Month: Aug 2020

Handling of Placenta Previa in the Blood Bank

drzeyd

The following protocol is the one I made for National Guard Health Affairs in Riyadh and has been updated to include the use of a blood bank computer system.

Medinfo has an emergency mode that facilitates release of blood components even if all the usual testing is not available

If Medinfo software is used, one can write a protocol based on the diagnosis of placenta previa to automatically allocate the blood and keep it on hold at all times.

Ward Responsibilities:

  1. As soon as a patient with high-risk placenta previa is identified, order type and crossmatch for 4 units PRBCs.
  2. Immediately forward the specimen and its requisition to the blood bank for expedited processing.  BE CERTAIN TO INDICATE ON THE FORM AND/OR IN THE COMPUTER SYSTEM THAT THIS IS A PLACENTA PREVIA CASE!!
  3. Send a new specimen for crossmatching every 3 days until delivery.
  4. Phone the blood bank immediately when blood is needed for the patient before coming to the Blood Bank.  DO THIS BEFORE SENDING SOMEONE TO THE BLOOD BANK TO PICK UP THE BLOOD!

Blood Bank Responsibilities:

  1. Check the order comments for placenta previa.
  2. Handle all such requests as emergency or STAT.
  3. Enter a comment in the computer that this is a placenta previa case.
  4. Verify that the specimen has been properly collected and labelled.
  5. If the specimen is not acceptable, request new specimen.
  6. In emergencies, use emergency release/emergency mode in Medinfo.
  7. If specimen valid:
    1. Perform ABO/Rh typing and antibody screen if one is not available within the past 3 days.
    1. Check for previous history of ABO/Rh typing and antibodies—performed by blood bank computer system.
  8. Allocate 4 units, electronic crossmatch or full AHG as indicated by our rules.
    1. Provide antigen-matched units accordingly.
  9. When the ward calls that a placenta previa patient needs blood, immediately prepare the blood for release.  This is an emergency request of the highest priority.  VERBAL REQUESTS FOR BLOOD IN THESE CASES ARE ACCEPTABLE.
    1. Use emergency mode/emergency release in Medinfo if all the testing is not done or current.

Processes and Software Building 30: Donor HCV Screening Tests

drzeyd

The testing algorithms may trigger additional testing, repeat of current testing at some future date, or permanent deferral.  One of the most complex processes is for HCV testing.  The following criteria are based on US FDA CBER guidelines, but are modified for the availability of test methodologies not licensed in the USA.

For HCV, we use the following testing in all donors:

  1. HCV antibody EIA
  2. HCV NAT
  3. If any of the tests are non-negative, then we do the HCV LIA immunoblot assay. 

HCV LIA is more sensitive than RIBA-3 (now no longer performed in the USA) but is not available in the USA.  This test has been incorporated into the testing algorithm from CBER:

  1. Hepatitis C:
    1. HCV-RNA positive confirmed, regardless of other HCV results:  permanent deferral, refer to Infectious Disease clinic
    2. HCV-RNA borderline:  repeat all HCV testing after 6 months
    3. HCV-InnoLIA positive, regardless of other HCV results:  permanent deferral, refer to Infectious Disease clinic
    4. HCV-InnoLIA indeterminate:  repeat all HCV testing after 6 months
    5. HCV-Ab positive, HCV-RNA negative, do HCV-InnoLIA:
      1. If HCV-InnoLIA positive, permanent deferral, refer to Infectious Disease clinic
      2. If HCV-InnoLIA indeterminate or negative, repeat all HCV testing after 6 months
    6. Repeat Hepatitis C Testing After 6 months:
      1. HCV-RNA or HCV-InnoLIA positive:  permanent deferral, refer to Infectious Disease clinic
      2. HCV-RNA or HCV-InnoLIA borderline:  permanent deferral, HCV infection not confirmed
      3. HCV-Ab positive or borderline without positive HCV-RNA or positive HCV-InnoLIA:  permanent deferral, HCV infection not confirmed
      4. HCV-Ab negative, HCV-RNA negative, HCV-InnoLIA negative:  reenter donor into donor pool

Note that indeterminate HCV results may be carried forward repeatedly by CBER rules but I decided to permanently defer the donor after 2 cycles of indeterminate results.  The donor must wait SIX MONTHS before the next round of testing.  Should he/she return before that time, those results may not be used for determining donor eligibility (unless the results have become clearly positive).

To Be Continued:

10/8/20

Processes and Software Building 29: Donor Marker Testing Overview

drzeyd

Donor marker testing algorithms are very complex and serve multiple objectives:

  1. Is the blood safe for the recipient, i.e. minimize likelihood of disease transmission?
  2. How do we to counsel the affected donor?  Does he need referral for treatment or follow-up?

Often the donor disposition is unclear based on a single encounter and a temporary deferral must be triggered so the current results may be compared to future ones, usually after 8 weeks, 6 months, or one year—depending on the pathogen in question.

Regretfully, the significance of reactions that do not meet the criteria for positivity may be unclear.  It is very difficult to explain to the donor that he has abnormal results and cannot donate but we as physicians do not know what their significance is.

Thus, the testing algorithms may trigger current additional testing, temporary deferral with repeat of testing at some future date, or permanent deferral.

At my previous positions, I started with the AABB/FDA CBER Uniform Donor Questionnaire UDQ and then modified it to include some advanced methodologies not available in the USA.

In the next series of posts I will elaborate on the processes developed for this for each marker.

To Be Continued

9/8/20

My Opinion: Separate Transfusion Medicine from the Laboratory

drzeyd

Transfusion Medicine includes laboratory and non-laboratory functions.  The non-laboratory and purely clinical functions are unique and have no analogy within the general laboratory.

The transfusion service/hospital blood bank laboratory is the closest to a laboratory operation, but there is component modification and complex manual testing, especially for reference immunohematology testing.  The staff must make detailed manual decisions, the errors for which could be life-threatening for the patient.

The blood donor center manufactures a pharmaceutical, i.e. blood components with collection, donor qualification, donor abnormal results review, infectious disease marker testing, component production, and donor immunohematology testing—all subject to Good Manufacturing Practices.  Never forget:  Blood is a drug!!

No other laboratory section is directly responsible for treatment of critically ill patients.  Therapeutic apheresis is essential for organ and stem-cell transplants, nephrology, neurology, etc.  No other laboratory section is directly responsible for treatment of critically ill patients.  Transfusion Medicine physicians are functioning as intensivists.  There is no hiding in the laboratory from clinical medicine.

There may also be an industrial manufacturing plant to extract various blood derivatives (e.g. factor concentrates, albumin, Rh immune globulin, etc.)  This is pharmaceutical manufacturing on a large-scale basis.  There is medical, technical, and special administrative expertise.

Many functions may operate 24/7.  The transfusion medicine physician may be on-call for donor issues and review of complex immunohematology problems to acutely decide which blood component (and phenotype) should be given as well as review all adverse reactions to transfusion.

The unique blend of clinical skills is unlike anything else in the laboratory.  Also, those outside the blood bank rarely have the skills or judgments for the best course of action for transfusion medicine or for its operations.

The clinical transfusion medicine physician must make acute, life-threatening decisions unlike anyone else in the laboratory.  The blood bank technologist is at the cutting edge of the battle with his testing and interpretations.  No other area of the laboratory is at such risk for injuring or even killing the patient.  There is high stress and burn-out.

I have talked with many blood bankers and many seem to share the exasperation that the laboratory does not understand us.  The latter looks at blood bank testing like that coming off a hematology or chemistry analyzer—although patients rarely would have severe morbidity or mortality like the blood bank from errors in those analyzers.

No laboratory pathologist has the pressure of the blood bank physician on-call.  It really is 24/7 and requires a broad, clinical background to make the right decisions.  It is very stressful and does not permit a good night’s sleep.

Thus, I make my case to separate us from the laboratory.  We can form our own more effective administrative organization and optimize our own planning.  Regretfully, I have never worked in such an administrative structure.  I also am a realist that cost-containment nowadays makes it much less likely high administration would permit this change for a mere cost center.  This will probably never happen during my career.

Finally, Transfusion Medicine is an essential service.  Blood components are essential drugs.  The operations and staff must be free of political influences.  This is a service for the entire region or country like the fire department, civil defense, etc.

8/8/20

Processes and Software Building 28: Donor Questionnaire

drzeyd

Donor Collection 6

I started building this using the Uniform Donor Questionnaire UDQ from the AABB;  however, I modified it to include coverage for Chikungunya, Zika, etc. and to include enhanced processes for malaria based on the Australian Red Cross.

For each screening question, I prepared the exact wording (usually the UDQ’s) and set the deferral to temporary (how many days) or permanent.

Some questions were more open-ended, and the interviewer manually entered a medication, surgical procedure, etc.  The transfusion physician would review this and assign a temporary (specifying the interval) or permanent deferral.

The questionnaire was constantly being updated by changes.  My role was to review different accreditation systems (AABB, CE, etc.) and the World Health Organization’s websites.  I would then prepare an interim policy and pass the specifications for the changes to the Medinfo software engineer and when ready, finally to the Super Users for testing.  If there was an urgent change, the whole process could be completed in less than one day including validation testing.

The following shows examples of the software processes:

  1. Medications
  2. Body fluid exposures
  3. Vaccinations
  4. Malaria
  5. Ebola/Zika

I emphasize that all of these settings are user-definable (at least in jurisdictions that permit all open, non-turnkey software).

Medication Questions:

Vaccinations:


Blood and Body Fluid Exposures:

Malaria Example:  DMAL refers to the malaria antibody test.


Ebola and Zika Examples:

7/8/20

Neonate Born to Bombay Oh Mother

drzeyd

We had a mother (R1R1 K-neg) from Tamil Nadu who had several visits to our hospital.  Anti-H lectin was negative.  Here is a summary of her workup:

Mother’s ABO/D Typing:

Mother’s Antibody Screen:

Mother’s Antibody Identification:

She gave birth to a baby girl, group B, R1R1 K-neg.  This is the neonate’s workup:

Despite the weakly positive IgG DAT, the eluate was negative.  The neonate was asymptomatic.

Anti-H is mainly an IgM antibody and does not cross the placenta, thus no HDFN was noted.

6/8/20

Processes and Software Building 27 Donor Center 5

drzeyd

Building the Software Processes for the Donor Collection 5: Donor Physical Examination and Adverse Reaction Reporting

Donor Physical Examination and Adverse Reactions

Donor physical examination, along with the donor questionnaire, are important both for donor and patient safety.  In general:

Is it safe for the donor to donate?

Is it safe for the patient to receive the blood even if it is safe for the donor to donate.

Any donor who does not feel well must not donate.  This may be the single most important step in ensuring a safe blood supply.

The donor physical examination includes the vital signs (blood pressure, pulse, temperature, heart rate, and temperature).  I have attached a sample set of criteria for review.  All are user-definable.  Note how the arm examination is also included (looking for scarring, skin lesions, etc.)

For all types of donations, there may be adverse reactions.  These must be documented in the record along with the disposition of the donation.  Will the donor need an extended deferral if the RBCs in the apheresis run are not returned?  This can be built from the reaction documentation.  Note the following sample table of reactions.

To Be Continued

5/8/20