Blood Components and Transfusion Practice Flashcards
Hemovigilance
Consists of the collection of information on the complications of transfusion, analysis of these data, and subsequent data-driven improvements in transfusion practices. Goal: to improve the reporting of transfusion-related adverse events.
Why irradiate
- Premature Neonates <1200g 2. known or suspected cellular immunodeficiency 3. significant immunosuppression (chem/radiation) 4. components from blood relatives 5. HLA/crossmatched plt 6. Granulocytes
How much radiation
1500 (for the entire bag) 2500 directed at the center of the bag
Why perform exchange transfusion vs. simple transfusion
In sickle cell to prevent iron overload from multiple units transfused.
What time of patient has highest rate of alloimmunization
Sickle Cell Disease Patient
How do you treat iron overload in neonates
Chelation therapy
Why leukoreduce blood
decrease risk of CMV, decrease HLA alloimmunization, preven febrile nonhemolytic transfusion reaction
volume reduction washing
decrease plasma in products for patients that cannot handle increased vascular volume (renal ischema, compromised heart function
Do units labeled Rh positive require confirmation testing of whole blood group
only require front type A and B, do not require Rh typing, D negative labeled however do require D typing (do not require weak D testing)
How is cryoprecipitate made?
Must come from WB derived plasma, the plasma is frozen and then ‘slow thawed’ at 1-6 degrees. Certain elements are not soluble at 1-6 degrees and therefore precipitate. This is then cold centrifuged and the supernatant is pulled off the top leaving 10-15 mL.
Cryoprecipitate contains which factors?
Fibrinogen, Factor VIII, vWF, fibronectin, Factor XIII
What are the requirements for Factor VIII quantity per bag
80 IU per bag
What is the requirement for quantity of fibrinogen in cryo bag?
150mg of fibronogen per bag.
Component preparation from WB 1st step
Red Cells step 1 soft spin, platelets are suspended in plasma (platelet rich plasma) and is transferred to a second bag, red cells remain in original bag and additive solution is added to bottom layer ( AS-1 AS-3 AS-5)
Component preparation from WB 2nd step
Platelets step 2 hard spin, this packs the platelets. platelets in one bag with 50-70mL plasma, supernatant plasma transferred to a different bag.
Component preparation from WB 3rd step
Plasma must be frozen, if frozen with 8 hours called FFP, if frozen within 24 hours PF24
PF24
Plasma Frozen within 24 hours of phelebotomy
FFP
fresh frozen plasma, frozen within 8 hours of collection.
Cryo production
Frozen Plasma (must be WB derived) thawed at 1-6c. Hard spin AT 1-6C, the cryo-reduced plasma transferred out leaving ~10-15mL in the cryo bag
Indications for Red Blood Cell Transfusion
to treat SYMPTOMATIC anemia in patients who need an increase of oxygen carrying capacity and red cell mass
Typical Hgb levels for transfusion
<6g/dL usually requires transfusion >10g/dL usually does not require transfusion
Washed RBCs
prevent severe allergic reaction, to remove IgA in IgA deficient individuals or haptoglobin in haptoglobin deficient individuals
Frozen RBCs
for use in rare red cell units, or autologous units
Laboratory tests for platelet functin
platelet aggregation test, platelet count, NOT BLEEDING TIME
Platelet contraindications
do not transfuse platelets to patient with conditions of rapid platelet destruction: ITP, DIC, HIT, TTP. definitely not HIT or TTP- could cause thrombosis, DIC is subjective depending on the level of clotting vs. bleeding, cryo is more appropriate. ITP does need platelet transfusions however the concern is recurring destruction and damage to spleen, in spleenectomy of these patients platelets can be given once the vascular pedicle is clamped
One does (1 apheresis or 5-6 pooled donors) will raise platelet count how much?
30-60k in an adult
Volume of apheresis platelet
200-400 mL
QC requirement for platelet
3 x 10^11
Advantages of apheresis platelet vs. pooled donor
can provide matched-HLA type, wouldn’t be able to find 5-6 donors in order to provide a full unit, also can reduce the donor exposure with number of HLA antigens/HNA/HPA the patient is exposed to.
Platelet transfusion count indications
10,000/uL standard in most places, 50,000uL in active bleed or surgical patients 100,000/uL in patients with intacerebral damage or surgery
If thrombocytopenia is due to sepsis or fever
Platelet transfusion is largely ineffective, need to treat sepsis
non-immune causes of Platelet refractory
massive bleeding, splenomegaly, fever, sepsis, DIC, drugs and patient related (chemo)
drugs that can cause platelet refractory
amphotericin B and vancomycin
why is it important to give type specific or compatible platelets
- Because platelets carry ABH antigens, if an A platelet is given to an O patient, the anti-A in patient can destroy the platelets- not as much of a bump 2. Because Platelets have antibodies if you give an O platelet (with anti-A) to an A patient it could bind to red cells and DAT may be positive, hemolysis is pretty rare.
platelet type to give baby
match the babies blood type, however if baby had HDN due to ABO antibodies (ex. anti-A from mom) you would want to give O platelets instead
platelet transfusions: bloody platelets
If Platelet has > 2mL of red cells- you must crossmatch, this will be grossly bloody
platelets: Rh
there are not RH antigens on platelets, however, there are red cells in platelets, try not to give RH pos platelets to an Rh negative patient, could make anti-D (if unavoidable you can give RHIG- (in women of child-bearing age especially) 1 Rhig vial is enough to protect against D positive Red cells in 7 apheresis platelets or 30 individual platelets
Thawed plasma
FFP/PF24 thawed but not transfused within 24 hours can be relabeled to ‘thawed plasma’ All of these contain therapueutic clotting factors including V and VIII
Contraindications for plasma transfusion
Do not transfuse when coagulopathy can be corrected more effectively with specific therapy: factor concentrates, Cryo or vitamin K
Uses for plasma in transfusion
- Reversal of warfarin (second choice behind PCC) 2. massive transfusion 3. preoperative or bleeding patients with multiple factor deficiencies (liver diease, DIC, dilutional coagulopathy due to massive transfusion)
Dose of plasma
~10-15 ml/Kg
What percentage of factors are necessary for normal hemostasis?
40% of factors need to be present
what volume of plasma has 100% factor activity
1 Liter
how much does each FFP unit raise coagulation factors in adult
10% (if you think patients approx plasma volume ~3000, each plasma unit ~300 and each unit contains 100% factor this equals 10%)
Liquid plasma
plasma separated any time up to 5 days AFTER expiration of the whole blood, stored at 1-6 degrees. Expiration: CPD=26 days CPD-A1 40 DAYS, indicated for treatment of massive hemmorhage. This is only good for 5 days after WB expiration date, if it’s separated 5 days after expiration it expires that same day.
Cryo reduced plasma
by product of cryo productin, deficient in fibrinogen, factor VIII, factor XIII, vWF, may be used in therapeutic exchange for TTP
recovered plasma
Includes plasma (frozen) and liquid plasma. unlicensed not for transfusion, expiration depend son short supply agreement, used for fractionation into albumin, AT-III, Factor VIII, IX, or immunoglobulin.
Short supply agreement
When Recovered [] Plasma is to be used in licensed products, it must be shipped in full compliance with the provisions of 21 CFR 601.22 (Short Supply) by the short supplier (the initial manufacturer) or an authorized agent (the licensed manufacturer’s agent) solely to the manufacturer under whose license the short supplier or an authorized agent is on file. Recovered [] Plasma for use in manufacturing licensed products may be pooled by the short supplier if complete records, including donor numbers for each unit pooled, are maintained. Any product manipulated by an authorized agent cannot be shipped under the short supply provisions.
