Transfusion Therapy

Question 1

What should we consider when deciding whether or not to give a patient a tranfusion?

Answer 1

PCV, Severity of Anaemia & Chronicity
Anticipated disease course
Treatment plan- e.g. surgery where more blood is going to be lost

Question 2

What weight does an animal need to be in order to donate blood?

Answer 2

25kg canine
5kg feline

[this is lean body fat btw]

Question 3

What are some requirements a blood donor should fit into before they donate?

Answer 3

No history of travel abroad
No previous transfusion themselves
Up to date vaccination/ worming

Blood testing- FeLV, Mycoplasma

Question 4

What is Emla cream used for?

Answer 4

local anaesthetic cream to make blood donating painless

Question 5

How much blood can a dog donate?

Answer 5

450ml

Question 6

How much blood can a cat donate?

Answer 6

12ml/kg

Question 7

What can we transfuse patients with? (5)

Answer 7

Whole blood
Packed RBC
Fresh frozen plasma
Cryoprecipitate
Cryosupernatant

Question 8

When is a whole blood transfusion indicated?

Answer 8

When blood is required immediately e.g. in acute haemorrhage or in haemorrhage due to haemostatic disorders

Question 9

What do we mean by Component therapy?

Give an example.

Answer 9

get multiple products from one donation e.g. the precursors for blood

e.g. Packed red blood cells

Question 10

Why is component therapy preferred? (3)

Answer 10

Decreases number of donations needed as patient is given precursors to make their own blood
Decreased risk of volume overload as less is needed
Less chance of Transfusion reaction

Question 11

What do we mean by packed red blood cells?

Answer 11

Centrifuged whole blood (no plasma)

Question 12

When is Packed red blood cell transfusion indicated?

Answer 12

Patients with anaemia without hypovolaemia (they have a normal fluid volume in their body)- lost cells not volume

Question 13

How is fresh frozen plasma prepared for donation?

Answer 13

Taken from centrifuged blood- separated within 24 hours and can be frozen for up to one year

Question 14

When is transfusion with fresh frozen plasma indicated?

Answer 14

It’s high in all clotting factors so any pathology that has…
Coagulopathies e.g. toxin ingestion due to Rodenticide
When animal needs Albumin e.g. in liver disease (this is less reliable)

Question 15

How long does liquid plasma last?

Answer 15

Refrigerated for 24 hours
can be frozen for up to 5 years

Question 16

What does liquid plasma lack that fresh frozen plasma has?

Answer 16

Factors V and VIII
and Von Willebrand Factor

Question 17

What is Cryoprecipitate?

Answer 17

Fresh frozen plasma that has been partially thawed, centrifuged and then re-frozen
It is enriched in factor VIII, vWf and fibrinogen (unlike frozen plasma)

Question 18

What is Cryosupernatant?

Answer 18

It’s the plasma supernatant remaining after we have removed the cryoprecipitate from the frozen-thawed plasma
It contains all the remaining soluble plasma proteins.

Question 19

What is Cryosupernatant high in and therefore when is it indicated?

Answer 19

High in vitamin K dependent clotting factors, Albumin and Anti-thrombin
Used for Rodenticide toxicity, vitamin k deficiency and Haemophilia (clotting disorder)

Question 20

There are dog blood banks available for canine but no feline blood banks- as a last resort what can we use to treat cats when feline blood is unavailable?

Answer 20

Xenotransfusion- transfusion of canine blood into a cat
Effective in increasing PCV- the transfused cells get cleared from the circulation in 4-7 days by the body

Question 21

Why is it contraindicated to give a Xenotransfusion to a Cat that has previously has one?

Answer 21

Cats have naturally occurring antibodies to canine red cell antigens so there is a risk of a severe transfusion reaction and death

Question 22

What is a blood type?
Why are non-match blood types destroyed?

Answer 22

Blood types are based on the type of antigen on the erythrocyte surface- if these don’t match the host then the body will destroy them

Question 23

What blood type categories are used in Dogs?

Answer 23

DEA 1 positive (most common)
DEA 1 negative

Question 24

What blood groups do Felines have?

Answer 24

Type A
Type B
Type AB

Question 25

Why is it important that we ALWAYS check the blood group of a Cat before transfusion?

Answer 25

Cats already have preformed antibodies against other blood types so will have a severe transfusion reaction if given the wrong one

[(apart from AB patients which have both A & B antigens so can be given either)]- universal recipients

Question 26

Why is it important to use a dedicated catheter for blood transfusion?

Answer 26

To ensure it doesn’t cross react with anything that has previously been used in the tube

Question 27

What should we monitor in the patient when performing a transfusion? (3)

Answer 27

TPR- every 15 mins for the first hour then hourly afterwards
Demeanour & Appearance in case of reactions
Haemoglobinuria

Question 28

If a patient has a transfusion reaction, what should we do?

Answer 28

Stop the transfusion
Check ECG & Blood pressure
Administer Adrenaline and CPR if needed
Administer anti-histamines or anti-pyretics