Transfusion

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Transfusion Medicine
Sarah Haldane, BVSc, MACVSc Jennifer Roberts, DVM Steven L. Marks, BVSc, MS, MRCVS, DACVIM Marc R. Raffe, DVM, MS, DACVA, DACVECC
University of Illinois

ABSTRACT:

Transfusion therapy is indicated in patients with many different diseases and conditions, including anemia, hemorrhage, coagulopathy, andhypoproteinemia. After whole blood is collected from a donor animal, it may be administered immediately or fractionated into its component parts (e.g., packed red blood cells, fresh-frozen plasma, cryoprecipitate, platelet products).Transfusion reactions may manifest as complications of blood product administration. However, selecting the appropriate blood product and carefully collecting, storing, andhandling blood, in combination with blood-typing and crossmatching, can decrease the risk of transfusion reactions.

here are many indications for transfusion therapy in veterinary practice, and with the increased availability of blood products, it is becoming more widespread. Fractionating whole blood into its component products has made it easier to treat a broad range of conditions when donorsare not available. Blood components accessible to veterinarians include fresh and stored whole blood, packed red blood cells (pRBCs), fresh-frozen plasma (FFP), cryoprecipitate, and platelet products. However, administering blood products is not a benign procedure. Red blood cells (RBCs) are very antigenic and can promote a significant immune response. 1 Administering foreign proteins, leukocytes,or platelets may also stimulate the immune system.2 The appropriate blood product should be selected based on maximum benefit with minimum risk to the patient.
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SELECTING BLOOD DONORS Blood donors should be healthy adult (i.e., 2 to 8 years

of age) dogs and cats. Dogs should weigh morethan 66 lb (30 kg); have a packed cell volume (PCV) of 40% or more; be fully vaccinated; and be free of heartworm infection, brucellosis, and tick-borne diseases (e.g., Ehrlichia canis, Babesia canis, Rickettsia rickettsi, Borrelia burgdorferi infections).3 It is also recommended that canine donors test negative for dog erythrocyte antigen (DEA) 1.1 (universal donors would also need to testnegative for DEA 1.2 and 7).4,5 Purebred and crossbred Akitas have high levels of intracellular potassium in their RBCs and should not be used as blood donors.6 Cats should weigh more than 11 lb (5 kg), be lean, and preferably be shorthaired. Feline donors should have a PCV greater than 35%; be fully vaccinated; and be free from FeLV, FIV, Toxoplasma gondii, and Hemobartonella felis (now calledMycoplasma hemofelis) infections. Cats should be blood typed before blood collection.5,7 Withdrawal of 10% to 20% of the blood volume from a blood donor should not result in clinically significant anemia. An 11-lb (5-kg) cat may have 50 to 60 ml of blood collected in
July 2004

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one donation, whereas a 66-lb (30-kg) dog may have 450 ml of bloodcollected. Hypovolemia can result if 20% or more of the blood volume is withdrawn; if this occurs, administering IV fluids is indicated. Blood should not be collected more than once every 4 to 6 weeks.8

Crossmatching a
• Collect serum and EDTA blood samples from the donor and recipient (at least 1 ml in each sample). • Separate the serum and RBCs into separate labeled tubes. • A whole-bloodtransfusion requires both a major and minor crossmatch, whereas transfusion of pRBCs requires only a major crossmatch.
Major Crossmatch

Canine Blood Groups Nine blood groups (i.e., DEA 1.1, 1.2, 1.3, 3, 4, 5, 6, 7, 8) have been identified in dogs.9 The most clinically significant are DEA 1.1 and 1.2.10 Spontaneously occurring antibodies (i.e., alloantibodies) to these antigens have not been...