Compatability Testing

Question 1

If a patient has a negative antibody screen, which phase of crossmatch is required?

Answer 1

Only IS

Question 2

If a patient has a positive antibody screen, crossmatching is required to be carried through which phase?

Answer 2

AHG

Question 3

How is a major crossmatch performed?

Answer 3

2 drops of patient serum mixed with 1 drop of donor cells

Question 4

What is a major cause of transfusion-associated fatalities?

Answer 4

clerical error in incorrect ABO grouping and transfusing ABO incompatible blood

Question 5

When should collection tubes be labeled?

Answer 5

before leaving the patient and the room

Question 6

The most common cause of error is…

Answer 6

misidentification of the patient

Question 7

What specimen type can be used for pretransfusion testing?

Answer 7

serum or plasma

Question 8

What type of anticoagulant can only be used when collecting a blood bank sample?

Answer 8

EDTA

Question 9

What is a disadvantage of using EDTA?

Answer 9

EDTA chelates Calcium, which can mask complement-activating antibodies

Question 10

What is an advantage and disadvantage of using plasma as a blood bank specimen?

Answer 10

Advantage: don’t have to wait for it to clot

Disadvantage: fibrin clots form

Question 11

How is a donor unit tested without contaminating the whole unit of blood?

Answer 11

Donor testing samples are prepared from segmented tubing that comes off the donor unit through which the donor blood was collected.

Question 12

What tests are performed on a donor unit?

Answer 12

ABO/Rh typing (including weak D) and disease testing

Question 13

What information regarding the patient’s sample should be kept in a record?

Answer 13

ABO/Rh, unexpected antibodies, and other unusual serological findings

Question 14

What does a visual inspection of a donor unit entail?

Answer 14

Observing serum level and color

Observing color and turbidity after mixing the unit

Question 15

What is the first choice when transfusing blood?

Answer 15

Type specific (Same ABO/Rh as the patient)

Question 16

When an unexpected antibody is detected in a patient, what type of blood should they be transfused with?

Answer 16

antigen-negative blood

Question 17

What is it called when patient serum is mixed with donor cells?

Answer 17

major crossmatch

Question 18

What is it called when donor serum is mixed with patient cells?

Answer 18

minor crossmatch

Question 19

An IS crossmatch verifies…

Answer 19

ABO/Rh compatibility

Question 20

What is the main purpose of the serological crossmatch?

Answer 20

A final check of ABO compatibility between donor and recipient

Question 21

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?

Answer 21

Crossmatch

Question 22

How much blood needs to be present for a crossmatch to be required on plasma and platelet products?

Answer 22

> 2mL of blood

Question 23

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

Answer 23

IS crossmatch

Question 24

Which cross match has the following advantages and disadvantages?

ADV: more specific for clinically significant antibodies
DIS: more time- and reagent-consuming

Answer 24

AHG Crossmatch

Question 25

What is a major disadvantage of IS crossmatch

Answer 25

Potential to work-up an insignificant antibody

Question 26

What is a major advantage to AHG crossmatching?

Answer 26

Detects clinically significant antibodies

Question 27

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.

Answer 27

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.

Question 28

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?

Answer 28

positive

Question 29

What is a computer crossmatch?

Answer 29

Electronic comparison of recent ABO serologic results and interpretations on file for both the donor and recipient being matched. This comparison determines compatibility.

Question 30

In order for a patient to be transfused with uncrossmatched blood, what MUST happen

Answer 30

The physician must authorize

Question 31

TRUE OR FALSE: A sample needs to be collected from a patient before they receive uncrossmatched blood.

Answer 31

TRUE

Question 32

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?

Answer 32

Testing the patient's serum for anti-A and/or anti-B (Forward typing)

Question 33

When are compatibility testing procedures required for the transfusion of platelet products?

Answer 33

If >2mL of blood is suspected in the sample

Question 34

Blood for intrauterine transfusions must be compatible with...

Answer 34

maternal antibodies capable of crossing the placenta

Question 35

Crossmatching for intrauterine blood transfusions is tested on...

Answer 35

maternal serum

Question 36

Blood transfused into a neonate must be compatible with...

Answer 36

maternal antibodies (could still be in neonate's circulation)

Question 37

Blood for neonatal transfusions cannot be older than...

Answer 37

7 days.

Question 38

A massive transfusion is described as (2 ways)

Answer 38

8-10 units into an adult patient in less than 24 hours OR 4-5 units administered in 1 hour

Question 39

TRUE OR FALSE: Autologous donations can be used for patients other than the one that donated it.

Answer 39

FALSE

Question 40

TRUE OR FALSE: Current testing procedures can guarantee the fate of a unit of blood that is transfused.

Answer 40

FALSE

Question 41

TRUE OR FALSE: A compatible crossmatch guarantees optimal RBC survival after transfused.

Answer 41

FALSE

Question 42

What step is the most critical for preventing mistransfusions?

Answer 42

Bedside check just prior to blood administration.

Question 43

What information must be identified on the label attached to the donor unit?

Answer 43

Identity of intended recipient, pretransfusion testing results, and donor unit number

Question 44

How many times, no matter what system is used, must information be verified before the transfusion of the blood product?

Answer 44

at least twice