Ok, time for another update. Protimenow and i have been in contact and I've gotten one of his CoagSense machines to test out on. So far, results are still puzzling. Monday I did three INR tests, all within an hour or so of each other. Lab Vein draw came in at 3.2. CoaguCheck showed 4.6 and CoagSense had 4.2. The CS was closer to the lab value but still signifcantly higher. BUMMER. I was really hoping the different testing mechanism of the CS would make the difference.
Protimenow in our privte conversation wondered if I'd had done lab testing at any other facilities and what were the results? He's thinking that maybe the problem is the lab results and not the macihines. I think Pellicle mentioned something similiar somewhere in this long thread. To answer both of them, yes I have been tested in different facilities and had the same pattern of results. The lab vein draws have been done at three different military hospitals while the POC machines have either been at the one ACC clinic or using NewMitral's machines (INRatio and CCxs.) Both times i had the labs drawn at a different hospital, I've been able to do a POC test fairly soon aftewards (either at my regular clinic or the one time, was on NewMitral's machine. A reminder, my ACC clinic uses CCxs machines. The labs have consistently, across facilities and numerous visits shown INRs at one value and the POC machines way above. Those not in the US military may not realize this, one oddity with the military is they don't all get their supplies and equipment from the same places. Each branch has it's own procurement systems and uses different suppliers. So the machines at a Navy hospital could be different than those at an Army hospital. Heck, it's only been within the last couple years that their computer records could talk to each other. We used to have to hand carry our records from one military facility to another if appointments were at different places. I know Bathesda Naval uses INRatio (well had until the recent difficulty) while the Army hospital I go to, uses the CoaguChecks. So lab testing machines and reagents very likely aren't the same across the three facilities I've used. Yet the results have been consistent. (labs in range, POCs high)
Protimenow also figured that there aren't many people in my facility who get tested both ways and that maybe the problem is the lab reagents and they just don't know it. I've looked into this already as well because I wondered the same thing and asked. Actually, it's standard procedure for ALL new patients to the ACC clinic to be tested with both vein and POC samples for the first intake visit. Just to get baselines. Also, with ANY patient in the ACC clinic who's POC shows higher than 4.0 they do two things. They first restest with a new fingerstick and if the second test also shows above 4.0 the Pt. is then sent to the lab for a vein check. It was both of these factors which started the whole thing with me. On my initial intake, my POC showed a level 5.2 (or something like that) but since I was going to the lab anyway for an initial verification level they didn't adjust my dosage until the lab results came in. I'd have to go back to the start of this thread to see the level, but it was within range and way lower than the POC. So, while not numerous (other than the new patients) there would indeed be at least a few pts. tested both ways within the facility. The pharmacists have checked these pts. records and I'm the only one showing this disparity between results problem.
What I haven't done to this point is do the two different blood samples (vein and finger) ON THE SAME MACHINE. I will be making arrangements to do this. This will at least maybe answer if the issue is a skin being pricked issue vs veinous blood. It would once and for all verify that the issue is vein vs finger and not machines and reagents causing the different readings. This might take some time to set up because while the two (lab and ACC are at the same hospital they are not set up to share samples (ie, me or someone transport vein draw sample or finger sample between the two areas.) I think the lab will be easiest but I'll have to make special arrangements and I need to see if their machine can process both sample types.
I've seen it discussed here, but can't remember, can the CoaguCheck do both sample types?
The other question that's come up is whether to use the lab results as the gold standard of what my INR is or the machines? Labs have been consistent (except once when I had a 6.0 INR via vein blood) (unfortunately, we had NOT gotten a POC sample that day to see what it would have shown.) BUT the POCs have been consistent as well (if running consistently high.) My inclination is to go with the lab results; I'd rather base on lab and accidentally be too high than base on POC and be accidentally too low. The real reason to keep persuing this is two fold to try saving my veins. I'm a very difficult stick (it took the phlebotomy guys 6 tries the other day to draw my blood.) Also, the ACC clinic keeps trying to extend my checks out to 10 days to 2 weeks. I'd really rather stay on weekly for safety sake. So far, there's always been a reason to go ahead and draw it at about the 1 week point, but they keep trying to get me to extend it. if having to get vein stuck for the rest of my life, I'll probably have to go ahead and extend out to longer times between tests just to save my skin and veins. Maybe as I get more comfortable with my coumadin management, I'll get more comfortable with extended checks but not yet. Also traveling would be more limited. But thankfully if I'm using a US military facility anywhere in the world both my standing orders and lab results are available so I could go when and wherever I need a test. Also, I'm now bloody curious as to WHY this is going on!
I just wish there was someone out there in a research position who deals with lots of people on Warfarin who could give me a definitive answer as to why i'm getting such wide range results between the two methods and better yet, what I could do differently to get the POCs to work. My clinic keeps thinking its a platelet, Antibody skin thing (even when I have NO other signs of such issues). And, from what I've read online, the APA problem causes the POCs to read values as false low, not false high. Why would I be the only person on the earth (maybe a slight exaggeration) who has this problem between the lab vein and finger sample tests???
Thanks to all of you guys out there who keep brainstorming for ideas as to what might be going on or what else to eliminate as a cause!
SPECIAL THANKS to Protimenow for sending me his spare machine and testing supplies!!!! Wish they'd worked!
Linda
