Category: Teaching

Teaching medical and technical staff transfusion medicine

Policy: Donor Collection

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5.4 POLICY: DONOR COLLECTION

Policy:

  1. All donors will be positively identified with a picture ID and by their Hematos identifiers (donor ID and session registration/specimen number).
  2. All previous processes (registration, donor deferral database check, questionnaire, and physical examination) must pass.
  3. The donor’s arm veins will be inspected for a suitable donation site and prepared by a suitable aseptic technique.
  4. Whole Blood:
    1. Only whole blood units collected within the specified time interval may be used for component processing.
  5. Apheresis:
    1. Apheresis units will be collected at frequencies to keep the total RBC loss below 200 in any 8-week period.
    2. Only apheresis units collected within the specified time interval may be used for component processing.
  6. Donors will be treated for adverse reactions as needed.
  7. All specimens and donor units will be labeled at the donor’s bedside before starting a new donor collection.
  8. Donors will be monitored post-donation for a reasonable interval before discharge.
  9. All processes will be documented in the Hematos blood bank computer system.
  10. All equipment and supplies will be used according to manufacturer’s instructions.
  11. The collection workstation and equipment will be cleaned before starting the next donor.
  12. All policies, processes, and procedures must comply with Qatari, HMC, and applicable accreditation standards (i.e. AABB, CAP, and JCI).

References:

  1. HMC 1001 Setting Specification, Version 1.5, Hematos IIG, Medinfo
  2. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, Maryland, USA, October 2013

How I Select Technologist Candidates for Work or Promotion

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As a transfusion medicine physician, I must know if I can trust my staff’s interpretation of immunohematology testing.  I may be called at night and they will provide me with results and I must use these to make a medical judgment.  If their interpretation is flawed, I might make a decision that harms the patient.

I really don’t like multiple-choice questions, but nowadays this is often the norm.  For my staff, especially senior staff and those who want to be promoted to senior staff, I have developed a series of projective exercises to help me understand their thought processes. I also used this approach on prospective candidates for hire.

Here is a sample exercise.  I have the candidate or staff review this panel and tell me to interpret it:

Most of them answer that this is an anti-Cw without hesitation.  However, they are basing that on only one Cw-positive cell.

More astute ones indicate it might be anti-Cw but ask to test additional Cw-positive cells and perform an enzyme panel.  These are the ones that I will consider for hire or promotion now.

Interfaces with Quantitative and Qualitative Results

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Processes and Software Building Part 7

This is an update of a previous post.

Blood Bank instruments may perform tests and release test results in a numerical or alphanumeric format or both.  For example, nucleic acid and enzyme immunoassay may release a qualitative result (e.g. positive, reactive, borderline/gray-zone, negative, nonreactive).  Alternatively, the machine may release the signal to cutoff ratio (S/CO) as a numeric result.

Blood bank software may use either kind of result on which to base interpretative rules for acceptability of the donor.  The qualitative result criteria are based on the quantitative SC/O but the equipment automatically interprets this.  The S/CO ratio of 1 is the cut-off point.  Thus a value of 0.99 is negative and the value 1.01 is positive.  But is it really so clear-cut since the difference between the two is so small?  Thus, some people have added the term gray-zone for values close to but below the cutoff.  Could a value of 0.95 be an early infection?

I personally prefer to see the actual cutoff but use the manufacturer’s criteria for interpretation.  As a physician, it is good to review the S/CO on serial exams.  If a borderline or gray-zone result becomes positive, then perhaps the original result indicated early infection.  The question still remains, what is the gray-zone?  0.95 to 0.99, 0.90 to 0.99, etc.  Some accrediting schema have not used gray-zone for interpretation.

With Medinfo’s blood bank software, I could choose either option or both—or at least store the S/CO as a nonreported result for subsequent review.  I could even chose, test by test, in a series between reporting either S/CO or the qualitative result.

Semiquantitative results, e.g. in {0, 1+, 2+, 3+, 4+} are qualitative and could also include mixed field (mf) and hemolyzed (h).  I showed examples of this with ABO/D antigen typing in a previous post—see attachment.

On the contrary, the results from blood production equipment may include parameters such as time of preparation, original volume, final volumes for each component, platelet yield index as an indirect measure of platelet count.  When there is pooling, the final total volume is critical to determine if pathogen-inactivation procedures and platelet additive solution can be used.  This is a much more complicated interface.

Process: Donor Physical Examination

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This is a sample process document for donor physical examination. Compare it to the previous post Policy: Donor Physical Examination.

5.3.1 PROCESS DONOR PHYSICAL EXAMINATION:

Process:

  1. The donor is positively identified by a designated picture ID and Hematos donor consent form with specimen/encounter number and barcode.
  2. Donor staff measures vital signs of donor and enters results into Hematos IIG.
  3. Donor staff inspects donor arms for suitable veins and checks for concurrent skin diseases and/or scarring.
  4. Medinfo Hematos IIG determines donor eligibility to collect components.

References:

  1. HMC 1001 Setting Specification, Version 1.5, Hematos IIG, Medinfo
  2. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, Maryland, USA

Policy: Donor Physical Examination

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This is another example of a short concise policy statement. The process example will follow:

5.3 POLICY: DONOR PHYSICAL EXAM

Policy:

  1. All donors will be positively identified with a picture ID and by their Hematos identifiers (donor ID and session registration/specimen number).
  2. The donor’s vital signs (BP, pulse, temperature, respiratory rate) will be measured by designated Donor Center staff.
  3. The donor’s arm veins will be inspected for a suitable donation site and evidence of scarring.
  4. Donor eligibility for actual collection will be determined by the Hematos IIG algorithms based on this data.
  5. All policies, processes, and procedures must comply with Qatari, HMC, and applicable accreditation standards (i.e. AABB, CAP, and JCI).

References:

  1. HMC 1001 Setting Specification, Version 1.5, Hematos IIG, Medinfo
  2. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, Maryland, USA

Antiglobulin Reagents

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Antiglobulin reagents are used to detect molecules bound to the RBC surface.  What they detect depends on their specificity.  Such detection can be performed in the routine immunohematology laboratory or elsewhere such as flow cytometry.  This discussion is for the blood bank laboratories, both routine and reference immunohematology.

This is how I classify and use the various reagents in my daily practice:

  • Routine use—DAT testing and compatibility testing
  • Antibody identification
  • Drug-related hemolysis and transfusion reaction workups
  • Special assays:  DAT-negative AIHA, prediction of clinical significance of reaction by IgG subclass determination

There are many types of antiglobulin reagents:

  • Polyspecific:  IgG and complement usually C3d but sometimes C3b specificity included
  • Whole Molecule IgG including mu heavy chains and kappa and lambda light chains
  • Monospecific gamma heavy chain, mu heavy chain, alpha heavy chain, C3c, C3d, C3b
  • IgG subclass:  IgG1 IgG3

Whole molecule IgG detects class-specific mu heavy chains AND light chains kappa and lambda.  Since kappa and lambda are found on all immunoglobulin classes, whole molecule reagents can detect IgM so there may be weak staining with cold antibodies that are not clinically significant.

C3d is the final breakdown product of C3b and does not cause hemolysis.  Its presence merely means that at some time—unspecified—complement was fixed.  C3c is an intermediate product in the breakdown pathway.  If detected, C3c positivity means ACTIVE complement fixation was occurring at the time of specimen collection.

General Use:

Routine DAT testing:

  • Polyspecific:  if positive, then use
  • Monospecific IgG and monospecific C3 reagents

Antibody workups:

Routine:  antibody screens and AHG crossmatch (if indicated)

  • Polyspecific
  • Gamma heavy-chain monospecific

Monospecific gamma heavy chain is preferred to minimize non-clinically significant, cold antibody interference.

Complicated—where detection of complement reactivity is especially important:

Polyspecific for drug-related hemolysis and transfusion reactions

Difficult antibody workups, e.g. to rule out anti-Jka and/or anti-Jkb

Specialty Reference Procedures:

  • DAT-negative AIHA:  mu heavy chain, alpha heavy chain for IgM and IgA mediated hemolysis (rare), C3c to detect active complement fixation
  • Predicting clinical significance:  IgG1 IgG3

Complement fixation may be important in various drug-related hemolysis and some transfusion reactions so I always use a polyspecific reagent in these situations.  Most antibodies can be detected by gamma heavy-chain specific reagents;  however, there are rare examples of anti-Jka and anti-Jkb which are only detected by complement.  Whenever I have a nonspecific reaction in an Jka-negative or Jkb-negative patient, I repeat the AHG panel using polyspecific reagents.  I do not use polyspecific routinely because of the nonspecific and non-clinically significant cold antibodies.

One way to assess for the clinical significance of an antibody is to determine its IgG subclass.  In general, IgG3 antibodies may fix complement and cause severe hemolysis.  Both IgG1 and IgG3 antibodies cross the placenta and may cause hemolytic disease of the fetus/newborn.

In summary, when reviewing immunohematologic reactions using AHG, I always remember to check which type of AHG reagent was used.  I always keep multiple types of AHG reagents in the laboratory for the reasons explained above.

TRALI TACO

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This is a revision of a previous post, incorporating an updated definition of Transfusion-Associated Cardiac Overload TACO from the National Healthcare Safety Network, Biovigilance Component Hemovigilance Module Surveillance Protocol,  Version 2.6.

Time: Appreciating Testing and Component Release Times

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This is a revised version of a previous post.

I have had many medical students, residents, and fellows rotate through my Transfusion Medicine section.  Hardly anyone has any interest in making my discipline his/her career.  It is a required rotation or an “easy” rotation during which the trainee may take his vacation.  The trainee will cram for the examination and then promptly forget it.

I left practice in the USA in 1990, in what I consider the golden age of laboratory medicine.  We had supervisors for each laboratory section.  In the blood bank, we had many staff with SBBs or who were SBB students.  We were very self-sufficient in handling immunohematology problems except for rare blood types or antibodies to high incidence/prevalence antigens.

When I returned to visit my old laboratory, I sensed a deprofessionalization of the laboratory and blood bank in particular.  Blood Bank now is a cost center, not an area of revenue.  Why hire experienced blood bankers for most hospitals?  Send the antibody workups to the Blood Center.  There are limited jobs for transfusion medicine consultants.  Minimize testing, don’t do extended antigen typings, etc.

Nowadays, I feel like one of the dinosaurs marching into oblivion like in Walt Disney’s Fantasia film, the section called The Rite of Spring.  Who will replace those retiring?  Have you ever noted the average age of attendees at the AABB annual convention?  I feel young when I go there (and don’t worry about the gray hair!)

I want to attract new doctors and scientists to Transfusion Medicine.  I really try, but most have no interest and look on their rotations as a necessary evil.

I have lowered my expectations for most medical trainees in Transfusion Medicine.  They don’t like it, they just want to pass it, and move on.  What must I impress them with for their future careers?  What is essential for them to remember?

I have had both pathology and non-pathology trainees.  Surgical and ob/gyn doctors used to spend one month whereas the hematology and pathology residents/fellows spent on average three months.  The few interested in the field might do multiple rotations.

I still gave them lectures on a variety of topics, especially how to transfuse blood components, basic ABO/Rh antigens, compatibility testing, and direct antiglobulin testing.  They would forget most of this, but I wanted them to remember TURN-AROUND-TIMES:

Examples:

HOW LONG DOES IT TAKE TO PERFORM THE TEST?  TO FIND COMPATIBLE BLOOD?  TO THAW THE PLASMA?  RELEASE AN MTP SHIPMENT?  TO PERFORM A TRANSFUSION REACTION WORKUP BEFORE RELEASING MORE BLOOD?

I am not discouraging people from entering the field, but I am a realist to know that few will share my passion for serology or want to take call on difficult immunohematology cases.  At least if they understand the pressure the technical staff are in and these turn-around-times this will make both their work as clinicians and mine as transfusion medicine more congenial.

Opinion: Outside Accreditation and Quality Consultants

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Sometimes, you may not have adequate resources for a project so you will consider hiring an outside consultant.  During my career, I have used several outside consultants for projects ranging from installing a new general laboratory computer system to assisting in getting international accreditations.

For a complex accreditation process such as AABB, I have used such consultants to audit operations in the donor center including processing and testing, hospital blood banks, and stem cell laboratory.  They are high-level technical specialists with highest blood bank qualifications (e.g. SBB(ASCP) or equivalent) and have considerable experience in practice of blood banking and quality systems.  They have been AABB Assessors so they can give you a dry-run accreditation assessment.

Depending on the project, you may need one or a group of consultants.  I have worked with both individual consultants and groups.  A group can complete the tasks quicker but this is not always necessary.  Organizations such as AABB have many different consultants with different types of expertise so you can select the most appropriate individuals to form a team for your needs.

These specialists can audit your operations and propose a model and if you want, actually help you to implement the processes.  They can help you with the accreditation formalities, especially if you do not have any staff with experience in the process.  It all depends how much you can spend.

In the Middle East, to bring in such consultants may mean expensive air fares, hotels, meals, plus the actual costs of doing the consulting.  This is a major investment for your organization but it is well worth it to expedite the process.  There are local consultants available as well and using them may greatly help with the expenses.

Although it is expensive upfront, it can be cheaper in the long run by establishing the appropriate framework in the first place.  You can engage the consultants to actually do much of the work themselves, but it is better for them to offer a train the trainer experience, i.e. engage your own technical staff to learn new skills and then have them cross-train the rest of the staff. 

Based on the findings, your local staff can implement the changes.  You can then consider rehiring the consultants to verify that the work has been done properly.

I have used both individual consultants and groups through AABB Consulting.  My staff and I have learned much from such interactions, and I highly recommend their use when local expertise is not available.