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.

The Use of Leukoreduced Blood

In general, it is preferable to use leukoreduced blood for all patients with he-matological malignancies. The rationale is to prevent primary alloimmunization to HLA antigens, since many of these patients ultimately will require platelet transfusions. Also, many of these patients will require multiple red cell transfusions, and avoidance of transfusion reactions is always desirable in multiply transfused patients (Chapter 32). The use of blood leukoreduced by filtration has been shown to be cost-effective in acute leukemia in that the reduction in sensitization to HLA antigens reduces the subsequent need for expensive HLA selected platelet products. An overall policy therefore to use leukoreduced blood in these patients is appropriate.

Cytomegalovirus Low Risk Products

Some patients with hematological malignancies who are CMV seronegative, may be appropriate candidates for CMV low risk products, if they are potential or actual candidates for allogeneic bone marrow transplantation. These patients should always receive CMV low risk products. In the past, the only acceptable CMV low risk product was a component from a donation which was serologically negative for CMV. However, leukoreduction by a method which prevents alloimmunization (less than 5 x 106 residual white cells), is considered essentially equivalent to CMV seronegative blood. Thus, a policy to use leukoreduced blood in patients with hematologic malignancies will also achieve the objective of preventing primary CMV transmission.

Irradiated Products

Irradiated products constitute another controversy in patients with hemato-logic malignancies. The most important disease in this category is Hodgkin's disease. Although more cases of transfusion associated-graft-versus-host disease (TAGVHD) have been reported with acute leukemias than Hodgkin's disease, the known cellular immune defect of Hodgkin's disease has received considerable prominence as predisposing to TAGVHD (Chapter 37). A policy to give irradiated products to all patients with Hodgkin's disease is appropriate. Some institutions provide irradiated products for all patients with hematologic malignancies. This is, however, neither a widespread nor an accepted practice and there is little data to indicate that the routine use of irradiated products in patients with acute leu-kemias, lymphomas other than Hodgkin's disease, or plasma cell dyscrasias is of benefit. However, the use of irradiated blood is appropriate at certain times in patients with acute leukemia or non-Hodgkin's lymphomas who are candidates for bone marrow transplantation (Chapter 16).

Last, there is the question of the role of erythropoietin in patients with hema-tologic malignancies. This relates particularly to patients with myelodysplastic disorders. Other patients with hematologic malignancies have defects in late stem cell progenitors due to chemotherapy or tumor crowding and, as such, the ability of erythropoietin to improve the anemia is more limited.

Platelet transfusions in patients with hematologic malignancies should be leukoreduced, prestorage, if at all possible (Chapter 28). This is useful in reducing bedside transfusion reactions such as fever and chills (Chapter 32). Red cells are preferably filtered prestorage, but bedside filtration is also effective in reducing reactions and preventing primary alloimmunization to HLA antigens.

Solid Tumors in Adults

Solid tumors represent approximately 90% of all adult tumors, and blood transfusion issues are very different. First, many of these patients are managed by local forms of therapy, such as surgery and radiation therapy: chemotherapy is supplementary or adjuvant to management. Exceptions to this rule, are small cell carcinoma of the lung and testicular tumors. The blood products most commonly used are red cell products which are transfused perioperatively due to bleeding or

on account of radiation induced myelosuppression. There is an ongoing controversy as to whether allogeneic blood transfusion is an independent risk factor in increasing tumor recurrence post surgery (Chapter 13). At this time, therefore, it would appear desirable to avoid allogeneic blood transfusion, if at all possible. A related controversy is the role for leukoreduced blood in preventing tumor recurrence. Since it is unsettled whether allogeneic blood transfusion is a determinant of tumor recurrence, the potential role of leukoreduction in this context is unclear.

Second, there may be a role for blood transfusion to increase the radiosensitiv-ity of tumors. Tumors may be more responsive to radiation therapy in the presence of well oxygenated blood, which acts as a radiosensitizer. When these patients are transfused to higher hematocrits (> 35), more oxygen may be off-loaded at target tissues, giving rise to an enhanced radiation effect. This effect is also being investigated with blood substitutes, such as the animal derived hemoglobins and the perfluorocarbons.

Third, extensive surgery in solid tumors can result in the need for massive transfusion. Most surgical procedures for patients with cancer are associated with modest use of blood products (less than 4 units of RBC). However, more extensive cancer surgery, particularly in patients who are anemic preoperatively, will be associated with large volume red cell transfusions, and the subsequent need to transfuse plasma, and, possibly, platelets (Chapter 14).

Outside of the context of massive transfusion, use of blood components other than red cells is not common in solid tumors. Chemotherapy associated cytopenias do occur, however, in ovarian carcinoma, small cell carcinoma of the lung and breast cancer, and platelet transfusion may be required. It is uncertain whether these populations of recipients benefit from leukoreduced blood products, although patients who require treatment with multiple courses of chemotherapy with associated thrombocytopenia will likely require platelet transfusion and, therefore, benefit from leukoreduced blood products.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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