Whole blood and plasma meter readings

Home Forums Living with type one Whole blood and plasma meter readings

Viewing 18 reply threads
  • Author
    Posts
    • #9939
      Tim
      Keymaster

      @Lizz mentioned the difference between whole blood and plasma readings on blood glucose meters here https://www.shootuporputup.co.uk/2010/07/review-%E2%80%93-bayer-contour-usb/#comment-2780.

      The Intermaweb tells me that whole blood tests are typically approximately 12 per cent lower than plasma tests. The glucose content of whole blood is usually lower than the glucose content of plasma.

      Does anyone find this a problem?

    • #12166
      lizz
      Participant

      To save you having to go to the link this is the gist:

      After Tim’s review, I went to look at the contour USB info and discovered it does indeed have the software available to download info to a Mac, unlike all other pumps and meters. I asked my lovely nurse and she happened to have a voucher and voila one turned up last week.
      I haven’t done a graph readout yet as I’m waiting till I have enough results, when I’ve got some more strips from the Dr.

      BUT the very best thing about this meter I have to say is that it reads WHOLE BLOOD!!!!! Who was saying they have to all read plasma now? This is so much better, I hadn’t realised how much trying to adjust the reading all the time was doing my head in.

      And what’s more I’m REALLY angry at Accu-Chek for deciding to change the way my blood sugars are displayed without properly explaining it, and for what reason, it just doesn’t make any sense to me at all. I’m comfy with knowing that 4 is low and that my pump is going to add more insulin in to a reading above 16. It’s so hard in the middle of the night to start trying to subtract 12.5% from a blood glucose of 17.1 so that too much insulin isn’t given. Even if I had received the promised chart to calculate the difference there’s no way I’d remember to take one up with me every night.

      I was quoted that the actual readings I am used to are 10% lower by my nurse, 12.5% lower by Accu-Chek, and I’ve just read on an Australian website the figure is anything from 10 -15% lower.

      GGGrrrrrrrrrrrrrrrrrrrrrrr. Why isn’t more being said about this?

    • #12167
      Anonymous
      Inactive

      @lizz Can I ask which Accu-chek meter you were using? I’ll be honest an say I have not heard of whole blood v plasma, so really interested to learn more.

      I have a humble aviva with me.

    • #12168
      lizz
      Participant

      Accu-Chek Aviva. Look at the boxes of blood test strips and see if it has a yellow square or a green square with diagonal black lines on it. If so, your meter is giving you plasma readings, not whole blood.

    • #12169
      Anonymous
      Inactive

      Right got that, thanks. The manual suggests that it is whole blood. ;-) but read the info sheet that comes with the strips as per your instructions, confirming that indeed the measure plasma.

      What next? When using the aviva you would knock of 12.5% off each reading?

    • #12170
      Cecile
      Participant

      Most new meters (Bayer‘s included) are supposed to give plasma-calibrated values – Roche persisted with whole blood values a bit longer than other manufacturers, so their vials are still required to carry @lizz‘s Mark of the Beast :D (I participated in a meter trial at my hospital in 2009, when only Roche’s meters still gave whole blood readings)

    • #12171
      lizz
      Participant

      But in the booklet that came with my new Contour USB, it says in large letters:

      The CONTOUR USB blood glucose monitoring system, (meter, test strips and controls) is intended for self-testing by people with diabetes and by healthcare professionals to monitor glucose concentrations in whole blood.

    • #12172
      lizz
      Participant

      Well – that’s what I was trying to do Mike, but at night trying to take 12.5% off of a reading that is too high and wondering if that makes it come under or over 16, or when I am low when I don’t think well at all, it becomes rather difficult and I don’t see why I should have to do it. I’m not suddenly after 30 years of blood testing going to be able to readjust my thinking to being low under 4.5 for example.

    • #12173
      lizz
      Participant

      Although – just read some info on the internet and it says the readings are: Test Result: Referenced to plasma/serum glucose.

      So does that mean they are readings for plasma?

      In that case, why are the factory settings for ‘low’ blood sugar still 3.9?

      Also, just did some searches, and found several pages where people are confused about differing blood readings form different meters. It’s clear that are comparing plasma readers with whole blood readers and have no idea that they are.

    • #12174
      Cecile
      Participant

      Whole blood (unless you’ve been whizzing around on the carousel :)) is what you put in, but results these days are all plasma-calibrated…

    • #12175
      Anonymous
      Inactive

      Now i’m simply Confused.com :-/

    • #12176
      lizz
      Participant

      So I go back to… why has it been changed? I have read that hospitals use plasma readings. And to make sure we are all going by the same system, we have been switched over to plasma as well. But the only reading I am ever given at hospital is my HAb1. There is no conceivable way that I am going to be muddled by a plasma reading from hospital and a whole blood reading I have received myself. So who is being helped here? Certainly not me.

      Oh, and what is more, they read the glucose in whole blood and then CONVERT it to what it (probably) would be if the meter had been given a plasma sample!

    • #12177
      Hairy Gnome
      Participant

      I’ve just read the insert that comes with the test cassettes for my A-C Mobile, and next to a drawing of a little stripy box it says, “This test cassette delivers results that refer to plasma as per IFCC, and the symbol [on the box] distinguishes it from earlier test cassettes that were subject to a clinically relevant maltose interference.” I assume from that, that the change was to correct an inherent error when testing whole blood. On the other hand, I have been known to be wrong! :)

    • #12178
      lizz
      Participant

      They changed to reading plasma some time ago, and at that time to differentiate (although clearly most people have no idea what it actually meant) a yellow square with diagonal lines was put on the box. Then they found that people taking some drugs were getting results that were inaccurate, and changed the strips so that they were ok for people taking these drugs, and instead of a yellow square they changed it to a green square with diagonal lines which means that the strips are ok for people using maltose containing or maltose producing products, and to tag the fact that they are plasma reading not whole blood reading. Although, as above, they don’t read plasma, they read whole blood and convert the reading.

    • #12179
      Anonymous
      Inactive

      @lizz & @teloz : You guys have now truly lost me! Do we know if eating Maltesers before testing has an impact?? ???

    • #12180
      lizz
      Participant

      Some type 2s use blood testing sticks and its their drugs 9maltose based or maltose producing) which made the strip readings inaccurate.

    • #12219
      Hairy Gnome
      Participant

      At the end of the day, it doesn’t really matter what is producing the reading, the point is, that you can find out if your readings are high or low and medicate accordingly. It’s the number that matters, not where it’s come from. It’s like measuring a carpet, you can measure in feet and inches, or metres and centimetres, but as long as you consistently use the same units, the result is the same. If you know, or have been told, that a meter reading of 6 is the optimum, any deviation from that requires attention. It doesn’t matter if it’s 6 mmol/L, 6 apples, or six elephants, 6 is good, everything else is wrong. :D

    • #12221
      lizz
      Participant

      But if you are used to 6 being the optimum and then find actually it’s suddenly changed to 6.9, and your meter reads 7.5, I suddenly find my brain is confused – in the past if the meter read 7.5, I’d do a correction. But now, it’s so near optimum, I wouldn’t need to – but I’d still worry about it. and not be able to work out how much above it would need to be before I’d instinctively know I should do a correction. Everything has suddenly changed for me, it’s not that easy at all.

    • #12226
      Hairy Gnome
      Participant

      I see what you mean now @Lizz, same meter, different strips different readings, I would definitely have a problem getting my head round that! Or as someone might have once said, “That way lies madness!” :P

Viewing 18 reply threads
  • You must be logged in to reply to this topic.