Re: Help w/data collection - serum vs ear poke plasma-calibr
MikeysMom said:
I know this isn't exactly what you were asking for, but someone on the Lantus board suggested I post it here, because it was very surprising to me and my vet.
When I went on on Thursday for a check-up, Mikey was at 254 on my vet's meter and their lab equipment.
Which meter was your vet using?
When you say "lab equipment" I assume that you meant that the serum was tested - not whole blood. If this is the case then you are saying that a (assumed) plasma-calibrated meter matched a serum result.
We tested the blood from the vial on my meter and got 161.
Hmmm....quite a discordance.
We tested a sample from a healthy cat that was 65 on their Alphatrak...23 on my meter (Relion Confirm).
Ok - you answered the question above - your vet is using an AT.
We both thought my meter was bad.
That depends on if the Relion Confirm is plasma-calibrated (PC) or not. If it isn't, then a lower value is to be expected.
I got another meter (Relion Micro) I took a BG right before we left for the vet and got 273. Got to the vet and they pulled blood; we tested on their Alphatrak and my Micro. The Alphatrak read 233, the Micro...144.
Is the Relion Micro supposed to be a PC meter? I am tired and drawing a blank here. I think it is supposed to be. In fact, most of the newer meters are supposedly PC meters.
But even if it is not a PC meter, that is too much of a difference.
We tested again, same thing. No way he dropped 150 in a half hour with no insulin, as stressed as he gets! Then, by chance, I said something to the vet about if there could be a difference between capillary and venous blood, because I'd tested his ear.
The difference between capillary and venous blood is negligible. We have been discussing this on VIN. Some studies have shown venous > capillary and some have shown the other way around. In the end, it is not worth worrying about.
He didn't think so, but we decided to try an ear test. Alphatrak: 293, Micro 285. Retest, same. Vet actually goes to the computer to check on this, because the difference was marked. Hmmmmm.... Vet finally came to the conclusion that the venous blood was more than likely reading low because of the anticoagulant in the vial.
But didn't you compare the AT with the Relion on the vial blood? If it was the EDTA, why would it affect the Relion reading but not the AT?
I don't know if this is of any help to you, but I thought is was worth posting.
Thank you. I appreciate - all data is worthwhile.
My vet thought it was significant enough to put a note to do a direct test from an ear or toe instead of just testing the pulled vial with the anticoagulant.
Unless I am too tired here and missing something, I am not sure that EDTA is the issue here if the vial was fully filled.