Transfusion Medicine Flashcards
What kind of transfusion is given to patients suffering from hemorrhage, erythrocyte destruction, or decreased RBC production?
(anemia)
RBC transfusion
*Goal is to minimize destruction of donated RBCs
What kind of transfusion would be given to patients with Vit K agonist rodenticide toxicity, hemophilia, or DIC?
(coagulopathies)
Plasma transfusion
*Goal is to minimize destruction of recipient’s RBCs
You begin a blood transfusion on an anemic patient, and within a few minutes the patient has hemoglobinuria and hemoglobinemia. What should you do?
Stop the transfusion and begin supportive care!
This is an acute hemolytic reaction causing intravascular hemolysis. These reactions are severe.
You perform a blood transfusion on a hospital patient, and about 24 hours later you note yellow serum and bilirubin in the urine. What kind of reaction is this?
Delayed hemolytic reaction (extravascular hemolysis)
*No intervention needed. Monitor.
You begin a blood transfusion on a patient who develops a fever and facial swelling, and begins vomiting within 15 minutes of starting treatment. How should you proceed?
Decrease infusion rate
*This is a non-hemolytic hypersensitivity reaction. Can give diphenhydramine to alleviate symptoms.
Acute hemolytic reactions to blood transfusions, characterized by hemoglobinemia, ^HR, ^RR, weak pulse, hypoxia (tremors, convulsions), and vomiting can lead to what issues?
DIC, hypotension, shock, acute renal failure, death
How can we prevent transfusion reactions by identifying inherited antigenic proteins on the RBC surface?
Blood testing
How can we prevent transfusion reactions by identifying circulating antibodies in the plasma?
Cross-matching
When performing a blood typing on a dog, are we more worried about finding DEA 1 or DEA 4?
DEA 1
Highly immunogenic and causes severe reactions (agglutination and hemolysis). 65% of dogs have this gene.
(DEA 4 is in 98% of dogs and is non-immunogenic)
What blood antigen is present in 93% of dogs, requiring cross-matching of donors even if they have a compatible blood type?
Dal
*Look to dalmations to find a compatible donor
What are the 2 feline blood systems?
AB group (they’re either A, B, or both)
Mik system (most cats have this too)
T/F: Like dogs, cats can get one free transfusion without blood typing and cross-matching.
FALSE
Cats already have the Ab to the other blood antigen
A North American breed of cat has blood type A has been transfused with blood from a type B donor. What kind of reaction do you expect.
Not so bad. Type A cats have weak isoantibodies against type B antigen.
A British breed cat has blood type B and has been transfused with blood from a type A cat. What kind of reaction will this cat have?
SEVERE and lethal! Type B cats have strong isoantibodies against type A antigen.
If a blood type B queen is mated with a type A or AB tom, what consequence does this have for the kittens?
Risk of neonatal isoerythrolysis due to production of type A or AB kittens.
Why are some purebred cats universal recipients, but not donors?
They are blood type AB
About 6% of cats don’t have the Mik antigen. These cats have anti-Mik alloantibodies and may suffer from an acute hemolytic reaction if transfused with blood from a Mik positive cat, even if the AB blood type matches. How can this be prevented?
Cross-match all donor/recipients prior to transfusion!
T/F: Pre-existing isoantibodies in large animals are rare and single, un-crossmatched whole blood transfusions tend to be well tolerated.
TRUE
*Cross match for repeated transfusions or plasma transfusions.
Large animal blood typing is impractical and transfusions are uncommon except in this species:
Equine
Equines have 7 blood systems, each with multiple antigens, for over 400,000 combinations. Which antigens are highly immunogenic and are implicated in neonatal isoerythrolysis?
Aa and Qa
What medical practice can sensitize a cow to foreign RBC antigens and may result in neonatal isoerythrolysis in calves?
Vaccinations of blood origin
Repeated transfusions in large animals require what compatibility test to prevent reactions?
Crossmatching only! Too many blood types to even bother with typing (except horses)
If a patient is given antiserum that has antibodies against RBC antigen A, and you see agglutination, what blood type is the patient?
Type A
Blood from this donor is given to a DEA positive recipient. What kind of reaction will occur?
No reaction. This dog is DEA negative.
Blood from this donor is given to a DEA negative recipient. What kind of reaction will occur?
Severe reaction! This donor is DEA positive.
A crossmatch is the final test of compatibility between a donor and a patient prior to tranfusion. What components are tested in the major crossmatch?
Recipient’s serum and donor’s RBCs
You perform a major crossmatch on a potential recipient and donor. Should you proceed with the transfusion?
No! The recipient has antibodies against the donor’s RBCs.
Why are minor crossmatches rarely performed?
Test the recipient’s RBCs against the donor’s serum, but since the volume of serum transfused is usually low, there’s not enough Ab in the donor serum to cause a significant problem.
You perform a crossmatch on 2 equine patients and see hemolysis in the glass tube. What kind of result does this indicate and should you proceed with the transfusion?
This is a positive result. DO NOT PROCEED.
You are performing a crossmatch on 2 feline patients. There is no macro-agglutination in the glass tube and no agglutination present on the microscope slide. What kind of result is this and should you proceed with the transfusion?
This is a negative result. PROCEED.
T/F: Crossmatching will detect even very low antibody titers.
FALSE
Doesn’t detect low titers, so reactions are not 100% preventable.
While small animals have agglutinating antibodies, horses have:
Agglutinating and hemolytic antibodies
