Friday, March 18, 2016

Pulmonary Function Testing (PFT) Explained Clearly

Pulmonary Function Testing (PFT) is an important part of each visit with Pulmonologist for an Idiopathic Pulmonary Fibrosis (IPF) patient, and a part of daily life for the transplant recipient. The PFT tracks the progression of the scarring in the lungs for the patient, and the condition of the lungs for the transplant recipient.

Maybe I should take a quick moment to describe IPF before going on.  IPF is a disease that involves the progressive scarring of the lungs with no known cause.  At some point in the IPF patients history, their lungs received some minor damage.  It could have been from a fiber, chemical fume, dust, cigarette smoke, or even bird dander.  The initial damage is unknown with IPF.  Once the lung is damaged, the body heals the damage and creates a scar.  This is a normal body function and if it stopped there all would be well.  The issue with IPF (and other types of PF) is that the lungs don't stop creating the scar tissue.  The scarring continues to grow, the lungs shrink and the get thicker. I usually describe it as my lungs were turning into raisins.  As the lungs get smaller, and stiffer, you can not get as much air into them.  And as the lungs get thicker with the scar tissue, they don't transfer oxygen to the blood as well.  Two months before my transplant, my lung capacity was down to 44.6% of normal, and I could only transfer 45.2% of the oxygen that I could get into my lungs to my blood, hence my need for supplemental oxygen.

Pre-transplant, I hated doing the PFT.  For a basic test, you take as large a breath as you can and blow it out as forcibly as you can until your lungs are empty.  I would come close to blacking out when doing this pre-transplant, it would also trigger a cough attack at times.  More in depth PFT's have you sitting in a box breathing helium and performing several tests, not fun but necessary.

I now do a simple PFT at home twice a day.  A declining function test is one of the earliest indicators of issues with transplanted lungs.  The test is much easier to do now that I can breath :)

One of the best explanations of Pulmonary Function Testing that I have found is a series of videos by MedCram.

Pulmonary Function Testing (PFT) Explained Clearly is a series of videos produced for the Med student, but easily understood by anyone who has taken the tests.  These videos also do a good job of explaining the differences between restrictive (PF) and obstructive (COPD, Emphysema...) lung diseases.

These videos are well worth your time watching if you want to learn more about what all of the numbers mean on your reports, and why they do some of the things they do during the testing.


  1. Nice post. DH had to do the PFT before being vented too, although his was a muscle issue related to the ALS. I hated when he had to do that as well. So glad yours is now easy. :)NM

  2. It is much more fun to do them now. The trend is improvement :)

    Much nicer than the downward graph of failing lungs.