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.

Accepted Answer

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

Accepted Answer

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

Accepted Answer

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

Accepted Answer

Although Rh phenotyping is not routinely performed,exposure to the c antigen may cause the recipient to make anti-c because the recipient is negative for the antigen.

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

Accepted Answer

Anti-K is incompatible with 1 in 10 units of red blood cells.

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

Accepted Answer

The compatibility test may prevent the formation of anti-D,but not all other antigens are matched.

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

Accepted Answer

The most likely reason for the incompatibility is that the blood unit has a positive direct antiglobulin test or the patient has developed an antibody to a low-frequency antibody.If the direct antiglobulin test is negative,testing the patient's serum against a selected cell panel of low-frequency antigen-positive cells should be performed.

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

Accepted Answer

Group O individuals have both anti-A and anti-B present in serum,which is incompatible with all blood groups other than group O.

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.

Accepted Answer

Samples must be labeled by the bedside following examination of the wristband and correctly identifying the patient.Identification of the phlebotomist and a unique ID number that does not change are also required.

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

Accepted Answer

Reissuing of blood products can happen if the unit has not been entered and the unit has not exceeded 1-10°C.RBCs must be returned to the transfusion service within 30 minutes if not stored in a monitored refrigerator.

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

Accepted Answer

The sample can be used for 72 hours if additional crossmatches are required.

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

Accepted Answer

The abbreviated or AHG crossmatch would not have detected this error because anti-D had not formed and the unit would have been compatible at IS and AHG phases.

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

Accepted Answer

Granulocytes may contain a significant amount of red blood cells because they are obtained from the "buffy coat" layer during apheresis.These units would require crossmatching before release.

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

Accepted Answer

Donor red cells and patient serum are tested for reactivity.

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

Accepted Answer

The antibody screen detects alloantibodies that the recipient made to red cell exposure from pregnancy or prior transfusions.

Question 16

What is the immunoglobulin class of antibodies detected in the immediate-spin crossmatch?
A) IgA
B) IgM
C) IgG
D) IgD

Accepted Answer

Immediate-spin reactions are typically due to antibodies of the IgM class.

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

Accepted Answer

The direct antiglobulin test is not required as part of the compatibility test.

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

Accepted Answer

The recipient's sample should be stored at 1° to 6° C for 7 days in case there is a transfusion reaction that requires investigation.

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.

Accepted Answer

IgG-sensitized red cells should be positive if adequate washing was performed and antihuman globulin reagent was added.

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

Accepted Answer

The maximum surgical blood order schedule outlines the typical number of blood units that should be set up for various surgical procedures.

Quiz 9: Compatibility Testing

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

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

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

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?

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?

Select the item that compatibility procedures will not address.

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?

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

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

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

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?

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

What are the two components of the major crossmatch?

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

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

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

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

To what does the abbreviation "MSBOS" refer?