PT with INR Disaster

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I was sent out to get a PT with INR on a patient whose previous level was way off (blood was like syrup coming out). So the doctor put her on 9 mg coumadin for 3 days then 5 mg daily after that.

So the woman is hard to stick, anyway. I start with a 23 gauge butterfly needle and she has some veins on her hand and I attempt to use those, but her veins are tough and you can literally see them roll as you try to push in them, but I get a return but it is very slow to come out and the vein blows. After that, I finally find a vein on the arm and using a 21 gauge I get return from that but the blood comes so slow and halfway down the tube it just stops. To the private duty nurse and me it looks like her blood is so thick it won't do anything. The nurse tells me she isn't suprised because the patient will hardly bleed enough to get a blood sample for the glucose monitor.

So I call the nurse at the doctor's office and explain what happened. She was very rude and said "I don't believe that!"

Then I told her the patient had an issue with this before and the doctor put her on 9 mg's coumadin for 3 days and then 5 mg daily. She said she didn't believe that, either. I told her I had the order in front of me and she put it on hold. Then she comes back and says to bring her in the office and they will do it there.

The nurse takes her to the doc's office. I call the residence about 15 minutes ago to see what happened, and the nurse tells me, well, they weren't very happy with us. They didn't draw her blood but they did a finger stick with this big lancet and got her PT that way but I don't think they got an INR, but her PT was 2.2 and they left her on 5 mg's of coumadin.

I did not know they could check her PT with a finger stick. Anytime I have brought that blue topped tube to a lab they said it is very important I fill it to the top.

Someone please explain what happened. What's this fingerstick deal? I feel like a real idiot. Why do blood draws for PT in the first place if all it takes is a fingerstick?

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Specializes in cardiac/critical care/ informatics.

2.2 is the number of an INR not a PT, and sometimes if the milk the finger enough they can do a fingerstick, and use a peds tube.

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Specializes in SICU.

Your not an idiot. You can not get correct results from a finger stick. The office nurse was the idiot.

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Specializes in Family.

We did fingerstick PT/INR's routinely in the office. She shouldn't have been ugly with you about anything though. ((((Hugs))))

ETA: I do recall having to use the tube if we sent the specimen to the hospital. I truly don't know why they need so much blood.

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at 2.2 she should not have had thick blood. It sounds like keeping her on 5 mg would be correct, but to recheck in at least a week. I am now using a protime monitor in the homes, on those pt's the physician ok's to use. Its so convenient to have a result during your visit, call it in and get further orders.

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Specializes in SICU.

Sorry, it seems I was wrong. Our lab however will only use the 3ml blue tube, no microcontainers. Also if we use a butterfly we even have to waste the first 3 ml's of blood and use the 2nd 3ml's of blood. I have no idea how you would be able to get the correct flow of blood from a fingerstick.

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at 2.2 she should not have had thick blood. It sounds like keeping her on 5 mg would be correct, but to recheck in at least a week. I am now using a protime monitor in the homes, on those pt's the physician ok's to use. Its so convenient to have a result during your visit, call it in and get further orders.

I can't explain it, but two of us saw it ourselves. The blood just stopped about halfway down the tube and when we tried to milk it you could see where it was clotting!

I just don't understand what was going on.

Next time can I arrange to get a fingerstick instead of try to draw the blood? I had to stick her about 5 times (though I have seen them come back from the hospitals with bruises up and down both arms from unsuccessful VP's)

Maybe I can use a peds tube and do the fingerstick using the same kind of lancet they used? The private duty nurse says she hardly bleeds enough to get a glucose reading with the regular lancets.

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Specializes in Home Care.

We use INRatio fingerstick machines for most of our patients in home health. We started using them a few months ago. Prior to that, though, I have occasionally had a patient where the blood would not entirely fill the tube to the line it was supposed to. In that case, the lab told us we could use pediatric blue top tubes for those INR's. Do you have access to a fingerstick protime machine in your agency? If so, I would definitely get an okay from the physician to go ahead and do it that way. It would save you a lot of hassle and the pt a lot of sticks. So far we have had very few problems with inaccurate results. The physicians we work with have basically said use one or the other...either fingerstick or venipuncture...but do not alternate between the two.

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Specializes in Critical Care, Cardiothoracics, VADs.

We get a lot of our VAD patients who live away from the hospital to use a "point of care" INR monitor called the Accuchek. It works just like a boold glucose monitor with fingersticks, and patient controlled coumadin (via algorithm) has actually been shown in research to result in better INR control. I've never heard of a hospital using one though - quite expensive.

http://www.accu-chek.com/index.html

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Specializes in Infection Preventionist/ Occ Health.

FYI in general, the point-of-care tests tend to be less accurate and precise than traditional laboratory methods for obtaining a PT/INR. If you ever receive a high or unusual result with a POC meter, it should be confirmed with a venipuncture sample.

Another FYI, there is no such thing as "thick" blood that clots too easily. Blood viscosity is entirely different from the amount and acitivity of the clotting factors.

The nurse at the doctor's office should not have been rude to you. Some people are just really difficult sticks.

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Specializes in Critical Care, Cardiothoracics, VADs.

BSNDec06, do you have some literature about this inaccuracy?

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Specializes in Infection Preventionist/ Occ Health.
BSNDec06, do you have some literature about this inaccuracy?

I apologize in advance for the length of my response, but I believe that it is important for other health care professionals to have a good understanding of where medical technologists and pathologists are coming from when they show resistance to implementing POC testing...

Point of care meters are not necessarily inaccurate, but they have a greater tendency to become so because they are typically not monitored as carefully as traditional lab methods.

It is my understanding that under the Clinical Laboratory Improvement Amendments of 1998 (CLIA '88), all laboratories performing work for Meidcare must participate in a proficiency testing program. This means that they must analyze samples provided by an approved agency such as JCAHO or the College of American Pathologists on a regular basis and provide the results to the accreditation agency. If there are too many instances where a particular lab's results to not agree with their peers using the same analyzer or method, they risk losing their accreditation and must take measures to correct any problems.

Point-of-care testing is not subjected to this kind of scrutiny as a general rule. It is up to the laboratory director at each individual hospital to decide how closely POC testing is regulated. Physician office laboratories are exempt from CLIA '88 if they are performing "waived" tests, which includes most POC testing systems. This means that they may never be subjected to external review, and any problems with precision or accuracy might not be brought to light. In order to gain status as a "waived" test under CLIA '88, a laboratory testing system must be determined to be simple enough that any minimally trained worker could perform the testing with a reasonable degree of certainty that major mistakes will not be made.

Many of the studies I found state that about 80% of their results were in agreement between the laboratory and POC methods. In my opinion as a laboratorian, I see this as a problem. If I were a physician, PA or NP, I would not want to take the chance that in 20% of cases my POC method would not agree with the "gold standard" laboratory method. However, physicians must decide whether the convenience to them and the patient is worth taking this chance, and sometimes it is.

More and more laboratorians today are beginning to embrace POC testing, but we more than anyone else are aware of the potential pitfalls. So, it is important for you to understand where I am coming from and how this affects my opinion on this subject.

Here are some research articles from a Medline search:

Am J Clin Pathol. 2005 Feb;123(2):184-8

Mayo Clin Proc. 2005 Feb;80(2):181-6.

Semin Vasc Med. 2003 Aug;3(3):243-54.

Thromb Res. 2004;113(1):35-40

J Clin Anesth. 2004 Feb;16(1):7-10

J Med Assoc Thai. 2003 May;86 Suppl 1:S67-75.

Pharmacotherapy. 2002 Nov;22(11):1397-404.

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