Transfusion medicine Flashcards
What clinical signs may be suggestive of reduced oxygen perfusion to tissues and that a blood transfusion may be needed?
Tachycardia
Tachypnoea
Lethargy
Weakness
What should you ensure before deciding whether do do a blood transfusion?
Patients volume concentration
If normovolaemic do not transfuse
What blood product should be transfused after blood loss?
Whole blood (gold standard) Packed red cells
What blood product should be transfused after haemolysis?
Packed red cells
What blood product should be transfused for a coagulopathy?
Fresh frozen plasma
Regular plasma
Or cryoprecipitate
Some practices have their own blood donor programme. How long do they store whole blood for?
Up to 21 days
Most practices use the UK pet blood bank. Which species has no blood/platelet products available?
Feline blood or platelets
Do dogs and cats need to receive type-specific blood/blood products?
Ideally for dogs (not essential if first transfusion)
Cats = imperative for blood, not strictly necessary for plasma
Which RBC antigen should be tested for before giving blood? Why?
DEA-1
Most animals naive, but causes strongest immune reaction
The aim of blood transfusion is to supply blood until animal can develop their own RBCs - how long until the donor blood is gone?
1 week
What is a naive dog in terms of blood transfusion?
Never received a blood transfusion
most donors naive
What happens if a donor and recipient have different blood types but a transfusion still takes place?
Initially saves life
3-4 days later = haemolysis
What symptoms would you expect to see from a dog that has received a transfusion from a different blood type?
Lowered PCV
Jaundice (from haemolysis)
What happens if a donor gives blood to a sensitised recipient?
Acute haemolysis (fast) Recipient already has antibodies to that blood type
What system is used for canine blood types?
Dog erythrocyte antigen system
DEA
What proportion of dogs are DEA negative?
50% = DEA negative 50% = DEA positive
There are many different types of DEA (dog RBC antigens). Which one is most important?
DEA-1
What is sensitisation in terms of blood transfusion?
When a DEA -ve dog receives blood transfusion from +ve dog
Has mild reaction to blood and becomes SENSITISED
Why is it not essential to match dog blood types if the dog has not had blood before?
Dog cannot be sensitised if not had previous transfusion
What happens if a DEA-1 negative dog receives blood from a positive dog?
Mild reaction
Becomes SENSITISED
What happens if a DEA-1 positive dog receives blood from a negative dog?
No reaction
What blood system is used in cats?
A/B system
What blood types can a cat have?
A
B
AB
Why is it essential for cats to be blood typed before receiving a transfusion?
Cats have naturally occurring auto-antibodies
1ml of blood can cause haemolysis and be fatal
What is worse, giving B cats A blood, or giving A cats B blood?
Giving B cats A blood = BAD
Giving A cats B blood = not as bad
What happens if you give a B cat type A blood?
Severe acute haemolytic reaction
Can be fatal
What happens if you give A cats type B blood?
Mild delayed haemolytic reaction
What is the gold standard for blood typing?
Sending off to lab - rarely time to do so
What in house methods can be used for blood typing?
Card method
Cassette based method (preferred - don’t rule out auto agglutination)
The casette/card based methods for blood typing only test for what blood types?
DEA 1
A/B
It is imperative to rule out auto-agglutination for which blood typing method?
Card based
If present, need to wash patients RBCs, hence cassette method is preferred
What is crossmatching in terms of blood transfusions?
Checking for haematological incompatibility
Do you need to cross match?
Yes if go has had previous blood transfusions
Possibly if received plasma products
What is the gold standard for crossmatching?
Sending to lab (IDEXX)
In house = inaccurate
For crossmatching, blood needs to be sent to a lab. Do they tend to find 100% compatible donors?
No - choose least risky
How can blood transfusions be administered (what routes)?
IV or IO
Transfusion reactions are usually dose dependent. How can they be reduced?
Start administering blood at slow rate
Then build up
It is essential to keep blood sterile during a transfusion. Why?
Blood = good growth medium for bacteria due to sugar
Is it better to administer blood transfusions by drips or syringe drivers?
Dogs = drip Cats = syringe
Blood transfusions must be given with what equipment?
Transfusion set with an in-line filter
What should you flush with after a blood transfusion?
0.9% NaCl
Why shouldn’t you give calcium fluids after a blood transfusion?
Causes clotting
Should you give medication in the same line as a blood transfusion?
No - use different lines
Should you warm donor blood prior to transfusion?
No - give at room temperature
Should you allow a patient access to food and water during a transfusion?
Allow water access
No food
What should you monitor a patient for after a blood transfusion?
Heart rate, RR, rectal temperature
Signs of anaphylaxis - swelling, urticaria, nausea, vomiting
Severe haemolytic reactions to blood transfusions are obvious, but mild reactions are not. What should you do if you suspect a mild reaction?
Treat symptomatically
Have 15-30 min break, restart at slower rate
Do NOT disconnect patient
What is the rough guidelines for how much blood to administer during a transfusion?
10-20ml/kg
