Page 135 - ONLINE PROCEEDING BOOK WSAVA 2017
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>40% and >13 g/dl in canine donors.
Blood Collection and Component Preparation
Canine donors are generally not sedated. Blood is collected aseptically by gravity or blood bank vacuum pump from the jugular vein over 5 to 10 minute period. Plastic bags containing citrate-phosphate-dextrose- adenine (CPD-A1) with or without satellite bags for blood component separation are optimal. These commercial blood bags represent a closed collection system in
which the blood does not come into contact with the environment at any time during collection or separation into blood components, thus minimizing the risk of bacterial contamination and allowing storage of the blood products. The maximal blood volume to be donated is 20 ml blood/kg or one regular blood bag unit of 450 ± 45 ml per ≥ 25 kg dog.
Blood components are prepared from a single donation of blood by centrifugation generally within 8 hours from collection; thereby, fresh whole blood can be separated into packed red cells, platelet-rich plasma or concentrate, fresh frozen plasma, and cryoprecipitate and cryo-poor plasma. Fluctuations in storage temperature signi cantly alter the length of storage; thus, temperature needs to
be monitored and the refrigerator/freezer are not too frequently opened. Partially used or opened blood bags should be used within 24 hours because of the risk of contamination.
Administration of Blood Products
For routine transfusion in the treatment of anemia, it is not necessary to warm blood after removal from the refrigerator. A temperature-controlled waterbath (37°C) is ideal to warm frozen blood products. A warm water bowl in which the water is periodically changed may be used to warm blood products. Care should be taken to maintain absolute sterility and to not overheat the blood products.
Blood bags are connected to blood infusion sets that have an in-line micro lter. A long (85 cm) blood infusion set with a dripping chamber and a short infusion set
for small dogs to connect with syringes are available. Use a latex-free infusion sets for platelet administration to avoid aggregation. Micro lter with 170 μm pores are commonly used to remove clots and larger red cell and platelet aggregates. Finer  lters with 40 μm pores will remove most platelets and microaggregates and clog after 100 ml. Leukocyte reduction  lters (expensive) may be used to decrease febrile adverse reactions to WBC components prior to storage.
Blood components are best administered intravenously with an indwelling catheter (16-22 gauge depending
on size of animal). An intramedullary (or intraosseous) infusion at the trochanteric fossa (or other sites) may be used when no venous access can be obtained while the
An Urban Experience
intraperitoneal administration is not recommended. Avoid concurrent administration of drugs or  uids other than physiologic saline through the same catheter in order to prevent lysis of erythrocytes and blood coagulation.
Rate of transfusion depends on the hydration status, degree of anemia, and general health condition of an animal. Initial rate is slow, starting with 1-3 ml over the  rst 5 minutes to observe for any transfusion reactions, even with blood typed and/or crossmatched transfusions. In animals with cardiac failure, do not exceed 4 ml/kg/hr. Transfusion of a single bag should be completed within
4 hours to prevent functional loss or bacterial growth. Volume of blood component to be administered depends on the type of de ciency and size of the animal. In anemia: Volume (ml) of whole blood = 2 x PCV rise desired (%) x body weight (kg) or in other words, administration of 2
ml whole blood/kg body weight raises the PCV by 1%.
If packed red cells are used without prior resuspension
in a red cell preservative, closer to half the volume is administered, since packed red cells have a PCV of 70- 80%. In the absence of bleeding and hemolysis, at least 80% of transfused erythrocytes survive 24 hours (required blood bank standard) and transfused erythrocytes may be thereafter expected to have a normal life-span (~110 days in dogs). Response to transfusion is carefully monitored by obtaining PCV/TP readings prior to, immediately, 2, 4, 6 and 24 hours post-transfusion, and observing the clinical parameters of a patient.
In thrombocytopenia or thrombopathia, platelet transfusions are only used with life-threatening bleeding. One unit of Platelet Concentrate, Platelet Rich Plasma
or Fresh Whole Blood will increase the platelet count by 10,000/μL in a recipient weighing 30 kg. Platelet counts are monitored prior, 1 hour and 24 hours after the platelet transfusion.
In coagulopathies and von Willebrand’s disease, Fresh Frozen Plasma at 6-10 ml/kg is an initial dose to stop bleeding or avoid excessive bleeding during surgery. In some cases, larger volumes may be needed to control bleeding. Depending on the coagulopathy, repeated administration of FFP may be required. Because of the short half-life of factor VII and VIII and von Willebrand factor, de cient animals need to be treated twice to four times daily. Other coagulopathies may be treated daily. Cryoprecipitate at a dose of 1 Cryoprecipitate unit/10
kg or 2-4 ml/kg body weight twice daily is ideal to treat hemophilia A and von Willebrand’s disease. Plasma support should be provided for an additional 1-3 days after the bleeding has been controlled to allow for healing and prevent rebleeding.
Supported in part by a grant from the NIH (OD
010939). The author’s laboratory PennGen is offering quantitative DEA 1, Dal and Kai typing. Alvedia and DMS Laboratories kindly provided reagents and kits for the authors’ studies.
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