Transfusion medicine

Question 1

What clinical signs may be suggestive of reduced oxygen perfusion to tissues and that a blood transfusion may be needed?

Answer 1

Tachycardia
Tachypnoea
Lethargy
Weakness

Question 2

What should you ensure before deciding whether do do a blood transfusion?

Answer 2

Patients volume concentration

If normovolaemic do not transfuse

Question 3

What blood product should be transfused after blood loss?

Answer 3

Whole blood (gold standard)
Packed red cells

Question 4

What blood product should be transfused after haemolysis?

Answer 4

Packed red cells

Question 5

What blood product should be transfused for a coagulopathy?

Answer 5

Fresh frozen plasma
Regular plasma
Or cryoprecipitate

Question 6

Some practices have their own blood donor programme. How long do they store whole blood for?

Answer 6

Up to 21 days

Question 7

Most practices use the UK pet blood bank. Which species has no blood/platelet products available?

Answer 7

Feline blood or platelets

Question 8

Do dogs and cats need to receive type-specific blood/blood products?

Answer 8

Ideally for dogs (not essential if first transfusion)

Cats = imperative for blood, not strictly necessary for plasma

Question 9

Which RBC antigen should be tested for before giving blood? Why?

Answer 9

DEA-1

Most animals naive, but causes strongest immune reaction

Question 10

The aim of blood transfusion is to supply blood until animal can develop their own RBCs - how long until the donor blood is gone?

Answer 10

1 week

Question 11

What is a naive dog in terms of blood transfusion?

Answer 11

Never received a blood transfusion

most donors naive

Question 12

What happens if a donor and recipient have different blood types but a transfusion still takes place?

Answer 12

Initially saves life

3-4 days later = haemolysis

Question 13

What symptoms would you expect to see from a dog that has received a transfusion from a different blood type?

Answer 13

Lowered PCV

Jaundice (from haemolysis)

Question 14

What happens if a donor gives blood to a sensitised recipient?

Answer 14

Acute haemolysis (fast) 
Recipient already has antibodies to that blood type

Question 15

What system is used for canine blood types?

Answer 15

Dog erythrocyte antigen system

DEA

Question 16

What proportion of dogs are DEA negative?

Answer 16

50% = DEA negative
50% = DEA positive

Question 17

There are many different types of DEA (dog RBC antigens). Which one is most important?

Answer 17

DEA-1

Question 18

What is sensitisation in terms of blood transfusion?

Answer 18

When a DEA -ve dog receives blood transfusion from +ve dog

Has mild reaction to blood and becomes SENSITISED

Question 19

Why is it not essential to match dog blood types if the dog has not had blood before?

Answer 19

Dog cannot be sensitised if not had previous transfusion

Question 20

What happens if a DEA-1 negative dog receives blood from a positive dog?

Answer 20

Mild reaction

Becomes SENSITISED

Question 21

What happens if a DEA-1 positive dog receives blood from a negative dog?

Answer 21

No reaction

Question 22

What blood system is used in cats?

Answer 22

A/B system

Question 23

What blood types can a cat have?

Answer 23

A
B
AB

Question 24

Why is it essential for cats to be blood typed before receiving a transfusion?

Answer 24

Cats have naturally occurring auto-antibodies

1ml of blood can cause haemolysis and be fatal

Question 25

What is worse, giving B cats A blood, or giving A cats B blood?

Answer 25

Giving B cats A blood = BAD | Giving A cats B blood = not as bad

Question 26

What happens if you give a B cat type A blood?

Answer 26

Severe acute haemolytic reaction | Can be fatal

Question 27

What happens if you give A cats type B blood?

Answer 27

Mild delayed haemolytic reaction

Question 28

What is the gold standard for blood typing?

Answer 28

Sending off to lab - rarely time to do so

Question 29

What in house methods can be used for blood typing?

Answer 29

Card method | Cassette based method (preferred - don't rule out auto agglutination)

Question 30

The casette/card based methods for blood typing only test for what blood types?

Answer 30

DEA 1 | A/B

Question 31

It is imperative to rule out auto-agglutination for which blood typing method?

Answer 31

Card based | If present, need to wash patients RBCs, hence cassette method is preferred

Question 32

What is crossmatching in terms of blood transfusions?

Answer 32

Checking for haematological incompatibility

Question 33

Do you need to cross match?

Answer 33

Yes if go has had previous blood transfusions | Possibly if received plasma products

Question 34

What is the gold standard for crossmatching?

Answer 34

Sending to lab (IDEXX) | In house = inaccurate

Question 35

For crossmatching, blood needs to be sent to a lab. Do they tend to find 100% compatible donors?

Answer 35

No - choose least risky

Question 36

How can blood transfusions be administered (what routes)?

Answer 36

IV or IO

Question 37

Transfusion reactions are usually dose dependent. How can they be reduced?

Answer 37

Start administering blood at slow rate | Then build up

Question 38

It is essential to keep blood sterile during a transfusion. Why?

Answer 38

Blood = good growth medium for bacteria due to sugar

Question 39

Is it better to administer blood transfusions by drips or syringe drivers?

Answer 39

``` Dogs = drip Cats = syringe ```

Question 40

Blood transfusions must be given with what equipment?

Answer 40

Transfusion set with an in-line filter

Question 41

What should you flush with after a blood transfusion?

Answer 41

0.9% NaCl

Question 42

Why shouldn't you give calcium fluids after a blood transfusion?

Answer 42

Causes clotting

Question 43

Should you give medication in the same line as a blood transfusion?

Answer 43

No - use different lines

Question 44

Should you warm donor blood prior to transfusion?

Answer 44

No - give at room temperature

Question 45

Should you allow a patient access to food and water during a transfusion?

Answer 45

Allow water access | No food

Question 46

What should you monitor a patient for after a blood transfusion?

Answer 46

Heart rate, RR, rectal temperature | Signs of anaphylaxis - swelling, urticaria, nausea, vomiting

Question 47

Severe haemolytic reactions to blood transfusions are obvious, but mild reactions are not. What should you do if you suspect a mild reaction?

Answer 47

Treat symptomatically Have 15-30 min break, restart at slower rate Do NOT disconnect patient

Question 48

What is the rough guidelines for how much blood to administer during a transfusion?

Answer 48

10-20ml/kg