Question 1

All of the following antibodies are clinically significant except:

Accepted Answer

Anti-Bg^a is not a clinically significant antibody as it is not known to cause hemolytic transfusion reactions or hemolytic disease of the fetus and newborn. The other antibodies listed (anti-C and anti-K) are known to cause hemolytic transfusion reactions and hemolytic disease of the fetus and newborn, and anti-Fy^a is a rare antibody that can cause hemolytic transfusion reactions.

Question 2

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

Accepted Answer

Single-donor screening cells are complementary among each other because they allow for the detection of a wider range of antibodies, as each cell may express different antigens. This is crucial for accurate antibody identification in patient samples.

Question 3

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

Accepted Answer

O-negative blood is known as the universal donor blood type and can be safely given to individuals of any blood type, even if the recipient's blood type is unknown. Therefore, it is the best choice for an intrauterine transfusion in this scenario.

Question 4

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

Accepted Answer

Passive acquisition of anti-A, B, AB may occur through bone marrow transplantation, as the donor cells can produce antibodies against the recipient's blood group antigens. RhIG injection is used to prevent D antibody formation in Rh-negative individuals exposed to Rh-positive blood. Bacterial injection and hepatitis vaccination do not result in passive acquisition of anti-A, B, AB antibodies.

Question 5

The ABO dipstick test is based on what principle?

Accepted Answer

The ABO dipstick test is based on the principle of dot immunobinding assays, where antibodies specific to the A and B blood group antigens are attached to dots on the dipstick. When a drop of blood is added to the dipstick, if agglutination occurs, it indicates the presence of the corresponding antigen in the blood sample. This test is commonly used for blood typing in situations where a rapid result is required, such as in emergency medical care.

Question 6

What is revealed in the minor crossmatch?

Accepted Answer

The minor crossmatch detects alloantibodies in donor plasma that could react with antigens on the patient's red blood cells.

Question 7

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

Accepted Answer

All of the above methods can be used to determine the ABO and Rh status of the fetus in utero.

Amniocentesis involves collecting a small sample of the amniotic fluid surrounding the fetus, which contains fetal cells that can be analyzed for blood type and Rh factor.

Chorionic villus sampling involves collecting a sample of the placenta tissue, which also contains fetal cells that can be analyzed for blood type and Rh factor.

Percutaneous umbilical cord sampling involves collecting a small sample of blood from the fetal umbilical cord, which can be analyzed for blood type and Rh factor.

Each of these methods carries some risk to the fetus, so they are generally reserved for cases where there is a specific medical need (such as identifying potential blood type conflicts between the mother and fetus).

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?

Accepted Answer

Asking the patient to state their full name, address, and Social Security number and matching these responses to the information on the requisition form is a secure method of patient identification, ensuring that the correct patient is being treated.

Question 9

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

Accepted Answer

The answer of In what circumstance would it be feasible...

Question 10

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

Accepted Answer

Protamine sulfate is used to reverse the effects of heparin by binding to it and neutralizing its anticoagulant activity. Adding protamine sulfate to samples from patients taking heparin can induce clotting. Antithrombin III, reptilase, and fibrinogen are not used to reverse the effects of heparin and would not induce clotting in samples from patients taking heparin.

Question 11

What is an abbreviated crossmatch?

Accepted Answer

An abbreviated crossmatch includes a type and screen of the patient's blood, followed by an immediate spin crossmatch, which is a simplified and quicker method compared to full crossmatching, used when the patient has a known blood type and no unexpected antibodies.

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?

Accepted Answer

The patient needs an increase of 1.9 g/dl in hemoglobin count (10 g/dl - 8.1 g/dl = 1.9 g/dl). Each unit of RBCs typically raises hemoglobin by 1 g/dl, so the patient needs 2 units of RBCs (1.9 rounded up to the nearest whole number). Therefore, choice B (2) is the correct answer.

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?

Accepted Answer

The answer of A type and screen is done on...

Question 14

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

Accepted Answer

Massively transfused patients are those who have received multiple blood transfusions, resulting in a high likelihood of already having developed antibodies against multiple blood antigens. Compatibility testing may still be necessary in certain cases, such as in the presence of suspected transfusion reactions or when transfusing rare blood types, but in general, it may be eliminated for these patients as their antibody screening results are often reliable indicators of potential transfusion reactions. Compatibility testing should not be eliminated in cardiac, anemic, or pregnant patients as they remain at risk for potential transfusion reactions due to their unique medical conditions.

Question 15

Why was the minor crossmatch discontinued?

Accepted Answer

Donor screening for antibody was incorporated into donor processing, making the minor crossmatch unnecessary. This also helped to prevent the detection of cold autoantibodies. Additionally, the availability of donor plasma allowed for the creation of a major crossmatch using the donor's plasma and the recipient's cells.

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.

Accepted Answer

The jagged edge appearance of cells in an antiglobulin crossmatch after the addition of AHG and centrifugation is indicative of a positive result, indicating that there is bound antibody present on the surface of the cells.

Question 17

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

Accepted Answer

Units issued on an emergency basis are tagged for emergency release, and segments are pulled for later testing to ensure compatibility and for record-keeping purposes.

Question 18

Autoantibodies are generally directed against which antigens?

Accepted Answer

Autoantibodies are typically directed against high-frequency antigens, which are common in the population, leading to potential reactions with most donor blood.

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?

Accepted Answer

To find compatible units, we need to look for RBC units that do not express the K and Jk^a antigens. The frequency of the K antigen is approximately 9% in the general population, and the frequency of the Jk^a antigen is very rare, estimated to be 0.0005%. Therefore, we would need to screen about 10 units (9% of 2 units = 0.18, which rounds up to 1; and 0.0005% of 2 units = 0.00001, which rounds up to 1) to find 2 units that do not express these antigens. So, the answer is B) 10.

Question 20

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

Accepted Answer

According to AABB standards, donor and recipient samples must be stored at 1°C to 6°C for at least 7 days after a transfusion to ensure availability if testing for delayed hemolytic transfusion reactions or other adverse events becomes necessary.

Quiz 10: Pre-Transfusion Testing

All of the following antibodies are clinically significant except:

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

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

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

The ABO dipstick test is based on what principle?

What is revealed in the minor crossmatch?

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

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?

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

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

What is an abbreviated crossmatch?

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 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?

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

Why was the minor crossmatch discontinued?

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

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

Autoantibodies are generally directed against which antigens?

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?

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

Quiz 10: Pre-Transfusion Testing

All of the following antibodies are clinically significant except:

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

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

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

The ABO dipstick test is based on what principle?

What is revealed in the minor crossmatch?

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

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?

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

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

What is an abbreviated crossmatch?

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 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?

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

Why was the minor crossmatch discontinued?

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

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

Autoantibodies are generally directed against which antigens?

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

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

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?