Transfusion Flashcards
What is contained in cryoprecipitate
- vWF
- FXIII
- FVIII
- Fibrinogen
What is the shelf life of platelet concentrates
5 days
What is the definition of massive transfusion
Transfusion of:
- Patient’s blood volume in 24h
- 50% of patient’s blood volume in 3 hours
- 1.5 mL/kg/min (90 mL/kg/h) of blood products for 20 min
- 150% of patient’s blood volume regardless of time
What are the storage conditions of: fresh whole blood, stored whole blood, pRBC, FFP, frozen plasma, liquid plasma (refrigerated plasma), cryoprecipitate, cryopoor plasma, platelet-rich plasma, platelet concentrate, lyophilized platelets, canine albumin
- FWB: up to 24 at room temperature under agitation (with preservatives)
- Stored WB: 28-35 days at 2-6°C (with preservatives) ; platelets active for 21 days
- pRBC: 35-42 days at 2-6°C (with preservatives)
- FFP: <-30°C for 1 year
- Frozen plasma: <-30°C for 5 years
- Liquid plasma: 2-6°C for 14 days
- Cryoprecipitate: <-30°C for 1 year
- Cryo-poor plasma: <-30°C for 1 year
- PRP: room temperature under agitation for 5 days
- Platelet concentrate: room temperature under agitation for 5 days ; or cryopreserved in DMSO -> -80°C for 1 year or -20°C for 6 months
- Lyophilized platelets: room temperature for 1 year
- Canine albumin: room temperature for 2 years
What coagulation factors are lost between FFP and frozen plasma / during storage of whole blood?
- Storage of frozen plasma: factors VIII and X
- Storage of whole blood: factors V and VIII
What is the formula to calculate volume of pRBC to transfuse based on the desired PCV
V (mL) = [(desired PCV - patient PCV) / donor unit PCV] * blood volume (L/kg) * BW (kg)
(Or V = desired PCV rise * 1.5 * BW)
What is the formula to calculate dose of canine albumin to transfuse based on the desired albumin
Dose (g) = 10 * (desired albumin - patient albumin) * BW (kg) * 0.3
What are platelet-containing blood products? By how much do they raise platelets?
- Fresh whole blood
- Stored whole blood
- Platelet rich plasma
- Platelet concentrate (fresh or cryopreserved)
- Lyophilized platelets
10 mL/kg of fresh whole blood raises PLT by 10x10^9/L
1 unit of PRP contains 80x10^9 platelets
What is the max delay between collection and freezing for FFP
8 hours
How much plasma is required to increase albumin by 1 g/dL
45 mL/kg
What type of hypersensitivity can happen with transfusion of human albumin to dogs
Type III hypersensitivity
What is the CPD:blood ratio for blood collection
About 1:7-1:8 (63-70mL in 450-500mL of blood)
What are indications for cryoprecipitate transfusion
- Hemophilia A
- vWD
- Hypofibrinogenemia
Name 3 canine RBC antigens
- DEA (dog erythrocyte antigen)
- Kai
- Dal
For what DEA blood groups can dogs have naturally occurring alloantibodies
DEA 3, DEA 5, DEA 7
What blood groups can cause an AHTR in sensitized dogs
DEA 1, DEA 4 (but >99% dogs are positive), Dal
What are the 3 breeds with the most Dal negative dogs
- Dalmatians (12%)
- Dobermand Pinschers (42%)
- Shih Tzus (57%)
What are blood groups where negative phenotype is more prevalent than positive
DEA 3 and DEA 5
(DEA 1 and DEA 7 are variable but can be close to 50%)
What breeds have more type B cats
- Devon Rex
- Cornish Rex
- British Shorthair
- Exotic Shorthair
- Turkish Van
What naturally occurring alloantibodies do cats have
- Type A cats have no or weak (IgG and IgM) naturally occurring anti-B alloantibodies
- Type B cats have strong IgM naturally occurring anti-A alloantibodies
- Cats can have naturally occurring anti-Mik alloantibodies
What is the breed over-represented for type AB cats
Ragdoll
True or false: Blood typing is required for plasma products in cats
True.
Cats have naturally occurring alloantibodies which will be present in the plasma of donors (not true for dogs)
What is the recommended time post-transfusion after which a crossmatch is recommended in dogs and cats
4 days in dogs, 2 days in cats
But some antibodies can develop before that and some will develop later (might still be recommended to repeat crossmatch just before a future transfusion)
What type of immunologic reaction is used in blood typing methods for dogs and cats
Hemagglutination
Briefly described crossmatching methods
- Standard tube method: donor RBC mixed with recipient serum (ideally, otherwise EDTA plasma is fine) in a tube and it is observed for hemolysis and agglutination (semi-quantified). Can be enhanced with addition of antiglobin.
Gold standard, only test looking for hemolysis. - Gel tube assay: donor’s RBC and recipient’s plasma mixed and allowed to migrate through a gel ; agglutinated RBCs get held at the top.
Sensitivity for incompatibilities is not good. - Immunochromatographic strip: donor’s RBC and recipient’s plasma are mixed and allowed to migrate along a strip containing antiglobulin ; RBCs that are coated with antibodies bind to antiglobulin at detection line. Better accuracy.
How to assess hemolysis in a blood unit? What is the acceptable limit for transfusion
% hemolysis = (100-Hct)*(plasma Hb/total Hb)
Can do visually but not reliable
Should be less than 1%
What pathogens should canine and feline blood donors be screened for
- Canine:
- Anaplasma phagocytophilum
- Anaplasma platys
- Babesia canis vogeli
- Babesia Gibsoni
- Bartonella henselae
- Bartonella vinsonii var. berkhoffi
- Ehrlichia canis
- Mycoplasma hemocanis
+/- Brucella canis
+/- Hepatozoon canis
+/- Leishmania donovani (in Foxhounds and travellers)
+/- Rickettsia felis
+/- Neorickettsia risticii
+/- Trypanosoma cruzi
Technically Dirofilaria immitis not part of it because cannot transmit heartworm to recipient but can carry Wolbachia and interfere with diagnostic testing + donor would not be considered healthy -> so should still screen
(Ideally for main pathogens both serology and PCR recommended)
- Feline:
- Anaplasma phagocytophilum
- Bartonella henselae
- Mycoplasma hemofelis
- FIV antibody
- FeLV antigen and PCR
+/- Anaplasma platys
+/- Cytauxzoon felis
+/- Mycoplasma haemominutum
+/- Mycoplasma turicensis
+/- Ehrlichia canis
+/- Neorickettsia risticii
What immunoglobulins are involved in AHTR vs DHTR
- IgM for acute (intravascular hemolysis)
- IgG for delayed (extravascular hemolysis)
What is considered an acute vs. delayed transfusion reaction
- Acute = within 24h
- Delayed = after 24h and within 28 days