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Pulmonary Function Tests (PFTs)

What are PFTs and why are they done?

PFTs are a group of tests that measure how well the lungs are functioning.  It allows us to find out how easy it is for a person to breathe and how effective their lungs are working at bringing oxygen to the rest of your body.  PFTs are ordered when a patient is showing signs of a lung problem, if they are exposed to certain substances in the environment or workplace, to monitor the progress of certain lung diseases such as asthma and COPD or to see how well your lungs are functioning before certain surgeries.

Full PFTs include spirometry which determines how quickly you can move air in and out of your lungs.  Your provider may also order a bronchodilator for a second spirometry to measure the benefit of the bronchodilator.  Full PFTs also include FRC or Volumes which measure how much air a patient’s lungs can hold, if there is air trapping and resting lung volumes.  Finally, a full PFT includes DLco or Diffusion which measure how well your lungs add oxygen and remove carbon dioxide from the blood.

PFTs are ordered because they are reliable, reproducible, and non-invasive.  PFTs provide information regarding an individual’s pulmonary physiology and give a quantitative measure of the severity of lung disease.

At Tucson Pulmonology, our PFTs are performed certified Respiratory Therapists.  They will take you through the test in one of our two machines.  One of our machines has a booth in which the door is closed for one test. All of the tests may take up to an hour.

How to prepare for a PFT  at Tucson Pulmonology and what to expect…

To prepare for a PFT, do not use your bronchodilator (rescue inhalers) for at least 4 hours prior to your testing time, stop using your daily or twice daily inhalers at least 12 hours before your test, and do not consume caffeine for at least 6 hours before your test.  All other medications are OK to take as prescribed and you can eat a light meal up to 2 hours before your test.  Rescue inhalers should be brought to your appointment.

You will be brought back with one of our certified Respiratory Therapists to a separate room.  Nose clips will be used to ensure that air does not pass through your nose during the tests as you breathe into a mouthpiece that is connected to a recording device.  Your test may include up to three different sections as described above.  It is very important to follow the directions given to you by our Certified Respiratory Therapists.