Help w/data collection - serum vs ear poke plasma-calibrated

This probably belongs on Think Tank but I need as many people to see it as possible.

I am looking for data comparing:

ear poke values obtained with your plasma-calibrated meters at the same time that your vet draws blood to send to an outside lab....

with

serum results obtained at a send-out lab such as Antech, Idexx, etc.

I am having a discussion about this with my VIN colleagues and this place is Data Central so I thought I'd ask here.

Thanks, all.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Lisa, this was done several years ago when I did a test with my OTU, Hope, and either Antech or IDEXX. Just cannot remember which of the two labs it was. I tested Hope, vet then drew blood, and I immediately tested her right after the draw . The OTU was off by 8 points. That is the regular OTU, not the 2 or the Smart or the mini.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Hope, I knew I could count on you for data.

If more data is posted by others, I will move this thread over to Think Tank.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Hi, Lisa and Hope ~

We're taking Butters to a vet appointment this afternoon for blood work. We plan to take our Relion Confirm and One Touch Ultra 2 along to do ear pokes at the time of blood draw to compare results. We'll let you know how it turns out.

"serum results obtained at a send-out lab such as Antech, Idexx, etc." -- Is this something we need to request or something our vet would typically have done by the lab he uses?

I'm very interested in hearing more results, too, Lisa.

Eva

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

It is important to make sure that the blood is allowed to clot for ~30 minutes and then is spun down and the serum is then separated from the clot.

Ask you vet if they routinely spin samples within 30-45 minutes of the sample being drawn.

Red cells eat glucose at a rate of ~10%/hour.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Eva, test before the vet draws and immediately after the vet draws.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

In re-reading this, why did you test twice? Just to get an average?

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

I wanted to see if there was any stress involved with blood draw. Peaceful with me, tested, vet comes in and takes her for blood and brings her back so I re-tested just to have that number because that is the blood number the lab would give back. Hope doesn't outwardly show any stress whereas Mishka is up front about it and lets you know ;-)

FWIW, I had also, for some unknown reason, went to using Bayer's Elite XL for a while. Going by those numbers Hope and Mishka were doing great so I ran a fructosamine. Not so great. Went back to OTU and started dosing by those readings and then ran fructosamine on both of them again and they both came back Excellent. None of that happens overnight as you well know, takes a few months, but have stuck with my trusty OTU ever since.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

I was thinking that it may have been to assess for stress but I don't think that the BG would reflect stress that quickly if it was just a matter of testing only a few minutes after the blood draw.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Well, I wasn't sure and wanted to cover the bases :roll:

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Lisa,

We just went through this about 3 months ago with one of our civies...Just for reference I tested Amon Ra with my Bayer Contour, off the same blood that my vet had collected from the blood draw...We were within 10pts of the test results. If it matters the test was Indexx. What I had him do was drop a bead of blood on my thumb nail after he was done drawing Ra's blood for the test, and tested the blood from there. Then I also did an ear poke, both readings on my meter were within about 7-8 pts.

Mel, Maxwell, Musette & The Fur Gang

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Hi, Lisa ~

Just got a call from our vet's office that the Antech blood glucose result was 160 from Butters' blood draw yesterday. Within three minutes of the blood draw, my husband did ear pokes to test our two meters. The Relion Confirm was 142 and the One Touch Ultra 2 was 143. I'm actually surprised that the OTU2 wasn't closer to the lab number. Strangely, this is one of the few times that our Relion and OTU2 gave such close numbers to each other. Wish my husband had taken another OTU2 reading, but enough stress already for sweet Butters. Next time, we'll test our Accuchek Aviva which usually tests quite a bit higher than our other two meters.

By the way, this wasn't a fasting blood glucose test. And I wonder if the blood glucose range tested will give different results for lab and meter comparisons.

Dr. Lisa, I'd be very interested to hear more as you collect additional data.

Eva

P.S. The vet tech was fascinated to watch how my husband did the ear pokes :smile: .

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

You probably don't want this data because it wasn't at the exact same time or blood sample.
My vet is 3 minutes from my house.
Last Friday, I tested J.D. before we left the house and he was 156. He had his biannual check up and blood drawn. We arrived home right at PMPS, so I tested then and he was 158.
The next day we received the blood results through IDEXX and the blood glucose was 170.
We use a OneTouch at home. So it was off by 12 to 14 points, including any vet visit stress.

Twice in the past, on two separate occasions, I have tested my OneTouch meter with whatever my vet uses, where we shared the same drop of blood, and the two meters were within 8 to 10 points. Sorry, I don't remember those numbers.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Good data because you did a pre-leaving the house and then when you returned and showed that his BG was not influenced by the stress of a vet visit.

Very good correlation. Thanks for the info.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Also good correlation.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

I used the AlphaTrak for 9 months. When I joined the Lantus Forum I used it for 3 1/2 months and switched to the ReliOn Ultima. I frequently compared the readings but the only record I currently have is from 5/26/10. At the vets for her yearly checkup, Tuffy BG with the AlphaTrak was 102, with the ReliOn Ultima it was 94. I never got a 50 point variance in all the time I compared them.

Lab IDEXX Glucose 120

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

I'm not sure how helpful these numbers will be. On 11/25 Gabby's AM test was 304. She tested at my vet's office at 363. This was pre-dental and on a reduced dose of insulin. I'll see if I can track down when they tested her. They were using the in house serum chemistry analyzer -- labs were not sent out. Our post-dental, in the door test was 334 (with bupe on board).

FWIW, Gabby does not travel well and is very stressed at the vet's office.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Ok, so far, it looks like the lab-generated serum glucose is a bit above the plasma-calibrated meters.

Plasma and serum should be pretty close to the same but the other piece of information that we don't have on each and every lab-generated value is....did the vet spin the red top tube down in a timely manner (within 30-45 minutes) and separate the serum....or not.

Or...did they send they use a clot tube or a regular RTT (non-clotting) tube and leave the red cells in contact with the serum.

In the latter case, however, the lab value should be LOWER since the red cells eat glucose. Lots of variables....

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

That would be ok since it is still using serum.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

I will call the vet on Monday and find out whether or not they spun it down within 30-45 minutes or used the clot tube or regular RTT tube.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

not sure if this is helpful or not, but fwiw, my husband checked his own BG with our Freestyle Lite at home and got 104. He got tested at a clinic lab about 30-45 minutes later and the result came back as 114.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Julie - I was kicking myself over the fact that I did not bring my meter with me when I had my blood drawn a few months ago for a routine panel. Next time I will bring it with me and check it when they draw my blood.

It sounds like your meter corresponded well with the serum result.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Hi, Lisa ~

"did the vet spin the red top tube down in a timely manner (within 30-45 minutes) and separate the serum....or not." -- Our vet said they did this within that time frame. Our vet's office used to use an in-house serum chemistry analyzer, but they told us it's cheaper to send the blood sample out to Antech Diagnostics. Wonder why that would be?

My husband asked why I think the lab's value is more accurate than our glucose meters. And I don't know...guess I just expect the lab to be more accurate. :?

We love Butters dearly and he's not a science experiment (all the time anyway :smile: ), but I find this fascinating, Dr. Lisa. And we will test different meters when we have lab blood work done for him.

Eva

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Chances are they won't be drawing a serum tube for a routine chem panel. The preferred specimen for chemistries is a green top tube with a lithium heparin anticoagulant. There are still a few tests that have to be done on serum but most labs that I know of are now testing on plasma. (and have been for quite some time)

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

I was going to share this with you Dr Lisa and thought it might be good to share this here with all. I took Morgaine to the vet on 3/16 as she had been sick and her Lab was 283, Vet's Alpha Trak was 247 and my Free Style Freedom was 140. Due to that variance I stopped using the FS and several others in the LL community found the same thing, much lower readings on the FS. We all thought our cats had much better control. I went ahead and did a comparison of 4 meters on myself for a few days and manipulated my BG since i am a type 1. The FS was consistently off well beyond the 20% variance. I know this is a little OT but I thought it relevant for this discussion. I have my data on the comparisons if you want it.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

I could swear that I saw a RTT but my memory is not the best. I will pay more attention next time. I had a bunch of tests run...panel...Vit D....lipid profile....folate....B-12....etc

Do they run the vitamin assays also on a GTT?

Thanks for the info above.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Not OT at all. In fact, good timing.

I was just working with a client who was using a Freedom Freestyle Lite and the cat's BGs were NOT in line with his clinical signs! Too low to match what the cat was showing.

Client compared the FFL with an Alphatrak and a Relion - the FFL was 100 points lower than the AT. The Relion was ~30 points lower than the AT which is acceptable.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Lisa:

I recently had Gracie at the vet and took my OTU. I checked her there and she was 212. The Antech lab result was 215.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

FYI, I have reported my personal data to Abbott's exec. for Diabetes care. I can't, of course, use the feline data but he is very attentive to me and is having his scientists take a look at my data. I have dealt with him before and he told me that there were few people who use the strips as i do, which is 8-10 times a day and therefore they seldom get reports/feedback with the kind of data I can provide. I will keep this board posted on what he has to say. The meter is clearly way off except at low numbers and it is a real problem for human diabetics so they have to take this seriously.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

At Weezer's appointment today the VestTest (IDEXX) result was 415 mg/dL, ReLion Micro was 319, FreeStyle Lite was 240. These results were all from the same sample.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

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. We tested the blood from the vial on my meter and got 161. We tested a sample from a healthy cat that was 65 on their Alphatrak...23 on my meter (Relion Confirm). We both thought my meter was bad. 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. 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. 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. This is good news for me because I can feel confident that my home test numbers are accurate.

I don't know if this is of any help to you, but I thought is was worth posting. 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.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

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.

Hmmm....quite a discordance.

Ok - you answered the question above - your vet is using an AT.

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.

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.

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.

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?

Thank you. I appreciate - all data is worthwhile.

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.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

Just a note...the AT reading DID change significantly on the ear blood...nearly 60 points. The vial was maybe 1/3 to 1/2 full.

Whatever the reason, I'm just glad that my meter seems accurate for home testing.

 

Re: Help w/data collection - serum vs ear poke plasma-calibr

The manual for the Confirm states:
The ReliOn® confirm blood glucose meter is referenced to a fresh
plasma sample. Your meter results may differ from clinical lab results. This
is due to normal variation.