Transfusion Medicine Flashcards
What underlying diseases cause anemia?
- hemolytic disease
- Hemorrhagic disease
- Severe non-regenerative disease
What underlying diseases cause Thrombocytopenia
- ITP
- DIC
- Severe bone marrow disease
What are the underlying causes of coagulation factor deficiencies?
- Congenital/hereditary
- Acquired
What blood products are available for transfusions?
- Fresh Whole blood
- Packed red blood cells
- Plasma products
- Cryoprecipitate/Cryosupernatant
What is Fresh Whole Blood? (contents, storage, uses?)
- RBC, WBC, platelets, and plasma proteins
- Refrigeration renders WBCs and platelets inactive: stable 28-30 days at 1-6C
- Indicated for anemic animals, especially if coagulation factors are needed
What is packed red blood cells (pRBC)? (contents, storage, uses?)
- Whole blood - plasma = pRBC
- Storage 3-4 weeks (refrigerate with RBC preservative)
- Storage leads to reduced deformability and 2,3-DPG levels within RBC
- Indications for use: anemia
what plasma products are there?
- Fresh/Fresh frozen plasma (FFP)
- Frozen Plasma
- Platelet-rich plasma
- Cryoprecipitate
- Cryosupernatant
What is Fresh/Fresh Frozen plasma (FFP)? (contents, storage, uses?)
- Administered immediately or frozen within 6 hours
- Pro-coagulant and anti-coagulant factors, Ig, albumin
- Uses: coagulopathy of any cause, DIC
What is Frozen Plasma (FP)? (contents, storage, uses?)
- Factors V, VII, vWF no longer considered viable
- Source of albumin, Ig, Vit K-dependent factors
- Uses: rodenticide toxicity, oncotic support
- ~45ml/kg required to increase albumin 1g/dL
What is Platelet-rich plasma? (contents, storage, uses?)
- Warm, slow centrifugation of fresh whole blood
- No storage
- Limited use: intracranial hemorrhage
What is cryoprecipitate? (contents, storage, uses?)
- Precipitate formed by thawing FFP
- vWf, fibrinogen, VII, XIII
- Uses: vonWillebrands disease, Hemophilia A
What is cryosupernatant? (contents, storage, uses?)
- Fraction remaining after production of cryoprecipitate
- Factors II, VII, IX, X
- Indications: Rodenticide, Hemophilia B
What is a transfusion trigger?
- Point were oxygen delivery has dropped enough to stimulate anaerobic metabolism
- Packed cell volume, HR, BP, Pulse quality, Alertness
What factors influence transfusion triggers?
- Concurrent disease
- Rate at which anemia developed
- Need for interventional procedures (Surgery)
What testing is required for canine blood donors?
- Routine health screening:
- CBC, Chemistry, UA, Fecal
- Blood type
- Heartworm, Babesia, Ehrlichia
- Anaplasma, Mycoplasma
What testing is needed for feline blood donors?
- Routine health screening:
- CBC, Chemistry, UA, Fecal
- Blood type
- FeLV, FIV, Mycoplasma
- Bartonella, others (?)
What are the canine blood groups? what are some important factors of each?
- Most greyhounds are negative for DEA 1.1 and positive for DEA 3
- Most Labs are positive for DEA 1.1
- Dogs negative for DEA 1/1 and ½ do NOT have naturally occurring antibodies and can be transfused one time
- 60% of dogs are DEA 1 positive
- DEA 4 also antigenic (~98% of days are DEA4 positive)
What are the downsides of blood typing?
- does NOT imply immunologic compatibility
- Affected by autoagglutination and severe anemia
What are the Feline blood groups? Importance of the groups?
- 3 Groups: A, B, AB
- Naturally occurring antibodies
- Type B cats have strong alloantibodies vs A blood
- Type A cats have weak alloantibodies to B blood
- AB cats (<1% in US) are universal recipients but cannot donate
- Small % of cats lack the MiK antigen and have antibodies against it
What is neonatal isoerythrolysis?
- Type A kittens born of type B queen
- Kittens nurse during the first 24 hours of life will infest anti-A antibodies from the queen
- results in life threatening hemolysis
What is cross-matching?
- Helps to define immunological compatibility
- Ideally should always be carried out
- Not always required in first transfusion if:
- Donor is DEA-1 negative
- Recipient is DEA-1 positive
- questionable value in cats for 1st transfusion
- Will not predict delayed immune-mediated reactions
- Recommended if previous transfusion > 7 days prior
What is a Major crossmatch?
- Donor erythrocyte + recipient serum
- Incompatibility predicts immune-mediated hemolytic reaction to donor blood
What is minor crossmatch?
- Recipient erythrocyte + donor serum
- Incompatibility suggests possible reaction against recipient erythrocytes
How much blood can a dog give?
15-20 ml/kg
How much blood can a cat give
10-15 ml/kg
How is blood collected from dogs/cats?
- Syringe method
- CPDA-1 or ACD anticoagulant added
- 1ml per 9ml blood
- CPDA-1 or ACD anticoagulant added
What is the protocol for transfusions?
- Administer blood through an appropriate filter
- Use largest IV catheter possible
- No pump with RBC products (syringe pump -ok)
- No medications through the same IV set-up
- Only 0.9% saline may be infused simultaneously
- flush with saline pre and post-transfusion
- Rate depends upon product and patient
- slow infusion recommended for first 10-30 mins while monitoring for incompatibilities (0.5-1ml/kg)
- Parameters monitored every 5-15 minutes for 15-30 minutes then every 15-30 minutes until completion
- Warm products to body temperature (water bath)
- complete transfusion w/in 2-4hrs
- Avoid volume overload
- Target PCV dependent on patient/disease
- Recheck PCV 2hrs post-transfusion then as required
- Keep transfusion record
- product information
- transfusion monitoring
What are the transfusion totals for the different blood/plasma products?
- Whole blood: 12-20 ml/kg
- pRBC: 6-15ml/kg
- FFP: 10-30 ml/kg (repeat if coag times not improved)
- Cryoprecipitate: 1 unit/10kg until hemorrhage controlled
- Cryosupernatant: 6-10ml/kg until hemorrhage controlled
- Platelet-rich plasma: 1unit/10kg
How is the WB/pRBC transfusion amount determined?
[(PCV desired - PCV actual)/PCV donor] x blood volume x weight
Why does a transfusion need to be completed in 2-4hrs
- Product viability
- risk of contamination
What are the different possible Transfusion reactions?
Why does Immune-mediated hemolysis occur after transfusion? signs? treatment?
- Recipients Ab’s react against donor RBC
- Type II hypersensitivity
- PCV drops 3-5 days after transfusion due to production of antibodies
- Not predicted by cross-matching
- Signs:
- Fever, salivation, restlessness, shock, hemoglobinemia, hemoglobinuria
- Treatment:
- Antihistamines, glucocorticoids, treatment for shock
Why does a non-hemolytic reaction occur following transfusions? how can this be prevented
- WBC-derived cytokines or recipient Ab’s react against donor WBC or plasma proteins
- Slow administration rate and/or hemolytic reaction, sepsis
- Minimized with leukoreduction filters during collection
Why do allergic reactions occur following transfusions? Signs? Treatment?
- Donor protein binds pre-formed IgE on recipient mast cells
- Type I hypersensitivity
- Signs:
- urticaria, hives, anaphylaxis, bronchoconstriction
- Treatment:
- antihistamines, treatment for shock
What is a Transfusion related lung injury?
- clinically resembles ARDS (acute respiratory distress)
- Occurs w/in 24 hrs and no pre-existing lung disease
- usually self-limitinga
What is Post-transfusion purpura?
- Thrombocytopenia develops 1-2 weeks after transfusion
- Usually self-resolving in 1-4 weeks
What is TACO?
- Transfusion associated cardiac overload
- At risk:
- normovolemia, cardiac disease, renal disease
Why does non-immune-mediated hemolysis occur?
- Incorrect warming
- incompatible solutions, medications
When does citrate toxicity occur?
- Massive transfusion (dogs >90ml/kg/day)
- Clinical signs reflect hypocalcemia and/or hypomagnesemia
