Transfusion

Question 1

What can rat bait cause in regards to the trachea?

Answer 1

Narrowing of the trachea due to a bleed- essentially a long haematoma that occurs around the trachea- causing tracheal narrowing

Question 2

Treating haemorrhagic shock

Answer 2

Large loss of blood, reduction of circulating volume that creates a lot of issues. Goal: stabilize. Use crystalloids first (electrolytes essentially), colloids second- larger molecules, transfusion is the 3rd go to because it is with risk, and it is expensive.

Question 3

Other than trauma, second most common reason for transfusions?

Answer 3

Anaemia- destruction- production- consumption/loss. Animals with a haematocrit level of 9, normal is 40

Question 4

Canine blood donor

Answer 4

Good temperment (lay down for 5-10 minute), volume removed from jugular vein- reasonably visible, no other health problems, vaccinated, >25 kg to allow collection of full unit (450 ml), negative for blood borne disease in your area, should never have received a transfusion, blood typed

Question 5

Feline Blood donor

Answer 5

> 5kg body weight (for 50 mL to be collected), no other health problems, FeLV/FIV/Mycoplasma negative, Ideally indoor cat, donors of both blood groups required

Question 6

Blood types, difference in cats and dogs when it comes to transfusion reactions?

Answer 6

Antigens on the surface of RBCs, circulating antibodies to the antigens must already be present for a transfusion reaction to occur

• *Dogs do not have naturally occurring alloantibodies (antibodies that are already circulating)– they would only produce those if they had a transfusion in the past
• *Cats DO have naturally occurring alloantibodies

Question 7

How many blood types in dogs? Examples?

Answer 7

8 blood tops
Dog erythrocyte antigen system (DEA) DEA 1.1, 1.2, 3, 4, 5, 7 (1.1 is the most antigenic one) All greyhounds are negative
**Universal donor- in other words, negative for all antigens- almost impossible to find- you would have to screen 1000 dogs- not feasible

Question 8

Neg blood–> neg recepient–> ?

Answer 8

No Ab production

Question 9

Pos blood–> neg recepient–> ?

Answer 9

Ab production

Question 10

Pos blood–> sensitised dog–> ?

Answer 10

Haemolytic rxn

Question 11

General rules of thumb- negative blood to who? positive blood to who?

Answer 11

• negative blood to negative or positive recipient

* positive blood to positive recipients

Question 12

Cat blood types

Answer 12

A>B»AB (very rare), type B common in AUS. Always have to type cats because strong alloantibodies especially type B against A antigen. So if you gave A blood to a B cat, it would be destroyed straight away

Question 13

Could you give type A cat, type B blood?

Answer 13

20% of type A cats have weak anti-B antibodies. In theory you could give them B blood.

Question 14

Does a type AB cat have alloantibodies?

Answer 14

No alloantibodies to A or B. Use AB blood or A if AB not available.

Question 15

Cross matching

Answer 15

Mixing donor and recipient blood looking for agglutination or haemolysis
Evaluates compatibility between donor and recipient at that point in time

Question 16

Collection of blood

Answer 16

Animals should be able to donate up to once monthly without becoming anaemic (typical frequency every 3 months), PCV should be checked, physical exam, don’t use animals that are pyrexic
Sterile collection is key- sterile glove, sterile skin prep

Question 17

Open vs. closed system

Answer 17

Only opening is the initial needle stick. Blood is a good breeding ground for bacteria, so very key. Closed system. This is the only way you can store blood.

Question 18

How long can you store blood and with what?

Answer 18

• 21-35 days
• anticoagulant and some nutrients for cells. (citrate, phosphate, dextrose, adenine)- 2,3 DPG and ATP better maintained.
• ADSOL can be used to increase storage time. (additive solution)

Question 19

Why citrate over heparin?

Answer 19

Heparin would make recipient coagulopathic (citrate for fresh whole blood only)

Question 20

Why can’t you store cat blood?

Answer 20

Normally take it with a needle, so not a closed system. You take so much less.

Question 21

How is plasma stored? PCV?

Answer 21

Plasma is frozen, PCV is in the fridge

Question 22

Giving transfusion

Answer 22

Do not warm more than 39C.
Takes time to warm to room temperature.
Water bath at 37C
Start slowly 2-5 ml/hr for 20 minutes to allow early recognition of transfusion reactions. Check patient demeanour and TPR every 5 minutes.
** as fast as you need to in peracute, life threatening situations (3-4 units within an hours if massive bleeding)
** give each unit over 4 hours- check patient every 30 minutes

Question 23

Whole blood used?

Answer 23

When need RBCs, plasma proteins, coag factors, platelets (functional). Best way to give platelets.
Haemorrhagic shock, coagulopathy coupled with anaemia

Question 24

Packed red blood cells given?

Answer 24

Anaemia where intravascular volume is normal (haemolysis e.g. IMHA, decreased production, slow, chronic loss like a GI bleed or fleas)
Given with asanguineous fluids for whole blood loss (crystalloids, FFP)

Question 25

Asanguineous

Answer 25

Resembling blood. Crystalloids, FFP (fresh frozen plasma)

Question 26

Euvolaemia

Answer 26

Normal circulating volume

Question 27

When to give a transfusion?

Answer 27

Especially with acute anaemia, hypovolaemia, factors that affect oxygen delivery are decisive- i.e. Hb, SaO2, Cardiac output

Question 28

When do transfuse based on PCV?

Answer 28

30% best tissue O2 delivery, 20% compromised O2 delivery, 15% increased lactate

Question 29

FFP

Answer 29

Fresh frozen plasma- all clotting factors, antithrombin, and anti-inflammatory proteins. Thaw slowly in warm water bath. Disorders of secondary haemostasis (i.e. rodenticides, SIRs/ sepsis, DIC), 20 ml/kg is a good starting point

Question 30

Frozen Plasma

Answer 30

Loses some clotting factors (mainly V and VIII) and anti-inflammatory proteins. Still provides vitamin K dependent factors II, VII, IX, X

Question 31

Cryoprecipitate

Answer 31

Involves thawing to a slush and then separating- can be stored for a further year. Mainly for vWF and Factor VIII

Question 32

Platelet Rich Plasma

Answer 32

used within 3-5 days. Thrombocytopenic animals- many units needed to provide adequate platelets. Reserved for larger specialty centers.

Question 33

When to transfuse platelets

Answer 33

Difficult to collect and store. FWB is easiest source. Reserved for life threatening bleeding due to thrombocytopenia (intracranial, pulmonary, massive GI bleed, perioperative)