Re: MB/ PFT and Desire to confuse you all

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Ok, don't really want to confuse everyone but just to stimulate some thought and conversation. When you get your blood pressure checked or your cholesterol or pretty much anything else you always deal in absolutes. Now in PFT's we often quote as percent of predicted, adjusted for sex, height, ethnic background and age. It is my understanding some programs consider weight and some don't but that it definitely affects scores. Also some go so far as adjust DLCO's for hematocrit (hemoglobin related) even. Does that sometimes mislead us? Perhaps. We also know PFT's are impacted by things other than the lung restriction. For instance obstruction certainly impacts some. Well, for someone with hay fever, sinus issues, allergies and sometimes very heavy congestion that plays a role. Certainly does for one with Asthma. Even something as simple as having just eaten a large meal impacts breathing or other pains.

Think of this....does a 70 year old need less than a 50 year old? Probably not but normal again would reduce expectation. So the same FVC would show up as a higher percentage of predicted but have the same effect on their breath and body. Now, does a tall man need more than a short woman? Probably so, but I don't know. I imagine some more to service a larger body and larger organs. But probably the difference in what is needed is not nearly as much as the difference in what is expected.

So, why all this? Well, lets compare my number to Beth's. We are very close to the same functional level today. Both get around, travel, and we use very similar levels of oxygen. Using my april PFT's versus her June, both at Centers of Excellence so same standards.

So, FVC, I'm at 36% and she's at 59%. Sounds like I'm much worse. But, my actual is 1.78 versus her 1.83. Darn close isn't it?

Let's try another. TLC. I'm at 48% and she's at 59%. Sounds like I'm worse. But, my actual is 3.57 vs. her 2.67. Ok, I need more for larger body.

Ok, one more. DLCO. I'm at 42% and she's at 59%. Sounds again like I'm much worse. But, my actual is 11.48 versus her 11.7. Very close again.

What do I conclude? Very little except one thing. You know how you feel. Don't compare percentages to others. If I compared to many of you and just looked at the percentages I'd panic. But I'm a 6-0 man, aged 68. The most useful aspect is to track yourself. In this case I think we can very fairly say MB is at least remaining stable and perhaps improving. So read and track your PFT's but don't let them undermine how you feel. My PFT's are depressing, but I don't feel that bad.

If you want to read an excellent document on PFT's I suggest is as follows. I especially like the part at the bottom with interpretation of actualy numbers. Interesting table.

http://home.columbus.rr.com/allen/pft_interpretation.htm

> > From: Beth mbmurthayahoo (DOT) com>> Subject: Tired but happy> To: Breathe-Support@ yahoogroups. com> Date: Wednesday, June 11, 2008, 6:43 PM> > > Hi everyone!> As you all know I had my 3 month check today at Duke. I had a PFT the results of which really surprised me. The spirometry portion was improved somewhat. The FVC for instance went from 55% of expected to 59 % of expected. Nice but nothing to get too excited about. My volumes were all well above 50% of expected. My TLC for example was 59% of expected up from 45%. Very odd.> But most curious was my DLCO. Normally the diffusion doesn't really improve for us, it generally only goes down. Mine went from 47% of expected back in March to 59% of expected today. The respiratory therepist had me do everything over and over to make sure we were getting valid results. Needless to say I'm very happy with this. It may be a one time thing and I could go right back down next time but for now I'm very happy. > Everything else was good, I've lost 36 pounds, my crackle has not returned and Dr. on is very pleased. I don't have to go back for 4 whole months unless I run into trouble. > > After my appointment I met up with Ann from Charlotte and her husband. She mostly lurks on the board but she got in touch with me since she had an app't at Duke today too. So we had a nice chat over coffee this afternoon. Her tests went really well and she sees the doctor tomrrow. Keep your fingers crossed for her, she's nervous.> > So that's the story, I'm exhausted but relieved that I got good news! Thanks for the support everyone!> Beth > Age 48 Fibrotic NSIP 06/06> > Change everything. Love and Forgive > > >