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PFT's
- Thread starter anonymous
- Start date
<blockquote>Quote<br><hr><i>Originally posted by: <b>Anonymous</b></i><br>Emily,
Actually, it is the FEF(forced expiratoy flow) 25-75, moot point I know. What they do is they take the first 25% and the last 25% and throw it out. That leaves you with mid-low airways. machines actually break it down further but docs rarley focus on it. PFT's are amazingly easy to read, considering some doc charge $40 to read them. It takes about 5 seconds to read one and I could teach anyone how to read them in about 5 minutes.
Luke I would love to know what some of the other numbers mean they only worry about the FEV1, FVC and my old doctor the 25-75 but I would love to know what the others mean for my own sake.
Thanks Shavonica
19/F with CF
Luke 29/cf a registered respiratory therapist who no longer practices<hr></blockquote>
Actually, it is the FEF(forced expiratoy flow) 25-75, moot point I know. What they do is they take the first 25% and the last 25% and throw it out. That leaves you with mid-low airways. machines actually break it down further but docs rarley focus on it. PFT's are amazingly easy to read, considering some doc charge $40 to read them. It takes about 5 seconds to read one and I could teach anyone how to read them in about 5 minutes.
Luke I would love to know what some of the other numbers mean they only worry about the FEV1, FVC and my old doctor the 25-75 but I would love to know what the others mean for my own sake.
Thanks Shavonica
19/F with CF
Luke 29/cf a registered respiratory therapist who no longer practices<hr></blockquote>
Shavonica,
To answer you question vaguely. There are 3 parts to a full PFT. Spirometry, Plethysomography(body box), and diffusion. The first thing to remember is that maybe with the exception of asthma you can't "diagnose" a disease with a PFT, it is only a piece to the diagnostic puzzle.
The spirometry has 3-4 numbers doc's concern themselves with;FEV1, FVC, FEV1/FVC and FEF 25%-75% and sometimes PEF(peak expiratory flow). As important as the nummbers is graph that it makes, a sort of lop sided loop. You can notice a disease process just by looking at the loop.
FEV1 is the amount exhaled in 1 sec- tells ostructive lung disease, normal >80,mild 67-79, moderate 55-66, <55 severe
FVC the amount of air you can get it, tells restrictive disease, use above values
FEV1/FVC determines how one process effects the other, example we are obtructive first, mulitple infections cause fibrosis causing restriction second
FEF 25-75 is a hard one to look at because it is sort of vague>60% is considered normal, ithe middle half off the test, mid-small airways.
PEF tells obstruction as well, it also tells the tech doing your test your effort level, so they can tell if someone is "cheating", awful I know but someone trying to get black lung money will do it!
Plethysmography shows lung volumes and resistance, this is very useful in conjunction with spirometry. This breaks down further by "section" for lung volumes and can help determine disease involvement
Diffusion shows oxygen transport through the lung, your either normal or not, ours is normally high because of bloody sputum.
It is hard to break it down over an email, if you have results you want my advise on let me know.
Keep in mind when doc's look at ours they are not diagnosing but trending for treatment effectiveness and need.
Luke.
To answer you question vaguely. There are 3 parts to a full PFT. Spirometry, Plethysomography(body box), and diffusion. The first thing to remember is that maybe with the exception of asthma you can't "diagnose" a disease with a PFT, it is only a piece to the diagnostic puzzle.
The spirometry has 3-4 numbers doc's concern themselves with;FEV1, FVC, FEV1/FVC and FEF 25%-75% and sometimes PEF(peak expiratory flow). As important as the nummbers is graph that it makes, a sort of lop sided loop. You can notice a disease process just by looking at the loop.
FEV1 is the amount exhaled in 1 sec- tells ostructive lung disease, normal >80,mild 67-79, moderate 55-66, <55 severe
FVC the amount of air you can get it, tells restrictive disease, use above values
FEV1/FVC determines how one process effects the other, example we are obtructive first, mulitple infections cause fibrosis causing restriction second
FEF 25-75 is a hard one to look at because it is sort of vague>60% is considered normal, ithe middle half off the test, mid-small airways.
PEF tells obstruction as well, it also tells the tech doing your test your effort level, so they can tell if someone is "cheating", awful I know but someone trying to get black lung money will do it!
Plethysmography shows lung volumes and resistance, this is very useful in conjunction with spirometry. This breaks down further by "section" for lung volumes and can help determine disease involvement
Diffusion shows oxygen transport through the lung, your either normal or not, ours is normally high because of bloody sputum.
It is hard to break it down over an email, if you have results you want my advise on let me know.
Keep in mind when doc's look at ours they are not diagnosing but trending for treatment effectiveness and need.
Luke.
I
IG
Guest
My last PFT... I'm almost 2 years post tx.
120 lbs.
18 year old female
FEV1=100%
FVC=89%
%FEV1= 113%
FEF 25-75=121%
PEF=123%
FEV3=93%
120 lbs.
18 year old female
FEV1=100%
FVC=89%
%FEV1= 113%
FEF 25-75=121%
PEF=123%
FEV3=93%
Hey you don't know that for sure! i've been in the 40's for 4 years. They just slowly dropped and dropped and then stabilised. Before Christmas they went down to 28. I was considered for transplant but now they've gone back to 41%. Its amazing what can happen! Be positive and don't lose hope!<img src="i/expressions/rose.gif" border="0">
Luke
I would be interested to learn more about the results of PFT"S. I am the parent of a young adult. At the childrens hospital the results of PFT's were in % predicted. We were given the % of fev1 fvc and fev1 was the figure they used being the amount of air you can get out in one second and identifies obstruction?? Often they said her lower airways were restricted and I remember it was the 25-75.
I always felt I understood where she was at in %. Since transferring to the adult hospital, they use an ancient machine and just give two figures ie 1.22/1.84 on admission 2.0/2.5 on dishcarge. I believe this is the first figure being fev1, 2nd fvc, am I corrrect? Not that it means much to me and young adults don't often tell their parents or even remember the figures themselves cos lets face it 1.53 over 1.99 is alot harder to remember than 50% or whatever. I have been told that they don't say a % because that is measured against others- % pred compared to people w/out CF and it is of no value as an adult needs to know their own fev1 fvc to know where they stand. Can u see where I am coming from and why does everyone else talk in % and is their a way to convert the two figure into a percentage? Does it involve height, age etc? I went to a cf conference last year and everyone from all over the world used %.
Thanks Mate
TJ
I would be interested to learn more about the results of PFT"S. I am the parent of a young adult. At the childrens hospital the results of PFT's were in % predicted. We were given the % of fev1 fvc and fev1 was the figure they used being the amount of air you can get out in one second and identifies obstruction?? Often they said her lower airways were restricted and I remember it was the 25-75.
I always felt I understood where she was at in %. Since transferring to the adult hospital, they use an ancient machine and just give two figures ie 1.22/1.84 on admission 2.0/2.5 on dishcarge. I believe this is the first figure being fev1, 2nd fvc, am I corrrect? Not that it means much to me and young adults don't often tell their parents or even remember the figures themselves cos lets face it 1.53 over 1.99 is alot harder to remember than 50% or whatever. I have been told that they don't say a % because that is measured against others- % pred compared to people w/out CF and it is of no value as an adult needs to know their own fev1 fvc to know where they stand. Can u see where I am coming from and why does everyone else talk in % and is their a way to convert the two figure into a percentage? Does it involve height, age etc? I went to a cf conference last year and everyone from all over the world used %.
Thanks Mate
TJ
TJ
the problem with using "true" numbers is that our predicteds change a little every year. Predicted levels are based on height, weight, gender, even race. To complicate it even further, not everyone uses the same predicted values. (E.G. in the US for adults and young adults we use Knudson as the reference). From center to center the true numbers are more important than the predicted because of this very issue. As a trending tool for your doc predicteds are an important marker of when to treat. The hospital your child went to has to have the ability to determine the predicteds, they just aren't telling you what it was. You just need to ask.
Luke
the problem with using "true" numbers is that our predicteds change a little every year. Predicted levels are based on height, weight, gender, even race. To complicate it even further, not everyone uses the same predicted values. (E.G. in the US for adults and young adults we use Knudson as the reference). From center to center the true numbers are more important than the predicted because of this very issue. As a trending tool for your doc predicteds are an important marker of when to treat. The hospital your child went to has to have the ability to determine the predicteds, they just aren't telling you what it was. You just need to ask.
Luke
TJ,
This is a website from one of the leaders in the US, actually it is the hospital that diagnosed me in 1975.
This should help...
<a target=new class=ftalternatingbarlinklarge href="http://www.hopkinsmedicine.org/pftlab/predicted.html
">http://www.hopkinsmedicine.org/pftlab/predicted.html
</a>
This is a website from one of the leaders in the US, actually it is the hospital that diagnosed me in 1975.
This should help...
<a target=new class=ftalternatingbarlinklarge href="http://www.hopkinsmedicine.org/pftlab/predicted.html
">http://www.hopkinsmedicine.org/pftlab/predicted.html
</a>