Transfusion medicine

Question 1

What indications would you have for blood transfusions in a patient?

Answer 1

Non-regenerative anaemia, blood loss (acute/ chronic), Haemolytic anaemia (?), thrombocytopenia, DIC

Question 2

What clinical presentation may indicate a blood transfusion?

Answer 2

Weak, ataxia, pale mm, reduced PCV, tachypnoea, dyspnoea, hypoxia

Question 3

How are blood types defined?

Answer 3

By the surface antigens expressed by the RBCs

Question 4

Which species has naturally occurring antibodies to RBC antigen that are not their own?

Answer 4

Cats

Question 5

Which species are seen to have an increase in RBC antigen antibodies post-transfusion?

Answer 5

Dog

Question 6

Name the different blood types expressed in dogs.

Answer 6

CEA 1.1, 1.2, 3, 4, 5, 7, 8

Question 7

Which of the blood types in dogs is considered the most important?

Answer 7

CEA 1.1 (test for positives and negatives)

Question 8

Which of the blood types in dogs is most associated with transfusion reactions?

Answer 8

CEA 1.2

Question 9

Which of the blood types in dogs may cause sensitisation and delayed haemolysis in negative dogs?

Answer 9

CEA 3, 5, 7

Question 10

Which of the blood types in dogs DO NOT cause haemolysis?

Answer 10

CEA 4

Question 11

How can platelets be affected by repeat transfusions in dogs?

Answer 11

MHC antigen on platelets may be sensitised - destruction of platelets

Question 12

How long would you expect transfused RBCs to last in dogs?

Answer 12

21 days

Question 13

Why would you be cautious of using a donor dog which was un-vaccinated and had recently travelled abroad?

Answer 13

Tick borne disease - babesia, leishmania, ehrlichia. Other blood borne illness

Question 14

Which breed of dog may be considered an ideal donor and why?

Answer 14

Greyhounds - most of them are CEA 1.1 negative

Question 15

What is the minimum interval which should be employed between a dogs blood donations?

Answer 15

28 days

Question 16

Why are CEA 1.1 negative dogs the most useful donors?

Answer 16

60% of dogs are CEA 1.1 -ve - DON’T give positive

Question 17

What is the difference between major and minor cross-matching?

Answer 17

Major - detects AB in recip against donor RBCs. Minor - detects AB in donor against recip blood

Question 18

In which situations is cross matching vital in dogs?

Answer 18

After repeat transfusions (when ABs are produced)

Question 19

After donation what is vital for the donor to recieve?

Answer 19

Crystalloids (2-3x volume donated)

Question 20

What blood types are found in cats?

Answer 20

A, B and AB

Question 21

Which blood type is most commonly found in DSH in the UK?

Answer 21

A

Question 22

British short hairs more frequently express which blood type?

Answer 22

Type B

Question 23

Which breed of cat is exclusively type A blood?

Answer 23

Burmese

Question 24

Which gene is dominant in A/B cats? How does this work?

Answer 24

A is dominant. In A/B cats an enzyme converts B to A on the cell

Question 25

What antigens are expressed in AB cats?

Answer 25

NeuGC and NeuA + intermediate forms

Question 26

How recently can cats have been vaccinated if they are to be blood donors?

Answer 26

14 days minimum

Question 27

Which blood borne infections should a donor cat be negative of before donation?

Answer 27

FIV, FeLV, M. haemofelis

Question 28

What minimal interval should be employed between blood donations in cats?

Answer 28

28-42 days

Question 29

In which transfusion cases in cats would a transfusion reaction be seen?

Answer 29

ALL ! Don’t give A blood to a B cat (severe) or B blood to an A cat

Question 30

Indications for packed red cells

Answer 30

Where only red cells are required

Question 31

Indications for plasma

Answer 31

Coagulopathy, hypoalbuminaemia

Question 32

Indications for platelet rich plasma

Answer 32

Thrombocytopenia

Question 33

How long can whole blood and packed red cells be stored safely?

Answer 33

4 weeks at 4-5oC

Question 34

What effect does storage have on red cell capability?

Answer 34

Reduced oxygen carrying capacity

Question 35

Before using stored blood products what should you do?

Answer 35

WARM! To 30-37oC. Monitor tissue perfusion (reduced oxygen carrying capacity)

Question 36

What sites can be used for blood transfusion?

Answer 36

Intravenous (cephalic, saphenous, jugular) or intraosseous (bone marrow!)

Question 37

In which situation would the highest rate of infusion be used? Hypovolaemia, normovolaemia, cardiovascular dysfunction, renal failure?

Answer 37

Hypovolaemia

Question 38

What clinical presentation may lead you to suspect a transfusion reaction in a recent recip DOG?

Answer 38

• Haemolysis - haemoglobinuria/ jaundice
• Circulatory overload
• Pyrexia - acute haemolysis, T1 hypersensitivity, sepsis
• Hypocalcaemia
• Vomiting
• Infectious disease
• Tachycardia - anaphylaxia, shock, sepsis

Question 39

What clinical presentation may lead you to suspect a transfusion reaction in a recent recip CAT?

Answer 39

• Face pawing
• Restlessness
• Tachypnoea
• Pyrexia
• Urticaria
• Vomiting

Question 40

What action should be taken in a haemolytic transfusion reaction?

Answer 40

• STOP transfusion
• Fluid therapy
• IV steroids
• Oxygen
• Antihistamines
• Adrenaline

Question 41

What can cause in vitro haemolysis?

Answer 41

1. Bacterial contamination - stored products
2. Overheating
3. Freezing - DON’T store whole red cells!

Question 42

Vomiting during transfusion is usually associated with what?

Answer 42

Too rapid administration

Feeding

Question 43

Circulatory overload during blood transfusion can be associated with what clinical presentation?

Answer 43

Pulmonary oedema (heart failure) - tachypnoea, dyspnoea, tachycardia, moist cough

Question 44

What is oxyglobin?

Answer 44

A colloid of bovine haemoglobin tetramer