How do spirometers work?
In a spirometry test, the patient breathes into a tight-fitting mouthpiece connected to the spirometer. Some test measurements require normal, quiet breathing. Others have the patient take a deep breath and, when told, exhale the air for as long, hard and fast as possible.
The spirometer records the amount and the rate of air that is breathed in and out over a specific period. Some spirometers have a transducer built in, while others require the patient to hold it. The transducer measures the pressure differential. Data is entered into an algorithm within the device, which calculates measurements. Most manufacturers use an algorithm that follows the American Thoracic Society guidelines.
Spirometry may be used to diagnose various lung diseases, such as asthma, bronchitis or emphysema; to determine the cause for shortness of breath; or to measure whether occupational exposure to contaminants affects lung function. Spirometry often is used to assess such therapeutic interventions as bronchodilator therapy or steroid treatment.
Some indications generally are not covered by Medicare, according to the American Thoracic Society. These include the following:
Spirometry measures the volume of air exhaled or inhaled over a specific time period. Some measurements provided by the test include:
Advances in technology
Early models were volume driven and required the physician to measure all data points himself. Today’s spirometers are smaller and flow based, thus reducing the risk of cross contamination. Spirometers now use ultrasound technology, which is independent of heat, humidity, gas composition and pressure, and helps eliminate errors caused by these variables. Ultrasound technology also eliminates the need for moving parts. There are no codes to enter, no screens to catch sputum and no disposables to calibrate. All interpretations and data calculations are done automatically within the microprocessor.
Spirometers can be customized to provide more or less information, depending on the needs of the physician’s practice. Today, data management reports can display data in graphical and tabular formats. Reports display predicted and actual changes in values. And, database queries help identify patients with common attributes.
Who are potential customers?