Peak flow averages question.

[Fuzzymooch]

Saw nurse this morning who told me she doesn't think I have asthma because although the preventer inhaler I was given has made my peak flows go up I get symptoms when my peak flow is above the average for my age height weight etc (450) and I don't feel I'm my normal self until I'm like 470-500. See specialist in Feb. More confused than ever.

[EmmaF91 Community Ambassador]

My predicted is 440. My best is 590-630. I have severe brittle asthma and technically start to get issues if my PF is 450-470 (unfortunately I’ve been so bad for so long I now don’t recognise an issue until I’m below 50% which gives me a lot of problems).

Not every asthmatic has a PF that drops. And a predicted score is not representative of an individual. The average takes in those who smoke, who have never exercised and who have different issues (and also come from a different country and a different time period). If you do a lot of sport or a sport at high level, sing or play wind instruments (to name just a few) you will have a higher than predicted. The fact that your PF has improved with inhalers indicates it may be asthma.

I hope that helps. Good luck with the specialist

[Bienkie in reply to EmmaF91]

Thank you so much for that.... It makes so much sense! My pulmonologist used to tell me my PF is 'practically normal' so he's not sure what I'm complaining about. I used to feel such a fraud! Thank you again.

[Lysistrata Administrator Community Ambassador]

I'm another like Emma with a best much higher than predicted - 630 Vs 450-470, played the oboe for years.

Mine also does not drop neatly in any way despite having severe asthma (I can be in A and E having a bad attack and still over 50% of my best), so I have had a lot of hassle about it over the years!

My favourite was the triage nurse who told me that only men could have my alleged best peak flow so he wouldn't use it because I couldn't have a best that good. It's true that the AVERAGE man does have a higher best peak flow than an AVERAGE woman of the same age and height...but really not how it works on an individual level. I'm also taller than the average woman - sorry any really tall women out there, according to this nurse you can't exist, only men can ever be that tall!

If I had the breath I would tell them what Emma said and give them a lecture on what average actually means.

Hope the specialist is more helpful than this nurse, fuzzymooch.

[Fuzzymooch]

Thank you. My logical brain said all of that, I even mention that I've been riding and looking after horses since 5 so possibly had a large lung capacity given how much I do, never smoked either. Was told that because we don't know that for sure we have to use predicted. I see a specialist in Feb for some answers hopefully.

[EmmaF91 Community Ambassador in reply to Fuzzymooch]

🤦‍♀️🤦‍♀️. Your best PF is easy to work out... it is literally your best score (hit within the last 6-12 months I think as it naturally changes with age as well... mine was 630 but cause i recently haven’t been well and when i was i forgot to check it I’m now technically 590 but hoping when my lungs calm I’ll be back at 630).

Good luck in feb

[Yellow75]

Peak flows are variable, the other thing to note is that it only really measures large Airways and not smaller ways. You may have inflammation in smaller airways that affects how feel but not picked up with peak flow

[hilary39]

I was going to say the same exact thing as Yellow75. I have very severe asthma and most of it manifests in my small airways so my peak flows are usually pretty stable. I wish more doctors and nurses were educated on that fact!!!

[Fuzzymooch]

That's really interesting, didn't know that. I've not been officially diagnosed with anything yet but I get breathless, wheezy and irritable when I feel off. I also get an odd feeling in my chest (usually, but not always in my lower right lung area I had a nasty chest infection in). Sort of like a fizzy feeling, or vibration, hard to discribe. Nurse has always maintained she doesn't think it's asthma, but at least one gp I saw was sure it was and another is on the fence. That combined with a chest infection that took ages to clear got me the referral.

[Superzob]

Sorry you have a nurse and pulmonologist who think everybody is "average"! You see so much of it on this forum. I won't add to the very sound advice given by others, other than to say that your Feb appointment should include spirometry, which should determine what's going on.

[Lysistrata Administrator Community Ambassador in reply to Superzob]

Just to add that I would hope someone does it with reversibility at some point if they haven't! Ie do it, take reliever, wait 15 mins, do again. They too often skip this if the first part is 'normal' - but as mentioned above it doesn't mean it is your normal and you can still get a lot of reversibility from a supposedly normal initial result. I feel way too many healthcare professionals treat asthma like COPD - asthma is VARIABLE! I can have a peak flow of 500 and still get 20% reversibility after using reliever - the cut off for asthma is usually about 15% increase post reliever.

[Fuzzymooch]

Hope so. Had spirometry before done by the same nurse who said it was fine and I didn't have asthma at that point, but since I was on a good day it was inconclusive.

[Lysistrata Administrator Community Ambassador in reply to Fuzzymooch]

Probably should have replied with my comment above to this one - a one off reading when you are fine is not much help in asthma. I think this nurse is treating it like COPD where you would expect to see it lower all the time.