POC not reading INRs correctly

[Aggie85]

This isn't regarding home testing but is about machine testing, so I hope I'm posting this in right place. It will ultimately affect if I'm able to even switch to home monitoring, so I think this is the right forum. I've also done a search as best I could for this and not getting the right hits, so please direct me elsewhere if I'm wrong.

Twice now, on two different machines that were checked after my results came out wacky, I've had POC readings at the AC clinic come out WAAAAYYYY higher than follow on, within a half hour, blood draw INRs did. The clinic uses CoagUCheck machines (not sure which specific models). When they open a new test strip box, they calibrate it with a lab check. Also, the pharmacist checked all other patient tests that day and mine was the only one out of alignment. For example: POC check read 6.5 & 6.7 (tested twice with new finger stick to make sure) and lab INR read 3.7. Slightly lower numbers on a different POC machine (above 5) this week, but still way out from lab reading of 3.3.

The pharmacist said there are occasionally patients who for some reason, the POCs never read correctly. Something to do with a phospholipid reaction antigen, or something.????

Has anyone heard of something like this? Would using a different brand machine make any difference? Will this resolve over time, say as I'm not so soon post-op and still healing (4 weeks out)?

Thanks
Linda

 

[Aggie85]

I was just reading Pellicle's thread with the video for getting enough blood for testing. In it he mentions that the CoaguCheck meter is .... "less sensitive to the tissue factors that lay under the skin that some users have commented make a big difference. "

Is this tissue factor what my AC clinic pharmacist is referring to in my starting post (the phospholipids thing)? Would testing procedures or how they get the blood sample be what's making the difference in results?
NOTES:
-the AC clinic and lab where I'm doing blood draws are the same hospital AND the AC clinic uses this same lab for its calibration tests.
-techs seem to have a standard routine that they use for getting the blood sample that is efficient and makes sense. I noted how they let a drop form, wipe it off and let another drop form to use for the sample.

Is there anything I can ask them to do differently that might affect how the machine reads my sample?

Thanks again,
Linda

 

[Aggie85]

I seem to be the only one posting here on this thread. but I'll just put my thoughts out there and maybe something I add will mean something to someone out there. Any immunologists out there who may know more about this?

The other pharmacist just called to discuss my messed up POC and lab INRs and to make sure I knew what to do over the weekend with my Warfarin. I was able to clarify with her what the issue with POCs might be. She said it's not phospholipids but an antibodies issue. That's where the antigen part in my first post came from. Anyway, she said they see this in people with certain types of rheumatoid arthritis and Lupus. They can't get accurate POC readings either. It's something with how antibodies react with the tissue injury and affect the INR in this type of device.

I don't have either of those issues but it does make me wonder since I am still fairly fresh post-op. My immune system is certainly working over time right now. I've also been running slightly high white blood cell counts since surgery.

So my follow on question is, has anyone else had this sort of issue and do you recall if it resolved itself in a few months out of recovery, ie... Resolved as body immune system adapted to new valve and surgical insult?

Linda

 

[pellicle]

Hi

firstly I've noticed Friday nights are quiet. Then there's the point that we all get on at different times in our day and then theres the other point that we all live in different timezones and I've just had my morning coffee (minutes after your last post).

Sat mornings are my INR test mornings.

In it he mentions that the CoaguCheck meter is .... "less sensitive to the tissue factors that lay under the skin that some users have commented make a big difference. "

I mentioned that because there has been discussion that a pinprick on the skin and a capillary blood sample may read different on machines due to the skin having 'tissue factor' in there (to trigger clotting on small cuts quickly) and vein sample will have less or none of that. I mention this because the new manual shows that the same meter and strips can be used equally for finger stick and vein samples.

For instance Wikipedia has a good summary of the coagulation cascade here.

you can see the 'tissue factor there'

Is this tissue factor what my AC clinic pharmacist is referring to in my starting post (the phospholipids thing)? Would testing procedures or how they get the blood sample be what's making the difference in results?

doubtful.

-techs seem to have a standard routine that they use for getting the blood sample that is efficient and makes sense. I noted how they let a drop form, wipe it off and let another drop form to use for the sample.

if by techs you mean the often lowly trained people who draw your blood then to be frank they would likely not have the faintest idea. If however you mean the people who mix up the chemistry for the measurements (proably at a big central lab) then they may. There is ample scope for variation when all they have to do is change who supplies the 'reagents' for testing who change what their chemistry is.

Is there anything I can ask them to do differently that might affect how the machine reads my sample?

that you can ask them to do? Do you mean in their handling of your blood, or do you mean ask them what you can do to ensure your sampling and testing is smooth?

I missed what machine you have, but as you may notice I use a coaguchek, the specifics of each machine vary a little but generally you need to be as regular as you can with how you do things. The things which are important are likely to be:

• time from pinprick to applicatoin of sample (keep to within 15 seconds from pricking to application, coagulation can start while its still hanging, especially if its past 30 seconds from blood appearing)
• time the strip sits before sample applied (mine have a 180 second window from 'ready' to 'too bad' and so it seems logical to me that the results may vary if you apply consistently in the first few seconds after the alarm compared to the end of its time. I have NOT tested this however)
• if you do any 'gymnastics' on getting blood (people massage and swing their arms around and all sorts of thigns ...
• size of sample being on the edge of too small (not quite triggering an alarm, but not enought)
• do not wash your skin with alcohol before pricking

when I did lab work I *know* that seemingly small variations in procedure can make an observable effect on results. I suggest having a clock or watch with seconds hand on it to keep track of what time is passing (or record it as a video on your phone and then time it / observe it later)

When I started (soon after my OHS) I was dreadfully brain effected. Could barely do basic maths without checking with my wife. At that time my INR as measured by my Coaguchek XS was often as much as 0.5 difference to the samples done by the clinic (and I wasted strips). After a 6 month break it was then much better with no more than 0.1 difference.

 

[pellicle]

Hi again

Anyway, she said they see this in people with certain types of rheumatoid arthritis and Lupus.

I see you note below that you do not have this condition - or did I get confused?

It has been noted that some variations exist between machines, for example in this test:

you can see that the lab i-stat machine results are quite different to the Coagucheck on some patients. The interesting thing here is that both machines use the same chemistry (and an electro chemical rather than a physical chemical interaction).

I don't have either of those issues but it does make me wonder since I am still fairly fresh post-op. My immune system is certainly working over time right now. I've also been running slightly high white blood cell counts since surgery.

right ... well in that case I'd not panic. It took me a good 6 months after surgery for my body to settle. Lets start with the assumption that you are not a 1 in 10,000 outlier and that you're normal. When that doesn't help solve problems then start looking at the other options.

From my discharge to about a year later my warfarin dose went up and up gradually. I was initially despondent (probably because I knew relatively little back then) and was concerned with things which were just fictions.

Now my dose is relatively stable (I tinker with it on occasions) and my INR is what I call stable. This is the chart from my 2013 readings

to me that's what you can expect as variation. Its important (to my way of seeing things) to apply STATS to that to properly understand it all. So for 2013 my basic stats were:
average INR = 2.5
STD Deviation = 0.3
and only 2 events recorded where my INR was out of 'range' (which with that standard deviation would be expected).


hope I haven't given you "too much detail, without answering your questions"

 

[Freddie]

Aggie, you mention that "they" wipe the the first drop off. With the coaguchek XS monitor you/"they" are suppose to use the 1st drop of blood.
Also, what are they wiping it with? A dry gauze or with alcohol? Rubbing alcohol is not necessary and could also effect the results.

FWIW

 

[Jkm7]

Aggie, you mention that "they" wipe the the first drop off. With the coaguchek XS monitor you/"they" are suppose to use the 1st drop of blood.
Also, what are they wiping it with? A dry gauze or with alcohol? Rubbing alcohol is not necessary and could also effect the results.

FWIW

I am thinking the same thing.
Ask them to use that first drop and see if it makes a difference.
Alcohol wipe can also impact the results if it has not fully air dried prior to getting the needed drop.

 

[Protimenow]

The CoaguChek machine that is being used is most likely the XS. (I have a doctor friend who self-tests, and he insists that he is using one of the original (1990s?) CoaguChek meters (although I doubt that there are still strips available for it).

I extensively tested a variety of meters - CoaguChek XS, CoaguChek X (when strips were still available), InRatio and InRatio 2, ProTime and ProTime 3, and Coag-Sense against one clinic and a hospital lab. I tend to trust the hospital lab as probably the most accurate.

In my experience, with an 'actual' INR in the 3-range, the CoaguChek XS reported considerably higher and the InRatio machines reported ridiculously higher in most cases. I've stopped using the InRatio, even though I had a good supply of strips, because of its apparent inaccuracies (with my blood, at least).

The meter that I have the most trust in is the Coag-Sense, which uses a physical method of measuring clotting (and resultant Prothrombin times and INRs), with the CoaguChek XS being a second choice.

In relation to your question, it is possible that your clinic is mishandling strips or performing errors when collecting blood. Although, as Pellicle reports, the CoaguChek XS can be used for a first drop or a later drop, the original instructions from Roche were to use the first drop. Also -- the CoaguChek XS strips are sensitive to exposure to air -- this is the reason that they're shipped in the tubes with an airtight cap. It may be possible that your AC clinic is leaving the caps open, or removing the strips from the tubes, or just exposing the strips to the tubes to enough air to skew the results. MAYBE.

Two days ago, I tested the 'later drop' theory using the CoaguChek XS. What I did was test with a Coag-Sense meter, and, with the same incision (which seemed to continue to bleed longer than expected), I tested on the CoaguChek XS. An hour later, I got a blood draw at the hospital lab.
My results:

Coag-Sense: 2.4
CoaguChek XS: 3.1
Hospital Lab: Pending

I suspect that the hospital lab's results will be somewhere between the two, perhaps a 2.7 or 2.8.

Personally, if I had to choose only one meter, I would choose the Coag-Sense. It reports INRs that seem to often be slightly lower than the labs (so a 2.0 on the Coag-Sense may mean a 2.3, and give me comfort about NOT being below 2.0 or at risk of another TIA). The CoaguChek XS is a good technology, but if it is reporting way too high to be of clinical value, you may consider a different meter.

You might try self-testing, with your own carefully protected supplies and meter, and see if this gives you results that are more accurate. It is possible that the lab, with its 'improper' collection techique (according to original Roche instructions), may also be mishandling other aspects of the testing, and that when you self-test, you'll get more accurate results.


(FWIW - the manufacturer of the Coag-Sense told me that at least one lab that uses other meters will use the Coag-Sense as a secondary test for any patients whose INR is reported to be 4.0 or above -- the Coag-Sense is, apparently, used as a control or test for accuracy when other meters report suspiciously high resuts. And, FWIW - I don't work for or have any financial interest in Coagusense (the company name))

 

[Aggie85]

Pellicle and Protimenow, let me see if I can answer all your points and clarify a few things. THANKS for getting back to me. And, yes, I realize we all answer at different times, we do all have lives to live, especially those not fresh postop. I really value those of you on here who are NOT new and who continue to come online and help those of us who are rookies and have lots of questions. THANKS! Just thought it was funny I was the one replying on my own post and was feeling self-conscious about that.

First, I'm not home testing yet. Dr.s here can't order machine until I'm 3 MONTHS postop, I'm only 4 weeks and have to also wait for stable INRs.

The tech I mention is the guy actually taking the blood sample for the POC machine. My statement was meant to convey a trust in him and to note his competency. I am a former Pediatric Cardiac nurse (BSN,RN), so know what to watch for. It was the same guy both weeks and he does 20-30 patients a day. I asked about the machine and their procedure for handling and calibrating the testing strips with each new bottle. He knew exactly what they were using, how it was calibrated when they opened new bottles and what they do when results are not what expected. He kept the bottle tightly closed and whole kit in a dark case when not directly being used. This is a anti-coag clinic run by a LARGE brand new military hospital in the DC area. The lab for blood draws is in the same facility and they work closely together. Also noted, when my results came out so odd, the pharmacist in charge had both machines retested for calibration, they were fine. She also went through the results for All the other patients each of the two days, and mine was ONLY one out of whack. When the first result was so high (on both testing days), the tech did a new finger stick and retested with the same machine and a new strip. I was then sent directly to the lab and did a veinous test draw. This was all hospital standard procedure when results so high. In other words, I'm very confident in the procedures and in the clinic's staff and abilities.

Having said that,.... About the procedure of alcohol wipes and using second drop of blood.
1. They do that with ALL patients so my result shouldn't be any more out of whack than anyone else's in the clinic.
2. Wouldn't using the second drop make the results abnormally low not high, since what you imply is that blood has more time to start the clotting cascade? High INR indicates less clotting started, correct? My results keep being higher than lab results. The second week, I did notice that he allowed the alcohol to dry and yes, he uses a gauze pad to wipe first drop off. I assumed it was to make sure there was no residual alcohol on skin and in blood drop.
HOWEVER, this week, I will ask him to test from first drop and see what that does, and see if they have any other brand machines to try.
3. Without a timer, I can't be certain, but am confident, given this guy's experience level, he's getting the sample on the strip in a timely manner and errors in sampling (other than the first vs second drop issue) aren't at play. Again, he's using same process for all patients so that variable can be ruled out.

Sounds like they are using the brand at least Protimenow is somewhat confident with. BUT, as noted, NO OTHER patients had issues on either of two weeks and on two different machines in the clinic. Same tech using the machines as well. The one thing I was surprised by was that they don't note on their sheet which number of the 4 machines they have was used for the testing that day. I asked, and they're answer was that each room has it's own machine and the machines don't go from room to room, so they don't feel a need to note which was used. Given my experience, I'm going to have them note which machine number they're using. Obviously the pharmacist was able to tell because she knew which machine to check and which patients charts to check for their results.

NO, I DO NOT have any immune conditions that could be causing this. That's why pharmacist is baffled. However, I do often react the opposite or extreme to many medications and stimulants, so there is something about my body chemistry or metabolism that is not in line with standard population. Examples: Benadryl, Percocet, Vicodin, Oxycodone, ... Most codiene derivatives, make me HYPERACTIVE and tachycardic not drowsy. Pseudopfed and other decongestants make me super hyper. BTW: Mt. Dew and Dr. Pepper make me drowsy! LOL

I'm not sure this addresses all you guys brought up. Salient points I need to explore;
1. verify I'm remembering machine name correctly. I could easily be getting CoaguCheck and CoagSense mixed up.
2. Check if they have any other brand machines and ask to be tested on them
3. Ask to test that first drop, not second
4. Anything else for the POC draw, I should check?????

HAPPY FATHERS DAY TO ALL THE DADS OUT THERE! THANKS FOR ALL DO YOU TO SUPPORT YOUR KIDS AND FAMILIES!

Linda

 

[pellicle]

Hi

First, I'm not home testing yet. Dr.s here can't order machine until I'm 3 MONTHS postop, I'm only 4 weeks and have to also wait for stable INRs.

understandable, I reckon that the results will be irregular for some time with all the other chemistry floating around in your blood ...

The tech I mention is the guy actually taking the blood sample for the POC machine.

ok, in that case its likely he knows nothing at all about it, but he may do if he has become interested in it. Many people do an hours worth of reading and that fills them with a confidence that they know "all about it" and they can calm others into believing that too.

To put a perspective on how I view this, I did a Biochem degree at Uni and two of my class mates are blood pathologist and pharmacist respectively. So when I'm talking "calibration" I'm talking at a whole different level to what amounts to me as nothing more than following basic instructions. There is no calibration in what you've described. Calibration involves setting up the chemistry (or electro chemistry which is done at manufacture) to provide correct results against known reactions.

My statement was meant to convey a trust in him and to note his competency.

understood ... he's probably a very trustworthy professional. I'd still check what he's doing and make sure he's not doing the wrong things in a repeatable and trustworthy way. Given you've just reported a very significant difference between a blood draw and a POC test there is clearly something going on and discounting points based on feeling is not a good way to get an understanding of it.

not that it matters ... as I assume you (or your manager) will take the blood test results as more credible data.

I asked about the machine and their procedure for handling and calibrating the testing strips with each new bottle.

to be clear this is not calibration

He knew exactly what they were using

if he didn't I'd walk out on the spot.

2. Wouldn't using the second drop make the results abnormally low not high, since what you imply is that blood has more time to start the clotting cascade? High INR indicates less clotting started, correct?

clotting should only occur with contact to the air or the tissue factors. That is why when they take a syringe full of blood it does not need to be dealt with within 15 seconds. There are standards for how to deal with that that I can probably get to you if you are interested. But like all standards everyone has different ones (for instance you call a Gallon 3.78L and I call it 4.54L which is the English standard)

The second week, I did notice that he allowed the alcohol to dry and yes, he uses a gauze pad to wipe first drop off. I assumed it was to make sure there was no residual alcohol on skin and in blood drop.

or perhaps because his meticulous procedures are actually not as machine precise and identical as you've felt they were.

I have not tested my coagucheck with a second drop of blood because I never felt it was required knowledge for me (as I simply follow the directions and use the first). I've compared against the vein draws to hone my procedure (following the directions with the exception of the addition of my rubber band).

However I do know of a nurse (who also has a mechanical valve) who has done comparisons and actually tested first drop and then vein draw. She took the vein draw and dropped a drop onto the test strip, then waited 5 minutes and did a third test. She reported all three were the same.

Its worth noting that since then Roche has added vein draws (which will NOT be the first drop of blood) to the uses for the Coaguchek (with the same strips) and so therefore I can only say that makes less difference than you'd think.

3. Without a timer, I can't be certain, but am confident, given this guy's experience level, he's

you can go "one onethousand . two one thousand . three one thousand" in your head and get an idea. Anyway when I asked, I thought it was you doing self testing ... in those situations ones sence of time can be distorted, however now that you mention it the nurse at the hospital that got me a high reading was taking longer than 15 seconds.

Salient points I need to explore;
1. verify I'm remembering machine name correctly. I could easily be getting CoaguCheck and CoagSense mixed up.
2. Check if they have any other brand machines and ask to be tested on them
3. Ask to test that first drop, not second
4. Anything else for the POC draw, I should check?????

seems about right ... I'd only add no squeezing no "milking the finger" to get flow.

Best Wishes

 

[Aggie85]

Pellicle,
Yes, both weeks, they went by the lab draw results instead of POC machine results. By calibration I meant the following.... The clinic checks the machine and lab strips to each other each time they open a strip bottle. Not sure exactly how, was just told that when a bottle is opened, they send the machine and strip bottle to the lab who verifies that they are "calibrated" to each other. Their term (not mine), which in that context I assume means, whatever the company requires to verify that the machine and strips are giving as close to accurate results as possible. When my results came back off between the machine and lab draw, the machines and strips were sent back to the lab and re-tested based on whatever their procedure is. One other note, the other lab I was going to go to (Bethesda Naval Hospital) had completely quit using their POCs because they couldn't get them calibrated to the strips. Initially that's all I was told, until I mentioned seeing recall issue for Allere here on the forum. When she understood that I was a well informed patient and understood the issues, the pharmacist then said, yes, they were caught in that and are still waiting for new test strips. NOTE, this is not the lab I ended up at, they sent me on to Ft. Belvoir because they still had POC available. It is interesting that both military hospitals in DC. area are using different machines but that's the military for you... Different branches often use different machines or have different procedures for the same thing.

He didn't milk finger either time. In fact, the first time when my INR came out at 6.5 I questioned him pretty closely because as I pointed out to him, I'd 1. Had trouble up until then even getting my INR in range and 3 days prior had only been at 2.3 2. Had NO symptoms of high INR (no spontaneous nose bleeds, no bleeding gums,etc ...) 3. That first finger stick quit bleeding pretty quickly on its own, ie clotted just fine. He rechecked with a new strip and new finger stick and it came back at 6.7. That's when pharmacist sent me to lab. Next week we encountered the same problem. Pharmacist is now recommending I get blood draw first and then we see what POC reads. But plan on going by blood draws for now and retry POC method in a month or so.

I plan to approach issue of technique, etc this week just to rule out those possible issues. That's why I'm asking for advice on what to check. And, very much appreciate you and Protimenow's input. I'll go on Wed for this week's test. It may not have been clear, but I've only had TWO weeks of clinic testing. We were doing blood draw monitoring via phone with my cardiologist until the clinic referral got set up. SIDE NOTE: I actually trust the clinic more. My cardio had that attitude that ANYTHING in range is ok (even if barely in range) while the AC clinic aims for mid-point of target range (may have wrong semantics, but the European view you guys were discussing in one of the other threads). I'm with you in believing that is a better and safer method than just hitting a range. My cardio at one point said that, "since it's a new valve we really don't have to worry about that the INR might be a bit low." YIKES! :eek2: Luckily I got put in with clinic right after that and even with this POC issue, I trust them managing the Warfarin levels a bit more after that.

One reason I'm so interested in figuring out the POC issue is that I'm a VERY difficult lab stick. So much so that they put a PIC Central line in for the time I was in hospital to reduce needle sticks. I've yet to have a lab draw done in less than 2 stick attempts using smallest butterfly needle and best veins available. The thought of forever (I know not really forever as once stable could test less often) having to get stuck twice or more each week is NOT a pleasant one. Hence, wanting to figure out what else could be going on with the POCs. Also, I really would like to eventually be home monitoring for all the reasons that are discussed on this forum. BTW I have spoken to the head of the lab department about the issue of phlebotomists arguing with me about how to approach blood draws to reduce the number of stick attempts and who to specifically ask for instead of getting random lab tech. each time. Yes, they are experienced (or like to think they are) but as you said many are good at faking it. I've found it's often more a matter of ego, who am I the patient to question their competency....??? Just the one who's had 30+ years of dealing with small uncooperative veins!!!!

Let's see what happens Wed. with both checking on techniques and seeing if other machines, if they have any, make a difference. Also need to verify again which machine they are using and whether or not that second drop use is an issue or a moot point. I may have remembered name wrong. I don't know which method the lab blood draw folks use, but their INR numbers at least do seem to be within a reasonable expected result and hence as accurate as any of all this can be. The issue is why are the POC machines reading so far out. Yes, the tech may be using wrong technique but he's doing the same thing for ALL patients and none of their results are coming out obviously wrong.

Thanks and I'll let all know what happens as we continue the quest.

 

[pellicle]

Hi

Pellicle,
Yes, both weeks, they went by the lab draw results instead of POC machine results.

good ...

... Initially that's all I was told, until I mentioned seeing recall issue for Allere here on the forum.

certainly something to think about.

Different branches often use different machines or have different procedures for the same thing.

not a good idea if you want to promote consistency of operations with the clinicians....

In fact, the first time when my INR came out at 6.5 I questioned him pretty closely

:eek2: as would I ...

3. That first finger stick quit bleeding pretty quickly on its own, ie clotted just fine. He rechecked with a new strip and new finger stick and it came back at 6.7.

my faith in them is going out the window ...

That's when pharmacist sent me to lab. Next week we encountered the same problem. Pharmacist is now recommending I get blood draw first and then we see what POC reads.

prudent ... personally I've been very comfortable with my coaguchek XS and most of the stuff I've read in journals seems to compare the coaguchek XS to the commerical machines. I suspect that the INRatio is an older tech machine (and I am not sure if its still using electro-mechanical).

My cardio had that attitude that ANYTHING in range is ok (even if barely in range) while the AC clinic aims for mid-point of target range (may have wrong semantics, but the European view you guys were discussing in one of the other threads).

I'm of the view that if you don't have trends to follow (and its not consistently trending down) that unless its out of range then "steady as she goes with dose and just see where it goes". It may actually just turn back. This blog post of mine may be too much too soon for you but you may find it interesting reading anyway.

One reason I'm so interested in figuring out the POC issue is that I'm a VERY difficult lab stick.

you mean for a vein draw? I normally think of stick meaning "finger stick" which is just a pinprick.

The thought of forever (I know not really forever as once stable could test less often) having to get stuck twice or more each week is NOT a pleasant one.

indeed, its what drove me for having POC myself. I've had enough veins in my arm damaged by previous catheter insertions they can only usually get one place on my left arm. Noone seems to want to do my left arm as they're all set up for the right...

The issue is why are the POC machines reading so far out.

its a good question, I'd be writing down what values with what machines. I'd be chasing which machine gives you the best match between vein draw and machine. I'm leaning towards the Coaguchek XS being the best (be careful to note its the XS and not the S ... not even sure they have the strips made for the S anymore.)

Best Wishes

 

[Aggie85]

Pellicle,
I have looked at your blog. followed it from the video you had or one of the other posts. It is indeed pretty detailed and a lot more math than I'm ready for at ANY time! LOL But still very informative. I actually sent it and a few other things I've found on this site regarding home testing to my pharmacist friend, who used to run a AC clinic, and who told me to STAY AWAY from home testing trying to convince him to reexamine his ideas. But that's beside the point to this thread's discussion.

Not sure why the lab tech doing a new finger stick to retest me when initial test came out so high degrades your confidence in him. I think it shows competency because he started over completely just to make sure there were no sampling errors with the first attempt. I don't mean to belabor this point, but it seems to keep being missed.... He is the same one who tested ALL the other patients that day, and ALL their results came out right or as expected. MINE was only one not right. This was checked by the pharmacist AFTER my results were so out of range and so far not in line with the lab results. if he was doing it wrong, the results for EVERYONE would be off, not just mine.

They only made a minor change to my med since my lab INR was a little high of my range, but for most part, have kept things stable. Again, using the lab draw results and not the aberrant POC ones. My concern was with the seeming nonchalance attitude of my cardiologist.

As far as I know, their not using INRatio machines at all. I suspect since this a brand new facility, opened about a year ago, they are using the newer XS machines, assuming I remembered the brand name right. I know it's not INRatio, just not sure if CoaguCheck or CoaguSense. I'll ask again, Wed.

Yes, by lab stick, I mean veinous draw. It almost always takes two or more attempts to draw veinous blood on me, depending on if I get a tech who'll listen to me. Both Antecubital (inside of elbow) areas have scarring from multiple cut downs for Caths that were done on me as a child, so they can't draw from their usual place. This often throws the phlebotomists off right from the start. Then I have small, rolling, tough to enter veins, that collapse as soon as they put the vacu tubes on. They check me on both sides because I'm so hard to even FIND veins on. They do seem to rarely find any on the left, but they always check. Now on top of it all, I'm on Lasix so can't really try to get super hydrated to pump my veins up.... I just pee and pee and pee it out. LOL That's why I really would like to figure out this POC machine issue. I've talked to the head of the lab dept. though, and have a list of their most experienced phlebotomists. So hopefully that will help. I think I'll be off the Lasix soon too, and that will help as well.

To address a couple of your other points:
1. Different branches of the military using different things for same job is VERY common. It boils down to each branch has its own budgets and own acquisition processes, so get different things. Just sticking with the medical side of things, even when the two major military hospitals in just this region supposedly work together, they use different machines or procedures. My Cardiologist sees patients at both facilities (one army, one Navy --- actually joint but let's not confuse things further) but has me redo the Echo at Bethesda (his main office--the Navy one) before my appointments because he knows their machine and their techs better, even if I had JUST had an echo done at the Army hospital on my side of the city and I bring a CD of the actual echo.

Consistency of clinicians is always an issue. Our primary care physicians are in teams of 4 (mix of Drs, PAs, and NPs), so when you call for an appointment, it's just who's available. At least now, I'm complicated enough, that I have my main PMCs actual number and email and can contact her personally if I really need to. Also, reason I'm VERY glad I'm in the AC clinic. They only have two pharmacists (there's another term for them because they're more trained than average pharmacist and can write prescriptions, I just can remember the term); who follow the patients together so there IS consistency of care. They told me on my orientation, to contact them first about any medical issues (colds, procedures, Ect...) and then they will coordinate directly with my Dr. to make sure Warfarin issue is taken into account with any meds prescribed. Nice thing about timing also, is that my Hubby retired last year before all this heart issues happened; so we won't be moving every two years anymore and I won't have to keep re-setting up Drs.

2. I keep a record going on my Ipad with ALL INR results, doses, changes, etc. I've noted each week which number machine was used when I found out there were different machines. Luckily, it'd only been two so was easy to start keeping track from beginning.

3. This brings up a point I figured I'd come across when actually doing home INRs but is sort of salient now. I've seen there are APPS for keeping track of INRs. (Some free, some for small fee)
Some are put out by the various companies and I assume go along with their programs. But others are independent. Do you (and Protimenow) just do your own spreadsheet type records or do you recommend any of the particular tracking options offered commercially?

Well, let's wait and see what happens Wed. I'll come back then with an update.
Linda

 

[pellicle]

Hi

I actually sent it and a few other things I've found on this site regarding home testing to my pharmacist friend, who used to run a AC clinic, and who told me to STAY AWAY from home testing trying to convince him to reexamine his ideas.

well fair enough, but just don't get your hopes up on converting them. There have been stories of AC managers being totally against POC machines, and even refusing to have them in their own places (but ignoring that they send their blood samples to a place using an i-Stat

its emperors new clothes for some....

Do you (and Protimenow) just do your own spreadsheet type records or do you recommend any of the particular tracking options offered commercially?

I do use a spreadsheet and its backed up onto my Dropbox automatically. I prefer Excel to anything in the app department because I actually want to read my data again in 10 years and I'm almost entirely certain that won't be the case with any APP (not to mention that the data is MINE and private and also Excel is an incredibly powerful tool that an APP will just not be able to match). I've already had experience in the last 20 years with proprietary systems vanishing in other domains. This is something I do know something about too, as my work in IT has led me to get into archival data systems.

Also I've been considering developing an APP but the whacko legal systems that make me liable for another person's incompetence (but choosing to sue me) makes such a thing very undesirable for me to consider (given there is almost no profit in it).

 

[Protimenow]

As far as I know, Roche stopped providing strips for the CoaguChek S a year or so ago -- and I don't think that they licensed any companies to make them for 'Third World' countries. I think that this is an orphan machine that only the ignorant or unethical try to sell to the unsuspecting customer.

I realized a few weeks ago that I've been self-testing for more than five years -- and there are others with even longer experience doing this.

It may be possible that some people, for some reason, often have higher values with the CoaguChek XS or InRatio meters than their lab (blood draw) values. It's been well documented that the difference between lab and meter widens as INR increases (in other words, a 2.5 on a lab test and a 2.6 with a meter may be common -- a 4.0 on a lab test may show up as a 5.0 on a meter).

In my case, this disparity is often even higher than expected.

My two 'usual' meters are now the CoaguChek XS and the CoagSense. My expecation (usually borne out) is that the CoagSense reports slightly lower than the lab result, and that the lab result is slightly lower than the XS result. (For example, on 6/12, the CoagSense gave me a 2.4, the hospital lab reported 2.8, and the XS gave me a 3.1). If my INR had been higher, the spread between the three values would probably have been somewhat wider.

In my case, I'd rather have a meter that slightly underreports (so I can avoid the low-INR danger range for me) than I would to have a meter that slightly overreports (because I'm not as concerned about a little extra bleeding than I am about another TIA). The XS is a good meter, and I hope that yours compares well to the lab.

So far, my veins have been good, so it isn't that big a deal getting the blood draw (although it's a lot less convenient than a finger stick at home).

If you do, finally, home test, you should be able to perfect your technique and should be able to learn how your results compare to lab tests. Armed with this knowledge, you should be able to manage your INR quite effectively.

---

A few things that may not have been addressed in this thread:

The reason the meters use the first drop is that there are factors in the skin that promote clotting. Later drops are more like venous blood and lack these factors, which can result in a longer detected prothrombin time (and higher INR). Although Roche seems to claim that it no longer matters with the XS, I'm not quite sure.

The reason that the insurers don't want to approve self testing for 90 days (or perhaps even 60 months) may be related to the difficulties in regulating INR during the post-op period. These difficulties may relate to the body's healing processes. I haven't looked into specific reasons for delaying the approval, but there may be medically valid reasons, and these reasons may also help to explain why the POC results were so different from lab results. It might just be that, short-term post-op, most meters just won't give a result as accurate as a lab result. (I suspect that the Coag-Sense, which uses physical clotting rather than electrochemical, may not have this problem).

Some of the problems people have had with getting that large drop may be partially related to use of the wrong lancet -- you should be sure to get one that is designed for INR testing (and not for blood glucose testing) and set the lancing devlce deep enough to get an adequate incision. Although I've got more than 1000 21 gauge lancets, I am getting better results with Unistik 3 Extra and ITC Tenderlette lancing devices. A few cents more for the lancing device may make it easier to get an adequate drop, and may also help prevent wasting an expensive test strip.

 

[Aggie85]

Protimenow, thanks for added info. I was supposed to go for AC visit today but discovered at least min. , luckily in time, that my cardio postop followup was TODAY, not tomorrow. So, didn't make it to AC clinic. Will go tomorrow. Cardiologist agreed with me (and you) that early recovery heightened immune system may be mucking up the POC results. If discrepancy is seen in auto-immune challenged patients, then it stands to reason that fresh postop could also affect results in some people.

However, especially given your info about first vs second blood drop effects, I will make sure to check this out tomorrow. I'm not going to give up on the eventual home monitoring idea, especially given difficulties w veinous drawing blood on me. I'll let you know what, if anything new I find out tomorrow.

Thanks again ALL, for inputs.
Linda

 

[UncleSteve]

Regarding the point about 'milking' the finger, I've had a terrible job getting large enough samples for strip testing on my CoaguChek XS, that I do have to milk my finger to get the blood out. I'm using the largest lancet and even modified it slightly to plunge deeper. I'm now getting reasonable sized samples, however I was wondering how much difference a 'natural' blood sample is to a 'milked' sample for INR readings?

 

[dick0236]

..... I was wondering how much difference a 'natural' blood sample is to a 'milked' sample for INR readings?

"Milking" does not seem to affect my INR values. That said, I try not to "milk" my finger. I find that holding my hand under hot water prior to testing assures a good drop. Using a rubber band wrap also works.

 

[pellicle]

Hi

I've had a terrible job getting large enough samples for strip testing on my CoaguChek XS,

try my method here

http://www.valvereplacement.org/for...2-video-demo-how-I-get-enough-blood-regularly

i now actually lance a little shallower and it seems to hurt (after lancing) for less time now too.

As I said earlier, that Roche now shows in their instruction manual that the XS works equally on vein samples as with finger sticks suggests that it is not sensitive to subcutaneous tissue factors.

 

[Aggie85]

Hi All,
Got to the AC clinic today. Talked to a different tech about discrepancy issue and idea of using first blood drop vs second. Got an interesting answer. She said a month ago, all the techs had to go through a recertification on the correct procedure for these POC machine draws. They were re-trained in the lab by a rep from the CoaguCheck company because the procedure had been changed. He told them the new procedure is to use the SECOND drop of blood. BTW the clinic is using the CoaguCheck XS machines. She agreed with me it would be a good idea to try both ways and see if it made a difference in my out of whack readings. Answer: NOPE both drops had POC machine MUCH higher than lab draw INR of 3.0. She used two machines side by side. One machine got the first drop, the other machine got the second. (Machine 1-- first drop, read 5.4, machine 2-- second drop read 5.3) Of course there could be some variance because two different machines were used, but results were essentially the same. POC reading was again MUCH higher than lab draw INR result.

So, I feel reasonably certain that the techs are well trained and within human limits performing their jobs well. For whatever reason, the POC machines are not reading my INRs even remotely accurately. Conclusion doesn't look good for my poor veins. The pharmacist and I discussed this and she's putting me in for routine weekly lab draws. :frown2: We'll do this for a few months and revisit the POC issue again after my body is a little more out of recovery mode.

Is there anyone anywhere in the northern Va. area who has a CoaguSense meter they'd be willing to let me take a test on??? (Both military hospitals I have access to use the same brand machines.) I'm just curious to see if a different brand of POC makes a difference. From what I read on here, the different machines process the blood in different manners and I wonder if that would make a difference. Buying my own machine for now isn't really practical until I figure out if I can use them AT ALL or if different brands make a difference.

Still really curious to what's causing this issue but at least my lab INR results are staying well in range. My poor arms and hands are sure looking black and blue. :redface2:

Hope all are doing well.
Linda