Platelet Products

Question 1

How long does the donation center have after collection to separate platelets from whole blood?

Answer 1

8 hours

Question 2

Describe the process of preparing a pooled platelet from whole blood.

Answer 2

Whole blood is centrifuged and the platelet rich plasma is removed. The platelet rich plasma in then centrifuged and the platelet poor plasma removed leaving the platelet concentrate at the bottom. 4-5 bags of platelet concentrate are then combined to form a pooled platelet.

Question 3

A unit of apheresis platelets must contain have a minimum of how many platelets to be acceptable?

Answer 3

3x10^11

Question 4

1. A platelet concentrate must have a minimum of chow many platelets to be acceptable?

Answer 4

5.5x10^10

Question 5

By how much does one whole unit of platelets (apheresis or pooled) increase the platelet count?

Answer 5

20,000-60,000/µL

Question 6

What is the minimum pH that is acceptable for a platelet to pass quality control?

Answer 6

6.2

Question 7

How does pathogen reduction of platelets work?

Answer 7

Use amotosalen (psoralen) and UVA light to inactivate pathogens. Psoralen is activated by the ultraviolet A light and the psoralen binds to nucleic acid base pairs of pathogens which prevents them from replicating.

Question 8

How do large volume delayed sampling (LVDS) platelets reduce the bacterial contamination risk?

Answer 8

Platelets are collected and then cultured at either 36 hours or 48 hours after collection. They then incubate the cultures for 12 hours to see if anything grows. This extended time given for bacterial growth should make any pathogens present more likely to be detected.

Question 9

If platelets are not pathogen reduced or LVDS, how do we ensure there is no bacterial contamination?

Answer 9

Platelets are cultured at 24 hours and incubated for 12 hours. At this point they can be used for 3 days after collection. To extend the expiration to 5 or 7 days a new culture must be performed on day 3 or 4 or rapid testing must be performed to ensure no bacteria has grown.

Question 10

Why would it be necessary for some patients to receive HLA matched platelets?

Answer 10

Patients can create antibodies to HLA antigens which are present on platelets. If they are transfused with platelets positive for the antigen they have an antibody to, they will destroy the platelets. Therefore, platelets must be found that are negative for the corresponding antigen.

Question 11

At what platelet level should a patient bleeding with DIC be transfused platelets?

Answer 11

<50,000/µL

Question 12

At what platelet level should a patient undergoing chemotherapy be transfused platelets?

Answer 12

<10,000/µL

Question 13

At what platelet level should a patient undergoing a cardiac bypass procedure be transfused platelets?

Answer 13

<100,000/µL

Question 14

At what platelet level should a patient being massively transfused be transfused platelets?

Answer 14

<50,000-100,000/µL

Question 15

If ABO matched platelets are unavailable, is it better to transfuse platelets that are red cell compatible or plasma compatible?

Answer 15

Plasma compatible

Question 16

Does the Rh of the platelet matter during transfusion? Why or why not?

Answer 16

Yes, platelets do contain a small amount of red cells that can cause the patient to form an anti-D if they are transfused D positive platelets. It is therefore suggested that women of child bearing age that are Rh negative only be transfused Rh negative platelets.

Question 17

What are signs and symptoms of low platelet counts that could indicate transfusion of platelets is needed?

Answer 17

Petechiae, ecchymoses, mucosal or spontaneous hemorrhage