1. INCOMPLETE CROSSMATCH

2. Intended Learning Outcomes (ILOs)
Compatibility Testing
Approaches Requiring Less Than a Complete Crossmatch
Is the Crossmatch Really Needed?
What can be given in an emergency transfusion?

3. Compatibility testing is done to avoid
Why do we care?
Compatibility testing is done to avoid
a hemolytic transfusion reaction
If the Host or Recipient recognizes
the donor RBC surface antigens as foreign,
the host will mount an immune response
to the donor RBC’s

4. Major Blood Groups
ABO

5. ABO blood group antigens present on red blood cells
and IgM antibodies present in the serum

6. Rhesus Major Blood Groups 47 Antigens make up the Rhesus Blood Group
The most significant is the D antigen

8. What is compatibility testing?
Also called pretransfusion testing
Purpose:
To select blood components that will not cause harm to the recipient and will have acceptable survival when transfused
If properly performed, compatibility tests will confirm ABO compatibility between the component and the recipient and will detect the most clinically significant unexpected antibodies

9. Compatibility testing
Can be divided into 3 categories:
Preanalytical procedures
Serological testing
Postanalytical procedures

10. Patient Identification
Must confirm recipient’s ID from bracelet ON the patient
Full patient name and hospital number
Name of physician

11. Sample Identification
The sample should also have the full patient name, hospital number, and physician
Date and time of collection, phlebotomist’s initials
All of this should be on the request form and the sample

12. Specimen Tubes
Pink Top - EDTA
Red Top – no additives

13. Serological Testing 3 tests: ABO/Rh Antibody detection/identification
Crossmatch

14. ABO/Rh Typing In the ABO typing, the forward and reverse MUST match
In the Rh typing, the control must be negative
Both of these will indicate what type of blood should be given

15. Anti A
Anti B
Anti A
Anti B A B
Anti A
Anti B
Anti A
Anti B AB O

16. Antibody screen
Also called the indirect Coombs test or the indirect antiglobulin test
The antibody screen will detect the presence of any unexpected antibodies in patient serum
If antibodies are detected, identification should be performed using panel cells (with an autocontrol) IS
37° (LISS)
AHG

17. Crossmatching Purpose: Prevent transfusion reactions
Increase in vivo survival of red cells
Double checks for ABO errors
Another method of detecting antibodies

18. Crossmatches According to the AABB Standards:
The crossmatch “shall use methods that demonstrate ABO incompatibility and clinically significant antibodies to red cell antigens and shall include an antiglobulin phase”

19. Crossmatch No agglutination ~ compatible Agglutination ~ incompatible
Donor RBCs (washed)
Patient serum

20. The procedure
Donor cells are taken from segments that are attached to the unit itself
Segments are a sampling of the blood and eliminate having to open the actual unit

21. Crossmatch Procedure if antibodies are NOT detected:
Only immediate spin (IS) is performed using patient serum and donor blood suspension
This fulfills the AABB standard for ABO incompatibility
This is an INCOMPLETE CROSSMATCH
If antibodies ARE detected:
Antigen negative units found and X-matched
All phases are tested: IS, 37°, AHG
This is a COMPLETE CROSSMATCH

22. Crossmatches… Will Will Not Verify donor cell ABO compatibility
Detect most antibodies against donor cells
Will Not
Guarantee normal survival of RBCs
Prevent patient from developing an antibody
Detect all antibodies
Prevent delayed transfusion reactions

23. Approaches Requiring Less Than a Complete Crossmatch

24. Type and Screen
Determines the ABO-Rh of the patient and the presence of the most commonly found unexpected antibodies(elimination of the crossmatch ).

25. Type and Screen
If an emergency transfusion is required after type and screen alone, an immediate-phase crossmatch is performed.
Blood given in this manner is more than 99% effective in preventing incompatible transfusion reactions due to unexpected antibodies.

26. Is the Crossmatch Really Needed?
If the correct ABO and Rh blood type is given, the possibility of transfusing incompatible blood is less than 1 chance in 1000.
ABO-Rh typing alone results in a 99.8% chance of a compatible transfusion,
The addition of an antibody screen increases the safety to 99.94%, and
A crossmatch increases this to 99.95%.

27. Physician responsibility in ordering uncrossmatched blood
In an emergency (ER or OR), there may not be enough time to test the recipient’s sample
It is your judgment that the risk of the patient dying from from anemia is greater than the risk of transfusing the patient without pre-transfusion testing

28. What can be given in an emergency?
Type-Specific, Partially Crossmatched Blood
An ABO-Rh typing and an immediate-phase crossmatch
An abbreviated format
Macroscopic agglutination.
This takes 1 to 5 minutes

29. What can be given in an emergency?
Type-Specific, Uncrossmatched Blood
The ABO-Rh type
Most ABO type-specific transfusions are successful.
Caution should be used for patients who have previously received transfusions or have had pregnancies.

30. What can be given in an emergency?
Type O Rh-Negative (Universal Donor), Uncrossmatched Blood
Type O blood lacks the A and B antigens
Type O Rh-negative, uncrossmatched packed RBCs should be used in preference to type O Rh-negative whole blood.
More than two units of type O Rh-negative, uncrossmatched whole blood, the patient probably cannot be switched to his or her blood type .

31. Specific Recommended Protocol
Infuse crystalloids or colloids.
Draw a blood sample for typing and crossmatching.
If crossmatched blood is not ready to give, use type-specific or type O Rh-negative cells or type O Rh-positive cells for males or postmenopausal females without a history of transfusions.

32. Summary
The crossmatch “shall use methods that demonstrate ABO incompatibility and clinically significant antibodies to red cell antigens
If an emergency transfusion is required after type and screen alone, an immediate-phase crossmatch is performed before transfusion (an abbreviated format )
If crossmatched blood is not ready to give, use type-specific or type O Rh-negative cells