Anybody who is new to any kind of breathing disorder may likely be asked to perform what is called a “PFT” test or Pulmonary Function Test. This provides your physician, or your specialist/pulmonologist with a baseline of how your lungs perform in a series of test situations.
Pulmonary Function Testing is not scary, but it can be a little tiring if you aren’t expecting it because the technician will be asking you to take lots of breaths, hold them, breathe in and out, blow out as hard as you can for some breaths, and do a lot of waiting in between. The test generally takes about an hour to complete. Taking all of these breaths in and out can not only make you dizzy, it can make you hyperventilate a little, but if you go in with the knowledge that this can happen, you will be less surprised if it does! You can make yourself rather anxious during these tests trying to do well — so the best thing to do is to go in as calm and relaxed as possible. Each test is repeated many times, so there is no chance of “messing up”. Be prepared for it to be tiring — get a good night’s sleep the night before, try to schedule your appointment for the morning, if possible. If you learn that you get lightheaded afterwards, learn to schedule your PFTs on a day when you have a light schedule.
Depending on what kinds of lung testing your doctor has scheduled for you (LAM patients will require different tests from asthma patients, and COPD patients may require other tests as well), when you get to the testing center, the technician will first check you in and go over with you what tests you have to do that day. He or she will likely give you a nose clip to plug off your nasal breathing, and a sterile mouthpiece collar similar to a piece of scuba equipment to fit inside your mouth that you will breathe into the machine with that will be testing your air volumes.
One standard and very common test is the FEV1, or Forced Expiratory Volume in 1 second. This is the amount of air that can be forced out of the lungs in 1 second. The range for healthy adults should be 80% to 120% of the average value. Other common parameters measured are Vital Capacity (VC) and Forced Vital Capacity (FVC).
In LAM, the FEV1/FVC ratio is important, as it is with other restrictive lung diseases, see your doctor for your own values and interpretations.
