home testing w/o a machine? may be an odd question

[LaughClown]

Ok, so this is something I've been wondering for awhile. Couldnt you theoretically do your own home testing with just a lancet and a stopwatch (like in a zombie apocalypse scenerio)? It has always seemed to me that if you had a controlled depth cut (like from a lancet) and waited to see how long it took to stop bleeding, and compared that to when testing with a machine as the control, that a person could monitor their INR that way. You may have to experiment to determine what times relate to what INRs, but maybe this was long established before there were efficient hospital labs, etc. I dont know. I did a quick google search but couldnt find this answered anywhere.

P.S. I had a vague idea for awhile, but then I saw an episode of House where they tested a little girl's INR by giving her shallow cuts with a scalpel on her forearm and testing the bleeding time (I guess it was more dramatic then a test strip. It made me laugh)

 

[Ross]

It wouldn't be very accurate. Might give you some sort of idea, but nothing trustworthy.

 

[dick0236]

P.S. I had a vague idea for awhile, but then I saw an episode of House where they tested a little girl's INR by giving her shallow cuts with a scalpel on her forearm and testing the bleeding time (I guess it was more dramatic then a test strip. It made me laugh)

There is an old saying, "believe none of what you read and only half of what you see". I think your comment "....more dramatic that a test strip" nailed it. I've had tiny cuts bleed for a longer time than some "not so tiny cuts". Like Ross said, it would not be trustworthy. I would not want to bet my life or health on it.

 

[Lynlw]

Ok, so this is something I've been wondering for awhile. Couldnt you theoretically do your own home testing with just a lancet and a stopwatch (like in a zombie apocalypse scenerio)? It has always seemed to me that if you had a controlled depth cut (like from a lancet) and waited to see how long it took to stop bleeding, and compared that to when testing with a machine as the control, that a person could monitor their INR that way. You may have to experiment to determine what times relate to what INRs, but maybe this was long established before there were efficient hospital labs, etc. I dont know. I did a quick google search but couldnt find this answered anywhere.

P.S. I had a vague idea for awhile, but then I saw an episode of House where they tested a little girl's INR by giving her shallow cuts with a scalpel on her forearm and testing the bleeding time (I guess it was more dramatic then a test strip. It made me laugh)

That sounds more like a "bleeding time test" http://medical-dictionary.thefreedictionary.com/bleeding+time there is a little device with 2 small blades and every 30 seconds you blot off the blood and see how long it takes to stop on your own. It wouldn't be nearly as exact you would need it to be to see if your INR is in range., but it works well to see if you have an abnormal bleeding time they usually do them before surgery in certain people. Then if it is abnormal they would do tests to see what is the problem

 

[catwoman]

And how would you report those results to your doctor?

"Gee, doc, the last time I tested, it took 5 minutes 33 seconds for a hole the size of a pencil eraser to dry up?" ;-))))

 

[Cris N]

I thought about this too at one point. The real problem with it probably has to do with actually controlling the right spot to poke. I could (and have) poke one spot that seems to stop bleeding right away and right next to it seems to take forever. All depends on the capillary & where you actually hit it.

 

[Philip B]

No Monitor Testing?

No Monitor Testing?

There was a post some while ago about someone in the early days of valve replacement surgery and coumadin use. If I remember correctly, dosage was adjusted by watching for blood in the urine... if blood started showing-up in urine coumadin dosage needed to be decreased. Thank god, we've progressed beyond those days!

-Philip

 

[Bill B]

The "prothrombin time" from which the INR is derved is just a small subset of the clot forming process, about 12-15 seconds normally. The test focuses on the part of the clotting pathway that is affected by vitmain-K dependent clotting factors, rather than the entire clotting process. It's much faster, more easy to standardize and reflects warfarin's activity much more closely. As Lyn said, you'd be doing a bleeding time test, which is more reflective of platelet function. In fact, warfarin has little effect on bleeding time, as many of us have noticed.

 

[Bina]

Ooops, for a minute I thought I was reading the Joke thread.....these are modern times and we have amazingly accurate INR Testers which I will continue to trust.

 

[dick0236]

There was a post some while ago about someone in the early days of valve replacement surgery and coumadin use. If I remember correctly, dosage was adjusted by watching for blood in the urine... if blood started showing-up in urine coumadin dosage needed to be decreased. Thank god, we've progressed beyond those days!

-Philip

I remember seeing a post like this shortly after joining this forum. I doubt that PT(prothrombin time) testing was ever that medieval. I never used such a crude measure to determine my PT. From my surgery until the introduction of INR, I always used a lab draw to determine my PT. Over the years, I have had blood in urine twice and it will get your attention and is a sure indicator that your blood is too "thin':tongue2:. I once had the "blood in urine thing" in the early '80s while I was in Spain on vacation. It scared hell outa me as I don't speak Spanish and I did not want to wind up in a hospital that was a long way from home. I stopped my coumadin for a couple days and drank a lot of water 'till my urine cleared up....I do not endorse this method of monitoring INR:tongue2:.

 

[Jkm7]

There was a post some while ago about someone in the early days of valve replacement surgery and coumadin use. If I remember correctly, dosage was adjusted by watching for blood in the urine... if blood started showing-up in urine coumadin dosage needed to be decreased. Thank god, we've progressed beyond those days!

-Philip

My father took coumadin for about 2 years starting in 1962 and there was no testing then. I don't remember him ever having a serious bleed and know he never had a stroke. I have no clue how his doctor 'guessed' what dose he should take. He died a very young man but not directly related to coumadin.

 

[Philip B]

Medieval Testing?

Medieval Testing?

As I recall, the blood in the urine test recounted the experience of one of the first guys to receive an artificial valve and use coumadin. It was specific enough to recount the experience of the guy by name. I remember thinking about how dangerous that monitoring method would have been.

-Philip

 

[yotphix]

My mother recalls doing ptt tests in a lab while doing her MSc in Biology. She said that they used a blood draw and then watched the prothrombin form under a microscope, or something like that. I have been meaning to ask her.
As ridiculous as it may sound, it has occurred to me before that if there was some sort of apocalyptic meltdown during my lifetime I would be somewhat skewered if I couldn't figure out how to do that without the test strips, and to regulate my intake of fermenting sweet clover just so to replace coumadin! I like to be prepared. It is a project I may experiment with someday. I'll take my Coaguchek and generic Warfarin over that any day though.

 

[Ross]

As I recall, the blood in the urine test recounted the experience of one of the first guys to receive an artificial valve and use coumadin. It was specific enough to recount the experience of the guy by name. I remember thinking about how dangerous that monitoring method would have been.

-Philip

That would be RCB and yes, it was just the Medievil.

 

[Protimenow]

The test you describe is a platelet aggregation test. It has little to do with the effect of warfarin. The test uses a standardized incision, (one of the devices designed to do this is called a Surgicutt) on the inside of the forearm, with a blood pressure cuff holding a standard pressure on the upper arm. The incision is deep enough that the effects of warfarin are pretty much immaterial -- it's the platelets that close the wound.

This IS somewhat relevant to the test machines a person chooses. Platelets are aggregated in the blood vessels - when you get a wound, the platelets are there in high concentrations to close it. When you do a fingerstick, some test machines (CoaguChek and, I think, InRatio) WANT the first drop of blood to test, and calculate the INR that includes the effect of the platelets at the wound site. Later drops of blood don't have the same concentration of platelets and other meters (ProTime meters) want the first drop wiped away and do the test based on blood with fewer platelets.

Other than a test in a lab, there's probably no alternative to the finger-stick and meter route for establishing INRs.

 

[Lynlw]

The test you describe is a platelet aggregation test. It has little to do with the effect of warfarin. The test uses a standardized incision, (one of the devices designed to do this is called a Surgicutt) on the inside of the forearm, with a blood pressure cuff holding a standard pressure on the upper arm. The incision is deep enough that the effects of warfarin are pretty much immaterial -- it's the platelets that close the wound.

This IS somewhat relevant to the test machines a person chooses. Platelets are aggregated in the blood vessels - when you get a wound, the platelets are there in high concentrations to close it. When you do a fingerstick, some test machines (CoaguChek and, I think, InRatio) WANT the first drop of blood to test, and calculate the INR that includes the effect of the platelets at the wound site. Later drops of blood don't have the same concentration of platelets and other meters (ProTime meters) want the first drop wiped away and do the test based on blood with fewer platelets.

Other than a test in a lab, there's probably no alternative to the finger-stick and meter route for establishing INRs.

A platelet aggregation test is different than a Bleeding time test (which is the cut on the forearm) for the platelet aggregation test you draw a tube of blood, like most other blood work and they used to look for clumps under microscopes in slides or now they test with machines

 

[Protimenow]

Ineresting. The Surgicutt docs called it an aggregation test.

 

[Lynlw]

Ineresting. The Surgicutt docs called it an aggregation test.

I'm not sure why, it checks platelet function, but is a completely different test than the aggregation. Was this in person or do you have a link?

 

[Protimenow]

NO, actually when I re-read the package insert, they said it was for Bleeding Time. You can find the link at http://www.itcmed.com/Product-Support/Package-Inserts/Surgicutt. It's the package insert that discusses the test and the testing procedures. I'm sorry I didn't go back and recheck this document. The first paragraph of the document talked about platelets aggregating, and I assumed it was a platelet aggregate test.

Just click on the Package Insert link and you'll get the PDF of this insert -- you'll probably have to increase it to 125% or more to be able to read it.

 

[Lynlw]

Ok I was just confused when you said the surgicut docs, I thought you were talking about doctors, not the document. IF the bleeding test showed a long time, then they would do other tests like the aggregation to figure out why /where the problem is.