Ch. 2 - Blood components (collection)

Question 1

What are some advantages of PVC blood containers over glass?

Answer 1

More malleable and resilient to damage, improved gas exchange (important for eg. platelets)

Question 2

What is the maximum amount of blood (per kilogram of donor weight) which can be collected? What is the typical volume of a donated whole blood unit?

Answer 2

10.5mL/kg; whole blood units are generally 450-550mL (for a 500mL bag) or 405-495mL (for a 450mL bag).

Question 3

What blood products can be used from a low-volume whole blood unit?

Answer 3

Red cells only

Question 4

What anticoagulants are used for whole blood collection? What are their shelf-life?

Answer 4

CPD, CP2D (21 days)

CPDA-1 (35 days)

Question 5

What are the four possible additive solutions added to increase blood shelf-life? What is the resulting shelf-life?

Answer 5

AS-1, AS-3 (no mannitol), AS-5, AS-7

All extend the shelf-life to 42 days.

Question 6

Outline the typical process by which a whole blood unit is converted to individual products.

Answer 6

Soft centrifugation followed by manual expression yields a unit of pRBCs and platelet-rich plasma (PRP), which may be further processed into an acrodose platelet unit + platelet poor plasma (or cryoprecipitate + cryo-poor plasma)

Question 7

What information must all blood products be labeled with?

Answer 7

1. Unique facility identifier
2. Lot number relating to the donor
3. Product code
4. ABO/Rh type of the donor

Question 8

What are the storage and transport requirements of whole blood? What is its shelf-life?

Answer 8

Storage at 1-6C, transport at 1-10C.

Shelf life ranges from 28-42d depending on storage media

Question 9

In what context is whole blood used besides for isolation of blood components?

Answer 9

Whole blood is transfused in the military or civilian trauma setting.

Question 10

What are the AABB requirements for RBC units concentrations? For pheresis units?

Answer 10

Hematocrit no higher than 80% (most are closer to 55-60%). Apheresis units must have at least 50g hemoglobin or RBC volume greater than 150mL.

Question 11

Fill in the blank: “For all RBC units, the amount of hemolysis present at the end of storage needs to be less than _% with at least _% of the transfused cells remaining after _hrs proven by in vivo labeling studies.

Answer 11

Less than 1% hemolysis

At least 75% of transfused cells should be in circulation after 24hrs post-transfusion.

Question 12

What physiologically occurs in storage to reduce RBC viability?

Answer 12

Decrease in pH, ATP, and 2,3-DPG plus peroxidation, increase in potassium. Results in decreased deformability and increased osmotic fragility.

Question 13

What is the visual inspection of a blood unit before release from the bank meant to identify?

Answer 13

Hemolysis
Clot formation
Color change suggestive of bacterial infection

Question 14

What are the AABB requirements for platelet unit number and pH? (whole-blood derived and pheresis)

Answer 14

Whole-blood: 5.5 x 10^10
Pheresis: 3.0 x 10^11
pH should be greater than or equal to 6.2

Question 15

What are the storage requirements for platelets? What is their shelf-life?

Answer 15

Storage at room temperature with agitation (no longer than 24hrs without).
Shelf life of 5d owing to risk of bacterial contamination.

Question 16

What are AABB standards for quantity of cells in a granulocyte unit? Does it have to be ABO/Rh compatible?

Answer 16

85% of collections must have at least 1 x 10^10. If there is >2mL of contaminating RBCs, it should be ABO/Rh compatible (nearly all are anyway).

Question 17

What special treatments do granulocyte units receive? What is the role of hetastarch?

Answer 17

All units are irradiated.

Hetastarch improves RBC-granulocyte layer separation during pheresis collection.

Question 18

Distinguish between FFP, PF24, PF24RT24. How long are they good for after thawing?

Answer 18

FFP: Frozen within 8hrs of collection.
PF24: Frozen within 24hrs of collection. Largely equivalent to FFP.
PF24RT24: Frozen within 24hrs and held at room temperature up to 24hrs. Only pheresis plasma.

24hrs thawed at refrigerator temperature. After which, they must be labeled as thawed plasma.

Question 19

For how long is thawed plasma good? What factors is it short in relative to frozen plasma?

Answer 19

Up to 5 days (actually 4, as the first 24hrs after freezing count towards this).

Thawed plasma has fewer cofactors V and VIII. Still has other factors, fibrinogen, ADAMTS13…

Question 20

For how long can FFP (or PF24, or PF24RT24) be stored?

Answer 20

1yr if kept at -18C

7yrs if kept at -65C

Question 21

Describe the function and storage requirements of cryo-reduced plasma.

Answer 21

Still contains fibrinogen and ADAMTS13(?). Can be stored at -18C for up to 1 yr (as long as it is refrozen within 24hrs).

Question 22

What is liquid plasma?

Answer 22

Plasma derived from whole blood at any time during storage, which is kept at fridge temperatures for up to 5 days. Used primarily for manufacturing plasma product derivatives.

Question 23

What is solvent detergent plasma?

Answer 23

An industrial product for pathogen-reduction. It is generally pooled from 2500+ donors and treated with a solvent and detergent for viral inactivation. It has slightly reduced levels of all factors and is kept frozen at -18C.

Question 24

How is cryoprecipitate produced? What are its storage requirements?

Answer 24

Produced by slow thawing of FFP at fridge temperatures (1-6C). Cryo must be refrozen within 1hr and stored at -18C for up to 1yr. Once thawed, it lasts 6hrs.

Question 25

What does cryo contain?

Answer 25

Factor VIII (at least 80IU)
Fibrinogen (at least 150mg/dL; most have much more)
von Willebrand factor
Factor XIII
Fibronectin

Question 26

What modifications can be performed on blood components after processing?

Answer 26

Leukocyte reduction
Irradiation
Cryopreservation
Volume reduction
Washing
Pooling

Question 27

What is the consequence of performing any post-processing blood component modification on shelflife?

Answer 27

Shelflife becomes reduced to 24hrs for any product stored at refrigerator temperature, 4hrs for any stored at room temperature (cryo, platelets).

Question 28

When is leukocyte reduction generally performed? How many leukocytes are allowed to remain?

Answer 28

Usually prestorage (far superior to bedside leukoreduction). No more than 5 million leukocytes should remain.

Question 29

What adverse effects are reduced by leukocyte reduction?

Answer 29

FNHTR
HLA alloimmunization
Cytomegalovirus transmission

Question 30

What is the purpose of blood product irradiation? What products may be irradiated?

Answer 30

Reduce TA-GVHD by removing donor lymphocytes in cellular blood products. Done for all granulocytes, and can be done for RBC units, liquid plasma, platelets…

Question 31

What is the requirement for radiation dosing of a blood product?

Answer 31

25Gy to the center of the bag and 15Gy to the remainder of it. No more than 50Gy should be given (damages RBCs).

Question 32

How is cryopreservation performed? What’s the point?

Answer 32

Mix RBC unit with glycerol and freeze to -65C within 6d of collection. Stores for up to 10yrs. Useful for preserving rare phenotype units.

Platelets may be preserved with DMSO and stored for 2yrs, but this is rarely done

Question 33

What is the purpose of volume reduction of blood products?

Answer 33

For patients who are at risk of volume overload. Also helps to reduce potassium of the unit (dialysis patients, cardiac patients).

Question 34

What are the indications for blood washing?

Answer 34

Patients iwth severe allegic/anaphylactic reactions (usually IgA deficiency)
NAIT (maternal platelets)
Removal of excess potassium, glycerol
“T-antigen activation”

Question 35

What blood products are routinely pooled?

Answer 35

Acrodose platelets (6 to 1)
Cryoprecipitate (10 to 1)