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Most common cause of ABO incompatibility?
Clerical errors
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What virus has the greatest likelihood of transmission from blood transfusion?
- cytomegolovirus
- 7% occurrence if blood is not leukocyte reduced
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S/sx of cytomegalovirus
- benign and self limiting infection
- can cause fatal infection if pt is immunocompromised
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Who is at risk for cytomegalovirus?
premature infants, pregnant women, bone marrow transplant pts, pts with depressed immune function
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AHTR
acute hemolytic transfusion reaction
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Is AHTR restricted to the IV space only?
No, can also affect the reticular endothelial system (spleen, liver, and bone marrow)
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S/sx of AHTR
- fever and chills
- N/V/D
- hypotension and tachycardia
- flushing and dyspnea
- chest and back pain
- oliguria
- diffuse bleeding
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What actions should be taken if one suspects AHTR?
- stop the transfusion
- recheck pt, blood unit and labelling
- send blood and pt sample to blood bank
- support BP, adequate hydration
- get baseline labs (coats and renal function)
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Why can AHTR cause renal injury?
- The hemolysis releases Hgb which must be excreted by the kidneys
- this along with other components of the destroyed RBCs can damage the renal tubules
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Mechanism of AHTR
- incompatible blood administered
- (ABO incompatibility)
- antibodies and complement in recipient plasma attack donor antigens
- hemolysis occurs
- factor 7 activated, bradykinin is produced causing increased capillary permeability and arterial dilation
- hypotension
- complement is activated, histamine and serotonin are released
- bronchospasm
-DIC may result
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What can occur with transfusion of incompatible FFP?
- Hemolysis of RBC
- remember, there are antigens on the RBC and antibodies in the plasma!!
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3 most common causes of transfusion related deaths in the US?
- ABO incompatibility
- TRALI
- bacterial contamination
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2 types of immune mediated transfusion reactions
AHTR (acute hemolytic transfusion rxn) and delayed hemolytic transfusion rxn
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What types of virus can be transmitted via a blood transfusion?
Hep B, C, HIV, cytomegalovirus, Epstein-Barr, West Nile, malaria, HTLV (human T cell lymphocyte virus)
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Delayed hemolytic transfusion reaction
- -pt has had previous exposure due to prior transfusion or pregnancy
- -ex: pt does not have Kell antigen and has no issue upon receiving the blood with the antigen
- -the pt develops a Kell antibody
- -years later the pt receives blood with the Kell antigen and has DHTR
- -unlike AHTR, these rxns involve minor antigens
- -1-2 weeks after transfusion the pt develops hemolysis
- -usually mild and self limiting
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Types of white cell reactions
- febrile
- TRALI (transfusion related acute lung inj)
- graft vs host
- TRIM (transfusion related immunomodulation)
- transfusion induced inflammatory response
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#1 cause of death associated with a blood transfusion
TRALI
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TRALI overview
- -non cardiogenic pulmonary edema resulting after administration of a blood product
- -associated with all plasma containing blood products (FFP, Plts, RBCs)
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TRALI s/sx
- begin within 6 hours following transfusion
- fever and chills
- dyspnea
- non-cardiogenic pulmonary edema
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Non-infectious risks associated with blood transfusions
- hypothermia
- volume overload
- dilutional coagulopathy
- decreased 2,3 DPG
- acid-base changes
- Hyperkalemia
- Citrate intoxication
- Microaggregate delivery
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What effect does decreased 2,3 DPG have on O2 delivery?
- O2 dissociation curve is shifted to the left
- This means that O2 unloading to the peripheral tissues is impaired
- May occur after a transfusion because the stored blood is depleted of 2,3 DPG
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What blood type is the universal donor?
- O
- No antigens on its red cells, but it does have antibodies in its plasma
- But if giving PRBCs, you're only giving a small amount of those antibodies
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What blood type is the universal recipient?
AB
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T or F, if a pt has to receive a unit of a different ABO group, only packed cells may be given as there are antibodies in the plasma?
T
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For an overall healthy and stable pt what is the transfusion threshold
- Hgb 7-10, Hct of 21-30
- Morbidity and mortality are not increased until values drop below Hct of 21 or Hgb of 7
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What factors will decrease anemia tolerance?
- Increased O2 demand
- Limited ability to increase CO
- Occlusive vascular disease (brain or heart)
- Left shift O2-Hgb curve
- Abn Hgb
- Impaired oxygenation
- Ongoing or acute blood loss
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What conditions will increase O2 demand?
- Hyperthermia
- Hyperthyroidism
- Sepsis
- Pregnancy
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What conditions will limit ability to increase CO?
- CAD, myocardial dysfunction
- Beta blockade
- Inability to redistribute CO
- Low SVR states (sepsis, post-CPB)
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How can we compensate for anemia
- Increase CO
- Redistribute blood flow
- Increase O2 extraction
- Changes in O2-Hgb dissociation affinity
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Why is there an issue with bacterial contamination with Plts?
- They are stored at RT (22 C)
- Storage is limited to 5 days
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Is ABO compatibility required for Plts?
No, it is ideal, but not required.
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What does FFP contain?
All clotting factors expect Plt
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Thawed plasma
-what is it?
-advantage and disadvantages
- -FFP that was thawed and kept at 6 C for a max of 5 days
- -Adv- immediately available (ideal for trauma)
- -Disadv- levels of factors 5 and 8 decline with storage
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Is ABO compatibility required with FFP?
Yes
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Why is FFP frozen and thawed just prior to use?
To preserve labile clotting factors 5 and 8
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Indications to give FFP
- correction of microvascular bleeding and abnormal PT or PTT
- massive transfusion (>1 blood volume)
- reverse coumadin
- TTP
- correction of single coag factor deficiency for which specific concentrates aren't available (factor 5)
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Cryoprecipitate indications
- replacement of factor 8, von willebrand factor, fibrinogen, fibrinonectin
- microvascular bleeding when there is a disproportionate decrease in fibrinogen
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Is ABO compatibility required for cryo?
Ideal but not required
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Plt administration threshold
50,000-100,000
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How much will Plt count increase after administration of unit of Plt in a 70 kg pt?
5,000-10,000
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