INRatio results vs. Doctor's office

[SusanC54]

I received my brand new INRato machine about a week and a half ago, did my telephone training with QAS, etc. My first test was 2.2 (my range is 2.5 -3.5), so I was a little low. I called my result in to the doctor's office and they weren't quite sure what to do with me......lots of nurse anxiety about liability, giving me dosing advice etc. It turns out that of 1000 people that they monitor, I am the only one doing home testing. So.......I increased my dose slightly ( I was on 4 days a week at 5 mg., 3 days at 7.5)......I added one more day of 7.5. The clinic promised to get back to me with a plan and to have me show the doctor that I knew how to use the machine. For a week, I got no phone call from the clinic with a plan or appointment.

Here's the problem. A week after my first test, I home-tested again and I was at 1.6. That night I took an extra 5 mg. and decided to add one more day of 7.5 mg. The 1.6 reading really kind of concerned me so I called the result in to the clinic again to prod them about my required demonstration of my proficiency to use the machine, etc. . Apparently my case had kind of slipped through the cracks because the nurse was really apologetic that no one had called me with a plan. I was given an appointment for today, to bring my machine in, show the doctor that I could use it, have them also perform a fingerstick with their Coaguchek machines (since the debacle with the strips, they continue to test with two machines each time.) The doctor wanted me to have a blood draw if our machines differed to a great degree.


This afternoon here were the results:

My machine: 2.6
Clinic's machines: 2.0 and 2.1
Blood draw: 2.1

The doctor suggested that I try my machine again this evening to see what the reading would be. I just did another test and my INRatio once again tested me at 2.6.


Is this much variation from Coaguchek to INRatio machines normal? Anyone have any thoughts on any further action that I might need to take?

Thanks so much for everyone's input on this thread......I have learned so much about home testing and dosing from everyone, that I feel pretty confident but I still need some second opinions.


Susan

 

[Ross]

Coaguchek has an ISI of 2 and INRatio ISI of 1. I'll have to find you the chart to look at to explain this. Expect a +/-30% variation between testing machines and lab. http://www.hemosense.com/docs/5500258_TechBull103_INR_ISI_revB.pdf

Actually Susan, I think the 1.6 you got was an error and should have retested. There is no way it could be that low with an increase such as you made.

Don't get overly concerned about the varations. It could be completely different at another time. NONE OF THEM IS PERFECT.

 

[SusanC54]

Thanks for the quick response, Ross. I looked at the technical bulletin that you included in your answer. I'm not quite sure that I understand about the ISI. Perhaps you can explain it simply to me.

Susan

 

[Lorraine]

Good Advice Ross. I just received my INRatio a week ago Thursday. Last Saturday I trained withQAS and my INR was 3.0. I went to my Cardio's office on Thursday for my training approval with them. They took my INR with their INRatio and it was 3.4. It was then my turn to show i could do it myself. My machine reading was 4.0. The Coumadin nurse assistant (who takes my INR all the time) was speechless and didn't know what to say. I am their first patient who will be home testing. She conferred with the head nurse and they said I should have my machine either calibrated at QAS and come back and test again. I came home and had a long chat with Jerry a clinical tech from QAS. He explained the same thing to me Ross about the variance. He directed me to the Hemosense website and we looked at a lot of the litarature together. He asked me a lot of questions of the procedures my cardio's office use in taking my INR. I told him I know that as far as getting the blood onto the strip, they usually lancet my finer and then take a tube to suck up the blood to put on the testing spot. I told him my method was to stick my finger and then try to get the blood to drop onto the testing strip. He informed me that first, the nurses were lazy to use the tube metheod. He asked me if they used a glass tube or a plastic one. Plastic is a No No! I told him I wasn't sure. Then he also said that the longer it takes me to get the blood onto the strip, the blood is already coagulating and I won't get a proper reading. He asked me if there was still blood in the well as well as running up the strip. I admitted that no, the blood i managed to get on it just all went up the strip and the well was mostly dry. He said my coumadin nurses assistant should have noticed that. Hmmm! I guess I may have to teach my clinic the proper way to to train patients on their home machine.

This was only the second time I had tested myself. I know I have to practice on my technique to get the blood to flow quckly and in abundance so that I get a ample amount of blood on the strip. He had stated how important that was. I was little irked after I talked to him about my clinic. Jerry said they should have had me test again. I go back to my clinic on April 6th. I plan to do a couple of home test and work on my technique so i get a more accurate reading. The cardio nure feltthe readings shouldn't have had that big of a variance. Jerry said I should show them the Hemosense website about variance. If all finally goes well, I'll be testing at home from now on. I think they said every four months they want me to come in for aoffice visit and the months in between i can call in my results. I just wanted to let Susan know to be aware of her blood amount on the strip and as you said the variance. QAS has great support!

 

[Ross]

He asked me if they used a glass tube or a plastic one. Plastic is a No No!

Oh really, you should have asked him why microsafe tubes are plastic and that's what QAS has for INRatio's. Tubes do not matter at all. Disregard his remark.

I dare you all to give your labs the challenge I gave mine, take the same sample and test it twice, tell me you got the same numbers both times. It's very likely not going to happen. My PCP is in charge of the lab where I go. He is dead set against finger stick testing and denied it existed. I asked him to prove to me that his lab was anymore accurate then my machine. He didn't accept the challenge. I then asked him why he was so against it when the Cardiologists clinic uses fingerstick testing. His answer, the aren't accurate enough.

INR is INR, the figure you get is a ball park marking, not an exact thing. We don't have exact instruments anywhere in the world. You can test back to back with your machine and come up with .2 or more of a difference back to back.

 

[Ross]

Thanks for the quick response, Ross. I looked at the technical bulletin that you included in your answer. I'm not quite sure that I understand about the ISI. Perhaps you can explain it simply to me.

Susan

Try this one. I know what it means, but my explaning it will only leave you more disoriented then ever:

http://www.hemosense.com/docs/TechBulletin102_StandardizationPTINRTesting_revB.pdf

 

[Blanche]

Perhaps this article will help. It explains how the INR is calculated.
http://www.enw.org/Research-INR.htm
Blanche

 

[SusanC54]

Thanks to everyone for all the technical references. I believe that I now have a better understanding of how INR's are calculated.

I also now believe my INRatio machine more than the Coaguchek machines at the fingerstick clinic after I tested my husband today and his INR was a perfect 1.0............

Thanks again to everyone!

Susan

P.S. I just watched the Today show video with the misinformation about warfarin and the ingestion of green leafy vegetables and I have also sent an e-mail to [email protected]