Transfusion
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The following review will detail the current knowledge in massive hemorrhage with regard to the pathophysiology of the coagulation disturbance, the role of plasma, the role of alternatives to plasma, and the clinical value of having a massive transfusion protocol. The coagulation disturbance in trauma patients is more than just the result of consumption of clotting factors at sites of injury and dilution from the infusion of intravenous fluids and red blood cells (RBCs). Even before substantial amounts of fluid resuscitation and RBC transfusion, one-quarter of trauma patients already have abnormal coagulation variables. ⋯ This therapy must be included in hemorrhage protocols. If we are to improve the care of massively bleeding patients on a firm scientific ground, we will need large-scale randomized trials to delineate the role of coagulation replacement and the utility of laboratory monitoring. But even until these trials are completed, it is clear that a massive transfusion protocol is needed in all hospitals that manage bleeding patients, to ensure a prompt and coordinated response to hemorrhage.
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General use of plasma components includes replacement for multiple coagulation factor deficiencies, for treatment of single coagulation factor deficiencies for which a concentrate is unavailable, and as a replacement fluid used in therapeutic plasma exchange for thrombotic thrombocytopenic purpura. Four major products currently transfused are fresh-frozen plasma (FFP), plasma frozen within 24 hours of phlebotomy (FP24), cryoprecipitate-poor plasma (CPP), and thawed plasma. ⋯ Pathogen-reduced plasma may contain reduced levels of certain coagulant and/or anticoagulant factors compared to FFP. Clinical findings with pathogen-reduced plasma have provided an impetus to the US Food and Drug Administration to promulgate specific requirements for approval of novel plasma products, some of which may be too burdensome for the industry to readily overcome.
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Review
Plasma transfusion for bedside, radiologically guided, and operating room invasive procedures.
Frozen plasma (FP) is commonly used in an attempt to correct coagulation defects before performing bedside, radiologically guided, or operating room procedures. Use of FP prophylactically is closely linked to results for standard coagulation tests in the laboratory, including prothrombin time, but there is a general lack of evidence supporting the predictive value of abnormalities of these tests for bleeding. Use of FP has little effect on correcting abnormal coagulation tests when mild and moderate results are recorded. ⋯ When the lack of clinical effectiveness is combined with the risks of FP transfusion, such as transfusion-related acute lung injury and transfusion-associated circulatory overload, the need to challenge continued preprocedure prophylactic use of FP becomes pressing. In clinical practice, abnormalities of standard coagulation tests should not be interpreted in isolation, but alongside review of clinical bleeding history and other hemostatic markers such as platelet count. A more appropriate transfusion strategy may be one that emphasizes the therapeutic use of FP.
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Fingerstick blood samples are used to estimate donor venous hemoglobin (Hb). ⋯ Fingerstick is considered a useful estimator of venous Hb. However, in some donor groups, particularly female donors with AIS, fingerstick overestimates venous Hb at the donation cutoff. This significant limitation should be considered in setting donor fingerstick Hb or Hct requirements.
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Transfusion-related acute lung injury (TRALI) is an uncommon but serious transfusion reaction. Studies have shown that the transfusion of HLA and HNA antibodies in donor plasma can lead to TRALI. Female donors are more likely to have such antibodies due to alloantigen exposure during pregnancy. Many blood suppliers have now implemented various TRALI risk reduction strategies to unknown effect. A retrospective analysis of TRALI reactions in plasma recipients before and after the conversion to low-TRALI-risk plasma (all-male donor plasma, male-predominant plasma, nulliparous female plasma, and HLA antibody-tested plasma) is reported. ⋯ The conversion to low-TRALI-risk plasma has reduced the incidence of TRALI reactions in plasma recipients.