It is common to underestimate quantitative blood loss in the setting of trauma. Careful and frequent monitoring of vital signs and hematocrit is critical in the detection of severe hemorrhage.
Massive transfusion protocols exist to supply O-negative blood and other essential blood products for the resuscitation of the hemodynamically unstable trauma patient.
Mild-to-severe reactions can occur during the transfusion process including fever, chills, nausea, hypotension, or shock. Whether this is caused by blood type incompatibility, antibodies to donor cells, or blood product contamination, the transfusion must be stopped immediately and the symptoms of the reaction treated aggressively.
Transfusion of blood and blood components is often necessary in the emergency department (ED). Whole blood, packed red blood cells (PRBCs), platelets, granulocytes, fresh frozen plasma (FFP), cryoprecipitate, specific clotting factors, albumin, and immunoglobulins each have specific indications and risks associated with their use. As blood for transfusion is a scarce commodity, the component that will specifically address the patient’s need is generally transfused.
Transfusion of whole blood is rarely performed but may be indicated for prompt restoration of red cells and volume after trauma. While long used by the military, a growing body of evidence in civilian settings supports the use of cold-stored whole blood for resuscitation of patients with traumatic hemorrhagic shock. The use of whole blood avoids the increased amounts of anticoagulants and additives associated with component therapy, and exposes recipients to fewer donors than reconstituted blood in a 1:1:1 ratio of RBC, FFP, and platelets. The increasing availability of platelet-sparing whole blood leukoreduction filters may increase the use of this blood product in the future.1
PRBC units contain approximately 50 mL of plasma and have a hematocrit ranging from 55% to 80%, depending on the preservative used for storage. Units are stored in solution with anticoagulant and preservative for up to 42 days. There are no functional platelets or granulocytes in this preparation. For patients with a previous history of febrile reactions to transfusions or if the risk of cytomegalovirus (CMV) transmission is to be particularly avoided, filtered, leukocyte-poor red cells are recommended. Leukocyte depleted preparations contain <5 × 106 leukocytes per unit.2 In many institutions all PRBC units are routinely leukocyte depleted.
Platelet concentrates are obtained by either pooling multiple individual platelet concentrates from approximately four to eight individual whole blood donors (commonly known as a “6-pack”) or from plateletpheresis of a single donor. There may be advantages to the reduced donor exposure of the single donor product; however, platelet product choice varies by institution and availability. Products usually contain approximately 5.5 × 1010 platelets in approximately 50 mL of plasma. They should be ABO and Rh compatible, but cross-matching is not necessary. For larger children, a transfusion dose equivalent to 4 to 5 units of random donor platelets is recommended, or in younger children <30 kg, 10 to 15 mL/kg. Platelet transfusions are indicated for patients with active bleeding due to thrombocytopenia or platelet dysfunction. When caused by marrow disease or the effects of therapy, thrombocytopenia of less than 10,000/μL is usually treated by prophylactic transfusion. Counts above 20,000/μL rarely result in spontaneous bleeding. Patients with immune thrombocytopenia or thrombotic thrombocytopenic purpura do not benefit from platelet transfusions except in cases of life-threatening hemorrhage since the ongoing antibody-mediated disease process destroys the transfused platelets rapidly.2,3
FFP is produced by freezing plasma shortly after collection. It consists of the non-cellular components of blood, including procoagulant clotting factors such as factors V and VIII, the anticoagulants protein S, protein C, and antithrombin III. ABO compatibility is important, but cross-matching is not necessary. The most common indications for using FFP include situations where multiple factor deficiencies are present simultaneously, guided by coagulation testing (INR >1.7, PTT >1.5 × upper limit of normal range). Table 107-1 reviews the indications for use of FFP. It is used at a dose of 10 to 20 mL/kg. The risk of disease transmission is similar to that of whole blood transfusion, and allergic reactions are possible. FFP is not indicated for acute volume expansion.2
