SAbarry

[SABarry]

What do other do require for transfusing patient's with a strong WAA or strong CAA?  What type of crossmatch is used and what antigen are being honored for these patients?  We currently use 'in vivo' or biological crossmatches  but am curious to see what others do.

 

This is what we do for WAA:

 

1. T&S-Initial testing will be on ECHO;  If patient has a known WAA, testing is performed with LISS to avoid WAA interference.

2. Perform panel and DAT.  Expected results panagglutination and DAT positive.

3. Perform elution studies.  Expected result, panagglutination with eluate.

4. Complete phenotype or partial phenotype (Rh, Kell, Kidd) if patient has not been transfused.  Perform PeG auto or allo-adsorptions with W.A.R.M. treated cells as necessary.

5. If patient has been transfused, perform triple allo-adsorption with donor cells.

6. Send patient sample for molecular phenotyping for future transfusions.

7. Crossmatch with neat plasma.  If incompatible, perform ‘in vivo’ crossmatch with Rh, Kell, Kidd matched units with emergency release.

8. CAA with incompatible blood are also 'in vivo' crossmatched with Rh, Kell, Kidd matched units with emergency release

 

 

[TreeMoss]

We send our Warm Auto / Cold Auto specimens to the reference lab to determine if there are any underlying allo-antibodies.  We give least incompatible units using the in vivo crossmatch procedure -- antigen-negative units, if applicable.

[David Saikin]

Have always used in vivo xm for these patients.  Don't like "least incompatible" as terminology, incompatible is incompatible.  Personally, I think that if there are no underlying allos an immediate spin xm should suffice.  I know of institutions that follow this algorhythm but I have never been able to convince my Medical Directors of such.

I only honor the pt's Rh phenotype.

Edited January 12, 2017 by David Saikin

[Malcolm Needs ☆]

On 10/01/2017 at 5:57 PM, SABarry said:

What do other do require for transfusing patient's with a strong WAA or strong CAA?  What type of crossmatch is used and what antigen are being honored for these patients?  We currently use 'in vivo' or biological crossmatches  but am curious to see what others do.

 

This is what we do for WAA:

 

1. T&S-Initial testing will be on ECHO;  If patient has a known WAA, testing is performed with LISS to avoid WAA interference.

2. Perform panel and DAT.  Expected results panagglutination and DAT positive.

3. Perform elution studies.  Expected result, panagglutination with eluate.

4. Complete phenotype or partial phenotype (Rh, Kell, Kidd) if patient has not been transfused.  Perform PeG auto or allo-adsorptions with W.A.R.M. treated cells as necessary.

5. If patient has been transfused, perform triple allo-adsorption with donor cells.

6. Send patient sample for molecular phenotyping for future transfusions.

7. Crossmatch with neat plasma.  If incompatible, perform ‘in vivo’ crossmatch with Rh, Kell, Kidd matched units with emergency release.

8. CAA with incompatible blood are also 'in vivo' crossmatched with Rh, Kell, Kidd matched units with emergency release

 

 

Presumably, these are known patients, and this is how I am going to answer.

1.  We would ABO and D test by automation.  If this did not work, we would test manually.  These days, if there is a mixed-field reaction (ABO) we would (eventually) cross-match group O blood (even if we have known the patient's ABO type for decades! - I know, I know - this totally ridiculous rule was not written by me)!

2.  We would perform a DAT and an abbreviated IAT panel (waste of time doing either a full IAT panel or an enzyme panel).  

3.  We would not bother with an elution (waste of time and reagents, and, therefore, money) UNLESS there was a very good reason, such as clinical signs of a transfusion reaction.

4.  We would do a "quick and dirty" genotype, rather than rely on a phenotype.

5.  We would perform an alloadsorption (minimum x 2, maximum x 8) with R₁R₁ and rr red cells of known phenotype (and, on rare occasions, R₂R2 red cells of known phenotype).

6.  See 4.

7.  Cross-match with the adsorbed plasma, honouring the Rh and K type (and, of course, any alloantibodies detected under the auto-antibodies).

8.  See 7, but, if the case is so urgent that we cannot wait for the adsorbed plasma, we would give ABO compatible blood that is honouring the Rh and K phenotype (and, of course, any alloantibodies detected under the auto-antibodies) and hope!

[SABarry]

Thanks for your replies.  We very much want to get away from using the 'in vivo' crossmatch procedure.  Unfortunately this procedure has been used in our facility for over 20 years and the physicians are reluctant to let it go. 

Malcolm, if crossmatched units are incompatible, do you ask for an emergency signature from the physician?  How often is the WAA work-up repeated?

[Malcolm Needs ☆]

1 hour ago, SABarry said:

Malcolm, if crossmatched units are incompatible, do you ask for an emergency signature from the physician?  How often is the WAA work-up repeated?

What happens in the UK Reference Laboratory situation when the cross-match is incompatible is that we then telephone one of our own Consultants (senior doctors) and explain the situation (in huge detail) and then they telephone the Consultant (senior doctor) looking after the patient at the hospital, and our doctor tells their doctor what to do.  All of this is recorded verbatim on forms, and woe betide if the two notes (us to our Consultant, and then our Consultant to their Consultant) do not match!

The work-up can alter from one case to another.  If it's a new case, it is done every three days.  If it is an established case, with no alloantibodies detected, then Guidelines say that this time period can be extended, as long as a risk assessment is done on each patient, and then signed by the doctor in charge of the patient.

[SABarry]

For the facilities that perform 'in vivo' crossmatches, do you mind sharing your procedure?  The procedure we use involves washing an antigen matching units for Rh, K, and Kidd.  A pre-plasma hemoglobin is testing on the patient, followed the transfusion of 10mLs.  A post transfusion hemoglobin is again collected and tested.  Pre and post results are compared and acceptable RBC compatibility is determined.  A change of less than or equal to 10mg/dl-unit will be transfused;  11-19 mg/dl physician must approve transfusion; greater than or equal to 20mg/dl do not transfuse unit, consult physician to determine if another unit should be prepared.

This process is timely and creates delays in patient care.  Are your procedure more streamlined? 

We us 'in vivo' at my current location but I have not used it anywhere in my 20+ years of being a blood bank.