Hello Anna in such a case I would draw blood for Ab Sc on Monday at admission since the possibilty of finding allo Abs in this case and having to find pheno comp blood is very low.

wrong thread...

I quite see from where you are coming Colin, and I totally agree with your post, but I can envisage a situation where antigen positive blood may have been given.

Supposing a patient is transfused at hospital A. The patient develops an anti-Jka (an antibody that is notorious for disappearing in vivo quite rapidly).

Despite the patient being issued with an antibody record card, the patient loses it/forgets to show it/shows it, but it is ignored when, a few months/years later, they go into a different hospital (let's be original, and call this hospital .

Hospital B has no access to the records of hospital A, and transfuses cross-match compatible blood, that just happens to be positive for the Jk(a) antigen.

BANG! There is an anamnestic response in the patient, and they have a reaction.

I know that this does not add to the subject, in that the anti-Jka would not be detected in the plasma, however fresh the sample may be, but it is, nevertheless, an example of where antigen positive blood could, quite innocently, be transfused, and a further argument for a national computer database.

:eek::eek:

This actually happened to us. We ended up unfortunately being Hospital B in that scenario and the patient did subsequently pass due to complications of that DHTR and kidney failure.

Does anyone think that maybe we all go a little over the top with these rules sometimes?

Is is 3 days or 72hrs?

When does the clock start ticking- the moment you book the sample/request into the LIMS or the time sample was actually taken?

Do you enter the actual time the patient received the first unit of blood, so your system/ staff know to the minute when a sample is no longer valid?

If a clinician asks how long a sample previously sent is valid for- is this quoted to the actual day and hour?

We need to keep this simple- KISS!!!!

There will always be an element of risk with blood transfusions, but this has to be balanced with providing as good a service as possible and minimise disruption to both staff and patients.

How many patients have really been affected when a sample did not meet exact , to the minute testing criteria?????

Edited October 1, 201014 yr by RR1

Years ago the AABB standards changed from stating a sample was good for 48 hours to 72 hours. The next edition of Standards changed it to read 3 days. Now you will read descriptions that say the day of draw is day 0 so a sample can expire at midnight after "3 days" and be 1 minute shy of 96 hours old. We have been doing this for nearly 30 years and patients are not keeling over like they got a hospital-acquired infection (kills way more patients every year than blood does).

The 3 day rule is about the sample representing the patient's immune status at the time of transfusion. If no recent history of transfusion, that immune status won't change over a period of at least weeks. If a transfusion has occurred in the prior 3 months, the day after you draw the sample could be the day their new antibody finally becomes detectable and then on day 3 when you transfuse them they could have a good titer and a reaction. But requiring a draw the same day was impractical so they used 2 days (48 hours) and when they didn't have a large problem with transfusion reactions they put their toes a little farther in the cold water and tried how it would go with 3 days. No big problems so it seems like a reasonable compromise.

As for patients with history of antibodies, yes, doing the screen when it is fresh is easy and seems like a good idea so why not. An antiglobulin xm can't be about complement anymore due to using anti-IgG and EDTA samples. So, how good is your aged specimen at reacting with antigens to which you know the patient has a historic antibody as well as antigens (probably low frequency) to which you didn't know they had an antibody? (You only care about the known ones if you can't antigen type the units or need to catch an error in that typing.) Probably fine since so many places do it. You could validate it by saving antibody specimens till they are as old as you want to use and testing them for their known specificities. You could compare reaction strengths to the original. Soon you would know what you should do and you can tell all the rest of us and maybe publish your little study as well. Or maybe you could take the easy way out and find such a study someone has already done. I suspect that different antibodies will behave differently--often by specificity (Kidds) but also individually.

If everyone on this thread did 10 such samples out, say, 21 days trying to cover the common specificities, we could get an interesting pool of data. Lots of variables to capture--methodolgy, specificities, sample age, EDTA vs serum, etc. Hmmm. Sorry if I am getting a little crazy on you.

We also use 72hrs for inpatients and 14 days if no pregnancy or transfusion in last 3 months OR any known antibody hx. If any one requirement is not met we draw "no more than 72 hrs before surgery."

This is a reaccuring issue in our lab, we have a patient that previously had a positive anitbody screen, and now it is negative. Our debate is, if the patient hasn't been stimulated in the last 3 months (ie transfusion, pregnancy or surgery, then the outdate should be 3 weeks. Others say, there is a history, it should only be good for 72 hours. Has anyone else run into this issue? Where can I find the literature to support this?

Thanks

dhil,

My question to you is how do you determine if the patient has been "stimulated" within the last 3 months. Do you check history at your facility? Do you check history at nearby facilities? Do you check history at facilities throughout your state, throughout other states, throughout the country, outside of the country, etc..? I apologize for being cynical but my point is that we only have the ability to check patient history usually within our own facility and so it is better to error on the side of caution and abide by checking the specimen every three days which is apparently the minimal number of days where we might detect the product of a sensitization event.

This actually happened to us. We ended up unfortunately being Hospital B in that scenario and the patient did subsequently pass due to complications of that DHTR and kidney failure.

Lara sorry to hear about your patient with the Jka and I do agree that the senario Malcolm describes may happen and is a potential danger for any patient admitted to hospital.

I go back to the original post, where a history was know and the current screen is negative so the real question I think we are being asked is do you treat this patient differently. So I think the thing you need to concider about is this patient is, are they at any more risk of producing an antibody as a secondary or amnestic response than any other patient since the current sample was drawn. Where there is a history of an antibody you should always select antigen negative blood whether the antibody is detectable or not so what is the risk that after selecting and crossmatching blood there will be a delayed haemolytic transfusion reaction due to a non-detectable antibody in your current sample. So I stick to my original post this sample has the same validity as any other sample, so if like Liz you have a maximum of 72 hours this sample has 72 hours. I would crossmatching antigen negative units and then apply the BCSH table I posted earlier to decide when we needed a new sample.

This thread has prompted some interesting debate about sample validity in general despite a fairly specific question being posted.

Edited October 3, 201014 yr by Colin Barber
Typo

we have several sickle patients which goes to different hospitals in same area and it becomes very tricky. All our sickle patient, we check history every time patient gets admitted. Sometime this patient goes to three different hospital in one month not realizing that it is very dangerous for them.

History is very important. we have s sickle patient with multiple allos and all cells are reacting, patient went to neighbouring hospital where they thought patient had warm auto and gave best compatible where we have been giving phenotypically matched units to this patients. luckily patient came back to us next week and we followed our protocol and patient did OK.

We expire samples at 72 hours no matter the history. The exception is neonates in which we keep the sample until they are 4 months old or are discharged to outpatient.

:cool:In our facility, we have the same policy as Kate's place. Account numbers are not used for BB identification, only a permenant medical record number. We routinely perform pre surgical testing using the extended specimen outdate of 14 days, providing the criteria are met. If the patient requires transfusion during surgery or post op, this is ordered under the current billing number. We know it is the same patient because their MR# is the same.