The ABO and Rhesus Systems
Although there are now in excess 26 known different blood group systems identified with an associated 254 separate antigens on human red cells, only the red cell antigens within the ABO system and a single antigen D within the Rhesus system, are routinely assessed. Antigens in the other blood group systems are only assessed in certain circumstances. These blood group systems, known as minor blood group systems, will not be discussed further except in some specific situations for clarification...
Platelet Autoantibodies
Platelet autoantibodies are most commonly seen in idiopathic thrombocytopenic purpura ITP . It is important to appreciate that, although such patients may have low platelet counts lt 10 x 109 L , the platelets are larger in size and the hematocrit is usually normal. This differentiates these patients from other patients with thrombocytopenia, such as acute leukemia, where the platelets are normal or reduced in size and the hematocrit usually decreased. Patients with ITP may show evidence of...
Pediatric Malignancies
Pediatric malignancies differ from adult malignancies in that a larger percentage of the tumors are hematologic tumors and chemotherapy is often the primary form of therapy. For this reason, in general, transfusion support of patients with pediatric malignancies is closer to the treatment of adult hematologic malignancies and the same issues and controversies exist with regard to the use of leukoreduced blood, CMV low risk products and irradiated products. It is prudent to treat all of these...
Neonatal Thrombocytopenia
This may result from impaired production or increased destruction of platelets. Platelet transfusion is often indicated in neonates and young infants with Table 25.2. Indications for exchange transfusion All components used for intrauterine transfusion or in neonates of 1.2 Kg or less must be irradiated and should have a reduced risk of CMV transmission such as seronegative donors, deglycerolized, leukocyte reduced by filtration. They must be cross match compatible with maternal serum. 1....
Blood Transfusion in Medicine V Acute Gastrointestinal Bleeding
Gastrointestinal bleeding as a clinical entity accounts for a significant proportion of all red blood cell transfusions and such patients require a prompt response in component availability from the Blood bank. Although acute spontaneous gastrointestinal bleeding has some similarities to transfusion problems seen in patients with massive trauma Chapter 14 , patients with trauma undergoing massive transfusion are usually hemostatically normal prior to the onset of the trauma, and hence,...
Hematological Malignancies In Adults
The major hematological malignancies requiring blood transfusions are the acute leukemias, advanced stage lymphomas, myelomas, myeloproliferative and myelodysplastic disorders. Early stage lymphomas and many of the chronic leukemia in early stages are uncommonly associated with blood transfusion. There are several important blood transfusion considerations in adults with hemato-logical malignancies. In general, it is preferable to use leukoreduced blood for all patients with he-matological...
Red Cell Autoantibodies
A classification of red cell autoantibodies is shown in Figure 22.1. Red cell autoantibodies are arbitrarily divided into cold and warm antibodies, but the distinction is not absolute. Cold antibodies are antibodies which preferentially agglutinate red cells at low temperatures. They characteristically agglutinate red cells at 4 C and at room temperature 22 C , but tend not to cause agglutination at 37 C. Warm antibodies on the other hand tend to be inactive at room temperature but do cause...
Informed Consent and Explanation of Blood Options
One of the most important and difficult areas in clinical transfusion medicine is the question of informed choice consent for blood transfusion and an adequate explanation to potential blood recipients of blood options All Blood Options . In understanding informed choice, it is important to appreciate the following 1 There is a need to discuss the risks, benefits, and alternatives to blood transfusion and to ensure and that the potential recipient or his her representative has an opportunity to...
The Administration of Blood Products
The administration of blood products requires proper compliance with a written procedure, the important elements of which are outlined in Table 8.1. First is proper recipient identification and ensuring the compatibility of the product. For red cell transfusions, both ABO and Rhesus compatibility should be ascertained. If there are any questions at this point they should be immediately addressed to the blood bank for clarification. Under certain circumstances, non-identical ABO blood will be...
Sickle Cell Syndromes
The blood transfusion support of patients with sickle cell syndromes includes patients with hemoglobin SS disease, patients with hemoglobin SC disease, and hemoglobin S 3 thalassemia. The first consideration in the transfusion of patients with sickle cell syndromes is to define a desired post-transfusion hemoglobin target . Without transfusion, these patients will have a hemoglobin in the range of 5-8 g dl, and transfusing to hemoglobins in excess of 12 g dl is probably inadvisable because of...
Preoperative Hemodilution Or Preoperative Apheresis
Preoperative hemodilution or preoperative apheresis is essentially the same type of procedure. Anticoagulated blood is collected immediately before i.e., within 2 hours a surgical procedure. The end product of preoperative hemodilution is a unit of unprocessed whole blood in CPD as anticoagulant. Preoperative apheresis is a procedure in which blood components, most commonly platelets, but sometimes plasma, are collected preoperatively with the intention of transfusion, usually towards the end...
Compatibility Testing and the Importance of Proper Recipient Identification
Compatibility testing is the major process which separates the transfusion of red blood cells from the administration of other types of pharmaceutical products Chapter 1 . The purpose of compatibility testing is the avoidance of a hemolytic reaction. This is of cardinal importance, since some types of hemolytic reactions can result in a fatal outcome. The technical procedures used in compatibility testing have undergone significant changes over the past few decades. The critical steps in this...