'Least incompatible' terminology.....

[silverblood]

We occasionally have to transfuse units using the terminology 'least incompatible'. These would be patients who have cold or warm autos or low frequency mostly. The physicians have to sign for these units and some balk at this terminology I think because it has the word 'incompatible' in it.One physician insisted on waiting until we found units for his patient that were entirely compatible which was virtually impossible. However, technically we cannot call the units 'compatible' as our testing does show reactions. Does anyone out there use a different terminology for these situations?

[rcollins]

We also call those "least incompatible." You're right, it's not like you can physically prove they're compatible...you just have to trust blood bank theory, and therefore their impact on the patient. I wonder what the physicians would rather you call them--"probably compatible?" "most likely safe?" Maybe if you have a supportive medical director he can talk to the physicians?

Every place I have worked or heard of have called units "least incompatible." I'd be interested to see any other terms.

Becky

[Eagle Eye]

We use Best compatible.

[Malcolm Needs ☆]

If we are cross-matching for a patient with a low-frequency antigen or a patient with WAIHA or CHAD, where we actually find the cross-match compatible, we will call the cross-match "compatible".

If we are cross-matching for a patient with WAIHA or CHAD, where the cross-match itself is either incompatible, or we are cross-matching with adsorbed plasma, or we are cross-matching for a patient with an antibody against a high-frequency antigen, such as anti-Kna, where we know that there are no clinically-significant atypical alloantibodies present, we will use the term "blood suitable for...Joe Doe...".

There was an excellent editorial by Lawrie Petz a few years ago on this subject, which is still very valid and worth a read.

Petz L. "Least incompatible" units for transfusion in autoimmune hemolytic anemia: should we eliminate this meaningless term? A commentary for clinicians and transfusion medicine professionals. Transfusion 2003; 24: 1503-1507.

:):)

[adiescast]

We actually changed last year to simply calling the crossmatch incompatible. I think "least incompatible" is rather meaningless, since it really refers to the strength of the in vitro reaction, and could have a 4+ (maximum, for those not using a 1-4 system) strength if everything is reacting at 4+. I like Malcolm's "suitable for" teminology, although I don't know if that would fly against the AABB standard that requires a compatibility interpretation. If we have a physician who questions the "incompatible" terminology, we explain that there is no compatible blood and why. they usually go ahead with the transfusion anyway (which is a whole different question...). We do not make them sign an emergency release form unless we cannot rule out underlying allo antibodies.

[tbostock]

I totally agree with adiescast. We banished the term long ago, I think it gives a false sense of security to the physician that if one unit reacts only 1+ it will cause the patient less problems than if it reacts 4+, which we know is not at all true. We call it "incompatible" with a statement attached that this is a high risk transfusion due to a warm auto preventing detection of potential underlying clinically significant alloantibodies. Then we make the physician sign...it always amazes me how many of them do.

Check this out:

Least incompatible.pdf

[Townsend]

We do the same. We eliminated the "least incompatible" and now just call them either compatible or incompatible.

We are very lucky to have an involved TS Medical Director who usually talks to the physician in these cases. It is almost always a (sickle) patient with a warm autoantibody, so the physicians involved are pretty familiar with these cases.

We also attach a form that says "Transfuse with caution" and warns the nurse of the complex antibody presentation and the incompatible crossmatch results

Stephanie Townsend, MT(ASCP)SBB

[Malcolm Needs ☆]

We do the same. We eliminated the "least incompatible" and now just call them either compatible or incompatible.

We are very lucky to have an involved TS Medical Director who usually talks to the physician in these cases. It is almost always a (sickle) patient with a warm autoantibody, so the physicians involved are pretty familiar with these cases.

We also attach a form that says "Transfuse with caution" and warns the nurse of the complex antibody presentation and the incompatible crossmatch results

Stephanie Townsend, MT(ASCP)SBB

Yes, when we issue blood as "suitable for", we always warn that the blood should be transfused slowly and that observation of the patient during the transfusion is of paramount importance (not that it isn't anyway, but you know what I mean).

:):)

[jcdayaz]

We still use the term "Least Incompatible". We only use this term and transfuse if the AHG crossmatch reaction is weaker than the patient's DAT reaction. Least Incompatible transfusions require a specific written order from the physician stating..."Transfuse Least Incompatible blood". Our doc's are all on board with this procedure. It is typically the Heme-Onc patients this situation happens in. These Docs are very knowledgeable in transfusion theory/knowledge.

If we cannot find AHG crossmatched units that react weaker than the DAT then the blood would be labeled Incompatible. This would require a whole different array of approvals, paperwork, notifications, etc.

It is amazing, however, when an "urgent" transfusion on a patient becomes less urgent when you report to a Doc there is no compatible/and/or Least Incompatible blood available. We recommend to our Doc's to try a hefty steroid regimen for several days and then try again.

[L106]

I'm curious. Are there any references or studies to support the theory that donor units showing incompatible crossmatches weaker that the patient's Direct Antiglobulin Test are any safer (or survive better) than donor units showing incompatible crossmatches that are stronger than the patient's DAT?

[Malcolm Needs ☆]

I'm curious. Are there any references or studies to support the theory that donor units showing incompatible crossmatches weaker that the patient's Direct Antiglobulin Test are any safer (or survive better) than donor units showing incompatible crossmatches that are stronger than the patient's DAT?

Actually, in certain circumstances (CHAD) there is evidence that the opposite is true!

This is shown under, References, Document Library, Educational Material, "Laboratory investigation of Autoimmune Haemolytic Anaemia" (which is listed on the second page), Slides 80 and 81.

:):)

[jcdayaz]

Actually, in certain circumstances (CHAD) there is evidence that the opposite is true!

This is shown under, References, Document Library, Educational Material, "Laboratory investigation of Autoimmune Haemolytic Anaemia" (which is listed on the second page), Slides 80 and 81.

:):)

Sorry to be dense...what is CHAD??

[jcdayaz]

I'm curious. Are there any references or studies to support the theory that donor units showing incompatible crossmatches weaker that the patient's Direct Antiglobulin Test are any safer (or survive better) than donor units showing incompatible crossmatches that are stronger than the patient's DAT?

I will try to reference the origination of this procedure when I get to work today. I'll get back to you. It was in place far prior to my association with the hospital.

I do know it is HEAVILY supported by our BB Medical Director. The premise is that if you introduce blood into a patient that the patient's body is "fighting" less than his/her own blood it will have better survival time. Certainly still not the ideal 3 months.

[jcdayaz]

I totally agree with adiescast. We banished the term long ago, I think it gives a false sense of security to the physician that if one unit reacts only 1+ it will cause the patient less problems than if it reacts 4+, which we know is not at all true. We call it "incompatible" with a statement attached that this is a high risk transfusion due to a warm auto preventing detection of potential underlying clinically significant alloantibodies. Then we make the physician sign...it always amazes me how many of them do.

Check this out:

VERY informative attachment in your post. Thank you.

[jcdayaz]

I totally agree with adiescast. We banished the term long ago, I think it gives a false sense of security to the physician that if one unit reacts only 1+ it will cause the patient less problems than if it reacts 4+, which we know is not at all true.

Check this out:

I am VERY interested in references/studies you might have on this topic. I would be very grateful if you could provide them.

Another question...What do you call AHG compatible crossmatches with absorbed plasma on a patient with a warm auto? Yes, the crossmatches will appear compatible in vitro, but what happens when you introduce that blood into the patient's body??

[Malcolm Needs ☆]

Sorry to be dense...what is CHAD??

You are far from dense!

It is the fault of UK terminology!

It stands for Cold Autoimmune Haemolytic Anaemia, and so, therefore, it would be far more logical for it to have the acronym CAHA, but CHAD is what it is!!!!!!!!!!!!!

:)

[Malcolm Needs ☆]

Another question...What do you call AHG compatible crossmatches with absorbed plasma on a patient with a warm auto? Yes, the crossmatches will appear compatible in vitro, but what happens when you introduce that blood into the patient's body??

In my opinion (and I know I am very opinionated), this is where the phrase used by the NHSBT in the UK, "suitable for", comes in so handy, because it makes no definitive statement about compatibility after either auto- or (more importantly) alloadsorption.

:)

[adiescast]

We call units that are non-reactive with absorbed sample and reactive with neat sample "incompatible." The neat sample is representative of what is in the patient's body. The absorbed sample is only to help us see past the autoantibody and does not represent what will happen in vivo.

[adiescast]

You are far from dense!

It is the fault of UK terminology!

It stands for Cold Autoimmune Haemolytic Anaemia, and so, therefore, it would be far more logical for it to have the acronym CAHA, but CHAD is what it is!!!!!!!!!!!!!

:)

Hey Malcolm, I found the term on the CAP checklist... it is cold hemagglutinin disease (CHAD)... does that help?

[Malcolm Needs ☆]

Hey Malcolm, I found the term on the CAP checklist... it is cold hemagglutinin disease (CHAD)... does that help?

Thanks. That's the one!

:D:D:D:D

[jcdayaz]

I will try to reference the origination of this procedure when I get to work today. I'll get back to you. It was in place far prior to my association with the hospital.

Sorry L106, I didn't get a chance to research the origination of the procedure yesterday. We were swamped with work!! I work again on Sunday and will try then...

[RR1]

We call units that are non-reactive with absorbed sample and reactive with neat sample "incompatible." The neat sample is representative of what is in the patient's body. The absorbed sample is only to help us see past the autoantibody and does not represent what will happen in vivo.

Just a thought...do you think the patient might worry if they saw this on the blood unit being transfused?

[Joseph78]

We still use "least incompatible" but I agree with Malcolm (suitable for - is more appropriate). If we have patient with warm auto, we have the physician sign a consent but we put a comment: "The patient has warm autoantibody and all crossmatches will be incompatible. I request the least incompatible packed RBC's (NOTE: Units are crossmatch compatible with autoadsorbed serum at reference lab)."

[Mary Ann]

We occasionally have to transfuse units using the terminology 'least incompatible'. These would be patients who have cold or warm autos or low frequency mostly. The physicians have to sign for these units and some balk at this terminology I think because it has the word 'incompatible' in it.One physician insisted on waiting until we found units for his patient that were entirely compatible which was virtually impossible. However, technically we cannot call the units 'compatible' as our testing does show reactions. Does anyone out there use a different terminology for these situations?

Hi,

We have the same requirement for incompatible blood,the path consults with the physician.

[jcdayaz]

We still use "least incompatible" but I agree with Malcolm (suitable for - is more appropriate). If we have patient with warm auto, we have the physician sign a consent but we put a comment: "The patient has warm autoantibody and all crossmatches will be incompatible. I request the least incompatible packed RBC's (NOTE: Units are crossmatch compatible with autoadsorbed serum at reference lab)."

Question...what do you consider "Least Incompatible" at your institution???