Blood Collection and Processing Flashcards
Is whole blood transfusion used often? When is it used?
Not often due to the availability of blood components which are usually a better choice for blood transfusions.
Whole blood is transfused in cases of SEVERE SHOCK and BLOOD LOSS (blood loss >25% of blood volume).
What percentage hematocrit of packed red blood cells indicates sufficient plasma removal from the unit?
> 80%
1 unit of packed red blood cells raises hemoglobin by how much?
1 gram
1 unit of packed red blood cells raises hematocrit by how much?
3%
What happens to plasma in packed red blood cells during prolonged storage?
Increased NH4 and K+ due to hemoylsis
Decreased pH (due to increase lactic acid leakage) and sodium (plasma becomes diluted)
Can a unit of red blood cells be returned for use if it was transported in 11C container with the seal undisturbed?
NO. Has to be 1-10C transportation and seal undisturbed
Can a unit of red blood cells be reissued if it was transported in 1-10C but the seal is broken (open unit)?
NO.
Why would a CLS want to wash red blood cells with saline?
To prevent allergic responses to plasma proteins and anaphylactic shock in IgA deficient patients who can create anti-IgA.
(If blood gets transfused to this IgA deficient pt, they can get a reaction from the donor blood that contains normal plasma IgA.)
It also removes anti-HPA-1a from maternal blood
Removes complement
What is the expiration of washed red blood cells?
24 hours because the seal has been open (open unit)
What should the hemoglobin value be in apheresis RBCs?
> 60g
What is the concentration of leukocytes in leukoreduced apheresis RBCs?
< 5x10^6 leukocytes per unit with final hgb of > 51g
What does reducing leukocytes in red blood cells do? (Leukocyte-reduced red cells/leukoreduced red cells)
Reduces leukocytes to < 5 x 10^6 to prevent febrile nonhemolytic rxns, HLA alloimmunization and transmission of CMV
How do leukocytes/WBCs cause febrile nonhemolytic reactions?
The presence of cytokines released from white cells or alloimmunization to HLA or leukocyte antigens
Expiration: Frozen cells
10 years
What % of glycerol is used to protect frozen cells in ultra low temperatures?
40% glycerol
What temperature must frozen cells be thawed at?
37C
What temperature are frozen cells stored at?
< or equal to -65C
If you remove glycerol and wash the cells, store at 1-6C
Why would you want to freeze cells?
Usually used to store rare cells.
All red blood cell-type units (packed, adenine/saline added, washed, leuko-reduced, irradiated) with the exception of frozen cells, are stored at what temperature??
1-6C
What is the most common type of RBC unit used?
RBCs adenine, saline added
What is the shelf-life/expiration of RBCs with CPDA-1 additive?
35 days
What is the shelf life of RBCs adenine, saline added?
42 days
Once a seal has been broken on a unit of red cells, what is its shelf life?
24 hours
What does irradiating blood and components do?
Prevents Graft vs Host disease
Who would benefit from irradiated blood components?
Anyone at risk for graft versus host disease
A fetus receiving intrauterine transfusion
Donor is blood relative or recipient
Donor is HLA matched
Congenital immunodeficiency
What does irradiation do at the cellular level?
Inactivates donor T-cells
What is the shelf life of irradiated RBCs?
Original expiration or 28 days from irradiation, whichever comes first
How is Fresh Frozen Plasma (FFP) prepared?
Centrifuge whole blood, separate plasma from cells. Freeze plasma within 8 hours of collection.
Expiration of FFP after initial freeze and after thawed?
1 year if stored at or equal to <-18C
once thawed, 24 hours
Does FFP have to be ABO compatible or identical with its recipient?
ABO compatible is ok
What is FFP used for?
Multiple coagulation deficiencies
Factor XI deficiency
Who should FFP never be collected from and why?
FFP should never be collected from pregnant females or females who have been pregnant to prevent TRALI.
It is collected from males and never-pregnant females.
What is the abbreviation for plasma frozen within 24 hours of phlebotemy?
PF24
How is cryoprecipitate prepared?
Prepared by thawing FFP at 1-6C, removing the plasma portion and refreezing it at -18C within 1 hr
How much fibrinogen must a bag of cryoprecipitate contain?
> or equal to 150 mg of fibrinogen
How much Factor VIII (8) must a bag of cryoprecipitate contain?
> or equal to 80 IU of Factor 8
What factors does cryoprecipitate contain?
Fibrinogen
Factor VIII (8)
vWF
Ristocetin cofactor activity
Storage temperature for Cryoprecipitate?
-18C
Shelf life of frozen cryoprecipitate?
1 year from date of phlebotomy
Shelf life of cryoprecipitate after thawed?
Must transfuse within 6 hours of thawing
4 hrs after pooling in an open system
6 hours after pooling in a closed system
What is cryoprecipitate used for?
To replace fibrinogen loss due to DIC
Massive bleeding
Dysfibrinogenemia with active bleeding
Recombinant Factor VIII concentrate is given to who?
People with severe to moderate Hemophilia A and von Willebrand disease
What would you give to a person who has severe/moderate Hemophilia A versus a person with mild Hemophilia A and type 1 vWD?
Severe/moderate Hemophilia A: Recombinant Factor VIII concentrate
Mild hemophilia A/Type1 vWD: DDAVP
What concentrate can be given to treat someone with Hemophilia B?
Recombinant Factor IX (9)
Prothrombin Complex Concentrates
What do Prothrombin complex concentrates contain?
Vitamin-K dependent factors: II, VII, IX, X
Giving this may increase risk of thrombosis
A patient gets into a car accident and is bleeding. She has mild von Willebrand disease. What blood component should be given?
DDAVP - used for ppl with mild hemophilia A or type 1 vWD.
What does DDAVP do?
increases circulating Factor VIII and vWF.
How are platelets prepared?
Whole blood is centrifuged at a light spin first to remove RBCs
Followed by a heavy spin to spin down platelets and WBCs
Supernatant plasma is expressed into another bag for freezing (FFP)
Remaining plasma, platelets, and WBCs = platelets
When would platelets be given?
Severe thrombocytopenia and platelet dysfunction
When should platelets not be used? (contraindicated)
TTP and HIT
What is platelet refractoriness?
Lack of expected platelet response even after platelet transfusion due to antibodies to HLA class I antigens or platelets specific antigens
One unit of platelets raises platelet count by how much?
5000 - 10,000 platelets/ul
One unit of apheresis platelets raises platelet count by how much?
20,000 - 60,000 platelets/ul
Platelets are stored at what temperature?
20-24C with gentle agitation
Expiration of platelets?
5 days
What should the pH of platelets be?
> or equal to 6.2
Stored in vol of plasma necessary to maintain pH, usually about 40-70 cc
What concentration of platelets should be in one unit?
> or equal to 5.5 x 10^10 platelets/unit
What blood component must have a method to detect and limit bacterial contamination?
Platelets. More at risk for bacterial contamination due to storage at RT
If an Rh negative woman of child bearing age has received D+ platelets, why might you consider giving RhIg?
Platelets might contain residual RBCs; might become sensitized
How are granulocytes obtained/prepared for blood transfusion?
They are collected from apheresis
When would granulocytes be transfused?
For neutropenic patients with documented gram negative sepsis who have not responded to antibiotics
Why is giving granulocytes risky?
Can transmit CMV, induce HLA immunization, cause graft versus host disease if not irradiated
What temperature are granulocytes stored at?
20-24C
Expiration of granulocytes?
24 hours, but should be transfused ASAP
Why would recombinant factor VII (7a) be a better choice for a patient with Hemophilia A with inhibitors than Factor VIII (8) concentrate?
Factor 7a would bypass Factor 8 and activate Factor 10 to achieve hemostasis.
If factor 8 were used, it would be neutralized by the inhibitor and pt would still be bleeding!!
If a patient has hemophilia A with inhibitor, what blood component would you use?
Factor 7a
