Blood Transfusions Flashcards
what blood products are available to dogs?
whole blood
packed RBCs
fresh frozen and frozen plasma
cryoprecipitate and cryoprecipitate poor plasma
what blood products are available for cats?
no pet blood banks stock feline blood products - whole blood can be obtained locally
where cat feline blood products be obtained from?
cats of consenting clients, friends, family, colleagues
local donor colonies
donors from the animal blood register
when is whole blood considered fresh?
<6 hours after collection
what does fresh whole blood contain?
physiological concentrations of RBCs
some functional platelets, proteins and coagulation factors
what is stored whole blood?
blood used >8 hours after collection
has no functional platelets
lost labile clotting factors
how should stored whole blood be stored?
between 2-6°C maximum 21 days
how are packed RBCs separated?
by centrifugation
what is the PCV of packed RBCs?
70-80%
how should PRBCs be stored?
similarly to whole blood
expires ~42 days after extraction
what does fresh frozen plasma contain?
all coagulation factors
physiological concentrations of albumin and other plasma proteins
how should FFP be stored?
-18°C <1 year
what is frozen plasma?
FFP that is >1 year old or that has thawed and been re-frozen
how does frozen plasma differ from FFP?
stable coagulation factors will remain but labile factors will be lost e.g. VIII and vWF
how should frozen plasma be stored?
-18
5 years
how is cryoprecipitate formed?
by slowly and partially thawing FFP which is then centrifuged again - cryoprecipitate is then collected from this second centrifugation
what does cryoprecipitate contain?
rich in fibrinogen, VIII and vWF
which common diseases may benefit from transfusion therapy?
hypovolaemic anaemia
euvolaemic anaemia (immune-mediated haemolytic anaemia)
coagulopathies
thrombocytopaenia/thrombopathia/
hypoalbuminaemia unlikely to see long term positive effect
when would we consider transfusing an anaemic patient?
if there are clinical signs of anaemia - weakness, tachycardia, tachypnoea, high blood lactate
what are the symptoms of a transfusion reaction?
fever tachycardia dyspnoea muscle tremors vomiting weakness collapse haemoglobinaemia and haemoglobinuria
what antigens can be present in canine blood?
dog erythrocyte antigen (DEA) - 1, 3, 4, 5, and 7
which blood antigen is the most antigenic?
DEA 1 - typed for in clinical practice
do dogs possess antibodies against DEA 1?
dogs possess no naturally occurring antibodies against DEA 1
how are dalmatians different?
they are Dal negative - cannot be typed for in-house
blood must come from another Dalmatian or need to be cross-matched
what type of blood should DEA 1 negative dogs receive?
only DEA 1 negative
what type of blood should DEA 1 positive dogs receive?
DEA 1 positive or negative blood
what type of blood can be given in an emergency to an untyped recipient?
DEA 1 negative
why can a dogs first transfusion be untyped?
dogs do not possess naturally occurring alloantibodies
what is always important to consider with subsequent transfusions in dogs?
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
what are the 3 blood types of cats?
A B AB
why must cats always be cross matched for blood type?
naturally occurring alloantibodies are present in plasma without prior exposure through transfusion or pregnancy
what blood should a type AB cat be given if AB blood is not available?
type A blood - has anti-B alloantibodies but they are weak and low in number
why is cross matching performed?
used to determine the serological compatibility between blood - looks for signs of agglutination
what is mixed in a major crossmatch?
recipients serum and donors red blood cells
what is mixed in minor crossmatch?
donors serum and recipients red blood cells
cross-matching should be performed when…
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
what criteria should donors meet (dogs and cats)?
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
how large should canine blood donors be?
> 25kg
how large should feline blood donors be?
> 4kg, BCS 4-6/9
what additional criteria should feline blood donors meet?
must be blood typed
should have ‘clear’ disease screens - FIV, FeLV, mycoplasma haemofelis
ideally only indoor cats
what are the volume limits for donation?
dogs - 15ml/kg
cats - 10-12ml/kg
what should cats be given post-donation?
IVFT replacement - isotonic crystalloids at double volume of blood collected
what is the disadvantage of open donation?
1+ additional sites of potential bacterial contamination
what are the advantages/disadvantages of closed donation?
a - longer shelf life, less exposed to contaminants
d- only suitable for large dogs
how do you administer blood products?
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
how much blood should be transfused?
10-20ml/kg (approx 1% increase in PCV for each 2ml/kg of whole blood given)
how rapidly should blood products be given?
1ml/kg/hr for 20 mins (allow early recognition of transfusion reactions)
rest over 4-6 hours
can patients be fed during transfusion?
no - may cause vomiting, may confuse with transfusion reaction
can you administer any other drugs through the transfusion catheter?
no - only 0.9% saline
could cause haemolysis/blood clots
how often should transfusion patients be monitored?
prior to transfusion
every 15-30 mins during
1, 12, and 24 hours after transfusion
which parameters should be monitored before/during/after transfusion?
mentation rectal temperature pulse rate/quality RR and character MM colour and CRT plasma and urine colour
when should PCV/TS be tested?
prior to, upon completion and 12-24 hours following transfusion
what types of immunologic transfusion reactions are there?
antigen-antibody sensitivity reaction
cytokines from product storage/leukocytes within product
allergic/hypersensitivity reaction (IgE mediated)
give some examples of non-immunologic transfusion reactions
volume overload citrate intoxication coagulopathy/thrombosis ammonia intoxication bacterial contamination of the unit pre-transfusion haemolysis
