Most common cause of ABO incompatibility?
What virus has the greatest likelihood of transmission from blood transfusion?
- 7% occurrence if blood is not leukocyte reduced
S/sx of cytomegalovirus
- benign and self limiting infection
- can cause fatal infection if pt is immunocompromised
Who is at risk for cytomegalovirus?
premature infants, pregnant women, bone marrow transplant pts, pts with depressed immune function
acute hemolytic transfusion reaction
Is AHTR restricted to the IV space only?
No, can also affect the reticular endothelial system (spleen, liver, and bone marrow)
S/sx of AHTR
- fever and chills
- hypotension and tachycardia
- flushing and dyspnea
- chest and back pain
- diffuse bleeding
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)
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
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
- complement is activated, histamine and serotonin are released
-DIC may result
What can occur with transfusion of incompatible FFP?
- Hemolysis of RBC
- remember, there are antigens on the RBC and antibodies in the plasma!!
3 most common causes of transfusion related deaths in the US?
- ABO incompatibility
- bacterial contamination
2 types of immune mediated transfusion reactions
AHTR (acute hemolytic transfusion rxn) and delayed hemolytic transfusion rxn
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)
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
Types of white cell reactions
- TRALI (transfusion related acute lung inj)
- graft vs host
- TRIM (transfusion related immunomodulation)
- transfusion induced inflammatory response
#1 cause of death associated with a blood transfusion
- -non cardiogenic pulmonary edema resulting after administration of a blood product
- -associated with all plasma containing blood products (FFP, Plts, RBCs)
- begin within 6 hours following transfusion
- fever and chills
- non-cardiogenic pulmonary edema
Non-infectious risks associated with blood transfusions
- volume overload
- dilutional coagulopathy
- decreased 2,3 DPG
- acid-base changes
- Citrate intoxication
- Microaggregate delivery
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
What blood type is the universal donor?
- 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
What blood type is the universal recipient?
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?
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
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
What conditions will increase O2 demand?
What conditions will limit ability to increase CO?
- CAD, myocardial dysfunction
- Beta blockade
- Inability to redistribute CO
- Low SVR states (sepsis, post-CPB)
How can we compensate for anemia
- Increase CO
- Redistribute blood flow
- Increase O2 extraction
- Changes in O2-Hgb dissociation affinity
Why is there an issue with bacterial contamination with Plts?
- They are stored at RT (22 C)
- Storage is limited to 5 days
Is ABO compatibility required for Plts?
No, it is ideal, but not required.
What does FFP contain?
All clotting factors expect Plt
-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
Is ABO compatibility required with FFP?
Why is FFP frozen and thawed just prior to use?
To preserve labile clotting factors 5 and 8
Indications to give FFP
- correction of microvascular bleeding and abnormal PT or PTT
- massive transfusion (>1 blood volume)
- reverse coumadin
- correction of single coag factor deficiency for which specific concentrates aren't available (factor 5)
- replacement of factor 8, von willebrand factor, fibrinogen, fibrinonectin
- microvascular bleeding when there is a disproportionate decrease in fibrinogen
Is ABO compatibility required for cryo?
Ideal but not required
Plt administration threshold
How much will Plt count increase after administration of unit of Plt in a 70 kg pt?