Transfusion medicine Flashcards
How is cryo obtained
FFP is thawed and largest proteins precipitate out (vWF, factor XIII, fibrinogen)
- then centrifuged, expressing off cryo-poor plasma
What is aphaeresis?
Centrifugation of blood to separate into plasma and platelets
What is pathogen reduction technology
- technology that inactivates broad spectrum of pathogens and T-cells (thus may reduce risk of GVHD) in blood products
- not yet readily available in the US
Only indication for transfusion above 7
ACS NOT CAD
Platelet goal if bleeding
50K
Platelet goal for neurosurgery
100K
Platelet goal if septic
20k
platelet goal for bone marrow biopsy
20k
Per ASCO what is the indication for transfusion for thrombocytopenia patient
NO THRESHOLD to transfuse unless bleeding
- They can be walking around with platelets of 6
platelet threshold for central line placement
20k
General rule of thumb for increase in platelet count from 1 aphaeresis unit or 4-6 whole blood pooled
40K
When do you see a marked increase in GI bleeding in terms of platelet level + why
Platelet count less than 5k (the daily requirement for vascular endothelial maintenance is around 7k)
Indications for FFP
1) PT or PTT greater than 1.5x with active bleeding
2) Massive transfusion
3) MAHA (TTP or HUS)
4) reversal of nutritional vitamin k deficiency or warfarin overdose with active bleeding
Use of FFP for INR reversal in the absence of bleeding
Not well supported but common in practice
PCC is FDA approved for what?
Urgent reversal for supra therapeutic warfarin with active bleeding
PCC contains
vitamin-k dependent clotting factors
what does cryo have
- vWF
- fibrinogen
- Factor VIII, Factor XIII
Common indications for cryo
- think about what it contains
1) hypofibrinogenemia (less than 100)
2) factor XIII deficiency
3) vWF if no DDAVP
4) uremic platelet dysfunction
Rule of thumb for how much cryo will increase fibrinogen
10 units to increase fibrinogen by 100 mg/dL
Products that are leukoreduced
RBC and platelets (leukoreduction…)
How leukoreduction works
Filters out WBC’s
Indications for leukoreduction
1) transplant patients (Reduce HLA alloimmunization)
2) Hx of febrile transfusion reactions
3) Reduce CMV (immunocompromised, CMV seronegative pregnant women, transplant CMV-seronegative patients)
How irradiation works + purpose
- Gamma radiation blocks replication of donor T lymphocytes.
- it is an additional step on top of leukoreduction which can help prevent transfusion-associated GVHD
Indications for irradiation
- basically anyone who’s severely immunocompromised
1) stem cell transplant patients (Reduce HLA alloimmunization) + prevent transfusion-associated VHD
2) congenital immunodeficiency
3) Treatment with potent immunosuppressive therapies (purine analogs, ATG, monoclonal antibodies)
Presentation of delayed hemolytic transfusion reaction
- typically asymptomatic
What to think when patients don’t respond to platelet transfusion
HLA alloimmunization (exposure to HLA antigens on donor WBC causes platelet refractoriness)
Indications for plasmapheresis
- TTP
- HUS
- myasthenia gravis
- GBS
- Goodpasture syndrome
- CIDP
- Paraproteinemic polyneuropathy
Indications for red cell exchange
1) acute CVA
2) CVA prophylaxis in SSD
3) malaria
Indications for leukopheresis
1) hyperleukocytosis in AML
virus who’s transmission can be prevented by leukoreduction
CMV (leukocytes can contain CMV)
Why transplant patients need irradiated blood
- reduce transfusion-associated GVHD
- TA-GVHD doesn’t occur after most transfusions because the donor lymphocytes are destroyed by the recipients immune system before they can mount a response against the host.
Most common pathogen transmitted through blood transfusion
Hep b
