Deck 9: Compatibility Testing

Question 1

If an emergency exists and there is not enough time to perform a crossmatch for red cells,what is the correct procedure?

A) Release group O, D-negative whole blood.
B) Release group O, D-negative RBC units.
C) Release group AB fresh frozen plasma until the blood type is performed.
D) Release ABO-compatible blood based on the patient's prior record in the computer.

Answer 1

B
Group O D-negative red blood cell units should be released and the crossmatch procedure completed as soon as possible.

Question 2

When is the immediate-spin or abbreviated crossmatch an acceptable procedure for the recipient?

A) No prior or existing clinically significant antibodies
B) Never been pregnant or transfused
C) Needs blood before a sample can be obtained
D) Using blood from a directed donation

Answer 2

A
An immediate-spin checks the ABO incompatibility only.It must only be used if no clinically significant antibodies are detected.

Question 3

A group O patient was crossmatched with group B red blood cells.What phase of the crossmatch will first detect this incompatibility?

A) Immediate-spin
B) 37° C low-ionic strength solution
C) Indirect antiglobulin
D) None of them; unit is compatible

Answer 3

A
ABO incompatibilities should be detected on immediate-spin.

Question 4

A recipient is group O with the following Rh phenotype: D+C+c-E+e+.
If this recipient is transfused with red blood cells from six random group O D-positive donors,what Rh alloantibody could this patient produce as a result of transfusion?

A) Anti-E
B) Anti-C
C) Anti-c
D) Anti-D

Question 5

Given the following red cell antigen frequencies:
K 10%
E 30%
K 90%
P₁ 80%
Which of the following red cell alloantibodies would be responsible for incompatible crossmatches with one 1 of 10 random donor units?

A) Anti-K
B) Anti-E
C) Anti-k
D) Anti-P₁

Question 6

Select the item that compatibility procedures will not address.

A) Prevent formation of all red cell antibodies
B) Prevent life-threatening transfusion reactions
C) Maximize in vivo survival rate of red cells
D) Check ABO compatibility

Question 7

An antibody screen on a patient with a prior history of transfusion was negative.The patient had an indication to perform an AHG crossmatch on file.The crossmatch was incompatible with 1 of 5 units selected at AHG phase.What is the next step in the investigation?

A) Perform a prewarm procedure for crossmatching
B) Perform a direct antiglobulin test on the incompatible unit
C) Redraw the patient and begin a new crossmatch
D) Crossmatch a new unit and discard the incompatible unit

Question 8

When type O blood is not available for transfusion for a type O recipient,what is the next alternative?

A) Group A red blood cells
B) Group AB red blood cells
C) Washed group B red blood cells
D) None

Question 9

Select the correct statement regarding the collection of a blood sample for compatibility testing.

A) The sample must be labeled at the bedside.
B) The sample requires a new numeric identifier for the patient for each admittance.
C) The sample may be labeled at any time in an emergency.
D) The sample does not require a means to identify the phlebotomist.

Question 10

If not stored in a monitored refrigerator,how long can RBC units remain outside the transfusion service to allow reissue?

A) 15 minutes
B) 30 minutes
C) 45 minutes
D) 60 minutes

Question 11

If the recipient was transfused within the last 3 months,how long from the time of collection can a sample be used for the crossmatch?

A) 3 days
B) 5 days
C) 7 days
D) 10 days

Question 12

Your blood bank mistakenly released a D-positive red blood cell unit that subsequently transfused to a patient who typed as D-negative.The patient had no history of a previous transfusion or pregnancy.Antibody detection testing was negative in pretransfusion testing.Predict the crossmatch result in this case.

A) Compatible at immediate-spin
B) Incompatible at immediate-spin only
C) Not necessary to perform
D) Incompatible at antihuman globulin only

Question 13

Which of the following blood products requires a crossmatch before issuing?

A) Group AB fresh frozen plasma that is transfused to a group O
B) Human leukocyte antigen-matched platelets
C) Cryoprecipitated AHF
D) Granulocyte concentrates that have more than 2 mL of red blood cells

Question 14

What are the two components of the major crossmatch?

A) Recipient red cells and donor serum
B) Donor red cells and recipient serum
C) Reverse ABO cells and recipient serum
D) Screening cells and donor serum

Question 15

Why is a recipient's antibody screening performed as a component of compatibility testing?

A) Detects red cell alloantibodies
B) Detects irregular antigens on the recipient's red cells
C) Detects human leukocyte antigen antibodies
D) Detects incompatibilities with the donor's red cells

Question 16

What is the immunoglobulin class of antibodies detected in the immediate-spin crossmatch?

A) IgA
B) IgM
C) IgG
D) IgD

Question 17

Which of the following tests is not included in routine compatibility testing?

A) ABO phenotyping
B) Direct antiglobulin test
C) D typing
D) Antibody screen

Question 18

How long following transfusion must the recipient's sample be stored?

A) 5 days
B) 7 days
C) 10 days
D) 14 days

Question 19

A patient was admitted to the hospital with acute bleeding.Anti-E was detected in the patient's serum.Four E-negative units of blood were crossmatched for the patient.The units were compatible at immediate-spin and following the antiglobulin test.After the antiglobulin test was performed,IgG-sensitized red cells gave a 2+-agglutination reaction.What is the proper interpretation of this 2+-agglutination reaction?

A) Antihuman globulin washing procedure was adequate.
B) IgG-sensitized red cells spontaneously agglutinated.
C) Crossmatch was incompatible.
D) Patient's anti-E reacted with the IgG-sensitized red cells.

Question 20

To what does the abbreviation "MSBOS" refer?

A) Monthly surgical blood order schedule
B) Minimum surgical blood order staffing
C) Maximum blood order schedule
D) Minimum safe blood order schedule

Question 21

A donor unit with a positive DAT would cause reactions at what phase of the crossmatch?

A) Immediate-spin
B) Antiglobulin
C) None; it would be compatible
D) All phases

Question 22

What can be done to increase the sensitivity of the antibody screen in a compatibility test?

A) Extend the incubation time.
B) Increase the serum-to-cell ratio.
C) Use an enhancement such as polyethylene glycol.
D) All of the above are correct.

Question 23

How many units of red blood cells are required to raise the hematocrit of a 70-kg nonbleeding adult man from 24% to 30%?

A) 1
B) 2
C) 3
D) 4

Question 24

A tube was received in the blood bank for crossmatching.The label was torn and the only information that was visible was the patient's last name and the medical record number.Which of the following is an acceptable procedure?

A) Request a recollection of the specimen.
B) Call the phlebotomist back to relabel the tube.
C) Reprint a label using the MRI as the identifier.
D) Use the tube since the MRI is visible.

Question 25

The use of the electronic (computer)crossmatch is restricted to recipients who:

A) are group O.
B) do not have a clinically significant antibody.
C) have had successful transfusions in the past.
D) have transfusion history that has been documented in the computer.

Question 26

A 29-year-old female was admitted to the emergency room with severe bleeding.The blood type was group AB,D-negative.Six units of RBCs are ordered STAT.Of the following types available in the blood bank,which would be the most preferable for crossmatch?

A) AB, D positive
B) A, D negative
C) A, D positive
D) O, D negative