Joanne P. Scannell

As I wrote earlier, if the patient qualifies for 'electronic' crossmatch for whatever reason, we leave the result in the computer as 'CMBT' (Compatible by Blood Type) ... ie. no backpeddling is necessary. Yes, our comment CMBT qualifies, it IS the interpretationof a crossmatch. We are not on official electronic crossmatches yet BUT we do stop crossmatching after the 12th unit during a trauma.

No one is saying that an 'electronic' crossmatch (for whatever reason) need be converted to a serological/physical crossmatch just because it went out EMR ... And we are all saying the SAME thing here! ie. If qualifies for 'electronic' ... it stays as is. If it's serological, need to do the serological testing and record those results. Ok, enough?

Ummm, isn't that what we have all been saying?

Uncrossmatched vs 'Uncrossmatched' ... same term, different functional meanings ... 1. Uncrossmatched for purposes of Emergency Release ... yes, the physical crossmatch must be done and recorded. So, when we perform that function, we go back and enter the test results. If need be (and I haven't had an inspector ask for this yet), the actual time of all entries by techs can be visualized in the computer system. 2. Uncrossmatched because we are going 'electronic' (eg. CMBT) for the reason we have already issued enough units (ie. massive transfusion policy) or if you are performing 'electronic crossmatches' routinely, no physical crossmatch is ever done ... ergo, it stays CMBT forever. 3. Another use of CMBT is when we have a strong cold agglutinin ... but that's another story!

I think we are muddying up the waters here. Electronic crossmatch is, for all intents and purposes, a 'no crossmatch' situation in our minds. We determine whether we can 'no crossmatch' for various conditions. 1. Rules regarding testing ... eg. no clinically significant antibodies, double ABO/Rh, ... set by the regulatory agencies and hardwired into some of our computer systems. 2. Rules regarding situation ... eg. massive transfusion ... set by the individual institution The first one is 'easy'. The second one, as stated in all these emails, varies. So, the techs make the determination 'at the time'. Patient may qualify today but not tomorrow by reason #2. Following that line of thinking, since the tech is responsible for the determination, he/she allocates the unit and puts 'ND' (=Not Done) in for the test result with the interpretation as 'CMPBT = Compatible by Blood Type'. This way, the records are clear.

All are carried by the pharmacy except RH-Immune Globulin (#3 + #4) ... and I'm planning on working on moving those, too. (They aren't blood products, they are officially pharmaceuticals ...) Rationale: Does the Chemistry department stock/dispense insulin because they perform the glucose tests? No.

Q1. Re: Labeling these 'prescreened' units. We are using patient plasma for prescreening more and more now that these reagent costs have gone so high. This raises a few questions: 1. Labeling: I plan to make a label that says something like 'Prescreened, Presume Negative/Positive for xxx' ... design it on your PC and print it on blank labels (Avery, Staples, etc.). 2. Information in the computer. It would be very helpful to have these units flagged in the BB IS so that they cannot be used for any patient will this antibody, etc. If they are testing positive with the 'preliminary' screen, a code for example, 'Presumed c-Pos', could be entered and the parameters set up in the system to not allow allocation of this unit to patients with Anti-c. 3. Charges: There is a CPT Code for screening using patient serum. I'm not at work right now so I can't look it up. I plan to use that when we use patient serum other than the intended recipient. If we are using the recipient's plasma, then it's a full crossmatch. And yes, we put that into our computer system (ie. allocate it). It should still be tagged for future reference/specimens since the computer cannot carry the incompatibility across for the patient. Gel ... I suggest the IgG cards ...

I agree! If it's a false negative, then the typing with the reagent antisera will show that. This preliminary screening is not reportable. If the saved serum/plasma was going to be used as the 'antigen testing', eg. an antibody unavailable as a reagent, then yes, controls would be necessary.

The refrigerator?! Over kill! The reason we are concerned is because we about cold agglutinins is to determine the need of a blood warmer. There are many opinions about this but I do believe that we really don't care what happens at 4oC ... in fact many of us produce cold agglutinins that react at 4oC ... no significance whatsoever. I instruct 'my' techs to check under the scope. If they SEE rouleaux, then perform Saline Replacement. If it's gone, then no blood warmer is needed. The rationale for that is - even if they did wash/dilute a cold aggluntinin, with such small amounts, it's not worthy of a blood warmer. Yes, there are those who will argue that a blood warmer is not necessary at all if the cold agglutinin only reacts at 22oC. We are being overly cautious, I agree. The alternative is to perform a Thermal Amplitude to determine if the cold agglutinin will react at transfusion temperatures. Do you really want to do that each time? It's not always necessary ...

Not sure if it's in the literature, but we have noted 'artifact' and even 'are these positive?' reactions in gel if the sample is not spun down enough. We are using an EBA20S at 4800rpm for 3 minutes ... so far, that seems to be keeping the problem under control. The manufacturer of the Pink Top EDTA tubes we use for pretransfusion testing has recommended that we mix the tubes by a few inversions just prior to spinning. Not sure how or why this works, but it does.

I don't agree that 'now you are a manufacturer' and you need to keep all this information on these patient samples, run QC, etc. You are not reporting the test results using this 'unlicensed antisera'. What IS being reported DOES use a licensed product, namely reagent antisera from a bonafide manufacturer. And I'm assuming the required QC is run with that. Let's not get crazy here ...

We perform a DAT as routine with all our Pretranfusion Type and Screens. And it is our policy to inform the physician (documented). There are basically two reasons, not just one that is mentioned in here. 1. As stated, it will detect post-transfusion positive DAT due to a DHTR ... either by going from negative to positive or by increasing in grade. 2. It also provides additional information to the physician ... perhaps even set him/her in a different direction regarding diagnosis and treatment. We have had many transfusions cancelled because the physician did not know the patient had a positive DAT and when informed, chose another avenue besides transfusion, eg. medication. As far as do we do the 'workup'? If the patient has been transfused in the past 3 months (looking to change that to perhaps 6 weeks), we will perform an elution.

Titers are done using tube testing and NO enhancement medium. That is what is in the AABB Technical Manual and that is the method the literature had referred to when setting up 'guidance' for the obstetricians, eg. significant titer, two-fold changes, etc. As far as I know, 'we' (the blood bankers of the world) are still in the validation stages of trying to correlate tube titers with gel titers with not much overwhelming success. Tube vs gel are very different mechanisms ... can we really expect to correlate? And are the MD"s really aware of the difference when looking at the report? If you look at the CAP Surveys for titers, there is a vast difference in titers tube vs gel. Grading is different, titers are different ... is the 'two tube' significant difference really valid for gel? So then, why are 'we' using gel when its not supported by the literature that was written based on tube testing with no enhancement? Until the literature catches up ... what is the real significance of gel titer reports?

I don't see the crossmatches being related to the antibody identification. Crossmatch: If there are clinically significant antibodies, a 'full' crossmatch is mandatory. Period. (Again, back to the actually statement of the 'law' ... 'clinically significant' being the key words people often leave out.) Antibody ID: I send out a 'high caution' to anyone using heterozygous cells to rule out antibodies that tend to or can show dosage. If the antibody is not demonstrable with heterozygous cells, it doesn't matter how many you run ... you will get a negative result and erroneously eliminate that antibody. I've seen many antibodies that react ONLY with homozygous cells ... some quite strongly (eg. 2+). Don't put yourself into a false security situation. Unless you like surprises during the crossmatching ...

I'm interested in these ideas and hearing about your experiences, too! We are planning an 'online' SOP for the whole lab. Right now, our procedures are stored on a 'shared drive' that all the supervisors can access. We want to have them accessed via the 'intranet' so they are available from any computer by anyone who can sign on to the system. These are mearly links that point to the document in a 'read only' mode. If the document is modified by a supervisor, after the system refreshes (every 10 minutes, I'm told) the new version will be seen. Each procedure has a 'Document Control' section at the end that bears all the document control info, including annual reviews. We haven't implemented this yet. Has anyone has experience using 'electronic' procedures like this? If so, I'd love to hear your thoughts.

Interesting ... you all rule out with just ONE cell all day, every day as you call your Antibody Screens 'negative'. Why would a panel be treated any differently? The 3-cell rule is too often misused and misquoted. Yes, you need 3 reactive positives to be on the statistical side of right (eg. 3 K1-pos cells to call it Anti-K1) OR you need 3 non-reactive negatives to confidently identify an antibody to a high incidence antigen (eg. 3 Kpb-neg to call it Anti-Kpb). The statistical 'rule' is not '3 pos PLUS 3 neg'. Nor is it 'you can't say it's not there without 3 cells ... otherwise, we'd have to run full panels instead of 'antibody screens'. I, too, speak from experience ... and yes, we use only homozygous cells to rule out (with a few exceptions, such as Anti-K1 which is both almost impossible to find a homozygous cell and doesn't tend to show dosage anyway). (And two heterozygous does not equal a homozygous, as some people have expressed in these conversations, so we don't go that route.) And yes, got to keep an open mind to those 'hints' that sometimes haunt us ... eg. reacts to some, not all, homozygous cells. But that's whole 'nother ball game ...

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Sure. Code Yellow STAT Packs: 2 O neg (once) TRAUMA PACK: First Cooler = 4 RBC Subsequent Cooler = 4 RBC + 2 FFP Platelets and Cryo are packed when ordered. OBSTETRICAL CRISIS PACK: Two coolers are set up immediately. One RT with 2 u Plateletpheresis, the other cold with 4 RBC. Subsequently, RT cooler has 1 Cryo (pool) + 2 Platelets. Cold coller has 4 RBC + 4 FFP. CARDIAC CRISIS PACK: Same as OBSTETRICAL except they didn't want RBCs in subsequent coolers. Not to say these are right for every hospital ... these combinations were decided upon by the affected groups. How frequently? The Trauma packs are a few times a week. The others ... may be weeks or months between them. Once they order one though, we keep making them up until they stop coming to get them (effectively staying ahead). Returns are treated just like any other returns. The temperature of the cooler is taken and if acceptable, the units are returned to inventory.

Yikes! Better review some contemporary literature about massive transfusion ... don't need a 1:1:1 ratio to maintain hemostasis, etc.

I've attended lectures that support that what we see in the tube doesn't necessary predict RBC survival, the immune system is much more complex than any routine testing we do. So far, the only good predictor of RBC survival that I've heard about is Monolayer Assay. This is where 'risk just may outweigh the need' ...

Yes. If we have no sample, all the stuff goes out 'Emergency Release' until we have a sample and have completed all necessary testing.

Yes, I agree! We select 'the best we can'. I guess it comes down to 'at what point does the Blood Bank say, 'we can't be held responsible for this one'?' 99.9% of the time, the BB can find something 'suitable' ... but it's important to have some protocol in the SOP for that rare situation when we can't.

We have a similar protocol ... all in an effort to give them what they need asap and without a thousand phone calls! Taking the idea away from Burger King/McDonald's/Taco Bell ... we have pre-defined 'Packs' ... and once ordered, we keep making more until they stop coming to get them. This way, we KNOW ahead of time what the needs are and can plan our activities/staff/inventory accordingly AND there are 'no more' phone calls to interrupt and confuse us. We have 4 'Packs' defined, the contents of which were determined by a collaboration between the Blood Bank and the specific department, eg. ED for Trauma Pack, Birthplace for Obstetrical Crisis Pack, Cardiac Team for Cardiac Crisis Pack. I have a little color coded chart posted at each station in Blood Bank so that when these packs are ordered, everyone is clear about what they need to prepare.

Again, I agree with David. Informed Consent is required ... but who is supposed to provide the 'Informed' part? At our hospitals, the physician is given that 'burden'. So, to be consistent here, it is the physician who gets the additional information and he/she needs to figure out how to relay all this to his/her patient. Some risks are simple, some are more complicated. Documentation of informing the physician of additional risks such as outlined here is a good idea from a liability point of view ... don't want physicians claiming in court that they were not informed of the increased risks. However, I don't agree with having the physician sign a 'release'. If you think about it, the determination of which unit is used for transfusion is under the license of the Medical Director of the Blood Bank. So, 'we' decide what is best to tranfuse, the ordering physician is made aware of any additional risks so that he/she can decide whether it is worth proceeding with the transfusion. IF 'we' don't feel that the blood is 'safe' to transfuse (eg. that hemolysis case described in this string), then we don't have any units to offer. If the physician wants blood anyway, he/she has to sign for 'uncrossmatched blood' and assume all the risks.

Ummm ... there are limited resources in the BB in Vietnam ... let's shift our thinking patterns here. I agree with David S. and those who say 'give it and see what happens' but only IF the transfusion is life-saving. To transfuse a patient with an auto-immune process such as this can be counterproductive ... it is best to treat the problem not the symptoms. As far as an 'in vivo crossmatch' ... that only works if there's a 'immediate' hemolysin, eg. ABO or ... gee, I can't think of any other! This solution hurts my teeth ... Again, I agree that this is most likely an auto-antibody. Yes, ordinarily we'd chase down what 'could be under there' ... but she's not in one of our hospitals where we have 'unlimited' testing resources. Here's where history comes in ... if the patient has never been transfused (or pregnant, albeit that immunization is low) then we do not expect any clinically significant antibodies under there. It doesn't mean the transfusion is 'safe' or will be uneventful, though ... transfusing a patient with an autoimmune process has it's inherent risks, one being the it can exacerbate the original problem [ie. the cause of the DAT]! My first choice would be to withhold transfusion and treat the real problem, that is the cause of that DAT and autoantibody. Buuut ... if you MUST transfuse, then transfuse with small amounts of incompatible blood (ok, choose 'least incompatible' if it makes you feel better) and monitor the patient for symptoms of overt adverse reaction ... keeping IV lines open and plenty of fluids running ... for a few hours post transfusion. (To sample for hemolysis may make the BB feel better, but unless the antibody causes immediate overt hemolysis, no color change will be seen in the plasma. Likewise, don't expect a DAT rise ... it's too small of a volume of RBC's to change the DAT grading.) I also agree ... a delayed hemolytic reaction is a lot easier to deal with than death. Just be sure that's the real risk ... I highly recommend medication for the cause of the autoantibody, not transfusion for the low hct values.