RED BLOOD CELLS
Packed Red Blood Cells
Red blood cells, or packed red blood cells, are prepared from whole blood collected in one of several approved anticoagulant solutions. The usual 250-300 ml unit of red blood cells (RBCs) has a hematocrit of 55-80%, with some platelets and/or white cells removed during processing. Red blood cells are the component of choice for patients with a symptomatic deficit of oxygen-carrying capacity. RBCs may also be used to help restore cells lost following significant hemorrhage. Removal of plasma reduces the risk of adverse reactions. Red Blood Cells can be enhanced by:
Whole blood contains approximately 500 ml of anticoagulated whole blood. The platelets and granulocytes are non-viable after a few days. Levels of labile clotting factors also decline with storage. Lymphocytes are viable. and can cause Graft vs. Host Disease (GVHD). Whole blood provides oxygen-carrying capacity and blood volume expansion. Whole blood may be useful in bleeding patients who have lost in excess of 20% of total blood volume. Patients with chronic anemia who have a normal blood volume should receive red blood cells (packed RBC's). Whole blood can be enhanced by being Irradiated, CMV Negative and Hgb S Negative.
Platelet concentrate contains platelets in 50-70 ml of plasma, and is prepared from individual units of whole blood by centrifugation. Platelet concentrates contain leukocytes which may transmit CMV, cause GVHD, lead to alloimmunization and cause febrile transfusion reactions. Platelets are used to treat bleeding caused by thrombocytopenia or functionally abnormal platelets. Prophylactic administration of platelets may be useful in patients with rapidly declining or low platelet counts (10,000 to 20,000/m L) secondary to cancer or chemotherapy. Platelets can be enhanced by being CMV Negative and Irradiated.
Each bag of Cryoprecipitate contains an average of 80 or more units of Factor VIII (FVIII:C) and at least 150 mg of fibrinogen in less than 15mL of plasma. Cryoprecipitate is used in replacement of fibrinogen and Factor XIII and in platelet functional defect (uremia); it also is used in the treatment of von Willebrand disease and Factor VIII replacement when specific factor concentrates are unavailable.
Plasma - Fresh Frozen
Fresh Frozen Plasma (FFP) is separated and frozen within 8 hours of whole blood collection. It contains plasma proteins and all coagulation factors. A unit of FFP contains about 200 units of Factor VIII plus the other labile plasma coagulation factor, Factor V. FFP is used mainly to provide replacement coagulation factors when concentrate is not available or appropriate. FFP provides normal levels of all clotting factors and is used for patients with thrombotic thrombocytopenic purpura (TTP), for antithrombin III deficiency, for immediate hemostasis and reversal of the warfarin effect, and for massive transfusion with coagulopathy.
Plasma - ( Frozen Within 24 Hours of Collection)
Plasma (Frozen within 24 hours of collection) is separated and frozen within 24 hours of whole blood collection. It contains all stable plasma proteins found if FFP. This component contains about 150 units of Factor VIII . There is little difference in the levels of labile coagulation factors between FFP and Plasma. Factor V levels studied were essentially the same in plasma frozen at 8 hours and at 24 hours. On average, the major difference is a 25% reduction of Factor VIII. Indications for use of Plasma include all the uses of FFP except for replacement of labile coagulation factors such as Factor V and VIII.