Deck 10: Pre-Transfusion Testing

Question 1

All of the following antibodies are clinically significant except:

A) anti-C.
B) anti-K.
C) anti-Fy^a.
D) anti-Bg^a.

Answer 1

D

Question 2

Why is it necessary to use single-donor screening cells instead of pooled screening cells for patient samples?

A) Pooled screening cells are devoid of Duffy antigens
B) Single-donor screening cells are free from HIV infection
C) Single-donor screening cells are complementary among each other
D) None of the above

Answer 2

C

Question 3

What type of blood must be given in an intrauterine transfusion if the blood type of the fetus is unknown?

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

Answer 3

B

Question 4

Passive acquisition of anti-A, B, AB may occur through:

A) RhIG injection.
B) bacterial injection.
C) bone marrow transplantation.
D) hepatitis vaccination.

Question 5

The ABO dipstick test is based on what principle?

A) Dot immunobinding assays
B) Dry plate methodology
C) Galvanic biosensors
D) Gel test

Question 6

What is revealed in the minor crossmatch?

A) Alloantibodies in patient serum reacting with donor RBCs
B) Alloantibodies in donor plasma reacting with antigen on patient cells
C) Autoantibody in donor plasma reacting with antigen on patient cells
D) Autoantibody in patient serum reacting with donor RBCs

Question 7

How can the ABO and Rh of the fetus be determined in utero?

A) Amniocentesis
B) Chorionic villus sampling
C) Percutaneous umbilical cord sampling
D) All of the above

Question 8

A phlebotomist enters a patient room to draw blood for a 2-unit crossmatch. The patient is not wearing a wristband. How can the patient be identified?

A) Call out the demographic information on the requisition form and ask the patient to verify it.
B) Ask patient to state their full name, address, and Social Security number and match responses to information on requisition form.
C) Look above the patient's bed for a nameplate.
D) Ask his roommate his name.

Question 9

In what circumstance would it be feasible to transfuse Rh-positive blood to an Rh-negative individual?

A) In a teenager with anti-D in his serum
B) During an emergency cesarean section
C) In an elderly woman
D) None of the above

Question 10

What may be added to samples from patients taking heparin to induce clotting?

A) Protamine sulfate
B) Antithrombin III
C) Reptilase
D) Fibrinogen

Question 11

What is an abbreviated crossmatch?

A) A minor crossmatch
B) A type and screen plus an immediate spin crossmatch
C) A type and screen plus a minor crossmatch
D) A type and screen plus an immediate spin crossmatch using pooled screening cells

Question 12

A male patient of average size has a hemoglobin count of 8.1 g/dl. The surgeon wants a hemoglobin count of 10 g/dl before doing surgery. How many units of RBCs need to be given before the surgeon will accept the patient into surgery?

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

Question 13

A type and screen is done on a 49-year-old woman who is scheduled for a hysterectomy in 1 week. Her blood type is A-positive, and her antibody screen was positive. What must be done before her surgery date?

A) Identify antibody
B) Identify antibody and phenotype units
C) Phenotype the patient
D) Identify antibody and phenotype platelets

Question 14

In some institutions, compatibility testing may be eliminated in which type of patient?

A) Cardiac
B) Anemic
C) Massively transfused
D) Pregnant

Question 15

Why was the minor crossmatch discontinued?

A) Too many cold autoantibodies were being detected.
B) The only product being made from donors was packed red blood cells, and plasma was residual.
C) Donor screening for antibody was incorporated into donor processing.
D) None of the above

Question 16

During an antiglobulin crossmatch, the cells had a jagged edge appearance after the addition of AHG and centrifugation. This indicates a(n)_____ result.

A) positive
B) negative
C) inconclusive
D) none of the above

Question 17

Which of the following regarding blood issued on an emergency basis without patient testing is true?

A) The patient sample is tested for only ABO and Rh at a later time.
B) Units are tagged for emergency release and no further testing is done.
C) Units are tagged for emergency release and segments are pulled for later testing.
D) The medical technician must authorize the emergency transfusion.

Question 18

Autoantibodies are generally directed against which antigens?

A) High-frequency
B) Low-frequency
C) Nonspecific
D) ABO

Question 19

A patient with anti-K and anti-Jk^a needs two units of RBCs for surgery. How many group-specific units would need to be screened to find two that are compatible?

A) 6
B) 10
C) 20
D) 36

Question 20

How long after a transfusion must donor and recipient samples be stored at 1°C to 6°C?

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

Question 21

Mixing patient serum and donor red blood cells together and observing for direct cell lysis or agglutination is known as:

A) the Donath-Landsteiner test.
B) a minor crossmatch.
C) a major crossmatch.
D) an autohemolysis test.

Question 22

Why are hemolyzed samples unacceptable for compatibility testing?

A) Agglutination reactions will be undetectable
B) IgG activation by antigen-antibody complexes will be masked
C) Complement activation by antigen-antibody complexes will be masked
D) Hemolyzed samples inhibit antibody binding

Question 23

Given the following results, what is the probable cause of a positive reaction in the major crossmatch? IS = 0 37?0°C = 0 AHG = 2+ CC = ND Auto-control was negative

A) Alloantibody in patient serum reacting with antigen on donor cells
B) Incorrect ABO grouping of patient or donor
C) Autoantibody in patient serum reacting with antigen on donor cells
D) Rouleaux

Question 24

In what phase of reactivity is rouleaux usually found?

A) IS
B) 37°C
C) AHG
D) None of the above

Question 25

What is an "electronic" crossmatch?

A) A database compiled by the American Red Cross for rare phenotype accessibility
B) Comparison of donor and patient ABO groups and serologic data from a computer file
C) A crossmatch performed in microtiter plates and read by a spectrophotometer
D) All of the above

Question 26

Which phlebotomy site is unacceptable for compatibility testing?

A) Vein above the intravenous line
B) Antecubital fossa
C) Vein below an intravenous line
D) Vein in the hand

Question 27

Which tests must be performed on the donor sample?

A) ABO, Rh, Du, antibody screen
B) ABO, Rh, antibody screen
C) ABO, Rh, DAT
D) All of the above

Question 28

If donor cells were coated with antibody resulting in a positive DAT, what phase of the major crossmatch would generally react?

A) IS
B) 37
C) AHG
D) None of the above

Question 29

What anticoagulant is used to eliminate false-negative reactivity caused by cold autoantibodies and rouleaux?

A) Heparin
B) Sodium citrate
C) EDTA
D) All of the above

Question 30

What blood type should be transfused when crisis does not permit time to collect and test a patient sample?

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

Question 31

What criterion governs the use of the electronic crossmatch?

A) Patient's ABO group must have been determined on two separate occasions
B) Patient's antibody screen must have been done on two separate occasions
C) Patient's DAT must have been done on two separate occasions
D) Patient's Rh group must have been done on two separate occasions

Question 32

Why is it acceptable to transfuse an AB person with A packed red blood cells but unacceptable to transfuse type A whole blood?

A) The anti-A in donor whole blood would sensitize recipient cells.
B) The anti-B in donor whole blood would sensitize recipient cells.
C) The anti-A, B in donor whole blood would sensitize recipient cells.
D) None of the above

Question 33

What testing should be performed after blood has been issued on emergency release?

A) A 3-cell screen IS
B) Set up panel to quickly identify alloantibodies
C) Nothing, the blood has already been issued
D) Continue the crossmatch; report antibodies or incompatibilities

Question 34

How can the sensitivity of antibody detection be increased?

A) Increase the ratio of patient serum to screening cells.
B) Extend the incubation time.
C) Add potentiators such as albumin.
D) All of the above

Question 35

What does MSBOS stand for?

A) Monetary surgical blood order supply
B) Minimum surgical blood order schedule
C) Military surgical blood order supply
D) Maximum surgical blood order schedule

Question 36

When would transfusing non-group-specific blood be warranted?

A) Anti-M that interfered with reverse grouping was present in patient serum
B) Anti-B is shown in an A person who has been massively transfused with group O blood
C) Anti-A is shown in an A person who has been massively transfused with group O blood
D) None of the above

Question 37

The transfusion nurse calls the blood bank 5 minutes after a unit of packed cells were issued to say that the unit is not needed at this time. It is important for the nurse to bring the unit back immediately so that the temperature of the unit does not exceed:

A) 4°C.
B) 10°C.
C) 22°C.
D) 37°C.

Question 38

Why is the transfusion product tagged before it is issued and transfused?

A) To identify the patient
B) To verify compatibility results
C) To verify the donor number
D) All of the above

Question 39

What does compatibility testing include?

A) ABO, Rh, antibody screen, major crossmatch
B) ABO, Rh, DAT, major crossmatch
C) ABO, antibody screen, major crossmatch, elution
D) ABO, Rh, antibody screen, minor crossmatch

Question 40

What must be done prior to transfusion of non-group O blood to an infant?

A) Testing infant serum for anti-A and anti-B at IS
B) Testing infant serum for anti-A and anti-B at 37°C
C) Testing infant serum for anti-A and anti-B at AHG
D) None of the above

Question 41

A 4-unit crossmatch is ordered on a patient for emergency surgery. The patient's blood type is group B-positive. The blood bank inventory only contains two B positive packed cells. What other type is ABO compatible with this patient?

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

Question 42

What is given to patients who have crossed over to an Rh-positive blood type via massive transfusion to prevent anti-D formation?

A) Cryoprecipitate
B) RhIG
C) Enzyme-treated cells
D) Factor VIII concentrate

Question 43

What is the optimal time interval for compatibility testing if the patient has been transfused in the past 3 months?

A) 5 days
B) Less than 72 hours after collection
C) Less than 24 hours after collection
D) 2 weeks

Question 44

What does the minor crossmatch consist of?

A) Mixing donor plasma with patient red blood cells
B) Mixing patient serum with donor red blood cells
C) An immediate spin major crossmatch
D) None of the above

Question 45

Recipient serum that reacted with one out of five donor units in the AHG phase and where the antibody screen was negative is probably due to:

A) an alloantibody directed against a high-frequency antigen.
B) an alloantibody directed against a low-frequency antigen.
C) an alloantibody coating the recipient cells.
D) an ABO mismatch.

Question 46

What blood-banking research product hopes to provide oxygen-carrying capacity without the need for compatibility testing?

A) Red blood cell stroma
B) Hemoglobin substitutes
C) Liquid agglutination
D) Solid phase adherence

Question 47

All of the following may be used for the antibody screen before transfusing an infant except:

A) maternal serum.
B) infant serum.
C) paternal serum.
D) infant eluate.

Question 48

What causes rouleaux to form?

A) Antibody-coated cells
B) Abnormal A/G ratio
C) Shortened incubation
D) Electrolyte imbalance

Question 49

What alternative type can be given to an O-positive person when group O blood is not available?

A) A packed cells
B) B packed cells
C) AB packed cells
D) None of the above

Question 50

All of the following may be used as potentiators in the antiglobulin crossmatch except:

A) papain.
B) albumin.
C) LISS.
D) PEG.

Question 51

An immediate spin crossmatch was performed using recipient serum and donor cells from a group AB unit. At immediate spin, the reaction was 4+. What is the reason for this positive reaction?

A) ABO incompatibility
B) An alloantibody
C) Positive DAT on donor cells
D) Positive DAT on recipient cells

Question 52

A 39-year-old male is hemorrhaging severely. He is AB Rh-negative. Eight units of blood are required STAT. Of the following types available in the blood bank, which is most preferable for crossmatch?

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

Question 53

What tests are not required on autologous units transfused within the collecting facility?

A) ABO
B) Rh
C) Antibody screen
D) None of the above

Question 54

Blood transfused to infants (less than 4 months old) must be less than_____ days old.

A) 5
B) 7
C) 10
D) 6

Question 55

What is the most common cause of clerical errors in transfusion therapy?

A) Entering an erroneous ABO type
B) Misidentification of the patient
C) Entering an erroneous crossmatch result
D) Labeling units as antigen-positive instead of antigen-negative when phenotyping

Question 56

Before compatibility testing commences, donor units should be observed for:

A) blood clots.
B) correct labeling.
C) abnormal color.
D) all of the above.

Question 57

The use of _____ in compatibility testing has allowed for the efficient processing of large numbers of donor units via solid phase technology.

A) cuvettes
B) glass tubes
C) microtiter plates
D) agglutination viewers

Question 58

Where are the donor red blood cells usually acquired from when performing a major crossmatch?

A) Pierced donor unit
B) Pilot tubes
C) Segments from donor unit
D) A separate phlebotomy

Question 59

Which statement best describes the relationship between a crossmatch and a compatibility test?

A) They are identical.
B) If a compatibility test were a pie, a crossmatch would be a slice.
C) If a crossmatch were a house, a compatibility test would be a room.
D) A crossmatch is a confirmation of the compatibility test.

Question 60

What is the primary objective of the major crossmatch?

A) To reveal the phenotype of the donor unit
B) To detect the presence of antibody in the donor's serum
C) To detect the presence of antibody in the recipient's serum
D) None of the above.

Question 61

What is the most critical step in blood transfusion?

A) Phenotyping units to ensure compatibility with alloantibody
B) Following quality control procedures
C) Checking patient identification and compatibility of donor unit
D) Monitoring the temperature control of donor units

Question 62

An ABO antibody will cause a more severe hemolytic transfusion reaction in a patient who has received mismatched blood than an alloantibody will.

Question 63

In an intrauterine transfusion, whose serum is used for compatibility testing?

A) Infant's
B) Mother's
C) Father's
D) None of the above