Spirometry measures the amount of air you can inhale and exhale. It also measures the speed of action of the tail. Spirometry results, if below average, indicate that your lungs are not functioning well.
Whenever you come to take the test:
The nurse or technician will give you specific instructions on how to perform the test. Listen carefully and make sure you understand everything that is said. Improper testing leads to incorrect results.
A clip is placed on the nose to close the nostrils.
The nurse or technician will ask you to take a deep breath and blow into a tube connected to a spirometer for as few seconds as you can. You may feel short of breath or dizzy for a moment after the test.
You need to do this test at least three times to make sure the results are accurate and consistent.
If your internal medicine doctor prescribes an inhaler to open your lungs (bronchodilator) after the initial test, you will need to wait 15 minutes and take the next test for a new measurement. In this way, the doctor can compare the results of the two measurements and conclude whether the drug used to dilate the bronchi has improved airflow. Each of these tests usually takes less than 15 minutes.
How to prepare?
Follow your doctor’s instructions on whether to avoid inhaled medications or other medications before testing. Other items include:
Wear loose-fitting clothing that does not interfere with deep breathing.
Avoid eating too much before the test, as this will make it harder to breathe.
Spirometric measurements include:
Mandatory critical capacity (FVC). Breathe as much air as you can after deep breathing. If the result is less than normal in FVC, it indicates shortness of breath.
Forced expiratory volume (FEV-1). The amount of forced exhalation is how much air you can blow out of your lungs per second. Doing this test is a good way to measure the severity of respiratory problems. A low FEV-1 value indicates a significant obstruction of FEV-1.