Pretransfusion Testing Flashcards
Mixing patient serum and donor red cells together and observing for direct cell lysis or agglutination is known as:
Major crossmatch
What does compatibility testing include?
ABO, Rh, antibody screen, major crossmatch
Why are hemolyzed samples unacceptable for compatibility testing?
Complement activation by antigen-antibody complexes will be masked
How long after a transfusion must donor and recipient samples be stored at 1 to 6 degrees C?
7 days
All of the following antibodies are clinically significant except:
Anti-Bga
Why is it necessary to use single-donor screening cells instead of pooled screening cells for patient samples?
Single-donor screening cells are complementary among each other
What alternative type can be given to an O-positive person when group O blood is not available?
none
In what circumstances would it be feasible to transfuse Rh-positive blood to an Rh-negative individual?
In an elderly woman
Which statement best describes the relation between a crossmatch and a compatibility test?
If a compatibility test was a pie, a crossmatch would be a slice
Why was the minor crossmatch discontinued?
Donor screening for antibody was incorporated into donor processing
What is an abbreviated crossmatch?
Type and screen plus immediate spin crossmatch
What is an “electronic” crossmatch?
Comparison of donor and patient ABO groups and serologic data from a computer file
All of the following may be used as potentiators in the antiglobulin crossmatch except:
Papain
When performing an Antiglobulin crossmatch, the cells had a jagged edge appearance after the addition of AHG and centrifugation. This indicates a(n) ______ result.
Positive
Recipients serum which reacted with one out of five donor units in the AHG phase and where the antibody screen was negative is probably due to:
An alloantibody directed towards a low-frequency antigen
Passive acquisition of anti-A, B, AB may occur through:
Bone marrow transplantation
What causes rouleaux to form?
Abnormal A/G ratio
Which of the following is true regarding blood issued on an emergency basis without patient testing?
Units are tagged for emergency release and segments are pulled later for testing
How can the ABO and Rh of the fetus be determined in utero?
Amniocentesis
Chorionic Villus sampling
Percutaneous umbilical cord sampling
All of the following may be used for the antibody screen before transfusing an infant except:
Paternal serum
What may be added to samples from patients taking heparin to induce clotting?
Protamine sulfate
What tests are not required on autologous units transfused within the collecting facility?
Antibody screen
Why is the transfusion product tagged before it is issued and transfused?
to identify the patient
to verify compatibility results
to verify the donor number
What blood-banking research product hopes to provide oxygen-carrying capacity without the need for compatibility testing?
Hemoglobin substitutes
