Transfusion Medicine Flashcards
What determines blood type?
- The presence or absence of antigens on the RBC surface
Is the first transfusion ‘free’ for dogs?
No
- If a patient negative for DEA is given positive blood for the first transfusion, a delayed reaction will occur from the sensitization of the immune system gradually increasing the anti DEA 1 antibody titer
- Mismatches always result in delayed hemolytic reactions and prime recipients for severe acute reactions upon second exposure
Can Type A cats receive Type B blood?
- Technically yes but shouldn’t
- Their anti B antibodies are fairly weak in affinity and low in titer level so they cause a mild or delayed hemolytic reaction
- Transfused cells will only have a 1/2 life of 2 days
Can Type B cats receive Type A blood?
- No
- Type B cats have very strong anti A alloantibodies and will have an acute and severe hemolytic reaction
What blood can be given to a type AB cat?
- Both as they do not have any alloantibodies
- However, alloantibodies in plasma of type A & B blood may cause a reaction due to presence of anti A or anti BN antibodies
- Therefore type A is preferred as anti B antibodies occur at lower titer in type A blood - using pRBC minimizes amount of plasma containing anti B antibodies being transfused
What does the MAJOR crossmatch check?
- Mixes PATIENT PLASMA with DONOR RBCs
What does the MINOR crossmatch check?
- Mixes DONOR PLASMA with PATIENT RBCs
A patient should be cross matched if they received a transfusion _____ ago
> 4 days
What is a massive transfusion?
The replacement of blood approaching or exceeding one total BV within a 24 hour period
What does stored whole blood NOT contain?
- Viable platelets
- Labile clotting factors: F V, VIII, vWf
What does FFP contain?
- All labile (F V, VIII, vwf) and non labile clotting factors, plasma proteins, albumin, and globulins
What does FFP not contain?
Platelets
What does FP contain?
- non labile F II, VII, X, albumin, globulin
- Can be kept for 5 years
What is cryoprecipitate?
- The precipitate of thawed FFP
- Contains vWf, FVIII, fibrinogen, FXIII
- These factors are found in FFP, but administering cryo allows the same result but with less volume
- Hemophilia A
What is cryosupernatent?
-Supernatant that was produced during creation of cryo
- LACKS FVIII, FXIII, fibrinogen, vWf
- HAS albumin and remaining coag factors, including Vit K dependent factors
- Hemophilia B
How does albumin play a role in coagulation?
- Regulates coagulation by mediating thromboxane A2 levels
- HypoA leads to increased TXA2 levels, contributing to a hypercoagulable state
What are immunoglobulins used for?
- Used as an immunosuppresant in refractory immune mediated disease
What is platelet rich plasma? (PRP)
- Platelets harvested from a unit of FWB that is less than 8 hours old and has not been cooled
- Room temp platelets maintain viability better than refrigerated ones
- Shelf life of 5 days and requires constant agitation
Should plasma be type matched?
Yes, to prevent sensitization from RBCs they contain
Does plasma need to be given with a filter?
Yes
What are the four categories of reactions?
- Acute immunological
- Acute non immunological
- Delayed immunological
- Delayed non immunological
What is an immunological reaction?
- Caused by antigen-antibody interactions between donor & recipient
- Antibodies present in recipient plasma recognise RBC antigens as foreign
Is premedicating with antihistamines or steroids recommended?
- Only if there is a history of a reaction
- It will not prevent a reaction but may mask the early signs of one
What is a WBC/platelet incompatibility reaction?
Occurs when antibodies form against donor WBC or platelet antigens
What is anaphylaxis to a blood component?
An immunologic reaction mediated by IgE or IgG molecules found on mast cells
What is TACO?
- Immunosuppression following blood component transfusion
- Immunological reaction
What is TRIM?
- Transfusion-related immunomodulation
- Immunosuppression following blood component transfusion
- Serum sickness/Type III hypersensitivity reaction occurs weeks later
- Immunological reaction
What is a non immunological reaction?
- Occurs from outside factors and are not directly related to RBC, platelets, or protein antigen-antibody reactions
- Most often occur from collection/storage/administration errors
- TACO
What are storage lesions?
- Progressive, morphological, metabolic, biochemical changes that occur to RBC during storage
- These changes reduce the number of viable RBCs and make them less effective as oxygen carriers
Does a filter need to be used when administering an auto transfusion?
Yes
Do anticoagulants need to be added to auto transfusions before administration?
No, blood pooled in body cavities has typically consumed coagulation factors & undergone fibrinolysis
Do cats have naturally occuring alloantibodies to DEA blood?
No, but the first exposure leads to sensitization and a delayed hemolysis that always occurs 4-7 days later
