Category: Patient

Includes compatibility testing (AHG, electronic, immediate-spin), antigen typing, antibody screening and identification, direct antiglobulin testing, elution, transfusion reaction and drug reaction workups, component typing tests upon receipt in hospital blood bank, release and return of components

Antibody Titration

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Principle:

The purpose of antibody titration is to determine how to follow a pregnancy at risk for hemolytic disease of the fetus and newborn (HDFN) or for organ transplant (e.g. ABO-incompatible renal or stem cell transplantation).

Titers are notoriously hard to compare across different institutions and different reagents and are subject to variation between technologists. Automated methodologies may help limit this variability.

Policy:

  1. Indications
    1. Pregnant patients with active anti-D to determine if a more aggressive intervention, e.g. percutaneous umbilical blood sampling, is needed to further assess the state of the fetus
    2. ABO-incompatible renal transplantation:  to determine candidacy and follow the effect of ABO column immunoadsorption and immunosuppression
    3. ABO-incompatible stem cell transplantation to follow the course of treatment
    4. External proficiency surveys
  2. Procedure and Interpretation:
    1. Titers may be done in saline or at antiglobulin phase.
    2. Titers may be performed manually or on automated equipment (e.g. Ortho Vision Max).
    3. If the titers are to be used as part of an external protocol, the method should be correlated with the external institution and found to be acceptable.
    4. Titers for organ transplant (e.g. kidney) will be done at saline and antiglobulin phase.
    5. The titer FOR PATIENT REPORTING is defined as the final tube showing a 1+ reaction.
    6. The titer for CAP surveys will be according to the instructions of the CAP, even it does not agree with our 1+ reaction rule.
    7. Any variances from this policy must be specifically approved by a blood bank consultant.

References:

  1. Technical Manual, Current Edition, Bethesda, MD, USA
  2. Standards for Blood Banks and Transfusion Services Current Edition, AABB, Bethesda, MD, USA

Processes and Software Building 56: Multi-Site Patient and Donor Considerations

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As our hospital network expanded, there were many patients who moved between locations.  They might first start in an emergency room and then be transferred to a specialty hospital.  These locations might be served from different hospital blood banks/transfusion services.  What happens if work is progress from one site when the new site receives the patient.  Must the previous workup be repeated or could it be used for transfusion at the next site?

For example, the ABO typing could be performed at one site and the antibody screen at a second site, and the antibody identification at still another site.  Could the results be used across the entire system?

I had multiple hospital blood banks and blood donor centers.  The general and specialty laboratories had multiple sites.  The hospital information system was set up so that the various tests could only be performed at specific designated sites.  This posed problems as patients were moved around or if some site(s) became inoperative since the specimens then had to transported at great distances for testing.  Only a few basic STAT tests were available at all sites.

It was my decision to allow all test categories at all sites, e.g. a DAT request from any site, any methodology, could be used to satisfy the order.  Similarly, all donor processes were available at all donor centers (the processes could be completed at one or more sites).  Different hospital blood banks had different equipment but all the test categories were the same across site—the methodologies might differ.  We had at least four different DATs across our system.

The interface between the blood bank and hospital system worked as follows:  In the hospital information system HIS, test orders pointed to a category of testing and any methodology for that category at any site could be used in the blood bank system for testing and reporting back to the HIS.  Any test in a category from any site could be used to satisfy the test request.  Blood bank staff would choose the particular test methodology to use.  It was NOT specified by the HIS!

In summary, for blood banks and donor centers within our system, the work could be flexibly moved between sites.  There was no need to repeat testing when a patient transferred to a new site.  The only type the work was repeated if testing was done at an institution outside our system.

Sample RBC Exchange Form

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This form was developed by my senior apheresis staff at HMC Doha in conjunction with me. It organizes the data to minimize the time needed to put the data in place so that the apheresis nurse can concentrate on the patient. It can serve as a good template from which to build a computer form.

I want to thank Ms. Mini Paul, Head Apheresis Nurse, and Dr. Saloua Al Hmissi, Consultant Transfusion Medicine for all their efforts.

ABO Antibodies

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Principle:

Historically, the Lui-Freeze-Thaw elution method was used to detect ABO antibodies in suspected cases of ABO hemolytic disease of the fetus/newborn HDFN.  However, the detection of such antibodies does not mean that they are clinically significant.  If a clinically significant antibody is suspected, perform acid elution instead.  If you want to detect ABO antibodies in a neonate or in a transplant setting, you can use this eluate against reagent A and B cells.

Policy:

  1. For suspected cases of significant ABO antibodies (HDFN, organ transplant), perform acid-elution:
    1. For ABO antibodies, test the eluate against reagent A and B cells using antiglobulin phase.
      1. If the mother is ABO-incompatible with the neonate and the neonate’s DAT is positive with a negative eluate against panel cells, then test against A and B cells to rule out ABO antibodies
      2. The same applies to organ transplant cases to detect ABO antibodies.
  2. For detection of non-ABO antibodies, test the eluate against an antibody panel (i.e. group O cells).

References:

  1. Technical Manual, Current Edition, AABB, Bethesda, MD, USA
  2. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
  3. Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition

Training Future Transfusion Medicine Physicians: Need for Technical-Medical Expertise

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In a previous post, I discussed transfusion training for hematology fellows and general pathology residents.  I have no expectations that most of them have any interest in the field so I suggested concentrating on the interpretation of the direct antiglobulin test DAT and turn-around-times for services.

In contrast, the transfusion medicine physician in-training needs to understand in detail all processes, donor and patient—especially test interpretation so that he/she can make medical decisions and variances.

During my training, I was fortunate to be in a residency training program that also had an American Specialist-in-Blood Bank SBB training program.  To a large extent, I attended the SBB program and even worked on the “wet” specimens.

I had no delusions that I would ever function as technologist or SBB in the blood bank.  However, that extended blood bank training has made me the physician I am.  I can correlate advanced, even reference, procedures to my medical knowledge and thus provide a unique offering.  In contrast, even the SBB is not a physician and cannot make the medical correlations.  Recently, I was flattered at an AABB meeting when the speaker thought that I was an SBB.

In certain regions where reference immunohematology laboratories and SBBs or equivalent are rare, the transfusion medicine should have sufficient technical background to help fill this gap.  In my practice, I review all antibody and DAT workups and make interpretative comments for the physicians and nursing staff.  These comments are entered into the blood bank computer system.

I personally tutor the trainees and make certain that they understand potentially dangerous patterns such as antibodies to high-incidence antigens, significance of the autocontrol in panreactivity, and assessing for fatal acute transfusion reactions—both hemolytic and non-hemolytic.

It also helps when I can discuss with my technical staff my interpretations and choices for clinical management.  They get a better idea how important their work is for patient care and understand how any errors may adversely affect the patient.

In regions where there are good immunohematology reference laboratories, some of this may be less necessary.  I lament that transfusion medicine physicians may not maintain these skills and must rely on others to their detriment.  Even if one is comfortable with this, the physician is still ultimately responsible for making the clinical decision.

Permissible RBC Type Mismatching

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The following was my interim policy at HMC for permissible matching and mismatching. This assumes that the patient is not being transfused while in a hypothermic state.

The prohibited options were blocked in the Medinfo Hematos IIG computer system. WAIHA least-incompatible release required physician approval. This protocol did not apply to low-titer group A or low-ABO-titer whole blood units, which were not available at the time.

Physician Review and Data Entry of Transfusion Reactions

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Physicians must enter their interpretations and recommendations for each transfusion reaction review.  In addition, they may enter comments against any of the data.  This post shows the process used in Medinfo Hematos IIG.

By highlighting Interpretation (left side), they then click on the Result Field (right side) and select their interpretation from the drop-down menu.  They can also select other and then enter a comment.

References:

  1. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
  2. Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition

Clarification on Quality Control of Reagents for Antibody Screening and Identification

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Principle:

This policy is a reiteration of current policy to QC reagents used for antibody screening and identification to document how current practice meets these requirements.  This policy is NOT a change from current practice.

Policy:

  1. Each cell used for antibody detection must be checked each day of use for reactivity of at least one antigen using antisera of 1+ or greater avidity:
    1. We will use reactivity encountered during the daily antibody testing:  reactions of 1+ in each screening cell will be deemed acceptable.  For panel cells, reactions of 1+ or greater for any specificity will be deemed acceptable.
  2. Typing reagents such as anti-D, anti-K, anti-Fya, etc. must be checked each day of use.
    1. Already defined explicitly in SOPs
  3. Anti-IgG reactivity of antiglobulin reagents may be checked during antibody screening and crossmatching:
    1. Currently performed as per manufacturer’s instructions (e.g., Immunocor, Biorad, Grifols, Ortho) for gel and tube reagents.
  4. Typing sera and reagent cells must be checked for reactivity and specificity on each day of use, including a check against known positive and negative cells or antisera:
    1. Already defined explicitly in SOPs

References:

  1. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
  2. Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition
  3. TRM.31400, CAP Checklist, current version

External Disaster Plan, Simplified

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Principle:

Maintaining an adequate blood supply and expedited compatibility testing are critical in disaster planning.  Medinfo Hematos IIG allows us to get dynamic updates of our blood supply and dynamically reallocate blood components as needed.

Policy:

  1. Determinate total available blood supply across all locations by using the Cumulative Stock Display program in Medinfo Hematos IIG.
    1. Recheck stock at least every hour during the disaster.
  2. At each transfusion service site, in conjunction with a Transfusion Medicine Consultant:
    1. Cancel reservations for elective surgical and non-emergency medical cases of affected ABO/D types.
    2. Retain reservations for antigen-matched, oncology, NICU, and high-risk obstetrical cases.
  3. Inform Donor Recruitment/Logistics to send SMS, radio, and television messages for blood donors—all types.
  4. Contact ALL staff and have them report to duty.
    1. At the Blood Donor Center, the Head Nurse, Recruitment, Supervisor, Component Processing, and Supervisor, Marker Testing will contact staff.
    2. At hospital transfusion services, the site supervisor will contact all staff.
  5. Process blood components using automated component technology (Reveos).
  6. Perform all donor marker testing including single-well NAT.
    1. Abbreviation of donor marker testing is only at the discretion of the Division Head, Transfusion Medicine.
  7. Transfusion Services:
    1. Release blood component according to the various protocols as needed:
      1. Massive Transfusion Protocols
      2. Emergency release
      3. STAT
      4. Priority
      5. Routine
  8. Compatibility testing will be electronic, immediate-spin, or full AHG as per our protocols.

References:

  1. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
  2. Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition

Data Entry Verification

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Principle:

This policy outlines steps taken to minimize the risk of data entry errors and is based on a dualistic approach:  review of results by a senior technologist and/or supervisor and various computer safeguards built into the Medinfo Hematos IIG blood bank computer HIIG system.  This policy also discusses the verification (here called authorization) and purge processes of HIIG.

Policy:

  1. Review by senior technical, supervisory, or transfusion medical staff:
    1. Designated test procedures require review by a second technologist before authorization.
    2. Complex immunohematology testing and specimens showing aberrant results (e.g. ABO/D discrepancies) are reviewed by the supervisors or designates and ultimately a transfusion medicine physician before authorization.
  2. Computer system HIIG rules:
    1. Privileges:
      1. System restricts which staff can perform specific tests
    2. Patient/donor identity:
      1. System asks end-users to verify patient/donor identity before starting any access to the patient/donor record.
      2. System performs historical database checking and flags any inconsistencies (e.g. historical ABO/D typing differences, etc.)
    3. Testing:
      1. Only selected staff have privileges to authorize or purge.
      2. ABO/D testing algorithms require entry of reactions, not interpretation of results and are compared to a truth table.
        1. Aberrant results require special review before ABO/D typing results can be authorized/purged.
        2. D-controls must be negative to allow D typing results to be authorized for liquid D-typing reagents.
      3. DAT results require appropriate controls to meet truth-table criteria.
      4. Eluates require last wash to be negative before authorization
    4. Blood components:
      1. Selection of RBC or plasma units requires two independent sample determinations within 72 hours of each other.
      2. ABO-incompatible RBC or FFP/FP24 transfusions are not allowed.
      3. Donors with any detectable antibodies are permanently deferred.
      4. Depending on the patient’s antibody history, release of RBC units may require antigen-matched units.  Examples:
        1. Mandatory matching (only antigen negative matched units allowed—no antigen positive or antigen-untyped units):  Antibodies against H, D, c, K, k, Kpa, Kpb, Jsa, Jsb, Jka, Jkb antigens, anti-PP1Pk
        2. Priority matching (incompatible or untested can be approved by a transfusion medicine physician):  C,E, e, Fya, Fyb, M, S, s
        3. Antigen matching not required:  Lea, Leb, N
      5. Least-incompatible crossmatch require special authorization to release
      6. Protocols to force irradiation or other modified components can be setup in HIIG.
    5. Donors:
      1. Donor tests have same criteria as the same test used in patient testing for controls, etc.
      2. Donor demographics are read directly from the Ministry of Interior database—no manual entry (bar code only used).

References:

  1. Workflows for Hematos IIG (1001 through 1005), 2013-2020
  2. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
  3. Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition