Blood Transfusion Flashcards
What are some common diseases that may benefit from blood transfusion therapy?
Hypovolaemic anaemia
Euvolaemic anaemia
Coagulopathies
Thrombocytopaenia and thrombopathia
Hypoalbuminaemia
What are the clinical signs of anaemia?
- Weakness
- Tachycardia
- Tachypnoea
- Indirect measures of poor oxygen delivery, such as high blood lactate
What are the blood products available for dogs?
- Whole blood
- Packed red blood cells (PRBCs)
- Fresh frozen plasma and frozen plasma
- Cryoprecipitate and cryoprecipitate poor plasma
How are blood products obtained for cats?
Feline blood banks are currently in their infancy so difficult to rely on these. Whole blood is more commonly obtained locally - cats of consenting clients, local donor colonies, animal blood register donors
What is fresh whole blood?
Used soon after collection, under 6 hours. Contains physiological concentrations of red blood cells, some functional platelets, proteins and coagulation factors
What is stored whole blood?
Over 8 hours of collection, no functional platelets, loss of labile clotting factors – V, VIII, vWF.
What is packed red blood cell blood product?
Separated from plasma by centrifugation. The PCV is higher than of whole blood, usually 70-80%.
What is fresh frozen plasma?
Stored at -20 to -40˚C for less than 1 year. Contains all coagulation factors and physiological concentrations of albumin and other plasma proteins.
What is frozen plasma?
FFR that is over a year older or that has thawed and been re-frozen. Stable coagulation factors will remain. Labile factors will be lost – V, VIII, vWF. Stored at less than -18˚C for up to 5 years.
What is cryoprecipitate?
Is made by slowly and partially thawing fresh frozen plasma which is then centrifuged again. The cryoprecipitate is the precipitate collected from this second centrifugation. Rich in fibrinogen, VIII and vWF.
How do you decide which blood product for patient?
It is ideal to use the product that most closely replaces what is missing. This can reduce the likelihood of transfusion complications and also allows a blood product to be most effective.
Which is the blood product is ideal for a patient with blood loss anaemia?
Fresh whole blood is ideal, can also use stored whole blood and packed red blood cells
Which is the ideal blood product for a patients with euvolaemic anaemia?
Packed red blood cell, as not looking to replace volume, but replace cells being destroyed by immune system. Can use whole blood but may have volume overload. Others are inappropriate as they do not contain RBCs.
Which blood product is ideal to use in a patient with thrombocytopenia/thrombocytopathia?
Fresh whole blood
Which blood product is ideal to use in a patient with an unknown coagulopathy?
Fresh frozen plasma is ideal, can also use fresh whole blood
What is the ideal blood product for a patient with rodenticide toxicity?
Frozen plasma is ideal, can also use fresh frozen plasma
What is the ideal blood product to use for a patient with Von Willebrands or Haemophilia A?
Cryoprecipitate is ideal, can also use fresh whole blood or fresh frozen plasma
What are the clinical signs of a transfusion reaction?
Fever
Tachycardia
Dyspnoea
Muscle tremors
Vomiting
Weakness
Collapse
Haemoglobinaemia
Haemoglobinuria
What are the canine blood types?
DEA (dog erythrocyte antigen)
Dal positive
What are the DEA types?
1, 3, 4, 5 and 7. A dog can positive or negative for each of these
What is particular about DEA 1?
Most antigenic
Only DEA that we can type for in clinical practice
Dogs possess no naturally occurring antibodies against DEA 1
Which dogs are Dal negative?
Most dogs are Dal positive. Dalmatians are Dal negative
How are dalmations given blood transfusions?
Ideally it would be from another dalmatian or they will need to be cross matched
How should DEA1 patients be transfused?
DEA1 negative dogs should only receive DEA1 negative blood
DEA1 positive dogs can receive either 1 positive or negative blood
Why can the first blood transfusion in dogs be untyped?
As dogs do not possess naturally occurring alloantibodies, the 1st transfusion could be untyped, although delayed reactions can still be seen
How should dogs be given blood transfusions in an emergency?
DEA1 negative blood can be given to an untyped recipient. Do not forget to collect a blood sample prior to the emergency transfusion
What does the plasma of a DEA1 negative dog with previous exposure to DEA1 positive blood contain?
Red blood cell does not possess DEA1 antigen, but its plasma does contain anti-DEA1 antibodies.
What occurs when a DEA1 negative dog is exposed to DEA1 positive blood?
Over the course of a few days it will develop anti-DEA 1 anti-bodies. If the patient is exposed to DEA 1 positive blood for a second time, it will have a transfusion reaction.
What are the 3 blood types in cats?
A, B and AB
Do cats have naturally occurring alloantibodies?
Yes. Antibody formation does not require prior exposure through transfusion or pregnancy. The antibodies may cause fatal transfusion reaction upon first transfusion and are also responsible for neonatal isoerythrolysis.
How are feline patients given blood transfusions?
Ideally be given blood which matches their blood type. When AB is not available for an AB patient, type A is the next best choice
How are feline blood transfusions given in an emergency?
As transfusion mismatches can be fatal, all donors and recipients will need to be typed, even in an emergency.
Distinguish major and minor crossmatching.
Major – the recipient’s serum and donors RBCs
Minor – the donor’s serum and the recipients RBCs
When should crossmatching be performed?
- Received a transfusion more than 4 days ago
- History of a transfusion reaction
- Transfusion history is unknown
- Previously pregnant
- Ideally all feline transfusions
- Dalmatians
How can obtain the blood product I need?
Pet blood banks
Local collection
What should all good animal donors be?
- Should be healthy and generally between 1-8 years of age
- No history of travel
- Should be receiving routine preventative health care
- Should have never received a transfusion
- Should have good jugular veins
What should canine donors be?
- Large (over 25kg) and well-tempered
- Should have clear disease screens? (cost-benefit analysis for dogs)
What should feline donors be?
- Large (over 5kg), BCS 4-6/9
- Must be blood typed
- Should have clear disease screens
How do administer the product?
Every 15-30mins during and 1, 12 and 24 hours after a transfusion:
What should be monitored following blood transfusion?
Attitude/mentation
Rectal temperature
Pulse rate and quality
Respiratory rate and character
Mucous membrane colour and CRT
Plasma and urine colour
When should packed cell volume and total solids be checked?
Prior to, upon completion and 12 to 24 hours following transfusion
What are the 2 types of immunologic transfusion reaction?
Antigen-antibody sensitivity reaction - IgG and IgM mediated
Allergic/hypersensitivity reaction - IgE mediation
Describe antigen-antibody sensitivity reaction.
Haemolytic, fever, mild-severe, tachycardia. dyspnoea, muscle tremors, vomiting, weakness, collapse, intra/extravascular haemolysis.
Describe allergic/hypersensitivity reaction.
Not haemolytic, no fever, mild, pruritis, urticaria, erythema, angioedema, vomiting, dyspnoea, anaphylaxis rare
What are the non-immunologic transfusion reactions?
Volume overload
Citrate intoxication
Bacterial contamination of the unit
What do you do in the face of transfusion reactions?
- Stop the transfusion
- If signs of distributive shock = fluid resuscitation
- If hypersensitivity reaction = anti-histamines
- Bacterial contamination = sample for microbiology, treat with broad spectrum IV antibiotics
- Dyspnoea = oxygen
- Check patient and product for evidence of haemolysis
- Intravascular haemolysis = monitor renal function
- Signs of volume overload = slow infusion rates, diuretic therapy
