Transfusion Medicine Flashcards
Describe common indications for blood transfusion
- no magic cut off and should be based on clinical signs
- look for signs that are suggestive of reduced oxygen provision to the tissue such as tachycardia, tachypnoea, lethargy, weakness - if can’t walk
- see if normovolaemic
- cats PCV 10-15% does
- dogs PCV 15-20%
What is PCV and what deos low PCV mean
The packed cell volume (PCV) is a measurement of the proportion of blood that is made up of cells.
means red blood cell loss from any variety of reasons like cell destruction, blood loss, and failure of bone marrow production
What deos increased PCV mean
Dehydration
increased PCV generally means dehydration or an abnormal increase in red blood cell production
What must you need to ensure being doing a blood transfusion
Ensure patients are normovolaemic (normal blood volume) before deciding whether to transfuse
Fluid therapy bag of crystalloids much cheaper
If patient has blood loss then what should you transfuse?
Replace with whole blood or, if not available, packed red cells
Whole blood – pet blood bank
If patient has haemolysis what should you transfuse?
Replace with packed red cells
- haemolysis = destroying RBC so NEED RBC as anaemic NOT hypovolaemic so doens’t need the volume
If patient has Coagulopathy what should you transfuse?
Replace with fresh frozen plasma, regular plasma, or cryoprecipitate depending on the cause
How long can you store whole blood for?
up to 3 weeks
What do you have to think about when doing a blood transfusion with cats and dogs
What is the patient’s blood type?
Ideally give type-specific blood to dogs
Imperative to give type-matched blood to cats prior to transfusion
If in doubt about dog’s blood type what should you administer?
If in doubt administer DEA 1 –ve blood to dogs
What happens if you don’t blood match?
Can lead to a type 2 hypersensitivity/ haemolytic reaction reaction = haemolysis
Antibodies against Ab on RBC membrane, remove RBC
What does a dog with DEA 1+ve mean?
it has DEA +ve antigens on its RBC so must only receive DEA +ve blood, otherwise will induce a type 2 hypersensitivity reaction
What does a dog with DEA 1 -ve mean
RBC don’t have any antigens on their surface so is a universal blood donor and universal blood acceptor
If you have given a DEA 1 -ve dog a DEA +ve blood transfusion what happens….
in 3-5 days will produce antibodies so blood transfusion may not last as long as normal (month in dogs, bit less in cats) But will be enough to save its life
You have DEA -ve dog that needed a transfusion.
Received DEA +ve blood.
a week later it needs another transfusion..
By this point the DEA-ve dog will have generated antibodies against DEA1+ve
Therefore if gave +ve would cause acute haemolysis = could kill!
