Peak flow confusion

Sorry, seem to have been on here a lot and posting a lot recently! Apologies in advance for length, I don't do short ;)

I'm a bit confused though. Due to see consultant on Thurs (finally!) and while I've been keeping a PF diary for the last month, I also decided to get out my 2-week diaries from last year to take along. These were taken when my asthma (if it is that) was not as bad as it is now - some breathlessness but not every day and no cough, plus I could still do pretty much everything normally whereas now I'm finding some things I can't do (like walk at my normal speed) and feel pretty rubbish and breathless after long walk on Saturday (no infections, colds or anything recently).

Also taken with the same meter. Different medication - the earlier of the 2-week ones is a trial of Clenil 800 mcg/day, the second Clenil 800 mcg/day plus Serevent 50 mcg/day. I noticed no improvement in symptoms with either of these, and these diaries were what led my previous gen resp consultant to say it wasn't asthma.

However, I've noticed that the first one starts at 340 and goes down to 300, not getting above 450 for the 2 weeks; the second lot (not continuous) is 450-550! I know this is good for what I'd be predicted for age/height and it's relative but my recent best (post-lots of Ventolin), when it's been much worse than it was before, was 660, and during this last couple of not good months it's rarely gone below 500 (I get stuck for days and days on 540)! I'd put the weirdly high PF down to singing/oboe playing and if you take 660 as best it's not brilliant, but HOW is it better than last year when I felt so much better?!

Worried now that this cons. is going to say not asthma as well when s/he sees this and leave me as puzzled as ever. Has this happened to anyone else? I know PF is not always a reliable guide but I don't understand how it can have gone up so much when the symptoms have gone down.

Thanks for reading all this and in advance for any replies.

3 Replies

  • These are completely wild guesses and probably totally wrong, but I have two possible (I emphasise the possible, there's no medical knowledge to this, just logical thinking) reasons:

    1. I looked at your age on your profile - for women, predicted peak flows (I know yours is well above, but I expect it would follow a similar pattern, just higher) increase through childhood, teenagers and early adult, peaking at 30 years (there's no hope left for me... :D). Based on that, everything else being equal, you would expect your peak flow this year to be better than last - but maybe not as 'better' as it is.

    2. Have you had more input from docs/nurses this year which 'may' have helped your peak flow technique resulting in more accurate readings now?

    As I say, just random thoughts...

  • HI Ratty,

    Thanks for your reply. The age thing never even occurred to me - I'm used to thinking of things more or less stopping after puberty, so maybe age has contributed.

    I did think after I posted that perhaps my technique has got better - even now my first blow when I take PF is lower and they go up. Even though I should have known how to do them as I had asthma when I was younger, I found doing PF properly quite difficult - doctors were always looking and saying 'you can do better than that'. Bizarrely, I think it's the singing/oboe again - though they do help with actual lung function, they don't help with PF technique, because you're taught slow, controlled breathing out, not the short sharp breath you need for PF. I'm used to conserving my breath rather than letting it out all at once.

  • Peak flow confusion.

    Hi I'm on clenil 2oo inhaler and my peak flow goes up and down between 200 and 300.

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