Any Documentation on Same day INR Results

[Jackie]

I am having a discussion on INR testing with Kaiser. They have changed from same day results on INR testing results to 24 - 48 hous. Does anyone know of any documentation on this subject. I talked with the supervisor of the Anti-Coagulation Clinic and she said that her department is against sending the blood draws out but the lab is doing it anyway. Any sugestions?

Jackie

 

[Ross]

That is just plain BS. They know full well that Coumadin is a very slow acting drug, that the results of a INR test must be reviewed immediately or they are meaningless. Let's see if Al has something on it. Being that it takes up to 3 days for a dose to show in a result, a test result given 1 or 2 days after it has been taken tells you nothing about what the result is at present.

 

[Nancy]

In my opinion, this is malpractice! The results are not valid the second or third day. Absolutely unbelievable. Kaiser has some strange ideas about lab tests.

This is not to your benefit at all. It is only to Kaiser's benefit.

As soon as I could, I dumped my Kaiser related insurance. I am not the heart patient here, but I was going through chemo at the time, and they had strange ideas about my necessary lab tests during chemo. Not realistic and it was detrimental to my health and wellbeing.

 

[catwoman]

Jackie:
Are any of these people you've been talking with at Kaiser pharmacists (by any stretch of the imagination)?
A pharmacist would understand much better the need to get immediate results to the patient, rather than waiting 48 hours. By then the INR will no doubt be different. Any dosage change initiated then based on results from 48 hours before could be too much, perhaps not enough, even unneeded.

 

[Jackie]

Jackie:
Are any of these people you've been talking with at Kaiser pharmacists (by any stretch of the imagination)?
A pharmacist would understand much better the need to get immediate results to the patient, rather than waiting 48 hours. By then the INR will no doubt be different. Any dosage change initiated then based on results from 48 hours before could be too much, perhaps not enough, even unneeded.

Yes, it is suppose to be stocked with pharmacists.

 

[sue943]

It is not vey comforting for those of us with no option but to have 'out of date' readings, to be told here that they are useless. The standard practice here is to attend the warfarin clinic in a morning, have blood drawn, the results are then sent by post and we either receive then the following, but normally two days later. There is no alternative other than to spend quite a lot of money on self testing equipment and supplies, and that isn't an option - the warfarin clinic at the hospital is free . I have it checked normally every two weeks but if it is out of range then this drops to weekly (or if necessary it can be less) until the range has stabilised. If urgent action is required they phone the same day.

Only about three times in sixteen months have I received a call telling to double up or skip a dose, my readings are fairly consistent and mostly within range of 3.0 - 4.0.

 

[DrAllan]

I find this to be a fascinating thread. I have some criticisms of the tone of it however. The best way to put this is that there is a certain ?MacDonald?s? approach to it that as soon as one goes thru the order line the hamburgers should be ready at the pick up window.

Let me remind you that I am the one who self tested daily for 6 months and found marked variations in my INR regardless of the various regimes of strict diet, exercise, altering dosage or no changes to dosage. The bottom line to that is that for myself a stable INR just doesn?t happen.

Now let me address the question of delay from drawing to INR result reporting and possible drug changing. Historically, the morning blood draw came about because it took some time for the test to be done and get the results back to the physician in order to get in touch with the patient for a drug change before the office closed. This reflects the tendency to want to correct any abnormality, i.e. if something is high lower it and conversely if low raise it.

The dynamics of Coumadin and INR are complex. There are several phrases often repeated on this site that have some degree of scientific validity. The one of concern here is that it takes about 5 days for a change to be noted in the INR when the dosage is changed. This is to a great extent very true. However many have posted that when told to hold even a single dose because of an elevated INR, it ?drops like a rock: the next day. On the face of it, these seem to be somewhat contradictory statements. Again, remember the pharmokinetics. The effect of Coumadin on liver production of clotting factors occurs soon after the drug is taken and lasts for approximately 13 hours. However, the already circulating clotting factors (perhaps as many as 5-6) are normally cleared from the blood stream over time ranges of 8 hours to five days. Prothrombin, that which is mainly measured by the INR takes the 5 days to disappear.

Put all these factors together. Does it really make any difference in the timing of the test to the drug change? Look at it another way in relation to how often you are being tested and when the change in the INR that needs to be corrected occurs. You are tested weekly, the change occurs on day 2 and you are not tested again until day 7. Thus there are 5 day between the onset of abnormality and the awareness of the change. Given the same facts with biweekly testing then the ?delay? is 12 days, and if tested monthly the delay is 28 days.

Now put this all together with another mantra of this site, ?easier to replace blood cells than brain cells.? If you truly believe that, then so what if you are high for the ?2? days that this thread is all about? Conversely what is you risk of a thromboembolic event until corrected? Don?t forget that not every thromboembolus results in going to the brain, and that not every blocked brain blood vessel shows any effect on the patient.

I?m not sure that I have clearly articulated my thoughts, but there is enough to stimulate some thinking on the part of others.

 

[Hank]

Fascinating

Fascinating

This whole topic is fascinating.

Thank everyone for their input on subjects like this when they arise.

I feel that regular self testing with a properly performed finger stick is all that I need to be able to know what my INR is and I feel very comfortable with that.

My cardiologist feels the same and it has worked that way for 5 years now. I am fortunate that my matabolism is predictable.

I will be following this thread with interest though because I just get this instinctual feeling that same day results are good, and results older than that are less good.

 

[Karlynn]

The other issue I have with not getting your INR results the same day, is that you wonder how long your tube of blood has sat around before it was tested. We know that this can impact the INR result and so the dosing can be done under "false" numbers.

 

[Jackie]

The other issue I have with not getting your INR results the same day, is that you wonder how long your tube of blood has sat around before it was tested. We know that this can impact the INR result and so th
e dosing can be done under "false" numbers.[QUOTE}

How do you know that this can impact the INR result? When I bring this up to the AntiCoagualation Clinic and the Lab, it would be nice to have something to prove my point of view. Is there a site that might give the information? I am going to do a google search and see if I can find something.

Jackie

 

[Guest]

I know Dan Witt, a Kaiser Pharmacist - Executive fairly well. He was formerly the head of Kaiser's Anticoagulation cliniuc in Denver where they have 7,000 people being managed. During an earlier controversy over Kaiser (in California) policies I asked Dan a question and asked if I could quote him without using his name. He told me that it was OK to use his name and that anyone working for Kaiser could look up his e-mail address and phone number and contact him. I'd suggest doing that.

 

[Nancy]

If any of you are hospitalized, you know that you are going to get very frequent ProTime tests. Let me ask this question.

Do you suppose your doctor would be satisfied if the lab told him/her that they would not give him/her the results for 24-48 hours, period? I rather think not!!

I am sure all hell would break lose and possibly someone would lose their job.

So--Why should a patient out of the hospital have to put up with this kind of nonsense??

I don't recall at ANY time during ANY of Joe's enormous amounts of hospitalizations, that the results were not available within a couple of hours, and the nurses would continue to call until results were in.

AND the lab draws are done in the very early morning hours, sometimes at 4AM, so the doctors will have the results when rounding at 8 or 9 AM.

We have been told that if lab results are not available when they come around, they catch all kinds of grief.

I just feel this is shoddy care.

 

[DrAllan]

Jackie,

Are you taling about 24-48 hours to get the test results back, or 24-48 hours before the test is done?

I googled the following phrase ‘inr changes in blood tests with delay after drawing' and there were several interesting hits on the topic, two of which are copied below. The second is the more valuable and scientifcally proven paper.

The American Society for Clinical Laboratory Science

Table 4: Causes of Protime (INR) Variability
• Missed dosage
• Dietary changes: foods high in vitamin K
• Blood collection variations: short draw, clots, high temperature, delay cause high INRs
• Blood collection variations: long draw, prolonged chilling, shaking cause low INRs

Blood collection errors also cause protime changes. The laboratory scientist must ensure that the blood reaches the collection tube "fill line" and must gently mix it within seconds of the time it is collected to make sure it does not clot. "Short draws" or clotted blood both give erroneously high INRs. Blood that is transported at temperatures above 80° Fahrenheit or stored at room temperature for more than 24 hours also causes high INRs. On the other hand, if the scientist overfills the blood collection tube, or the blood is stored in the refrigerator for more than 24 hours, the INR will be falsely low. And if the blood is shaken too vigorously in mixing, its cells may rupture, also causing false low values. If there is any suspicion that a collection error has occurred, the test should be repeated before the dosage is adjusted.


Clinical Chemistry. 2005;51:561-568.)
Preanalytical Variables and Off-Site Blood Collection: Influences on the Results of the Prothrombin Time/International Normalized Ratio Test and Implications for Monitoring of Oral Anticoagulant Therapy

Abstract

Background: The quality of oral anticoagulant therapy management with coumarin derivatives requires reliable results for the prothrombin time/International Normalized Ratio (PT/INR). We assessed the effect on PT/INR of preanalytical variables, including ones related to off-site blood collection and transportation to a laboratory.

Methods: Four laboratories with different combinations of blood collection systems, thromboplastin reagents, and coagulation meters participated. The simulated preanalytical variables included time between blood collection and PT/INR determinations on samples stored at room temperature, at 4–6 °C, and at 37 °C; mechanical agitation at room temperature, at 4–6 °C, and at 37 °C; time between centrifugation and PT/INR determination; and times and temperatures of centrifugation. For variables that affected results, the effect of the variable was classified as moderate when <25% of samples showed a change >10% or as large if >25% of samples showed such a change.

Results: During the first 6 h after blood collection, INR changed by >10% in <25% of samples (moderate effect) when blood samples were stored at room temperature, 4–6 °C, or 37 °C with or without mechanical agitation and independent of the time of centrifugation after blood collection. With one combination of materials and preanalytical conditions, a 24-h delay at room temperature or 4–6 °C had a large effect, i.e., changes >10% in >25% of samples. In all laboratories, a 24-h delay at 37 °C or with mechanical agitation had a large effect. We observed no clinically or statistically relevant INR differences among studied centrifugation conditions (centrifugation temperature, 20 °C or no temperature control; centrifugation time, 5 or 10 min).

Conclusions: We recommend a maximum of 6 h between blood collection and PT/INR determination. The impact of a 24-h delay should be investigated for each combination of materials and conditions.

 

[Jackie]

Dr.Allen,

Thank you for the information, I had found this site but some way I did not see this information. I am now trying to digest it all.

I think I am going to have to leave this quest that I am on for now. I just found out tonight that my 33 year old son is having back surgery as soon as possible. Spent the night in the hospital and will have a MRI on monday, and then.....................

Jackie

 

[Karlynn]

Jackie - my prayers for your son!

 

[Guest]

Being high is not as much of a worry as being low and not getting the results. Accepting 24 - 48 hours for results would look bad in a malpractice case when 45 seconds for results is available.

 

[sue943]

That information about testing is reassuring. My blood is always tested in under 6 hours from collection and isn't transported anywhere, just to the lab from the room in which they are drawn, perhaps a matter of a hundred yards or so. As I said, if there is an urgent change we are notified by phone the same day, otherwise we know the level has barely changed and can continue with same dosage.

 

[Ticky]

My doctor told me it takes 24 hours for the change in Coumadin dose to take effect. I've read different times on this. What is the "definitive" answer?

Lisa

 

[Karlynn]

3 days is usually what we say. Maybe 48 hours to show some effect, but certainly not 24 hours.

 

[ALCapshaw2]

I think the question needs to be divided into TWO scenarios:

HOLDING a dose can cause INR to "Drop like a Rock" in one day.

INCREASING a dose will take 3 or 4 days to be fully metabolized.

FWIW, while I agree that getting test results the Same Day is the IDEAL, next day is not catastrophic, especially if you take your meds in the Morning and can wait until the Lab / Doctor's Office is open to see if you need to change dose.

'AL Capshaw'