Your PFT’s test results are not consistent with the diagnosis of COPD. They are consistent with but not diagnostic of asthma.
I read somewhere that if your FEV1 and FVC are both in the normal range that your FEV1/FVC ratio does not matter. Is that true?
That is incorrect. So-called normal values are Mean Values. For a given individual his/her normal values may have exceeded the predicted values by 25% or more. In this circumstance, both FEV1 and FVC could be in the normal range with an actually low FEV1/FVC, indicative of obstructive lung disease, asthma or COPD.
Your test values are consistent with the diagnosis of asthma as is your cough. With so-called cough-variant asthma, routine PFT’s may actually be within the normal range.
A Methacholine challenge might be helpful in establishing the diagnosis.
DETAILS and SYMPTOMS:
I'm a 33 year old non-smoker. I was exposed to second-hand smoke as a child.
At the age of 13 I was diagnosed with exercise-induced asthma and given a puffer, which I used a little bit for a few months, but not again.
For the past 10+ years I've had a chronic cough, which I always thought was allergy related. Nine years ago I started allergy shots, which helped the cough, but still it never went completely away.
Over the past three or four years I've begun to notice minor breathing issues, particularly in hot, humid weather.
I recently went to the doctor to try to find a cure for the chronic cough and occasional breathlessness and did a spirometry test (see previous post). I also had a chest x-ray, which came back normal.
To clarify, in the original post my pre-bronchodilator fev1/fvc% was 72.
Expressed as a ratio, my fev1/fvc then was .72 (prebronchodilation)
Thanks so much David.
What would a spirometry result consistent with COPD look like? I've read that a post-bronchodilation FEV1/FVC% below 70% is consistent with COPD.
Is that the standard that you look for?
Do you consider the post-bronchodilation (as opposed to the pre-bronchodilation) FEV1/FVC% the key value in determining COPD (as it shows the reversibility of any obstruction)?
You said that my spirometry and symptoms were consistent with cough-variant asthma. I had read that for asthmatics the post-bronchodilation improvement would tend to be more exaggerated than mine was.
So, you are saying that a change (pre- to post-bronchodilation) of less than 9-12%+ for the FEV1 can still be asthma?
The most confusing part of my symptoms is the fact that I don't cough during the night. My doctor seemed to think that means my cough is a "habit cough." The reading I've done has pointed to perhaps a reflux-related cough.
Is it possible to have a "pseudo-asthma" that shows up on "borderline" spirometry like mine that is caused by mucus related to so-called silent reflux (also known as LPR, a variant of GERD)?
I read somewhere that some people's asthma is cleared up when their GERD or LPR (reflux) is treated effectively. Is that possible?
Could my spirometry improve to be normal pre-bronchodilation if I did have GERD and it was treated effectively?
The reason I am thinking that reflux could be contributing to the cough and breathlessness is that I tend to cough more after eating and when sitting down (in an upright position) or leaning forward. I tend to cough less when walking versus sitting and (as I mentioned earlier). Moreover, the breathlessness I experience tends to be more when sitting upright after a meal.
Perhaps I could have both cough-variant asthma and a form of reflux both causing these symptoms.
Thanks again, David, for your response. (Sorry for so many questions!) It's great to get answers from a professional like yourself.
More details: My doctor has put me on Pulmicort Turbuhaler (2X daily for a six week trial). At my next appointment I'm thinking of asking for a referral to an ENT specialist. I'm already scheduled to see an allergist in the fall.
One more question, David:
Is my pre-bronchodilation spirometry normal? Or is my pre-bronchodilation FEV1/FVC% of 72 outside of the normal range? Most discussions I've read have said that an abnormal spriometry would include a post-bronchodilation FEV1/FVC% below 70.
I haven't seen much about pre-bronchodilation values, other than mentions of the relevance of % improvements (post-bronchodilation) in FVC and FEV1 in diagnosing asthma.
You said that an individual could have cough-variant asthma with a normal spirometry (because with asthma obstruction varies).
Thanks again for your help and answers!
To simplify, in the post above, what I'm really asking is was my doctor accurate when he described my (pre- AND post-bronchodilation) spirometry as being "normal"?
(Though as you mentioned in the case of cough-variant asthma a routine PFT could be normal.)