Exam 1 - Transfusion Medicine Flashcards
how are blood groups defined?
defined by the inherited antigens on the surface of the red blood cell that are SPECIES SPECIFIC & vary in immunogenicity & clinical significance
important to know for immunologic transfusion reactions!
what are the most significant blood types in dogs?
dog erythrocyte antigen 0 DEA 1.1 & DEA 1.2
what dog blood type is extremely antigen?
DEA 1.1
how many blood group types are recognized in canines?
7+
what is the Dal part of canine blood types?
separate antigen with no correlation to known DEA antigens - needs further investigation to determine its significance
do you expect a transfusion reaction if you give a recipient DEA 1.1+ dog donor DEA 1.1+ blood?
no response
do you expect a transfusion reaction if you give a recipient DEA 1.1+ dog donor DEA 1.1- blood?
nope
do you expect a transfusion reaction if you give a recipient DEA 1.11 dog donor DEA 1.1+ blood?
YES - antibody formation!!!!!!
do you expect a transfusion reaction if you give a recipient DEA 1.1- dog donor DEA 1.1- blood?
no response
what are the blood types we see in cats?
type A, type B, & type AB
what cat blood type do you have to be careful with blood transfusions?
type B cats have a strong, potentially fatal reaction to type A donors
what is the MiK antigen in cat blood types?
newly discovered antigen independent of the AB system that may contribute to hemolytic reactions in typed patients
what antibodies do cats with type A (A antigen) blood have?
anti-B antibody
what antibodies do cats with type B (B antigen) blood have?
anti-A antibody
what is the desirable donor blood type of horses? why?
AaCa - most common blood type & less likely to have circulating antibodies
T/F: a small percentage of horses have naturally occurring antibodies making them a poor donor
true
what is the donkey factor?
auto-antibody present in many horses so donkeys shouldn’t receive horse plasma unless they are pre-screened!!!
for large animal blood transfusions, which animals are compatible & which aren’t?
alpacas & llamas are COMPATIBLE
sheep & goats are NOT compatible
pigs are only compatible with pigs
what situations should blood typing be done for companion animals?
recommended for all canine & feline patient red cell transfusions & plasma cell transfusions for cats
what do blood typing tests look for?
visible hemagluttination reaction between patient RBC antigens & a known reagent antisera
what bed-side blood typing tests are available for companion animals?
canine DEA 1.1 & feline type A, type B, & type AB
why do we use blood typing in horses?
used to select donors - want AaCa with no alloantibodies
also used to screen mares for NI 30 days before parturition
what is a major cross match? how is it done?
major cross match is used for detecting antibodies in recipient plasma
mix the donor RBC with recipient plasma & evaluate for agglutination
what is a minor cross match? how is it done?
minor cross match is used to detect antibodies in donor plasma
you mix the donor plasma with the recipient RBC & evaluate for agglutination
how is cross matching done in horses?
same as companion animals but you also check for hemolysins by adding the complement - one commercially available equine cross match kit
what blood typing do we do for ruminants? why?
don’t routinely type the donor, but ideally the donors would be j-factor negative
T/F: usually, ruminants get one ‘free’ transfusion before sensitization occurs
true - subsequent transfusions may be more rapidly broken down
when is cross-matching recommended prior to giving a blood transfusion?
patient has an unknown transfusion history
patient has had a hemolytic reaction on a prior transfusion regardless of a time lapse
more than 3 days since prior transfusion
if the patient is a donkey, mule, or hinny
recipient horse that is known AaQa negative - they are more likely to have naturally occurring alloantibodies
when doing a whole blood transfusion, what happens to the blood collected after 24 hours?
loss of coagulation factors & platelets
how long do anticoagulant products last when collecting whole blood?
sodium citrate - 24 hours
ACD - 3 weeks
CPDA - 5 weeks
what receptacle is best used when collecting blood from a donor animal for a transfusion?
plastic bags are better than glass bottles because glass will activate platelets
what is the effect of storage on whole blood products?
decreased oxygen release to tissues because of decreased 2-3 DPG (significant after 10 days of storage)
2-3 DPG can take 4-24 hours to be restored
hyperkalemia
how much blood can a donor horse give?
20ml/kg every 3 weeks
if you are considering doing a blood transfusion for a horse in acute need, what parameters are you looking at?
clinical signs & lactate (NOT PCV/TP!!!!!!!)
how much blood do you give to a horse with a chronic illness for a transfusion?
0.08 X BWkg X [(PCV desired - PCV recipient)/(PCV donor)
when are packed red blood cells indicated for a transfusion?
treatment of anemia - deficiency of red blood cells or hemoglobin (anemia may be well-tolerated, acute vs. chronic)
T/F: no transfusion trigger has been identified in veterinary medicine
true
what are the different formulas used for dosing packed red blood cells for transfusions in dogs?
volume administered = 90 ml/kg X BWkg X [(desired PCV - actual PCV)/(donor PCV)]
volume administered = 1.5mL X desired % increase in PCV X BWkg
10-20 ml/kg
what are your options to wash RBC for foals with neonatal isoerythrolysis?
cell saver, centrifuge, & sedimentation
what blood product should you use for a foal with neonatal isoerythrolysis?
use the DAM RBC - washed red blood cells
why do we see a decrease in regeneration in an animal that received a blood transfusion?
if you give them enough blood to restore their normal PCV, this decreases their own regenerative response
T/F: donor RBCs will have a shorter life span
true
T/F: increased volumes used for transfusions are associated with a greater potential for transfusion reactions
true
what is the dose used for plasma transfusions?
10-20 ml/kg
how long can plasma be stored as a blood product?
stored for 1 year & can be thawed & re-frozen within 1 hours
how is fresh frozen plasma collected?
removed from the RBC & frozen within 24 hours - contains therapeutic levels of labile & non-labile factors
what is the most common indication of plasma transfusions for horses? what are some other examples of times you would give it?
failure of passive transfer in the neonate (foal)
boutique plasma in farms with endemic diseases - plasma containing r. equii antibodies
administration of boutique plasma in specific disease - west nile & botulism
enterocolitis with protein loss - palliative measure
what are some indications for a platelet transfusion?
<10,000 platelets
<20,000 with active bleeding
<50,000 with a planned invasive procedure
documented thrombocytopathia
what is an autotransfusion?
collecting autologous blood from a cavity, filtering it, & returning it to the patient’s vascular space
T/F: transfusion reactions are uncommon in horses & ruminants
true
when do we see transfusion reactions in dogs?
3.3-13% in dogs receiving pRBCs or fresh whole blood
we use conservative or restrictive methods have been documented to decrease incidence of reactions
what is the most common immunologic transfusion reaction seen?
non-hemolytic febrile reaction
followed by hemolytic reactions
why do non-hemolytic febrile transfusion reactions occur? what is it defined as? what do you do for your patient if it happens?
result of proteins & WBCs in unit - increase in patient’s temperature by 1°C, but typically self-limiting
discontinue transfusion & wait for resolution & then restart the transfusion at a slower rate
why do hemolytic transfusion reactions occur? what is it defined as? what do you do for your patient if it happens?
incompatibility with RBC - patient develops hemoglobinemia, hemoglobinuria, & shock
discontinue transfusion & cross-match the patient to a new unit
animals with kind of disease have a greater risk for transfusion reactions?
patients with immune-mediated disease
what was the effect of premedication for patients receiving a blood transfusion?
administration of diphenhydramine and/or corticosteroid did not decrease occurrence - but diphenhydramine did reduce the occurrence of type I hypersensitivity reactions (allergic)
what premedication is used for horses before a blood transfusion? is there any risks associated with this?
horses & foals - flunixin meglumine often given
nephrotoxicity from flunixin is a concern
what monitoring is done during transfusions?
temperature, heart rate, & respiratory rate taken every 10 minutes for the first 30 minutes & then at every hour starting at an hour until the transfusion is finished
what is the maximum rate of a transfusion?
total volume to be given / 3.4125
what is the transfusion rate you use for the first 20 minutes? what about the following 40 minutes?
max rate / 4
max rate / 2
what is the target amount of time you should aim for when doing a blood transfusion?
done over 4 hours
what can you do for anemic puppies & kittens?
they typically are anemic due to intestinal parasites - bitch or queen are excellent donors, but for sure type the queen & kittens
T/F: in horses, you can easily sediment & remove red blood cells by letting a bag hang for 3-4 hours
true - acid-citrate dextrose bags
appropriate for storage from 21-28 days
when would you see an immediate transfusion reaction in a cat in regards to giving specific blood types?
doing a major cross match & the donor has A antigens & the recipient is type B & has B antigens & will immediately form anti-A antibodies
in doing a minor cross match, when would you see an immediate transfusion reaction in cat blood types?
donor has a-antigens & anti-b antibodies & the recipient is a type B cat
why may an animal have a delayed reaction on the next blood transfusion?
the first transfusion the animal becomes sensitized & forms antibodies
