Blood products incl. special prep Flashcards
(52 cards)
What is the “storage lesion” physiologically driven by?
Membrane changes (eg. microvesiculation), increases in free potassium, hemoglobin, and lysophospholipids, and decrease in pH, ATP, and 2-3-DPG.
What is the requirement for red cell yield after storage?
75% of the cells must survive in circulation 24hrs after transfusion. Less than 1% hemolysis is permitted.
Do platelets suffer from storage lesion?
Yes, they metabolize sugars and fatty acids to generate carbonic acid.
What are the indications for blood product irradiation?
Hematopoietic stem cell transplant
Directed donation
Intrauterine transfusion
Generally, impaired cellular immunity.
What is the required dose of irradiation for irradiated products?
25Gy to center of bag
15Gy to rest of bag
What are the requirements for leukoreduction?
3-log reduction in leukocytes (>99.9%)
For RBCs and pheresis platelets, no more than 5 x 10*^6 leukocytes.
For WB-derived platelets, no more than 8.3 x 10^5 leukocytes.
Can platelets be volume reduced?
Yes, but they should be allowed to sit 20-60min before re-agitation or dispensation.
What are the indications for washing of blood products?
Deglycerolization
Selective plasma protein deficiencies (IgA, Haptoglobin)
HPA-1a antibodies or post-transfusion purpura
IUT
How much cell loss is permitted with washing?
20% loss of red cell yield
33% loss of platelet yield
How should whole blood be reconstituted?
Use group O RBCs and group AB plasma and aim for a hematocrit of about 50%.
What is aliquoting? What are its indications?
Splitting into low-volume containers. For pediatric transfusions (reduces number of donor exposures) or for very slow infusions (which must complete in 4hrs)
What percentage of D-negative patients alloimmunize after receiving D-positive RBCs? Platelets?
22% immunize after RBCs.
2% immunize after platelets.
May be able to reduce with RhIG
What rate of transfusion defines massive tranfusion?
8+ RBCs in 24hrs, or 4+ RBCs in 1hr.
After a patient receives emergency-release blood products, how should the presence of anti-A or anti-B be treated?
Respect it, even if it is passively acquired. You may have to continue to only give group O RBCs.
What is the crossmatch to transfusion ratio?
The number of units that gets crossmatched for surgery relative to the number actually transfused. A high ratio indicates units being needlessly held up in crossmatch.
What are the benefits of pre-storage leukoreduction?
Leukoreduction reduces FNHTRs, alloimmunization, and CMV transmission.
What are the requirements for leukoreduction to be effective?
3-log reduction in leukocytes (<99.9%), down to <5 x 10^6 leukocytes per unit (sixth that for acrodose platelet)
What is in cryoprecipitated AHF?
Fibrinogen, factor VIII, vWF, fibronectin, and factor XIII.
What is the recommended number of granulocytes per transfusion?
4 x 10^10
How many units are in a pool of cryoprecipitate
Formerly 10, now 5
From what products can cryoprecipitate be made?
FFP, PF24, or PF24RT24
What are the minimum and expected amounts of fibrinogen and factor VIII in a unit of cryo?
Fibrinogen: 150mg minimum. 250mg expected.
fVIII: 80 IU
What are the indications for cryoprecipitate?
Correction of hypofibrinogenemia (liver dz, obstetrical hemorrhage, trauma/DIC), uremic coagulopathy, and rarely correction of fXIII deficiency.
What are the risks associated with cryo transfusion?
Infectious disease risk
Prothrombotic complications (due to fXIII, vWF)
TRXNs as seen in plasma-rich products.
