Highest INR you have heard of or experienced?

[carolinemc]

Years ago, I was able to get in touch with the CEO of Coagusense, makers of the Coag-Sense meter. He told me that there are some places (hospitals? clinics?) that switch from the CoaguChek meter to the Coag-Sense to validate results if the CoaguChek results are 4.0 or above.

I don't know who, or where, these places that use the Coag-Sense to validate high numbers, but since they changed management a few years ago, my confidence in the company and their test results has dropped so much that I haven't bought any more strips, and haven't tested with a Coag-Sense meter for well over a year. (And without any recent strips, I don't think I WILL, either).

My lab that uses that, when I went to 100, I had to go to the regular lab in the hospital and get a draw from the arm. My reading in the lab was 4.0. The other lab concurred the same, and we dosed accordingly.

 

[Protimenow]

You had an INR of 100? 10,0? Was it the Coag-Sense that gave you that high INR? (IIRC, the Coag-Sense won't give a reading above 8.0, or maybe 9,0)

 

[thomas999]

You had an INR of 100? 10,0? Was it the Coag-Sense that gave you that high INR? (IIRC, the Coag-Sense won't give a reading above 8.0, or maybe 9,0)

It was actually over 100, probably 120. This was measured by the local hospital lab, and in the emergency room at the hospital. I remember talking to a nurse who said that's impossible because it can't go over 100. I don't know why she would think it stops at 100, but the PT value peaked at over 12. I was starting to bleed out from all soft tissue in the body. I often wonder if there was bleeding in the brain, but I am no crazier than I was before, at least that's what I think, haha.

 

[pellicle]

I often wonder if there was bleeding in the brain, but I am no crazier than I was before, at least that's what I think, haha.

HA

I knew I should have read this earlier ;-)

 

[Lisa from LJ]

PT value peaked at over 12

I think your numbers are backwards. PT number is significantly higher than INR number. A PT of 100 would be an INR of over 15. An INR of 100 would be a PT in the 400s.

 

[Protimenow]

Lisa -- this makes a lot more sense than an INR of 100. And, FWIW, calculating the INR from the PT depends on the reagent value. The PT is divided by the reagent value to determine the INR.

FWIW - years ago, I was told by a clinic (probably mishandled my sample) that my INR was 7.1. I was careful for a few days, just in case the value was right My continued regular dose brought my INR back within range. I suspect that the lab was wrong - or the sample was mishandled so badly that an erroneous result was obtained.

(If the hospital got an INR of 100, it would have/should have, re-run the test immediately.

 

[SatoriFound]

Upon release from the hospital after valve surgery, and before I self tested, I was put on oral amiodarone. Amiodarone is used to help stabilize heart rhythm for afib patients and I had a couple of bouts of afib following my surgery. Within a few days, my INR shot from 3.1 to 9.7.
Of course I was very concerned. The coumadin clinic asked if I had any vitamin k at home. I just had vitamin k2. They had me take a megadose of k2, after doing some calculations. They also called in a prescription for one 5mg tablet of vitamin k, of which I was supposed to take half.

The vitamin k worked very well. In fact, so well that the next day I tested at INR 1.6 and now it was an issue being below range. Things soon normalized.

It turns out that amiodarone is well known to cause INR to go through the roof. Depending on the dosage of amiodarone, it can have the same impact as doubling your warfarin dosage. There were a number of people who should have alerted me to this and should have been watching my INR more closely, including the prescribing nurse, the hospital pharmacist and the coumadin clinic. To get my INR back in range, my warfarin dosage had to be droppep to about half of what I was taking previously. Once I was off the amiodarone, my dosage for warfarin returned to what it was pre-amiodarone.

I asked the clinic at what point I need to head to the emergency room. They said that INR of 11 was the threshold to seek ER attention. That is probably somewhat of a subjective call.

Yeah, I was just reading about the interaction with Amiodarone and Warfarin. At my husband's dosage he should be taking a 30% lower dose of Warfarin due to the interaction. So when he comes off of it, next month if he stays in normal sinus rhythm for that period, then they will have to completely revamp his dosage. Right now he is on 5mg two days a week and 2.5 the other 5. His inr spiked up to 4.8 in the second week out of the hospital.

 

[pellicle]

At my husband's dosage he should be taking a 30% lower dose of Warfarin due to the interaction

I think this is perhaps not the right way to look at it. Yes there is an interaction BUT for as long as you're on it you just need to think one way:

the intention to treat with warfarin is INR​

nothing more and nothing less ... the dose is only the bus number you take to get to that destination. That's all there is to it really ... keep within range.

This decision flow chart is from this post

https://www.valvereplacement.org/threads/complications-post-surgery.889636/post-934334

I think the information there about Paracetamol (Tylenol is one brand) is also beneficial knowledge too.

Best Wishes

 

[Lisa from LJ]

Lisa -- this makes a lot more sense than an INR of 100. And, FWIW, calculating the INR from the PT depends on the reagent value. The PT is divided by the reagent value to determine the INR.

You're correct about the reagent. I used a calculator with an average value, but didn't use exact values for that very reason.

 

[Lisa from LJ]

(If the hospital got an INR of 100, it would have/should have, re-run the test immediately.

True. I'm not sure it's even physically possible to have an INR of 100 without bleeding out from all parts of the body.

 

[SatoriFound]

I think this is perhaps not the right way to look at it. Yes there is an interaction BUT for as long as you're on it you just need to think one way:

​

the intention to treat with warfarin is INR​

nothing more and nothing less ... the dose is only the bus number you take to get to that destination. That's all there is to it really ... keep within range.

This decision flow chart is from this post

https://www.valvereplacement.org/threads/complications-post-surgery.889636/post-934334

I think the information there about Paracetamol (Tylenol is one brand) is also beneficial knowledge too.

Best Wishes

Yeah, I get that. LOL The literature does say exactly what I said though. That at a dosage of 200 for Amiodarone the average person requires a dosage of 30% lower than the norm of Warfarin to sustain an in range inr measurement. For him how this effected him is that when they gave him the normal dosage of 5mg of Warfarin his inr level was quite far outside the "therapeutic range" they have set for him. In looking at his current dosage, it is actually about 30% under the original amount he was told to take. We will see what his level is at when he has his next reading. For some reason they are waiting two weeks between the last one and this next one.

Since his afib hasn't come back, at least according to the readings we have been doing at home, since he went into normal sinus rhythm I will be interested to see whether they automatically up his dosage when they discontinue the Amiodarone. When he went to the doctor they gave him another wearable monitor, but after two days it fell off. His electro cardiologist was waiting to make sure his afib is sustained before taking him off the med, but I think he wanted the 24 hour readings that the wearable would provide rather than hubby manually taking ekg readings throughout his day since my husband doesn't seem to feel being in afib so can't take it when he might be having an episode.

Anyway, this will all be much simpler when he has the home monitoring set up. Less than 6 weeks to go until he qualifies to monitor at home.

 

[pellicle]

OL The literature does say exactly what I said though. That at a dosage of 200 for Amiodarone the average person requires a dosage of 30% lower than the norm of Warfarin to sustain an in range inr measurement

1. be careful about what you are calling "the literature" (publications by hospitals as guidelines do not count as "the literature")
2. these are as alluded to above "guidelines" and the definitive thing is INR

Best Wishes

 

[pellicle]

@SatoriFound

In academic terms, this first document (Managing Variability in dosing Warfarin) does not count as "the literature" but he cites a lot of "the literature. The Author.

This second one "Exaggerated Initial Response Warfarin Following Heart Valve Replacement" does count as part of the literature.

HTH

 

[SatoriFound]

1. be careful about what you are calling "the literature" (publications by hospitals as guidelines do not count as "the literature")
2. these are as alluded to above "guidelines" and the definitive thing is INR

Best Wishes

I am referring to the actual studies. In my line of work I read all kinds of different types of articles on new technology, lessons learned, theory.... I just thought others would do that too. LOL

 

[pellicle]

In my line of work I read all kinds of different types of articles on new technology, lessons learned, theory.... I just thought others would do that too.

I suspect that you'll find few professionals do ... in every area