Compatability Testing Flashcards
If a patient has a negative antibody screen, which phase of crossmatch is required?
Only IS
If a patient has a positive antibody screen, crossmatching is required to be carried through which phase?
AHG
How is a major crossmatch performed?
2 drops of patient serum mixed with 1 drop of donor cells
What is a major cause of transfusion-associated fatalities?
clerical error in incorrect ABO grouping and transfusing ABO incompatible blood
When should collection tubes be labeled?
before leaving the patient and the room
The most common cause of error is…
misidentification of the patient
What specimen type can be used for pretransfusion testing?
serum or plasma
What type of anticoagulant can only be used when collecting a blood bank sample?
EDTA
What is a disadvantage of using EDTA?
EDTA chelates Calcium, which can mask complement-activating antibodies
What is an advantage and disadvantage of using plasma as a blood bank specimen?
Advantage: don’t have to wait for it to clot
Disadvantage: fibrin clots form
How is a donor unit tested without contaminating the whole unit of blood?
Donor testing samples are prepared from segmented tubing that comes off the donor unit through which the donor blood was collected.
What tests are performed on a donor unit?
ABO/Rh typing (including weak D) and disease testing
What information regarding the patient’s sample should be kept in a record?
ABO/Rh, unexpected antibodies, and other unusual serological findings
What does a visual inspection of a donor unit entail?
Observing serum level and color
Observing color and turbidity after mixing the unit
What is the first choice when transfusing blood?
Type specific (Same ABO/Rh as the patient)
When an unexpected antibody is detected in a patient, what type of blood should they be transfused with?
antigen-negative blood
What is it called when patient serum is mixed with donor cells?
major crossmatch
What is it called when donor serum is mixed with patient cells?
minor crossmatch
An IS crossmatch verifies…
ABO/Rh compatibility
What is the main purpose of the serological crossmatch?
A final check of ABO compatibility between donor and recipient
What pretransfusion test can detect an antibody in the patient’s serum against an antigen on the donor cell when an antibody screen was negative?
Crossmatch
How much blood needs to be present for a crossmatch to be required on plasma and platelet products?
> 2mL of blood
Which crossmatch method has the following advantages and disadvantages?
ADV: saves time, reagents, and workload
DIS: Can end up working-up a non-significant antibody
IS crossmatch
Which cross match has the following advantages and disadvantages?
ADV: more specific for clinically significant antibodies
DIS: more time- and reagent-consuming
AHG Crossmatch
What is a major disadvantage of IS crossmatch
Potential to work-up an insignificant antibody
What is a major advantage to AHG crossmatching?
Detects clinically significant antibodies
According to the Code of Federal Regulations, all results must be recorded (?) in a (?) ledger by means of a logical system that allows them to be easily recalled.
According to the Code of Federal Regulations, all results must be recorded IMMEDIATELY in a PERMANENT ledger by means of a logical system that allows them to be easily recalled.
Incorrect ABO typing, abnormalities in the patient serum, contamination in the test system, or an allo- or autoantibody in the patient’s serum will cause what kind of crossmatch results?
positive
What is a computer crossmatch?
Electronic comparison of recent ABO serologic results and interpretations on file for both the donor and recipient being matched.
This comparison determines compatibility.
In order for a patient to be transfused with uncrossmatched blood, what MUST happen
The physician must authorize
TRUE OR FALSE: A sample needs to be collected from a patient before they receive uncrossmatched blood.
TRUE
If a patient needs to switch to second choice blood types for transfusion due to type specific blood being depleted, what testing must be performed before the new units are given for transfusion?
Testing the patient’s serum for anti-A and/or anti-B (Forward typing)
When are compatibility testing procedures required for the transfusion of platelet products?
If >2mL of blood is suspected in the sample
Blood for intrauterine transfusions must be compatible with…
maternal antibodies capable of crossing the placenta
Crossmatching for intrauterine blood transfusions is tested on…
maternal serum
Blood transfused into a neonate must be compatible with…
maternal antibodies (could still be in neonate’s circulation)
Blood for neonatal transfusions cannot be older than…
7 days.
A massive transfusion is described as (2 ways)
8-10 units into an adult patient in less than 24 hours
OR
4-5 units administered in 1 hour
TRUE OR FALSE: Autologous donations can be used for patients other than the one that donated it.
FALSE
TRUE OR FALSE: Current testing procedures can guarantee the fate of a unit of blood that is transfused.
FALSE
TRUE OR FALSE: A compatible crossmatch guarantees optimal RBC survival after transfused.
FALSE
What step is the most critical for preventing mistransfusions?
Bedside check just prior to blood administration.
What information must be identified on the label attached to the donor unit?
Identity of intended recipient, pretransfusion testing results, and donor unit number
How many times, no matter what system is used, must information be verified before the transfusion of the blood product?
at least twice
