Using Vitalograph asma-1 monitor

[ccccc]

Good morning all!*

*feeling slightly delirious after 8 steroids and 4 hours sleep last night due to my asthma...

I recently bought a Vitalograph asma-1 monitor as like many of you I find that my usual peak flow doesn't really pick up on how bad my asthma gets - had a bad week with the warm weather/pollen yet my PF has been stable- so as this records FEV1 too (which has been going up and down) I've been recording this and will take it to my next respiratory appointment in a few weeks.

I managed to find an instruction manual online (surprised it didn't come with one...) but I'm not only finding the PF reading is higher than the one I get on my usual Mini-Wright peak flow but the FEV1 is recorded as a number eg. 3.58 I know this is usually converted to a % when done in clinic but I cannot find anything online to do so as different manufactures seem to have different standards. Or perhaps I just haven't found the right chart. I don't mind just taking a list of readings but I would be interested to know what the FEV1 % is as that's usually what I remember. Anyone else use this?

[Lysistrata Administrator Community Ambassador]

HI,

Sorry to hear your asthma is playing havoc at night!

I've never had that particular digital monitor I don't think, but have an idea the asthma nurses use it in clinic. I've also used others and I have noticed that digital meters often tend to read higher for peak flow. I do have a personal best much better than predicted anyway, but my personal best is even higher by maybe 50l on the digital meter!

Regarding the %, that's presumably going to be % of your predicted best (so if your predicted best were 4.00l for example, 3.58l would be 90%). The machine probably won't show you that, you need to work out what percentage it is. You can calculate your predicted best here: patient.info/doctor/spirome...

Please be aware that predicted best FEV1, like peak flow, is very much an *average*. They tend to use it because you're not doing it often enough to build up an idea of your best, but your actual best may be lower or higher than the calculator shows based on all sorts of factors.

It's also worth bearing in mind technique with the electronic meters that do both PF and FEV1. Although the asthma nurses use them, the physiologist in my clinic who does full lung function tests, and who I honestly trust more than the asthma nurse or the cons on this topic, told me that it's hard to get an accurate reading for FEV1 and PF in the same blow. This is because the techniques are different (hard and fast for PF, more sustained for FEV1). You might want to consider doing the readings separately - for example sticking with your manual Mini-Wright meter for PF and just using the electronic one for FEV1 and recording that alongside.

There are probably videos that show you how to do FEV1 optimally. I know some specialists clinics use electronic meters for home monitoring, and they're also used in some clinical trials (often linked to an app), but I don't know how they train people to use them or how they address potentially different technique requirements. I have to say my attempts to use a different one were a disaster and my cons has now decided with no evidence at all that I can't use a Mini-Wright manual meter properly either (even though several of the team have said my technique is fine). So I'm a bit wary of them - but I know others have been fine! (Will also say my ability to actually do the test seems to reduce when I'm struggling - I not only get higher readings after I have Ventolin, they're also much more consistent).

[ccccc in reply to Lysistrata]

thanks for your reply, I am sticking with the Mini-Wright for the PF readings as I've always used this brand so will continue to. I'm learning that although the FEV1 readings are generally more reflective of how I feel sometimes I'm still blowing a decent reading but still not feeling too good. But as they say at the hospital it's only one part of asthma, though the more data I have to take with me the better I reckon.