CLS 3311 Advanced Clinical Immunohematology

1. CLS 3311Advanced Clinical Immunohematology Compatibility (Pretransfusion) Testing

2. Pretransfusion Testing • Purpose: To select blood components that will not cause harm to the recipient and will have acceptable survival when transfused. • When performed properly, pretransfusion tests will confirm ABO compatibility between the component and the recipient and will detect most clinically significant unexpected antibodies.

3. Donor Basic Testing (processing): ABO Grouping: Forward and Reverse Rh typing: Complete with Weak D IAT: Antibody screen Transmissible disease testing: HIV, HTLV, HCV, HBV and RPR Recipient Basic Testing: ABO Grouping: Forward and Reverse Rh typing: Only Immediate is REQUIRED. Exception is for neonates and women of child bearing age. IAT & Panel: Antibody Screen and Identification Pretransfusion Testing

4. Pretransfusion Testing The Actual Crossmatch (X-m) • Test DONOR CELLS with RECIPIENT SERUM • May include I.S., 37oC, & AHG Phase (extended X-M) • OR may just be Immediate Spin phase only to confirm ABO compatibility of Recipient and Donor • OR may be Computer Crossmatch !! PURPOSE • DetectPatient Antibodiesthat can react withDONOR Cells

5. AABB Requirements for Pretransfusion Testing • Positive identification of recipient and recipient sample • ABO group and Rh typing of recipient and donor blood. • Red cell antibody detection tests for clinically significant antibodies using recipients serum or plasma. • Comparison of current findings of recipients sample with record of previous patient results. • Selection of components of ABO group and Rh type appropriate for the recipient. • Performance of a serologic or computer crossmatch. • Labeling of products with the recipients identifying information.

6. Steps In Pre-transfusion Testing Review available RECIPIENT Records • Previous ABO & Rh and any PRIOR indication of Unexpectedantibodies • For any Prior Adverse Reactions to transfusion Donor Unit Id and ABO/Rh • Confirm donor unit # with the collecting facilities records, and confirm by retesting donor ABO/Rh • Confirm match between donor unit ABO/Rh and the patient ABO/Rh

7. Steps In Pre-transfusion Testing Correct Identification of: • Recipient by confirming patient identity from identification bracelet ON PATIENT • Recipient Sample by clear identification/ labeling on the recipient sample • FULL patient name & unique hospital #, • Name of requesting physician, • Date and time of collection, & phlebotomist’s initials • Information clearly written on both the request form and the sample itself

8. Steps In Pre-transfusion Testing Collecting Patient Sample • Sample must NOT be hemolyzed - • Unless the patient is doing the hemolyzing • Why? • Can use serum or plasma • Plasma prevents detection of complement dependent antibodies and… • Fibrin clots, which may form, can be mistaken for agglutination • If sample must be drawn from IV line: • Infusion should be stopped for 5-10 minutes and the first 10 ml’s of sample discarded. Why?

9. Steps In Pre-transfusion Testing Selection of Appropriate Donor Unit(s) • ABO & Rh compatible • Donor unit expiration date. • Correct component preparation for the patient needs such as thawing plasma, etc. Accurate Testing & Recording Of • Donor results: Computer data entry • Recipient results: Computer data entry • Do we ever make data entry errors in the laboratory?

10. Steps In Pre-transfusion Testing AT THE TIME OF TRANSFUSION Accurate Identification Of: • Recipient pre-transfusion records • Retrieve the correct patient’s records • Correct donor unit is retrieved & released • The correct recipient is identified on unit/ward prior to initiating the component’s infusion

11. Steps In Pre-transfusion Testing • Recipient sample&Donor segment should be stored at 1 to 6oC for minimum of seven days • Transfusion should occur within 72 hours of sample collection & testing • Patients transfused or pregnant within the last 3 months, may be developing a clinically significant antibody at a detectable level • If sample used is > 72 hrs. post collection, a clinically significant antibody may have formed and will be missed. Only a new serum sample will pick up the antibody.

12. Pre-transfusion Testing Procedures TYPE & SCREEN • Consists of ABO, Rh, IAT • Ordered most often for Pre-Surgical Patient with: • No abnormalities in ABO Grouping, Rh Typing • No unexpected Ab’s detected with IAT • No patient records of unexpected Ab’s or problems with prior transfusions • Patient ABO, Rh, & IAT are performed but no units are crossmatched or reserved for the patient.

13. Pre-transfusion Testing Procedures Supplying blood for the ‘type & screen’ surgical patient • Conservative Approach involves pulling the patient sample and the appropriate donor unit segments and doing an Extended Crossmatch with IS, 37 and AHG phases. • Moderate approach involves pulling the patient sample and the appropriate donor unit segments and performing an Abbreviated crossmatch such as an Immediate Spin Crossmatch only.

14. Pre-transfusion Testing Procedures Liberal Approach: Computer Crossmatch • Every keystroke in the computer system must be validated. • Donor Identification, ABO/Rh, IAT results entered • Recipient Identification, ABO/Rh, IAT results entered • Two different individuals must do the ABO (Rh) on the same recipient specimen • OR the same individual performs the ABO on 2 different collections of the same recipient

15. Pre-transfusion Testing Procedures Computer Crossmatch continued • The test results are entered into acomputerthat then selects the most appropriateDonor unitin terms ofABO, Rh, & expiration date for that recipient. • Computer system contains logic to detect and alert user of anydiscrepanciesbetween the recipient and donor. • ‘Tube’ crossmatch is NOT performed.

16. Pre-transfusion Testing Procedures Extended Crossmatch • Is to be Performed on Recipients with: • Unexpected antibodies • Prior records of unexpected antibodies OR • Problems with transfusion, ABO and/or Rh • The Antibody(s) should be identified prior to transfusion, if possible • Some may not be possible to identify, such as auto antibodies.

17. Pre-transfusion Testing ProceduresSpecial Circumstances Extreme Emergency • No time for even ABO and Rh testing • Initially, the unit of choice is Gr O Rh Negative • The Attending Physician must understand that a sample must be obtained from the patient as quickly as possible. Physician must sign waiver omitting pre transfusion testing. Specimen of choice is pretransfusion, if possible. • If recipient is Rh Pos then the he/she can be quickly switched to Rh Pos blood

18. Extreme Emergency • The physician must sign a Release Form before you release uncrossmatched blood for transfusion. • This release indicates that the clinical condition warrants the risks of transfusion in the absence of knowing about the ABO, Rh, & IAT • In cases where units are released without knowing the Recipient’s ABO & Rh, the established protocol for compatibility testing must be performed on the Recipient & Donor units after the fact. • Even if the units have already been transfused OR even if the Recipient Dies. All work must be completed. • All patient recordsmust be complete.

19. Pre-transfusion Testing Procedures Special Circumstances Extreme Emergency Continued • IF recipient is Rh Neg but has NO evidence of anti-D, is male or beyond child bearing age, then it may be more efficient to give Rh Pos blood • If a recipient is hemorrhaging heavily, you will end up replacing his blood volume more than once • If it is determined that giving Rh Pos units to an Rh Neg patient is appropriate, the attending Physician must be informed and consent must be obtained in advance.

20. Pre-transfusion Testing Procedures Special Circumstances • Transfusing NON - ABO Group Specific Blood • when the Recipient must be transfused the attending Physician must be informed and agree. • If group specific blood becomes available and the choice is to switch to ABO group specific blood, youMUST: • Test for the presence of anti-A and/or anti-B in the patient’s serum before returning to ABO group specific blood • If the Recipient doesn’t reverse group appropriately, they should be given Gr O packed cells

21. Pre-transfusion Testing Procedures Special Circumstances Intrauterine & Infant Transfusions • Blood must be compatible with MATERNAL antibodies that are capable of crossing the placenta. Crossmatch with Mom’s serum, if possible. • If the ABO & Rh of the fetus or infant is known, then group & type specific blood can be given • if no fetomaternal incompatibility has been detected • If the ABO & Rh are unknown, O Neg can be given

22. Pre-transfusion Testing Procedures Special Circumstances Massive Transfusion • Replacement approximating or exceeding the patients blood volume within a 24-hour period. • If the patient has no unexpected Ab’s, pretransfusion testing can be ELIMINATED • If the patient has an unexpected antibody, the units must be antigen typed, with commercial antisera, for the corresponding antigen and antigen negative blood must be transfused.