**3. Transfusion therapy**

Packed red blood cells (pRBCs) and fresh frozen plasma (FFP) are components generally provided for canine transfusions. If processed at once, 1-4 each unit (450 mL) of whole blood can be seperated into 1 unit of pRBCs and 1 unit of FFP. It is difficult to prepare components from a small volume of blood. Because of this cat blood transfusions are usually administered as fresh or stored whole blood. If patients requires specific components like pRBCs and FFP, in this case whole blood can be separated into them [39].

In veterinary medicine, red blood cell transfusions are used more frequent recently. They are the integral part of lifesaving. They are used in critically ill as advanced treatment. Situations required transfusions include life-threatening anemia from acute hemorrhage or surgical blood loss, hemolysis from drugs or toxins, immune-mediated diseases, severe nonregenerative conditions, and neonatal isoerythrolysis [40].

Indications of red blood cell transfusions are in the treatment of anemia caused by hemorrhage, hemolysis, or ineffective erythropoiesis. Oxygen is poorly soluble in plasma. Because of this oxygen in blood is mostly carried by hemoglobin (Hgb). In anemic patient, RBC transfusions increase the oxygen-carrying capacity. Therefore inadequate delivery of oxygen to tissues with consequent tissue hypoxia are prevented or treated [41].

The treatment of severe anemia caused by hemorrhage, hemolysis, ineffective erythropoiesis, auto-immune hemolytic anemia, or neoplasia is primary indication for blood transfusion. Lethargy and altered mentation, increased respiratory effort, pale mucous membranes and tachycardia are the clinical signs of anaemia. The body carry out a number of adaptive responses physiologically, to maintain carrying of oxygen to the tissues [42, 43]. The solution of oxygen in plasma is weak. Because of this hemoglobin (Hgb) carries approximately whole oxygen in blood [41]. The decision to conduct a RBC transfusion is generally based on a measurement of the patient's packed cell volume (PCV), hematocrit (Hct) or Hgb concentration (Hgb) and especially on clinical evaluation of the patient [41]. Clinically animals should be evaluated individually. Generally when the hematocrit is less than 10%, the treatment of anemia is transfusion. However, animals with acute-onset anemia usually require transfusion before their hematocrit decreases to 15%. This contrasts with the situation in animals with chronic anemia. Other indications for transfusion are hypovolemia, thrombocytopenia, clotting factor deficiency, and hypoproteinemia [1]. Electrocardiographic signs of myocardial ischaemia are similar to those identified in human patients with myocardial infarction. It can ocur with anemia [44].

324 Blood Cell – An Overview of Studies in Hematology

**3. Transfusion therapy** 

especially result in two fatal reactions. The first is acute haemolytic transfusion reactions, occur particularly in cat transfused with type A blood [32]. Feline neonatal isoerythrolysis (NI) is the second incompatibility reaction. It occurs when type A or AB kittens born to type B queens are nursing. Naturally occurring anti-A alloantibodies result in blood

Cats constitute non-self antibodies in contrast to dogs. As a result of this non-self antibodies potentially fatal antibody-mediated reactions can occur towards non-self red blood cells. Nearly 20% of type A cats have anti-B antibodies. These antibodies are usually weak. All type B cats have strong anti-A antibodies. In contrast AB cats do not have alloantibodies [32]. In previously unsensitized cats naturally occuring isoantibodies are responsible for transfusion reactions. Nearly all type B cats have highly titered anti-A agglutinins and hemolysins. RBCs can be destructed rapidly in type B cats taking type A blood. In type B cats the high titres of naturally occurring anti-A antibodies cause rapid intravascular destruction of transfused type A red blood cells [33]. This can be mediated by IgM, complement fixation and the release of potent vasoactive compounds. As a result of this shock can develop usually due to possessed antibodies towards the transfused RBCs [3, 34]. This can cause severe transfusion reaction and death even if as little as 1 ml of type A blood is administered to a type B-cat [2, 35]. Because of their endotheliochorial placenta newborn kittens have no alloantibodies. Nevertheless colostral transfer of immunoglobulin (Ig) G and a small amount of IgM occurs. Neonatal isoerythrolysis develops in cats. It is one of the cause of the fading kitten syndrome. Kittens that are type A or AB and those that are born to type B queens are at risk. In affected kittens Clinical sings can range from unapparent, to

incompatibility reaction in the type B queen's colostrum and milk [25, 30].

severe hemolytic anemia with hemoglobinuria, icterus, and death [1, 36, 37, 38].

pRBCs and FFP, in this case whole blood can be separated into them [39].

nonregenerative conditions, and neonatal isoerythrolysis [40].

Packed red blood cells (pRBCs) and fresh frozen plasma (FFP) are components generally provided for canine transfusions. If processed at once, 1-4 each unit (450 mL) of whole blood can be seperated into 1 unit of pRBCs and 1 unit of FFP. It is difficult to prepare components from a small volume of blood. Because of this cat blood transfusions are usually administered as fresh or stored whole blood. If patients requires specific components like

In veterinary medicine, red blood cell transfusions are used more frequent recently. They are the integral part of lifesaving. They are used in critically ill as advanced treatment. Situations required transfusions include life-threatening anemia from acute hemorrhage or surgical blood loss, hemolysis from drugs or toxins, immune-mediated diseases, severe

Indications of red blood cell transfusions are in the treatment of anemia caused by hemorrhage, hemolysis, or ineffective erythropoiesis. Oxygen is poorly soluble in plasma. Because of this oxygen in blood is mostly carried by hemoglobin (Hgb). In anemic patient, RBC transfusions increase the oxygen-carrying capacity. Therefore inadequate delivery of

oxygen to tissues with consequent tissue hypoxia are prevented or treated [41].

The usage of administration of FFP are for the treatment of a single or multiple clotting factor deficiency, vitamin K deficiency or antagonism, surgical bleeding or where a massive transfusion is required [45]. Hypoalbuminaemia and coagulopathies especially due to liver disease are the main reported indications for FFP transfusions in cats [46].

Stored blood is more than 8 hours old. The length of storage depends on the anticoagulant/preservative solution used. It varies from 48 hours for 3.8% sodium citrate (no preservative) to 4 weeks for CPD-A1 (citrate, phosphate, dextrose, and adenine). Acid citrate dextrose (ACD), citrate phosphate dextrose (CPD and CP2D), and citrate phosphatedextrose-adenine (CPDA-1) are mostly used as preservatives. The viability of RBCs is provided by the added dextrose, phosphate, and adenine. Due to the preservative used, the storage can extend up to 3 to 5 week ([3, 41, 47].

In patients that are hypothermic or receiving large volumes of blood, refrigerated RBC products should be prewarmed to temperatures between 22°C and 37°C immediately before transfusion. In the routine practice of RBC products to normovolemic anemic patients, refrigerated blood components do not need warming before transfusion. Warming may accelerate the deterioration of stored RBCs and may cause rapid growth of contaminating microorganisms [48].

In clinical practice advances in safety of blood transfusion is important in preventing transfusion-transmitted infections (TTI). The most frequent severe infectious outcome of transfusion has been known as bacterial contamination of platelets, with resultant sepsis in the recipient recently. Using automated or semi-automated blood culture devices, apheresis platelets and prestorage pooled platelets are most often tested [49].

Generally, before a blood transfusion is given to animals, blood typing and/or crossmatching of the recipent and donor should be done to avoid the likelihood of a transfusion reaction. Also, ineffective therapy is caused by shortened survival of transfused mismatched

red cells. In order to prevent primary sensitization and risk of developing hemolytic disease in breeding females, cross-matching and/or blood typing is important. In general veterinary practise, blood typing for canine DEA 1.1 and for feline types A and B is applied [1].

Principles of Blood Transfusion 327

commercially available systems whole blood can be separated into FFP and packed red cells if it is taken aseptically. The blood spun at 3800 rpm at 10C in a refrigerated centrifuge for

In hypoalbuminemic dogs and cats, human serum albumin has been used for therapeutic

Correction of coagulation by fresh platelets are shown by in vitro coagulation studies. Freshly collected platelets correct thrombocytopenia, control associated hemorrhage, and prevent death from bleeding. Hemorrhagic diathesis are prevented by platelet replacement

Severe thrombocytopenia or thrombopathia result in bleeding. Platelet transfusion is used for the control of this bleeding. In veterinary medicine platelet transfusion has been used rarely compared to red blood cell (RBC) and plasma transfusion. In dogs, reports related to platelet transfusion are generally associated with experimental hematopoietic stem cell transplantation. Platelet-rich blood products consist of fresh whole blood (FWB), plateletrich plasma (PRP) and platelet concentrate (PC). They are used for aggressive anticancer therapy and treating complex hematologic disorders. Centrifugation of whole blood constitute platelet-rich plasma (PRP) and centrifugation of platelet-rich plasma constitude platelet concentrates (PC). Platelet activation is induced by centrifugation so that the resuspension of the platelet pellet during PC preparation from dogs is difficult. The preparation efficiency of PC from dogs can be improved by addition of PGE1 in PRP before the centrifugation of PRP. Also therapeutic efficacy of the platelets are maintained. In 10-28 kg body weight dogs plateletpheresis has been used successfully. On the canine donor thrombocytopenia and hypocalcemia are the main adverse effects of

At room temperature (RT) (20-24°C), PRP and PC can be stored for 5-7 days with continuous or intermittent agitation. At RT FWB can be stored for up to 8 hours. The interest in freezed (4°C) storage of platelets is increasing because of the increased risk of bacterial proliferation at RT storage. Storage of human PRP and PC are limited to 5 days because of prevention of

Platelet transfusions as with RBC and plasma components should be performed with 170 µm filters standard blood administration sets. Transfusion sets which can bind platelets

The most common reaction to PC are febrile reactions. The frequency is decreased by prestorage leukoreduction. In immunocompetent dogs receiving multiple transfusions, alloimmunization to platelet antigens occurs. Leukocyte reduction and ultraviolet B irradiation are recently accepted methods for preventing the development of platelet

12 mins. Using a plasma extractor the plasma is extracted and stored at –20°C [57].

use [58].

**3.1. Platelet transfusion** 

for thrombocytopenia [59].

plateletpheresis [60-62].

should be exempt from latex [60].

alloimmunization [64-66].

bacterial proliferation at room temperature [60- 63].

To decrease adverse reactions one sould pay attention to blood typing and crossmatching procedures as much as monitoring. There is always risk in blood transfusions. For this reason, they should be performed only when warranted. When taking history, previous transfusion therapy should be asked and in a history of previous transfusion therapy crossmatching is necessary [1, 50].

Depending on availability and indication for transfusion, whole-blood or blood-component therapy may be administered. RBCs, white blood cells (WBCs), platelets, all the coagulation factors, albumin and immunoglobulins constitute whole blood (WB) [51].

In cats, fresh whole blood is the most common product used recently. Stored whole blood, packed red blood cells and fresh frozen plasma (FFP) are also given as transfusions [45].

The heavier cellular elements from the supernatant plasma are sedimented by centrifugation of whole blood sediments. Due to separation of blood collection within 8 hours all protein activity and concentration are maintained in the plasma. The obtained supernatant usually frozen. For subsequent transfusion, it is stored as fresh frozen plasma (FFP). In addition it can also processed to provide cryoprecipitate and cryosupernatant. It can also be transfused immediately as fresh plasma [52, 53]. Fresh frozen plasma have to be stored frozen at -30°C before used. Also it should be identified with the donor blood type, name and collection date. Samples thawed and not used sould discarded or stored in a fridge and used within 12-24 h and should not be refrozen [43].

Recently an ultra-purified polymerised bovine haemoglobin solution is the only commercially available alternative to red cell transfusion (Oxyglobin). It is not licensed in cats but it has been used in treatment of anaemia in cats and also in therapy of carbon monoxide poisoning [54, 55].

Hemostatic protein deficiencies lead to hemorrhagic disorders and the treatment is done principally by plasma components [56]. In animals with von Willebrand disease (vWD) and hereditary coagulation factor deficiencies active hemorrhage is controlled by plasma components. Plasma components are also used for preoperative prophylaxis in these diseases [53].

For preparation of plasma components sterile plastic bags are used. After that they are stored and transferred as frozen in individual boxes. Products have to be stored at -20°C or lower. Just before transfusion they warmed to 37°C in a water bath or incubator. Preferred route of administration is the intravenous transfusion of plasma components. If attempts at vascular access have failed, intraosseous transfusion can be used in emergency situations. When acut allergic reactions occur transfusion is stopped and antihistamines and/or shortacting steroids are given [53, 57].

Cats have antibodies to non-self blood types within the plasma. Because of this only typespecific plasma should be administered to cats in contrast to dogs. Using one of the commercially available systems whole blood can be separated into FFP and packed red cells if it is taken aseptically. The blood spun at 3800 rpm at 10C in a refrigerated centrifuge for 12 mins. Using a plasma extractor the plasma is extracted and stored at –20°C [57].

In hypoalbuminemic dogs and cats, human serum albumin has been used for therapeutic use [58].
