Blood Banking

Question 1

What does blood transfusion during surgery increase risk for?

Answer 1

Causation not proved- but if you have a transfusion in the OR you have a 25% increased risk of post-op infection

Question 2

Differentiate whole blood and automated donation

Answer 2

Whole blood- donate 450-500 ml of whole blood, then later it’s separated into components that are stored separately

Automated- machine separates blood into components then returns remainder to the donor (this is how transfused platelets are collected)

Question 3

Describe the components of collected whole blood

Answer 3

Total volume: 450-500 ml

-about 250 ml of plasma
-1.0 ml of platelets
.05 ml of white cells
200 ml of red cells

Question 4

Cellular blood product = RBCs

(a) method of storage
(b) fxn of transfusion

Answer 4

RBCs

(a) store in refrigeration for up to 42 days
(b) fxn = oxygen carrying capacity

Question 5

Cellular blood product = platelets (PLTs)

(a) method of storage
(b) fxn

Answer 5

Platelets

(a) stored at room temp for up to 5 days
(b) clotting

Question 6

Differentiate the two transfused acellular products: frozen plasma vs. Cyro

Answer 6

Frozen plasma

• larger volume (220-250 ml)
• fxn = clotting (has tons of clotting factors, more than cryo), NOT used for volume replacement

CRYO = cryoprecipitate

• much smaller volume (5-15 ml)
• fxn = very rich in certain clotting factors (vWF, fibrinogen, fibronectin) that sometimes can’t be replenished enough w/ FP b/c it would required too much volume

Question 7

Why are IgM used instead of IgG for blood agglutination testing?

Answer 7

Space btwn RBCs is 20 nm.

-IgM are 30 nm (large enough to span the gap), but IgG are only 12 nm (too small)

Question 8

Mode of inheritance for blood type

Answer 8

Codominant inheritance

Question 9

What blood type is the universal red cell donor?

Answer 9

Type O
-no antigens on the red cell

=> have both anti-A and anti-B => not plasma donor

Question 10

What blood type is the universal plasma donor?

Answer 10

Type AB- b/c since they have both A and B antigens on their surface they have neither anti-A nor anti-B antibodies

Question 11

Describe front and back type testing done in a blood bank

Answer 11

Two steps for ABO blood testing- do both to be super sure (dont want to cause intravascular hemolysis…)

1st- do front type testing = pt’s RBCs + reagent IgM (test both ant-A and anti-B)

2nd- do back type testing = pt’s plasma + reaagent RBCs, done to confirm expected results

-both types are indirect testing (by seeing what the pt’s products react/agglutinate with we can infer what they’re making?

Question 12

What is crossmatcing?

Answer 12

A last check for ‘compatible’ RBCs prior to a a transfusion

-do an antibody screen to identify non-ABO antigen’s in a pt’s plasma

Question 13

What is the most common rxn to a transfusion

Answer 13

• fever after 50% of transfusion

- pruritis not uncommon

Question 14

What is the most common cause of death cause by transfusion?

Answer 14

TRALI = transfusion related acute lung injury

-second most common = TACO = transfusion associated circulatory overload

Question 15

How to treat

(a) TRALI
(b) TACO

Answer 15

Treat

(a) TRALI w/ aggressive ventilatory support
(b) TACO w/ diuretics

Question 16

How does TRALI present clinically?

Answer 16

Presents w/in 6 hours of transfusion w/ rapid onset dyspnea and fever
-diffuse infiltrate seen on CXR

Question 17

Acute intravascular hemolysis

(a) most common cause
(b) clinical presentations

Answer 17

Acute intravascular hemolysis is an acute transfusion reaction

(a) generally due to anti-A or anti-B antibodies
(b) clinically presents w/ DIC, acute renal failure, or shock

Question 18

Describe the consequence of alloimmunization from a blood transfusion

Answer 18

Alloimmunization = body makes antibodyes against non-self RBC antigens

-causes delayed extravascular hemolysis, a few days after the transfusion the body will make antibodies against non-self RBC antigens