Indicated when acute blood loss is sufficient to produce hypovolemia, whole blood provides both oxygen-carrying capacity and volume expansion. In acute blood loss, hematocrit may not accurately reflect degree of blood loss for 48 h until fluid shifts occur.
RED BLOOD CELL TRANSFUSION
Indicated for symptomatic anemia unresponsive to specific therapy or requiring urgent correction. Packed red blood cell (RBC) transfusions may be indicated in pts who are symptomatic from cardiovascular or pulmonary disease when Hb is between 70 and 90 g/L (7 and 9 g/dL). Transfusion is usually necessary when Hb is <70 g/L (<7 g/dL). One unit of packed RBCs raises the Hb by approximately 10 g/L (1 g/dL). In the setting of acute hemorrhage, packed RBCs, fresh-frozen plasma (FFP), and platelets in an approximate ratio of 3:1:10 units are an adequate replacement for whole blood. Removal of leukocytes reduces risk of alloimmunization and transmission of cytomegalovirus. Washing to remove donor plasma reduces risk of allergic reactions. Irradiation prevents graft-versus-host disease in immunocompromised recipients by killing alloreactive donor lymphocytes. Avoid related donors.
(1) Hypertransfusion therapy to block production of defective cells, e.g., thalassemia, sickle cell anemia; (2) exchange transfusion—hemolytic disease of newborn, sickle cell crisis; (3) transplant recipients—decreases rejection of cadaveric kidney transplants.
(1) Transfusion reaction—immediate or delayed, seen in 1–4% of transfusions; IgA-deficient pts at particular risk for severe reaction; (2) infection—bacterial (rare); hepatitis C, 1 in 1,800,000 transfusions; HIV transmission, 1 in 2,300,000; (3) circulatory overload; (4) iron overload—each unit contains 200–250 mg iron; hemochromatosis may develop after 100 U of RBCs (less in children), in absence of blood loss; iron chelation therapy with deferoxamine indicated; (5) graft-versus-host disease; (6) alloimmunization (See Table 9-1).
TABLE 9-1RISKS OF TRANSFUSION COMPLICATIONS |Favorite Table|Download (.pdf) TABLE 9-1RISKS OF TRANSFUSION COMPLICATIONS
| ||Frequency, Episodes: Unit |
|Febrile (FNHTR) ||1–4:100 |
|Allergic ||1–4:100 |
|Delayed hemolytic ||1:1000 |
|TRALI ||1:5000 |
|Acute hemolytic ||1:12,000 |
|Fatal hemolytic ||1:100,000 |
|Anaphylactic ||1:150,000 |
|Hepatitis B ||1:220,000 |
|Hepatitis C ||1:1,800,000 |
|HIV-1, HIV-2 ||1:2,300,000 |
|HTLV-I, HTLV-II ||1:2,993,000 |
|Malaria ||1:4,000,000 |
|Other complications |
|RBC allosensitization ||1:100 |
|HLA allosensitization ||1:10 |
|Graft-versus-host disease ||Rare |
Use of pt's own stored blood avoids hazards of donor blood; also useful in pts with multiple RBC antibodies. Pace of autologous donation may be accelerated using erythropoietin (50–150 U/kg SC three times a week) in the setting of normal iron stores.
The main goal of red cell exchange transfusions is to remove sickle cells and replace them with normal red cells to interrupt the vicious cycle of sickling, stasis, vasoocclusion, and hypoxia that propagate sickle cell crises. The usual target is 70% hemoglobin A.
Prophylactic transfusions usually ...