Transfusion medicine (Yr 3) Flashcards
how should you determine if a patient needs a blood transfusion?
clinical signs of reduced oxygen perfusion (tachycardia, tachypnoea, lethargy…)
what should you ensure is normal before giving a blood transfusion?
normovolaemic
what blood product should be used in cases of haemolysis?
packed red cells
what blood product should be used in cases of coagulopathies?
fresh frozen plasma
regular plasma
cryoprecipitate
(depends on the cause)
what is the difference between fresh frozen plasma and frozen/regular plasma?
frozen plasma doesn’t contain vWF or factor IIX as they breakdown over the time it is being stored for
how long can whole blood be stored by a practice?
<21 days
what blood type should be given to a dog if you haven’t specifically matched the type?
DEA negative
do cats have to have type-matched blood?
yes (will kill it if it isn’t)
what type of hypersensitivity is caused if the blood type doesn’t match?
type 2 (antigen/antibody)
when will haemolysis of a transfusion occur?
if the donor has antibodies to the antigens found on the donor RBCs
who can DEA negative dogs donate a receive blood from?
they can donate to any
they can receive from any (only for the first transfusion)
what is the difference between a naive and sensitised DEA negative dog?
naive - first time receiving transfusion so will accept it
sensitised - after it has received DEA positive blood once it will create antibodies and haemolysis will occur if you give it again
what is DEA?
dog erythrocyte antigen
why are greyhounds very good blood donors?
they are always DEA negative
what is cats blood typing based on?
A/B system (A is dominant to B)
can you give type B cats type A blood?
no (this is BAd) it will cause severe acute haemolytic reaction
can you give type A cats type B blood?
yes (not As Bad) as it will cause a milder more delayed reaction
what can cause a cassette blood type test not to work?
auto-agglutination meaning the blood doesn’t move down the cassette (wash in saline)
what is crossmatching?
used to detect more haematological incompatibilities than just doing blood typing
what are the two types of crossmatching?
major
minor
what is a major crossmatch?
recipient has antibodies to the donor RBCs so don’t give transfusion
what is a minor crossmatch?
donor blood has antibodies against recipient RBCs (you can transfuse)
when should a patient be crossmatched?
if they have had a previous transfusion more than 3 days ago
what is a restrictive and liberal transfusion target?
restrictive - PCV 21-25%
liberal - PCV 35-45%
what has be used to give blood products?
a transfusion set with an inline filter (drip-by-drip better)
how fast should a blood transfusion be given?
1ml/kg/hr for first 30 minutes
5ml/kg/hr after 30 minutes
should you warm blood products prior to transfusion?
no (only at room temperature) will damage RBCs and increase likelihood of sepsis
how can transfusion reactions be categorised?
haemolytic
respiratory
non-haemolytic
what are the features of an acute haemolytic transfusion reaction?
happens within minutes
severe clinical signs… tachycardia, tachypnoea, nausea, vomiting, haemoglobinuria, death
what should be done if a patient is having a haemolytic transfusion reaction?
stop transfusion (it is due to an incompatible crossmatch)
what are the two types of haemolytic transfusion reactions?
acute and delayed
what are the features of a delayed haemolytic transfusion reaction?
milder slower haemolysis due to a mild antibody reaction
jaundice and bilirubinaemia with a slow reduction in PCV
how do non-haemolytic anaphylactic transfusion reactions present?
vomiting, nausea, panting, tachycardia, pyrexia
what should be done in cases of a non-haemolytic anaphylactic transfusion reaction?
pause transfusion (or slow rate)
can give maropitant
what are the types of non-haemolytic transfusion reactions?
pyrexia/anaphylaxis
citrate toxicity
sepsis
