Can't find expiration dates anywhere!

[dhil]

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

[David Saikin]

From the current edition of the AABB technical manual, p442: : "If histories of transfusion and pregnancy are certain and if no transfusion or pregnancy has occurred in the previous 3 months, no limit exists to the length of time tha a pretransfusion sample is valid for donor red cell selection." I believe this is irregardless of the antibody history. BUT, the type and screen must be performed within 3 days of collection.

[dhil]

So you have to read between the lines. Thanks Dave!

[Liz]

Whatever the history we keep the 3 day rule.

[dhil]

Meaning you perform the antibody screen within 3 days or you expire all of your samples within 3 days?

[Liz]

Our samples stay for 72 hours during which we would have performed the AbSc, after 72 hours they are "expired". We keep the samples for a total of 2 weeks to cover the post-transfusion period.

It is better not to have too many options. Keep it straight forward.

[kate murphy]

We do pre-admit samples for elective surgeries. The samples are tested upon receipt (same day of draw), accompanying document states that the patient has not been pregnant or transfused within the previous 3 months (pre-admit form signed by pre-admit RN taking the history). These specs are good at my hospital for up to 14 days, for type and crossmatch for surgery. In the BB, we identify these specs by putting green tape around the tube, and they are stored in separate racks. The expiration date in the computer system is changed from the default of 72 hours to up to 14 days.

[mhc]

From the current edition of the AABB technical manual, p442: : "If histories of transfusion and pregnancy are certain and if no transfusion or pregnancy has occurred in the previous 3 months, no limit exists to the length of time tha a pretransfusion sample is valid for donor red cell selection." I believe this is irregardless of the antibody history. BUT, the type and screen must be performed within 3 days of collection.

According to AABB standards, a patient who has a record of previously detected clinically significant antibodies, even if the antibody screen is now negative, still requires an antiglobulin crossmatch. My interpretation of the AABB standards is that the sample used for an antigloblin screen or crossmatch must be less than 3 days old.

[Dr. Pepper]

According to AABB standards, a patient who has a record of previously detected clinically significant antibodies, even if the antibody screen is now negative, still requires an antiglobulin crossmatch. My interpretation of the AABB standards is that the sample used for an antigloblin screen or crossmatch must be less than 3 days old.

mhc, I think that these are two different issues:

1. The antiglobulin crossmatch is done as an added level of protection if a patient has a present or past history of a significant antibody, instead of relying soley on a negative . The chances of having an incompatible AHG crossmatch with a negative screen have been calculated as 1 in 10,000. These odds change dramatically if there is an antibody: 1 in 10 with anti-K, 2 in 3 with anti-Fya etc.

2. The 3 day rule is an arbitrarily selected standard to detect newly appearing antibodies stimulated by recent pregnancy or transfusion. This really has no bearing on whether they currently have an antibody (or history) or not. So whether you do an IS or electronic XM or a full one, the same standard as quoted above by David should apply.

[bmarotto]

We do pre-admit samples for elective surgeries. The samples are tested upon receipt (same day of draw), accompanying document states that the patient has not been pregnant or transfused within the previous 3 months (pre-admit form signed by pre-admit RN taking the history). These specs are good at my hospital for up to 14 days, for type and crossmatch for surgery. In the BB, we identify these specs by putting green tape around the tube, and they are stored in separate racks. The expiration date in the computer system is changed from the default of 72 hours to up to 14 days.

Kate,

How do you close the loop for patient ID when the patient comes back in for surgery? We would love to implement something like this but our billing dept says we can't bill anything off the pre-admit billing account because now the patient is admitted with a new account number. I suppose we could merge the outpatient visit into the inpatient one on the day of surgery.

[Dr. Pepper]

bmarotto, we do the initial T&S on the outpatient pre-admit sample. Our admitting dept. also pre-registers the patients for the future OR/inpatient account. We do the crossmatches a day or two before surgery on that new account number. Name and MR# are our BB identifiers which don't change. We order the blood/crossmatches and an informational test (for our eyes only) "SPEC USED" to record the spec# of the original T&S. Works fine, no problem with reimbursement. We have Meditech.

[mhc]

Actually, I thought that the 3 day rule had to do with sample integrity for the antiglobulin test, specifically for complement dependent antibodies. I just followed the logic that if you have to do an antibody screen within 3 days, that an antiglobuling crossmatch, if needed, should also be done on a less than 3 day old sample.

[Malcolm Needs ☆]

If this were so, it is now largely outdated by the fact that most samples used these days are EDTA, which means that there will be no active complement in them (Ca++, Mg++ and Mn++ being chelated by the EDTA).

[Colin Barber]

Actually, I thought that the 3 day rule had to do with sample integrity for the antiglobulin test, specifically for complement dependent antibodies. I just followed the logic that if you have to do an antibody screen within 3 days, that an antiglobuling crossmatch, if needed, should also be done on a less than 3 day old sample.

The 72 hour validity rule I would have thought is based on transfusion history and aimed at secondary immune response following transfusion. In the UK our BCSH guidelines have a table which for those of you familiar with soccer I call the off-side rule, its as convoluted to understand as off-side. But I understand the new guidelines are going to simplify to a sample being valid for 72 hours following Transfusion.

I have attached our current off side rule as I call it.

[ATTACH]417[/ATTACH]

BCSH sample validity.docx

[Ellen Zeigler]

The 72 hour validity rule I would have thought is based on transfusion history and aimed at secondary immune response following transfusion. In the UK our BCSH guidelines have a table which for those of you familiar with soccer I call the off-side rule, its as convoluted to understand as off-side. But I understand the new guidelines are going to simplify to a sample being valid for 72 hours following Transfusion.

I have attached our current off side rule as I call it.

[ATTACH]417[/ATTACH]

As long as you have an accurate pretransfusion history, the issue becomes the licensure of your AHG antisera. Those with Antibody require the an AHG x-match so its in the hands of the Cooms sera package instert

[dhil]

soooo

Edited September 29, 2010 by dhil

[dhil]

mhc, I think that these are two different issues:

1. The antiglobulin crossmatch is done as an added level of protection if a patient has a present or past history of a significant antibody, instead of relying soley on a negative . The chances of having an incompatible AHG crossmatch with a negative screen have been calculated as 1 in 10,000. These odds change dramatically if there is an antibody: 1 in 10 with anti-K, 2 in 3 with anti-Fya etc.

2. The 3 day rule is an arbitrarily selected standard to detect newly appearing antibodies stimulated by recent pregnancy or transfusion. This really has no bearing on whether they currently have an antibody (or history) or not. So whether you do an IS or electronic XM or a full one, the same standard as quoted above by David should apply.

Does this apply to patients that have a negative history of antibodies? We will get Pre-op patients 2 weeks before their surgery. Post-op we will use the pre-op blood specimen dated 2 weeks prior to do an immediate spin crossmatch. Is this appropriate?

[Ellen Zeigler]

who's your antisera vendor?

[dhil]

who's your antisera vendor?

Immucor

[Ellen Zeigler]

who's your antisera vendor?

I pulled the Immucor Anti-Human Globulin (Anti-IgG, -C3d; Polyspecific), Isnert Code 3002-1; 10/2007.

A crossmatch is an indirect antiglobulin test (you just don't know the RBC antigen profile when you start). In the secion under Specimen Collection and PReparation, it refers to regulatory agencies, if yours has a limit and for red blood cells from donor units, you may go throughout the dating period of the red cells. The other issue to keep in mind is that evacuated tubes are medical devices and for most - 14 days is the limit. You can always chose to go shorter. We do all in patients as 3 days and up to 14 days for pre admit testing (with no transfusion or pregnancy history)

[Colin Barber]

This thread seems to have moved away from the original question, which to summerise was in a patient who's historical antibody is not currently detected and with NO recent immune stimulation - ? How long can you use the current sample. A very real situation we, I am sure, all see in from time to time in transfusion labs.

My feeling is if the antibody is genuinely sub detectable and there has not been a recent immunizing event, then sample has the same validity period as any sample in your organisation and will depend how you store the plasma/serum prior to a compatibility test.

The 3 day rule kicks in once this patient has been transfused (with antigen negative blood I hope), this is someone with a previous history of transfusions they may mount a secondary immune response and a "new" specificity may appear as a result of this transfusion. Therefore making the current sample invalid.

I hope this post helps answer the original question.

[Malcolm Needs ☆]

The 3 day rule kicks in once this patient has been transfused (with antigen negative blood I hope), this is someone with a previous history of transfusions they may mount a secondary immune response and a "new" specificity may appear as a result of this transfusion.

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:

[Liz]

Malcolm, absolutely and I would insert before the BANG! that as the patient reaches Hospital B you drew the 1st sample, BUT he was transfused a day prior to admission and the Abs are still undetectable. So 3 days later please do draw a second sample even if the patient was not transfused at your hospital during those 3 days, as the antibodies may be detectable after 3 days.

[Malcolm Needs ☆]

Excellent point Liz.

[galvania]

Yes, we all want to err on the side of caution BUT recently someone I know had to go into hospital in London for an operation where there was a real possibility that blood would be needed. This woman is 86 years old and cannot travel on public transport. A week before the op (scheduled for a monday) she had to go in to have all her pre-op tests - except her T&S. For that she had to come back again on the friday because of the 72hour rule. So - two visits with taxi fares at £20+ each time and two episodes of anxiety. OK - there's no guarantee that she hadn't been transfused during that week. I think at that age it is safe to say she hadn't been pregnant for well over 40 years! Are we sometimes at risk of forgetting ALL the consequences for the patients. (The operation was successful and she didn't need any blood