Overinflation on PFT

[windbeat]

Hello,  

I recently had a PFT for mild SOB. I am a 28 year old male, 5’9”, 132 lbs. I smoked a pack a day for about 7 years and also have a history of heavy marijuana use.   I quit all smoking 3 years ago and now exercise regularly. My results are as follows:

SPIROMETRY:

FVC: 6.54
FEV1: 5.64
FEV1/FVC (%): 86
FEF 25%:  8.64
FEF 50%: 6.60
FEF 75%: 3.33
FEF 25%-75%: 6.03
FEF Max: 10.03
FIVC: 6.22
FIF 50%: 4.86
FIF Max: 4.97

For the sake of space I will just mention the following  results:

Pulse Ox:  96% (mine usually ranges from 95-99%)
TLC: 8.93 (131% of predicted—5.09)
RV: 2.28 (152% of predicted—1.50)
RV/TLC: 26 (23 predicted)
DLCOunc: 44.32 (135% of predicted—32.88)
DL/VA:  5.46 (predicted 4.99)
VA:  8.12 (123% of predicted—6.59)

The report states:  “The FVC, FEV1/FVC ratio and FEF25%75% are within normal limits.  The airway resistance is normal.  The TLC, FRC and RV are increased indicating overinflation.  The diffusing capacity is normal.  However, the diffusing capacity was not corrected for the patient’s hemoglobin.  CONCLUSIONS:  Overinflation without concurrent obstruction is of uncertain significance.  

Could this be emphysema or something else serious such as a prior pulmonary embolism/infarction that was never diagnosed(I once broke my foot and never had it treated)?  My echocardiogram is completely normal, but I do have an incomplete RBBB and right axis deviation (about 100 degrees), which I know can be due to the heart shifting due to hyperinflation caused by severe COPD.   May I ask your impressions and suggestions?thxs

[National Jewish]

A spirometry evaluation is a reasonable test for doctors to order in people with shortness of breath and a history of cigarette smoking.  However, there are many causes of shortness of breath, for example problems in the heart and even anemia.  In asthma, the breathing tests can be normal.  However asthma can worsen with exercise and breathing tests would need to be done with an exercise challenge to assess that.

Your breathing tests do not show significant COPD.  Some of the overinflation may be due to your past smoking.  This type of breathing test abnormality is not usually seen with shortness of breath.  Your results are not typical of pulmonary embolism.

Given the information thus far, spirometry before and after a cardiopulmonary exercise test might determine the problem.

[PhysBrit]

A patient with emphysema would have a reduced FEV/FVC ratio and a reduced DLcO, yours are both increased so they don't tally with the diagnosis of emphysema or COPD. If you were anaemic your DLcO would be reduced, which it isn't and your pulse ox is normal too.

[windbeat]

Thank you NJC-R.N. and Physbrit for your feedback and suggestions.  

My chest x-ray shows significant bilateral hyperinflation.  I had thought this was usually due air trapping due to emphysema, but I understand asthma may also cause this.  I hadn't realized that PFT's may be normal in asthma.  I am having a stress echo next week but will also request an exercise challenge spirometry for asthma.  

I almost hope it is asthma, because then perhaps I can treat this and improve.  Of course I don't really hope to have a disease--I'm just trying to communicate that I want to be able to alleviate my symptoms--namely SOB.  

Thanks again for the feedback.  I will post my progress and findings as I find out more.

[windbeat]

Just to update, I saw a pulmonologist and he said I definitely don't have copd/emphysema, which in itself has made me breathe easier--much easier.  I also had a stress echo, and though I haven't received the official report the impression I got was that it was normal.    

Sometimes I think when I eat too much or too much fiber my intestines enlarge, making it more difficult for my diaphragm to expand and possibly causing some shortness of breath.  Just a theory.  

The doc didn't think I have asthma, but I may ask for a metacholine challenge test just to rule it out for certain.