Electronic Cross-matching

[NAN47]

Hi everyone,

I am giving a presentation on Electronic Issue next week to my peers and was just looking for any suggestions, advice or ideas on any issues which arises from using electronic issue.

My presentation involves looking at the risk assessment of the process, positives and negatives of electronic issue/retaining IAT crossmatching, MHRA's stance on E-XM, and how electronic issue works in hospitals which currently use it. Following the presentation there will be a question and answer session and if there are elements of the process etc which I may not have considered and may be questioned on.

Thanks in advance

[Mabel Adams]

Just make sure everyone knows that you can't do it when the computer is down.

[yhbiotek]

I am very interesting. Can you please send me your presentation. Miles

please send to mileshsu@ms72.hinet.net. Thanks

[mdcbk]

We presented a poster at last year's AABB on the use of EC at our hospital. We found that it decreased turnaround time, reduced re-draws for QNS, reduced blood wastage, and reduced costs for supplies. It saved us 1/2 FTE due to the near elimination of IS XM and also improved workflow and flexibility in using our workstations. Because our BB system is advanced enough to allow EC, we believe patient safety is improved by the use of electronic ID of patients, specimens, results and unit labeling. We're a pediatric hospital, and many of our patients weak or no backtype. From our perspective, EC is safer than IS crossmatch. We've not had any issues during inspections.

[Malcolm Needs ☆]

I am a great fan of electronic issue, as I think it is much safer than allowing a human being anywhere near a serological cross-match, but there is one paradox that I just cannot get my head around. Why is it that we believe an automated antibody screen implicitly, if it is negative, but if it is positive, we introduce falible humans!

If the antibody specificity or antibody specificities are correctly identified, and the units can be guaranteed to be typed as negative for the corresponding antigens, surely then, electronic issue is safer than human issue?

I know that someone who has been shown to be a responder is likely to make more than one antibody, but will a human detect all, second, third etc specificities? I doubt it. We then cross-match with blood that we know to be negative for the antigens against which we have identified the antibodies, whilst quite happily ignoring any other antigens against which we have not identified antibodies, whether these antigens are expressed in a homozygous or heterozygous dose, and we believe the cross-match!

It doesn't actually make any sense.

I know such a patient may have made antibodies against low incidence antigens, but then so may a patient in whom we have identified no antibodies.

[galvania]

Surely Malcolm, the answer lies in the IF-word. As you say, IF the antibody specificity or antibody specificities are correctly identified, and the units can be guaranteed to be typed as negative for the corresponding antigens then why do you need to crossmatch? What do you think is the risk of a 'fallible human' getting at least one of those factors wrong?

[Malcolm Needs ☆]

Surely Malcolm, the answer lies in the IF-word. As you say, IF the antibody specificity or antibody specificities are correctly identified, and the units can be guaranteed to be typed as negative for the corresponding antigens then why do you need to crossmatch? What do you think is the risk of a 'fallible human' getting at least one of those factors wrong?

Hi Anna,

I can see immediately from where you are coming, and I do agree with you to a certain extent. However, unless the antibody specificity/antibody specificities is/are anything but straightforward (say a monospecific antibody within the first 5 Rh specificities, or a combination, an antibody to the "simple" antigens within the other Blood Group System up to Kidd, or a simple combination), I would more than "encourage" confirmation of the specificity/specificities by a Reference Laboratory. Within the UK (at least, and this may be true for other countries [i honestly do not know]) if we send out a unit that has printed upon the ISBT label that it is, for example, K-, Fy(b-), Jk(a-), it will be K-, Fy(b-), Jk(a-), and we take full responsibility if this is not so.

I would argue, therefore, that if individuals are incapable of sorting out these kinds of antibody problems, they should not be working in blood transfusion, or that they have made a genuine human error. The point is that screening cells (in the UK, and I think in most other developed countries [if that is the PC phrase]) are chosen because they have homozygous expression for those antigens that are known to show dosage, so detecting a clinically significant antibody (unless directed against a low frequency antigen) in such a screen should be no problem if tried and tested procedures are adhered to.

In the case of a computer, this would be so (assuming it is programmed properly), but this is not so for all humans.

I admit that I am, to a certain extent, playing "Devil's advocate" here, but only to a certain extent. I still do, genuinely think that there is a paradox here that needs to be addressed.

:devilish::devilish:

By the way Anna, a propos of nothing to do with this thread whatsoever, did you manage to get the information you wanted about the Birmingham meeting?

Edited April 26, 2011 by Malcolm Needs

[NAN47]

Hi guys thanks for the posts

can i ask a specific question with regards to pregnant patients - are these patients still eligible for electronic issue?

in addition i appear to have come across conflicting data with regards to the eclusion time of post transplant/stem cell transplant patients receiving an ABO incompatible transplant. - have come across a source stating an exclusion period of 3 months and another which states an exclusion time of 1 year for these patients - could anyone clarify this for me?

thanks

[Malcolm Needs ☆]

Hi guys thanks for the posts

can i ask a specific question with regards to pregnant patients - are these patients still eligible for electronic issue?

in addition i appear to have come across conflicting data with regards to the eclusion time of post transplant/stem cell transplant patients receiving an ABO incompatible transplant. - have come across a source stating an exclusion period of 3 months and another which states an exclusion time of 1 year for these patients - could anyone clarify this for me?

thanks

This is ONLY my opinion, but no, pregnant patients cannot be considered for electronic issue, on the grounds that, at any time during the pregnancy, there is a chance of a foeto-maternal haemorrhage, which, when you think about it, is tantamount to a patient who has received a potentially sensitising transfusion, even if you cannot yet detect any alloantibody.

As for your second question, whether the transplant is ABO compatible or incompatible, I would be totally against giving such a patient blood via EI for at least a year - and the same goes for someone who has received a solid organ transplant. The "latest" research shows that chimerism is a lot more common than we first thought, and, if one of those clones produces an antibody, you could be in BIG trouble.

Others may, of course, have differing views, and they may well be correct.

[pluto]

What is opinion on haematology patients who have regular transfusions every month or even more frequent being excluded or not from electronic issue

[NAN47]

I am not sure what the general rule about haematology patients but i do know that patients with auto-immune haemolytic anaemia are excluded due to the presence of auto-antibodies, patients with a positive DAT are also usually excluded and due to the fact that many haematological conditions can affect serological testing ( ie myeloma patients and weakened blood group expression etc) this would require manual input into the process and would therefore result in these patients being excluded also.

[adiescast]

OK...perhaps I have missed something here. Why would pregnant patients be excluded from electonic matching if they have a negative screen and a negative history? Why would multiply transfused patients be excluded?

The only patients we exclude from electronic matching are patients with current or historical antibodies (not to argue with Malcolm's point several posts below, which is an interesting way of looking at it), patients for whom we were only able to obtain one type before emergent transfusion this round (automatically excluded by the algorithm), or patients that fall out because the computer has some special dislike for them (our sickle cell patients have information in the computer file about their antigen status so we can match them and the computer excludes them because of that).

On Malcolm's point about electronic matching for patients with antibodies, I think one part of the problem is that not everyone will guarantee that the unit is antigen negative (unlike his illustrious institution). I know we have received units that were incorrectly labeled. A second point is that there are antibodies for which we provide crossmatch compatible rather than antigen typed units. A computer algorithm would not be able to account for that situation.

Edited April 26, 2011 by adiescast
More thoughts

[Mabel Adams]

Maybe electronic issue in the UK means something different than electronic crossmatch here in the US. Here, it is as Adiescast says: neg Ab screen currently, no history of a significant antibody, 2 blood types on record and they qualify. Recent transfusion or pregnancy exposure would not enter into it. What this test replaced in the US was almost entirely Immediate Spin crossmatch so all we need is a check for ABO compatibility that is at least as good as the IS xm. It was never intended to be compared to a full AHG xm.

[Malcolm Needs ☆]

Yes, I think I am being a bit picky about pregnant ladies and multiply transfused patients upon reflection.

[David]

To those of you using ECM's: when do you bill for it, at time of unit selection, time of issue, or only when transfused?

[adiescast]

We bill when the "test" is completed (in other words, at the time of selection).