Transfusion medicine

Question 1

What does an antibody screen test?

Answer 1

Detects significant blood group antibodies

If antibodies found, donor units lacking the corresponding antigen are identified prior to transfusion

Question 2

What does a crossmatch test for?

Answer 2

Compatibility of recipient’s serum w/ donor RBCs

reconfirms ABO compatibility

Question 3

• What is coombs antisera?

Answer 3

Antibodies against human antibodies (angi-human globulin) ; looking for Iggs

Question 4

What is the universal plasma donor?

Answer 4

AB

Question 5

What is the universal blood donor?

Answer 5

O

Question 6

What is the antibody screening for “indirect coombs”

Answer 6

looks for antibodies in the patients PLASMA (that would only be there if they had been exposed to a transfusion before)

Question 7

What should be performed when a AB screen is negative?

Answer 7

Rapid crossmatch

Question 8

• What does a rapid crossmatch evaluate?

Answer 8

Confirms ABO compatibility between patient and donor

Question 9

What type of immunoglobin can agglutinate by itself?

Answer 9

IgM

Question 10

*What type of immunoglobin cannot agglutinate by itself?

Answer 10

IgG

you will need a coombs antisera to vause agglutination

Question 11

• What is involved in the clinical decision of RBC transfusion?

Answer 11

Extent of RBC loss

• Rate and chronicity of red cell loss
• Oxygen requirement of the patient; state of tissue perfusion
• Response of the circulation to red cell loss and reinfusion
• Desired rate of restoration

Question 12

At what hemoglobin level should a pt get a transfusion?

Answer 12

hemoglobin below 6 g/dL

Question 13

What hemoglobin range does not indicate a necessary transfusion?

Answer 13

hemoglobin above 10 g/dL

Question 14

What is the purpose of irradiation?

Answer 14

Prevents TA-GVHD (transfusion-associated graftvs host disease); impt in immunocompromised pts.

Question 15

• What is the NL volume of plasma?

Answer 15

250-350 mL

Question 16

*Why is plasma important?

Answer 16

It contains coagulation factors (can be used in tx of bleeding patients with prolonged PT/PTT values)

Question 17

Why are cryo products important?

Answer 17

Impt because they contain VIII, FACTOR XIII, FIBRINOGEN

Question 18

*What does Direct coombs (DAT) test for?

Answer 18

Looks for IgG and complement coated on the surface of a patient’s RBCs (Presence of these on the RBC surface could indicate that a patient may have a transfusion reaction