Hematology - Transfusions Flashcards
True or False: Blood transfusions are used to treat disease.
false - they are supportive
What are the indications for transfusion?
Temporary replacement of red cells, platelets, and plasma proteins/factors
What are the benefits to blood component therapy?
It conserves products, allows for the most specific and safe product to be used for each animal, and minimizes transfusion volume
What are the different forms of whole blood that can be transfused?
fresh whole blood and stored whole blood
What are the different forms of blood components that can be transfused?
Packed red cells, fresh frozen plasma, frozen plasma, and platelet rich plasma/platelet concentrate
What are the criteria for plasma to be considered fresh frozen plasma?
If it is frozen in less than 8 hours and stored for less than a year
What are the criteria for plasma to be considered frozen plasma?
If it is frozen in greater than 8 hours or stored for greater than 1 year and less than 4 years
How many units of packed RBCs and fresh frozen plasma do we get from 500 mL of whole blood?
2 half units of packed RBC (125 mls each) and 1 unit of fresh frozen plasma (240 mls)
What does fresh whole blood contain?
RBCs, all plasma components, platelets, and white cells
How quickly after collection should fresh whole blood be transfused?
within 4-6 hours of collection
What is the criteria for whole blood to be stored whole blood?
If it is older than 6 hours but less than 1 month old and kept at 4 degrees celcius
What does stored whole blood contain?
RBCs and plasma - it does not contain viable platelets or labile clotting factors
What are the indications for whole blood use?
patients need multiple blood components or the patients need volume
What does packed red cells contain?
Cells and small amounts of plasma and anticoagulant that remains after the plasma is removed from one unit of whole blood
What are the indications for packed red cells?
anemia
You have a patient that was hit by their owner’s car. They present collapsed with an open femoral fracture and a significantly swollen rear leg. HCT is 16%, total protein is decreased and the platelet count is normal. The patient is very shocky. What type of transfusion is preferred in this patient?
Whole blood because the dog has lost blood volume from bleeding at the site of truama and is very anemic
You have a patient that presented for lethargy and anorexia. This patient had a history of seizures, managed with phenobarbitol. They are anemic with a HCT of 9% and a normal TP. The heartrate was 150, the patient was hypotensive, weak, and 5% dehydrated. Your working diagnosis is bone marrow suppression from phenobarbitol. What type of blood product would you want to give to this patient?
Packed red cells because the patient was only missing RBCs. This patient would also be given crystalloids to handle the dehydration
What does fresh frozen plasma contain?
Coagulation factors, antithrombin and other anticoagulation factors, von Willebrand factor (vWF), albumin, and globulins
What are the indications for the use of fresh frozen plasma?
coagulation disorders resulting in hemorrhage or prophylaxis before surgery in an animal with known clotting factor deficiency
What clotting factor deficiencies would indicate the prophylaxis use of fresh frozen plasma prior to surgery?
Von Willebrand disease (congenital), Hemophilia A and B (congenital), Rodenticide toxicity (acquired), Coagulopathy due to liver disease (acquired), and DIC (acquired)
What should fresh frozen plasma not be used as a source of?
albumin
When should fresh frozen plasma not be given?
Unless you know there is bleeding
What does frozen plasma contain?
stable coagulation factors II, VII, IX, X and albumin
What are the indications for use of frozen plasma?
Coagulation deficiencies of II, VII, IX, or X resulting in active hemorrhage - this would be perfect for rodenticide cases
Where do blood products come from?
Commercial blood banks, in-house blood donors, and client owned pets (non-resident blood donors)
What is the most common indication for a transfusion?
anemia
What clinical signs in an anemic patient should indicate a transfusion?
Lethargy, tachycardia, and tachypnea
At what PCV level should you consider a transfusion?
less than 20%
What are blood groups defined by?
inherited antigens on the surface of the RBC
What can RBC antigens trigger in an animal that lacks that antigen?
antibody production
What is the blood typing system in the dog?
DEA - Dog erythrocyte antigen system
What are the five defined canine blood groups?
DEA 1, 3, 4, 5, and 7
What are the allele forms of DEA 1?
positive, negative, and weak positive
What are the allele forms of DEA 3, 4, 5, and 7?
positive or negative
What is the most immunogenic and clinically significant canine blood type?
DEA 1
True or False: There are preformed antibodies to DEA 1
false - there are no preformed antibodies to DEA 1, sensitization post transfusion
If you give a transfusion of DEA 1+ blood to a DEA 1- recipient what will happen?
The recipient will make anti-DEA antibody within 4-7 days
If a dog with DEA 1- blood gets a second transfusion of DEA 1+ blood, what will happen?
An acute hemolytic crisis will occur
What is the canine universal donor?
A dog that is negative for DEA 1, 3, 5, and 7, and positive for DEA 4
When should you crossmatch for a dog?
In dogs with prior transfusion greater than 3 days prior
Why can you give a transfusion to a dog without crossmatching if it is their first transfusion?
Because they lack clinically significant alloantibodies
How do you crossmatch?
Mix washed donor RBCs mixed with recipient plasma
What crossmatch result indicates incompatibility?
agglutination or hemolysis
What amount of pRBCs should increase PCV by 1%?
1 ml/kg
At what temperature should RBC, whole blood, and platelets be transfused?
room temperature
At what temperature should you thaw fresh frozen plasma to?
37 degrees celcius
How should blood be administered?
Via a dedicated IV line with no additives, through a filter, no pumps, over 1-4 hours, and start slow
What should you monitor and monitor for during blood transfusions?
TPR every 30 minutes, and watch for nausea, vomiting, diarrhea, and agitation
What blood typing system is used for cats?
AB system
What blood types do cats have and what is the most common?
Type A (most common), type B, and Type AB
Can cats receive a blood transfusion without crossmatching?
No! They have high levels of naturally occuring antibodies to foreign antigens
Type B cats have a ______ reaction to type A blood.
Strong; giving 1 mL can kill a type B cat
Type A cats have a _____ reaction to type B blood.
Mild; there will be shortened RBC survival
Is there a universal cat donor?
no
In what breeds are B blood types more common?
Purebreds - Devon rex, British shorthair, Cornish rex, exotic shorthair, and Scottish fold
What type of blood should AB cats receive?
They should receive either type AB or A blood products - AB is better
What type of blood should AB cats not receive?
B blood because of the strong anti-A antibodies present in donor B sserum
What do anticoagulant rodenticides inhibit?
Vitamin K1 epoxide reductase
Without active Vitamin K, what coagulation factors cannot be activated?
Factors II, VII, IX, and X
What products contain factors II, VII, IX, and X?
FFP, FP, and whole blood
What are the general types of tranfusion reactions?
Immune-mediated and Non-immune mediated reactions
What is an example of a type II acute, immune transfusion reaction?
Type B cats receiving Type A cells
What signs are associated with Type II acute, immune transfusion reactions in cats?
Occur within minutes - hemolysis, hemoglobinuria, apnea, dyspnea, hypotension, cardiac arrythmias, collapse, and forelimb extension
What should you do in a patient with Type II acute, immune transfusion reactions?
Stop the transfusion and begin crystalloid infusion to optimize blood pressure and maintain renal perfusion
What clinical signs are associated Type I with acute, immune transfusion reactions?
Allergic reactions ranging from hives (mild) to severe anaphylaxis
What antibodies mediate hypersensitivity reactions against proteins in donor plasma?
IgE
What do you do in a patient with Type I hypersensitivity reactions?
Stop transfusion and give antihistamines +/- glucocorticoids
What are febrile, nonhemolytic reactions?
When the temperature increases of more than 1 degree celcius associated with a transfusion
What causes febrile, nonhemolytic reactions?
Cytokines in blood product or anti-WBC or anti-platelet antibodies in recipient against donor WBCs or platelets
What do you do in cases of febrile, nonhemolytic reactions?
Slow the transfusion, consider stopping, and consider an anti-pyretic drug (steroid)
What are some non-immune transfusion reactions?
TACO, transfusion-associated sepsis, non-immune mediated hemolysis, and citrate toxicity
What is TACO?
Transfusion-associated circulatory overload
What are some clinical signs of TACO?
retching, vomiting, tachypnea, and dyspnea
How can TACO be treated?
Lasix and oxygen as needed
What causes transfusion-associated sepsis?
bacterial contamination of the blood products
What should you do in a patient with transfusion-associated sepsis?
Stop the transfusion and culture the unit
What causes nonimmune-mediate hemolysis?
Improper temperature exposure or mechanical hemolysis
What is citrate toxicity associated with?
the anticoagulant - hypocalcemia occurs
How are transfusion reactions prevented?
Type/crossmatch, filter blood, start slowly, and discard blood products if they have been at room temperature for more than 4 hours
What is the first step to managing transfusion reactions?
stop the transfusion
How do you treat volume overload as a result of a transfusion?
diuretics and oxygen
How do you treat hemolysis, shock, and anaphylaxis as a result of a transfusion?
fluids, ventilation, oxygen, epinephrine, and glucocorticoids
How do you treat urticaria, pruritus, and edema as a result of a transfusion?
diphenhydramine and dexamethasone
How do you treat mild febrile reactions as the result of a transfusion?
No specific treatment, but in more severe temperature elevations treat with fluid support and antipyretics
