Coumadin clinic

[psalmist]

I was asked to take part in a home testing study through the mayo clinic and agreed. I was sent home with an INRatio machine and have tested weekly and submitted the results by phone. I was asked by my coumadin nurse/manager to bring in my machine and test it with theirs (coagucheck). The first time I tested 3.8 on my machine and 4.5 on theirs a couple of hours apart. When I took my machine in we tested at the same time. 3.1 on mine and 3.7 on theirs. . . Any idea why the difference and what do I go by? Thanks Seth.

 

[geebee]

Go by your machine. It is always better to be a little high than too low.

If you are worried about the accuracy of your machine, test someone who is not on coumadin. If they test from .9 to 1.1, then your machine is fine.

 

[Ross]

Your comparing apples to oranges. Unless it's a brand spanking new Coaguchek meter, it is running at an ISI of 2.0 and INRatio runs at ISI 1.0. Different reagents will produce different results also. It's long and technical and I cannot explain it, but perhaps Brendan at Hemosense can. I know I cannot explain the technical end of it. I'll see if I can find you a chart that may help explain.

http://www.hemosense.com/docs/5500258_TechBull103_INR_ISI_revB.pdf

 

[Bina]

Seth, does your clinic have the newer Coaguchek XS?

Ross, I'm trying to find out what the ISI is on my new XS, the owner's manual does not mention ISI......it mentions PT seconds.
What does ISI mean? Thanks.

 

[Ross]

Seth, does your clinic have the newer Coaguchek XS?

Ross, I'm trying to find out what the ISI is on my new XS, the owner's manual does not mention ISI......it mentions PT seconds.
What does ISI mean? Thanks.

The XS strips are supposed to be ISI 1.0 As far as what ISI means, read the first link I gave Seth.

 

[Blanche]

For all those folks interested in knowing how the INR is calculated this link should help. When we have a test of our blood, we sometimes say we had an INR test. That is not quite so. What we do have is a p/t test (Prothrombin Time). The INR is merely the result of a calculation that takes into consideration differences in the other variables, such as the ISI.

I'm sure the article will explain this a bit more clearly.

http://www.medicine.uiowa.edu/Path_Handbook/Appendix/Heme/INR.html

ISI= International Sensitivity Index.

Regards,
Blanche

 

[Natanni]

They Mayo tells Nathan to always go by his INRatio vs the clinic ProTime, and even the nurses at the clinic go by Nathan's. He does bring his machine in and will check it with them from time to time, and they are usually at least .5 higher. The blood draws were always closer to his INRatio.