Path/Transfusion Medicine 2

Question 1

Important points about platelet prep and storing

Answer 1

can't refrigerate
most store at RT
shelf life of just 4-5 days
they express ABO
    (if pt has antibodies they will just clear!)

platelets come with donor plasma which may have A/B antibodies

platelets optimally need to be IDENTICAL to patient type, not just compatible

Question 2

Compare apheresis vs differential centrifugation method

Answer 2

Apheresis
5 platelet units
300ml per donor

differential centrifugation
1 platelet unit
50ml per donor

Question 3

Drawbacks to differential centrifugation method

Answer 3

• Leukoreduced to filtrate damage platelets

- Increased risk of contamination

Question 4

Apheresis exposes a donor to how much volume from one donor?

Answer 4

300 ml !!!!

Question 5

GI bleeding and platelet levels? !!

Answer 5

Patients don’t bleed spontaneously into their lower GI tract until the platelet count gets below 10 K/ul!! The normal range is between 150K and 450K!

!!

Question 6

What are the standards of care for transfusion of platelets before surgery?

Answer 6

Transfuse before surgery for platelet count < 75K

Transfuse before most invasive procedures for platelets < 50K

Question 7

How many platelets per day are regenerated?

Answer 7

For a normal platelet count (> 150K), they will MAKE >15K normal platelets in 24 hours.

Question 8

What’s the problem with repeated platelet transfusions?

Answer 8

Poorly understood immune response; when serious it’s called platelet refractory state

Question 9

Platelet transfusion in renal failure patients?

Answer 9

, if the patient has a normal platelet count, is acutely bleeding, and is in renal failure, standard of care is to give them platelets

Question 10

How much is in one unit of frozen plasma?

Answer 10

225ml

Question 11

What is found in a cryoprecipitate?

Answer 11

Fibrinogen, VII, XIII, vWF

Question 12

What is the volume of one unit of cryoprecipitate?

Answer 12

About 5-10 ml

Question 13

STUDY ABO PLASMA

Answer 13

IT’s ON THE TEST

Question 14

What are the reasons to use frozen plasma?

Answer 14

Coag factor deficiency
Rapid reversal of coumadin effect
Replace plasma during massive transfusion
Antithrombin III deficiency
Immunodeficiency due to protein losing enteropathy
TTP

Question 15

5 units of FFP is what percentage of a patient’s blood volume?

Answer 15

22.5%