Blood Transfusions

Question 1

what blood products are available to dogs?

Answer 1

whole blood
packed RBCs
fresh frozen and frozen plasma
cryoprecipitate and cryoprecipitate poor plasma

Question 2

what blood products are available for cats?

Answer 2

no pet blood banks stock feline blood products - whole blood can be obtained locally

Question 3

where cat feline blood products be obtained from?

Answer 3

cats of consenting clients, friends, family, colleagues
local donor colonies
donors from the animal blood register

Question 4

when is whole blood considered fresh?

Answer 4

<6 hours after collection

Question 5

what does fresh whole blood contain?

Answer 5

physiological concentrations of RBCs

some functional platelets, proteins and coagulation factors

Question 6

what is stored whole blood?

Answer 6

blood used >8 hours after collection

has no functional platelets
lost labile clotting factors

Question 7

how should stored whole blood be stored?

Answer 7

between 2-6°C maximum 21 days

Question 8

how are packed RBCs separated?

Answer 8

by centrifugation

Question 9

what is the PCV of packed RBCs?

Answer 9

70-80%

Question 10

how should PRBCs be stored?

Answer 10

similarly to whole blood

expires ~42 days after extraction

Question 11

what does fresh frozen plasma contain?

Answer 11

all coagulation factors

physiological concentrations of albumin and other plasma proteins

Question 12

how should FFP be stored?

Answer 12

-18°C <1 year

Question 13

what is frozen plasma?

Answer 13

FFP that is >1 year old or that has thawed and been re-frozen

Question 14

how does frozen plasma differ from FFP?

Answer 14

stable coagulation factors will remain but labile factors will be lost e.g. VIII and vWF

Question 15

how should frozen plasma be stored?

Answer 15

-18

5 years

Question 16

how is cryoprecipitate formed?

Answer 16

by slowly and partially thawing FFP which is then centrifuged again - cryoprecipitate is then collected from this second centrifugation

Question 17

what does cryoprecipitate contain?

Answer 17

rich in fibrinogen, VIII and vWF

Question 18

which common diseases may benefit from transfusion therapy?

Answer 18

hypovolaemic anaemia
euvolaemic anaemia (immune-mediated haemolytic anaemia)
coagulopathies

thrombocytopaenia/thrombopathia/
hypoalbuminaemia unlikely to see long term positive effect

Question 19

when would we consider transfusing an anaemic patient?

Answer 19

if there are clinical signs of anaemia - weakness, tachycardia, tachypnoea, high blood lactate

Question 20

what are the symptoms of a transfusion reaction?

Answer 20

fever 
tachycardia 
dyspnoea 
muscle tremors
vomiting 
weakness 
collapse 
haemoglobinaemia and haemoglobinuria

Question 21

what antigens can be present in canine blood?

Answer 21

dog erythrocyte antigen (DEA) - 1, 3, 4, 5, and 7

Question 22

which blood antigen is the most antigenic?

Answer 22

DEA 1 - typed for in clinical practice

Question 23

do dogs possess antibodies against DEA 1?

Answer 23

dogs possess no naturally occurring antibodies against DEA 1

Question 24

how are dalmatians different?

Answer 24

they are Dal negative - cannot be typed for in-house

blood must come from another Dalmatian or need to be cross-matched

Question 25

what type of blood should DEA 1 negative dogs receive?

Answer 25

only DEA 1 negative

Question 26

what type of blood should DEA 1 positive dogs receive?

Answer 26

DEA 1 positive or negative blood

Question 27

what type of blood can be given in an emergency to an untyped recipient?

Answer 27

DEA 1 negative

Question 28

why can a dogs first transfusion be untyped?

Answer 28

dogs do not possess naturally occurring alloantibodies

Question 29

what is always important to consider with subsequent transfusions in dogs?

Answer 29

regardless of blood typing and appropriate transfusion, subsequent transfusions can still lead to reactions due to sensitisation to the remaining DEAs or other RBC antigens

Question 30

what are the 3 blood types of cats?

Answer 30

A B AB

Question 31

why must cats always be cross matched for blood type?

Answer 31

naturally occurring alloantibodies are present in plasma without prior exposure through transfusion or pregnancy

Question 32

what blood should a type AB cat be given if AB blood is not available?

Answer 32

type A blood - has anti-B alloantibodies but they are weak and low in number

Question 33

why is cross matching performed?

Answer 33

used to determine the serological compatibility between blood - looks for signs of agglutination

Question 34

what is mixed in a major crossmatch?

Answer 34

recipients serum and donors red blood cells

Question 35

what is mixed in minor crossmatch?

Answer 35

donors serum and recipients red blood cells

Question 36

cross-matching should be performed when...

Answer 36

the recipient has received a transfusion >4 days ago there has been a history of transfusion reaction transfusion history is unknown recipient has been previously pregnant ideally all feline transfusions all dalmatians

Question 37

what criteria should donors meet (dogs and cats)?

Answer 37

healthy, 1-8 years of age no history of travel should be receiving routine preventative healthcare should never have received a transfusion should have good jugular veins

Question 38

how large should canine blood donors be?

Answer 38

>25kg

Question 39

how large should feline blood donors be?

Answer 39

>4kg, BCS 4-6/9

Question 40

what additional criteria should feline blood donors meet?

Answer 40

must be blood typed should have 'clear' disease screens - FIV, FeLV, mycoplasma haemofelis ideally only indoor cats

Question 41

what are the volume limits for donation?

Answer 41

dogs - 15ml/kg | cats - 10-12ml/kg

Question 42

what should cats be given post-donation?

Answer 42

IVFT replacement - isotonic crystalloids at double volume of blood collected

Question 43

what is the disadvantage of open donation?

Answer 43

1+ additional sites of potential bacterial contamination

Question 44

what are the advantages/disadvantages of closed donation?

Answer 44

a - longer shelf life, less exposed to contaminants | d- only suitable for large dogs

Question 45

how do you administer blood products?

Answer 45

visually inspect the bag frozen products should be gently thawed administer IV using blood giving sets/normal giving set with filter record baseline patient parameters and monitor throughout

Question 46

how much blood should be transfused?

Answer 46

10-20ml/kg (approx 1% increase in PCV for each 2ml/kg of whole blood given)

Question 47

how rapidly should blood products be given?

Answer 47

1ml/kg/hr for 20 mins (allow early recognition of transfusion reactions) rest over 4-6 hours

Question 48

can patients be fed during transfusion?

Answer 48

no - may cause vomiting, may confuse with transfusion reaction

Question 49

can you administer any other drugs through the transfusion catheter?

Answer 49

no - only 0.9% saline | could cause haemolysis/blood clots

Question 50

how often should transfusion patients be monitored?

Answer 50

prior to transfusion every 15-30 mins during 1, 12, and 24 hours after transfusion

Question 51

which parameters should be monitored before/during/after transfusion?

Answer 51

``` mentation rectal temperature pulse rate/quality RR and character MM colour and CRT plasma and urine colour ```

Question 52

when should PCV/TS be tested?

Answer 52

prior to, upon completion and 12-24 hours following transfusion

Question 53

what types of immunologic transfusion reactions are there?

Answer 53

antigen-antibody sensitivity reaction cytokines from product storage/leukocytes within product allergic/hypersensitivity reaction (IgE mediated)

Question 54

give some examples of non-immunologic transfusion reactions

Answer 54

``` volume overload citrate intoxication coagulopathy/thrombosis ammonia intoxication bacterial contamination of the unit pre-transfusion haemolysis ```