As much as 90% of the RBC component allocation can be performed without an actual crossmatch test—AHG or immediate-spin provided that certain criteria are met.

Enforcing these rules, however, can be cumbersome unless one has blood bank software that verifies that each rule is met.  In the Medinfo patient module, the transfusion history database is checked automatically.  If the rules are met, then Medinfo allows the selection (allocation) of RBC units without performing a crossmatch test.  Otherwise, it will check to see if the AHG crossmatch has been done within the past 3 days.  If not, it will prompt for new crossmatch testing with a new specimen.  If the situation is urgent, one can go to Emergency Mode and release components without the crossmatch.

The following is the latest document I prepared on this process before leaving HMC.  Please note that there was an extensive validation before this was activated for patient use.

INTERIM POLICY:  ELECTRONIC (COMPUTER) CROSSMATCH

Revised Date:  1/2/18

Principle:

In selected patient categories, no classical crossmatch may be required for release of RBC components.  The criteria are specified here as applicable in our Medinfo Hematos IIG computer system HIIG.

Policy:

1. An electronic crossmatch without antiglobulin or immediate-spin phase testing may be used for the following patient categories:
   1. The current ABO/D type matches the historical ABO/D type.
   2. The ABO/D type (forward and reverse) is clearly defined without any discrepancies.
   3. Two determination of the ABO/D group must be made:
      1. One from a current specimen (within the past 72 hours)
      2. The second by one of the following methods:
         1. Testing a second current specimen
         2. Comparison with previous records of ABO/D typing
         3. Retesting the same specimen
   4. The current antibody screen is negative
   5. There is no history of RBC antibodies or a non-negative antibody screen.
2. General computer system safeguards:
   1. The system contains the donor unit number, component name, confirmed ABO/D typing, two unique recipient identifiers, recipient ABO/D, antibody screen typing, and interpretation of compatibility
   2. A method exists to verify correct entry of data before release of blood or blood components.
   3. The system contains logic to alert the user to discrepancies between donor ABO/D group on the unit label and those determined by blood confirmatory tests and to ABO incompatibility between the recipient and donor unit.
3. HIIG will enforce the above rules.

References:

1. HIIG Workflow 1004, Patient Testing, 2013
2. Section 5.16, Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
3. FDA Guidance for Industry:  Computer Crossmatch (Computer Analysis of the Compatibility between the Donor’s Cell Type and the Recipient’s Serum or Plasma Type), April, 2011

The following post is based on my experience 2011-2020 at HMC through 16/4/20:

I have had many posts about the Blood Donor Center from registration, collection, processing, testing, and dispatch (inter-depot transfer).  The hospital transfusion service or hospital blood bank continues the process on selection of the appropriate blood component for the patient.  Specifically, it:

1. Verifies the ABO/D type of RBCs and ABO type of plasma components received
2. Physically examines each unit checking for leaks, labelling errors, etc.
3. Receives into stock the various components
4. Performs basic type and screen (group and save) testing of the patient including ABO/D type and antibody screen
5. Identifies antibodies if the antibody screen is non-negative
6. Performs direct antiglobulin test and elution if positive
7. Modifies components (thawing, aliquoting, irradiating, washing, pooling)—although in some sites, these latter functions may be performed in the Blood Donor Center
8. Performs compatibility testing and selects the appropriate method (electronic, immediate-spin, antiglobulin phase crossmatch)
9. Releases blood components to outside staff (nurses, doctors, etc. as allowed by the local authority)
10. Investigates transfusion reactions

When I was at HMC which included many hospital blood banks, we standardizes our methodologies/processes as much as possible, but we still had some differences based on the equipment at each site.  When we built the blood bank computer system, we had to build a specific process for each test, taking into account the methodology and the type of reagents used.  We used the manufacturer’s recommendations when establishing the criteria for each test.

There were manual and multiple automated tests, e.g. for ABO/D typing.  Rules were established when automated release was allowed and when a manual review was necessary.  Complicated cases were referred to the transfusion medicine physician for review and comment.

In our system, all tests could be ordered and performed from all sites.  Transfusion medicine physicians could review all work from all sites.  For technologists, they were restricted to the sites they worked or supervised except to review results.

All patient results across the entire system from the current and previous system were available and could be used to make/enforce rules.

In general, certain categories of results were referred to the transfusion medicine physician for review, but any test could reviewed by him/her, especially if a clinician requested it.  Everything was documented in the software.

Component modification (thawing, aliquoting, irradiating, pooling, washing) processes were the same at all sites AND the blood donor center.  Each modification changed the ISBT designation of the component, a new ISBT label was printed, and the outdate of the components were updated.

Antibody workups were still performed manually, but direct antiglobulin tests could be  manual or automated.  In each case,  review with an interpretative comment was made by the transfusion medicine physicians and might include recommendations for selection and use of components.  Rules enforced by the software could be made to enforce these recommendations.

To Be Continued:

1/7/20