Broken peak flow monitor?

[lucia_m]

I monitor my peak flow daily. Recently I’ve been getting some (for me) unusually good results, which I’ve put down to being on a high- dose steroid inhaler for the past month or so. My personal best has been increasing, from 465 to 490 and then 520 in the last couple of days. I’ve also gone from needing salbutamol pretty much every day to being virtually symptom-free.

Obviously this has all been very welcome and I’ve taken it as a sign that the new dose is working and my control is improving. However, I’m starting to think something must be a bit wrong, as this morning I blew 670 on the first go - a freakishly good result for me, as a 5ft 2 female. Even without the asthma I doubt I could genuinely blow that much - my lungs just aren’t that big.

Could my peak flow monitor be broken, and do I need to start doubting my other, slightly more believable personal bests? Or is it possible to record freak results because of faulty technique, or whatever? I think I’ll give the Asthma UK nurses a ring next week for advice, but wondered if anyone here has had similar experiences.

[PMRPete]

There are so many different peak flow monitors, it is difficult to answer your question without more information. 670 certainly seems a bit high for you!

[lucia_m in reply to PMRPete]

Thanks. It's a mini Wright.

[PMRPete in reply to lucia_m]

Usually Mini Wright's under record rather than over as you suggest, it is thought that they are only accurate for 200 readings.

[Foxydebs]

Ask your asthma nurse for a new Peak flow monitor and try that one and see what results you get. I did get better Peak flows when I changed from seretide to flutiform.

[Joolstom]

I had a similar thing prior to Christmas and it turned out I had a broken peak flow. Best try to get a new one go peace of mind x

[Matman]

My Peak Flows been consistently better recently. Your Post, plus the replies, has led to a decision to get a Second Meter to validate. Also, would be helpful if / when results go the other way (i.e. lower score) because a faulty metre could just as well indicate worse than ‘true’ results.

One thing to be aware of is that Meters with wider mouthpieces may return a lower result than those with narrower ones, so maybe important to ensure that your replacement has the same width mouthpiece, as that change alone may vary your result to some degree.

[lucia_m]

Thanks for all the replies - very helpful.