MLPAO Transfusion Medicine Fundamentals 2

Question 1

What is the purpose of the crossmatch in transfusion medicine?

Accepted Answer

To detect serological incompatibility between the donor red cells and patient serum before transfusion

Answer

The crossmatch is the final compatibility check that tests patient serum/plasma against donor red blood cells. An immediate-spin crossmatch detects ABO incompatibility. An antiglobulin crossmatch (full crossmatch) is required when the patient has clinically significant antibodies. Electronic (computer) crossmatch is used when the antibody screen is negative.

Question 2

What is the universal red blood cell donor type and why?

Accepted Answer

Type O negative, because O red cells lack A and B antigens and D antigen

Answer

Type O negative is the universal red blood cell donor because the red cells lack A, B, and D antigens, minimizing the risk of ABO and Rh-related transfusion reactions. O negative blood is used in emergency situations when there is no time for typing. However, it is a limited resource (about 7% of the Canadian population).

Question 3

What is the universal plasma donor type?

Accepted Answer

Type AB

Answer

Type AB plasma is the universal plasma donor because it contains no anti-A or anti-B antibodies, making it safe for recipients of any ABO type. This is the opposite of red cell donation, where O is universal. AB plasma is used in emergency situations and for patients with unknown blood types requiring plasma transfusion.

Question 4

What are the signs and symptoms of an acute hemolytic transfusion reaction?

Accepted Answer

Fever, chills, flank/back pain, hemoglobinuria, hypotension, DIC, and renal failure

Answer

Acute hemolytic transfusion reactions (usually ABO-incompatible) present with fever, chills, back/flank pain, chest tightness, hemoglobinuria (dark urine), hypotension, and can progress to DIC, shock, and renal failure. Immediate action includes stopping the transfusion, maintaining IV access, and notifying the blood bank for investigation.

Question 5

What is the required sample labeling for pre-transfusion testing in Canada?

Accepted Answer

Two independent patient identifiers on both the sample tube and the requisition, verified at the bedside at the time of collection

Answer

Canadian Standards Association (CSA) standards require positive patient identification at the bedside with two independent identifiers (typically name and unique identifier such as health card number or hospital ID). The sample must be labeled at the bedside, not pre-labeled. Unlabeled or mislabeled samples must be rejected — this is the single most important step in preventing fatal ABO-incompatible transfusions.

MLPAO - Medical Laboratory Professionals Association of Ontario Practice Test

MLPAO - Medical Laboratory Professionals Association of Ontario Practice Test

MLPAO Transfusion Medicine Fundamentals 2