Age of specimen for antibody screen

[Cliff]

I recently ran across this in the JCAHO Q&A.

I found it troubling that they require a specimen to be 3 days old or less when used for an antibody screen or crossmatch. I looked through their Standards and could not find the same requirement.

How long you you use a specimen for ABS / crossmatch?

[QJULI]

We will use the specimen RESULTS for greater than 3 days IF the patient has signed a statement that they have not been pregnant and have not been transfused in previous 3 months. We have to PERFORM the testing within 24 hours of collection. This question/poll seems a little misleading. . .what exactly were you trying to determine??

[kate murphy]

We use 3 days as a cutoff, with the exception of pre-op specimens with signed forms stating no pregnancy/transfusions within the previous 3 months. Those pre-op specs are 14 days.

[David Saikin]

While we usually perform the testing (absc) on the day of collection, our policy states that it must be performed within 3 days of collection. We may save the specimen for up to 7 days if no transfusions/pregnancy within the past 3 months.

[donellda]

We use our specimens for 3 days. In the case of preadmission testing, we can keep the specimen for 14 days as long as the patient had not been transfused or pregnant in the last 3 months.

[QJULI]

I would like to add that your reagents may have a limit as to the age of the specimen. . you should be checking your package inserts to see how old the specimen can be.

[Lcsmrz]

Some facilities (mine included) have different specimen storage limits for different assays:

ABO/Rh - either 2 or 14 days

Abs - 2 days

XM - either 3 or 10 days

Ag Typing - varies by antisera

etc

[Mary]

Most of the Immucor package inserts state that EDTA samples can be used for up to 10 days and clotted samples for 21 days, however in the preadmission environment we use them for up to 14 days.

[Sandy Jo]

I saw the same FAQ and am concerned about it because it states "If a patient's history is known and they definetely have not been transfused or pregnant in the preceding six months, protocols can be established for frozen retention of the patient's serum for a longer period."

It bothers me because:

a) It does not state anything about needing to freeze the specimen to use it >3 days later in the JCAHO standards (AABB wants you to comply with reagent manufacturer requirements).

AND

Could not find anything about negative transfusion/pregnancy history for six months in JCAHO standards. They state that SOP's should be consistent with AABB standards and AABB standards use three months for the negative history.

Has anyone addressed these issues with JCAHO or an inspector?

[bbbirder]

We will draw specimens for pre-op patients up to two weeks ahead (as long as there is no history of transfusions or pregnancy within 3 months). We do the blood type & antibody screen right away.

We use the specimen for crossmatching on the day before or day of surgery. Since the crossmatch doesn't involve any reagents, no product inserts apply, only the standards. (If you do electronic XMs the age of the specimen wouldn't be an issue at all.)

[EdSandlin]

How on earth can you trust a statement from a patient about when or if they have been transfused or pregnant? I've had nurses tell me that their patients "can't remember" if they have even been in a hospital in the last three months.

[Diane]

The 3 day rule is also required by the FDA, for antiglobuling testing. We do the antibody screen within 72. Crossmatches we go as far as 14 days, unless we have to do AHG crossmatches.

I believe what they are addressing here is the reactivity of the IgG antibodies in the patient's sample, and that it may decrease after 72 hrs. An immediate spin crossmatch is really an ABO match, so that's considered OK beyond 72 hrs.

[luhubert]

We use our pre-op type and screens for 10 days. If the question had been worded so that previous transfusions and pregnancy had been addressed, we could have answered the poll more easily. I can't answer the poll because, it the patient was pregnant or transfused in the last 3 months or if I don't know, then the TS specimen is only good for 3 days. Crossmatches are held for 3 days in our facility with the exception of autologous which stay crossmatched on the patient until discharge.

[Ellie Ross]

We normally use specimens for 3 days. We have an exception to this rule.

Exception: Our "Disclaimer" policy

PreAdmit patients are interviewed for transfusion history. If they are not pregnant and or have not been transfused or pregnant in the last 90 days we will extend the clot to 7 day expiration, a disclaimer is filed out and signed and sent to the Blood Bank. Upon admission the expiration date is then adjusted to 3 days upon transfusion of first NON Autologous unit within that 7 day period.

This has worked out great for our preadmit patients who come in 6 days prior to their procedure for the preop blood work.

[DANDERS]

We have a 72 hour cut-off for everything. It's easier that way.

[Geriann]

How do you determine if the patient has been transfused or pregnant in the last 3 mos.....do you call on each order if you have no previous records or your records are greater than 3 mos old? We are not staffed to check on all of these....Our Pre-Admit department does document this information but none of the others do. I have added to the order the question "Transfused/Pregnant within the last 3 months"

I get patients from L&D admit that the answer is either No or no infor available. As of yet I have not been able to inservice the entire hospital staff to properly answer this question.....As of now if the patient does not come from the Pre Admit department we hold specimens only 3 days. Any suggestions?

[Mabel Adams]

We are dealing with 2 issues here: regulatory and clinical.

If you can get someone to state (with a reasonable degree of accuracy) that the patient has been neither transfused nor pregnant in the past 3 months, then you meet the regulatory requirement.

For the clinical picture to matter, you would have to have a patient that was recently transfused or pregnant who presents with a neg Ab screen, but who was actually sensitized by the historic circumstance but the antibody titer was too low to detect at the time of the antibody screen. So, what are the odds that when you transfuse them 4-14 days later, the antibody will have acheived a high enough titer to cause a negative clinical outcome? To crunch the numbers (or even get a reasonable estimate) you have to put together the odds that the patient listed as non-pregnant/non-transfused really was; the odds of them being sensitized; the odds of them being in the "window period" of antibody production between the time of the draw and the time of the transfusion, the seriousness of the likely consequences should this all occur and your institution's comfort level with the level of risk this amounts to.

What happens if a patient does not accurately report a drug or latex allergy? How excited does the hospital's risk management team get about that? How many times have we all detected "serological transfusion reactions" for which no one detected any signs or symptoms except a need to transfuse again? Should we avoid these at all costs, or is there some cost/benefit ratio to consider? How does a given policy balance the clinical outcome risks and benefit against the resources required to implement the policy>?

Hopefully thinking through this will give some perspective. Did I leave anything out?

[bbbirder]

We only extend beyond 3 days for pre-op patients who have signed our form. For in-house patients, we use 3 days. It is much easier.

(And yes, we do take the patient's word for it as long as they are competent to answer the question!)

Linda Frederick

[Mabel Adams]

I think think part of the 2-3 day rule for doing an antibody screen (i.e. on fresh sample) was based on the deterioration of complement in the sample. If we are using anti-IgG instead of poly, that factor no longer applies. I think IgG is usually pretty stable in a sample, but of course we must follow the package inserts as others have said.

[cathy s rawcliffe]

Am retired now ...but that issue with the length of time that specimens that can be used was quite a big bang issue about 10 years ago ...with hospitals going to same day admits ...etc for elective surgeries.....our facility did an extensive study of running samples when they got their pre-op labs done and obtaining specimens for XM up to a month later and running parrellel testing to see if it made a difference...alll seriously documented. Of course this was on patients who had no transfusion history or pregnancies within the past 3 months .....our conclusion was that we had not one discrepancy in the months of parrallel testing that we did....(using monoclonal reagents)

also was an AABB inspector for about 12 years ...and my experience with CAP and JCAHO ...is that both of those organizations ...although they don't always get the wording right in their standards ...do adhere to the intent of AABB .....so if their standards are unclear, one can always defend yourself with clarifying what you are doing with AABB standards! Also ...if one is going to implement something different ...and you have done testing to prove the issue ...that can be passable too! Studies must be run to document that tho!

Hope this has been helpful!

[caj1018]

We have a policy that the antibody screen must be performed within 48 hours of collection, though rarely does the antibody screen test get performed greater than 4 hours after collection. I seem to remember reading somewhere - maybe the technical manual- suggesting the 48 hour deadline. We use the sample for 3 days for crossmatching.

[Mabel Adams]

In 1979, 48 hours was accepted as the amount of time that complement could be expected to be present in sufficient quantity to be sure complement-dependent antibodies were detectable. It was also the AABB standard for how long we could use the same specimen in the recently exposed patient. It was in the next couple of years that AABB changed the standard from 48 hours to 72 hours. Then a couple of years later, they clarified it as 3 days, not specifically 72 hours, which allowed many places to use midnight after 72 hours as a cut-off.