Plasma Transfusions

Chapter 467 Plasma Transfusions

Guidelines for plasma transfusion in children (see Table 467-1 on the Nelson Textbook of Pediatrics website at www.expertconsult.com) are similar to those for adults. Plasma is transfused to replace clinically significant deficiencies of plasma proteins (nearly always clotting proteins) for which more highly purified concentrates are not available. Two interchangeable plasma products are available for transfusion, plasma frozen within 8 hr of collection (fresh frozen plasma) and plasma frozen within 24 hr of collection. Although levels of factors V and VIII are lower in the latter plasma product, they are equally efficacious for literally all indications for plasma transfusions (see Table 467-1). Requirements for plasma vary with the specific protein being replaced, but a starting dose of 15 mL/kg is usually satisfactory.

Transfusion of plasma is efficacious for the treatment of deficiencies of clotting factors II, V, X, and XI. Deficiencies of factor XIII and fibrinogen are treated with cryoprecipitate. Transfusion of plasma is not recommended for the treatment of patients with severe hemophilia A or B, von Willebrand disease, or factor VII deficiency, because safer factor VII, VIII, and IX concentrates are available. Moreover, mild to moderate hemophilia A and certain types of von Willebrand disease can be treated with desmopressin (Chapter 471). An important use of plasma is for rapid reversal of the effects of warfarin in patients who are actively bleeding or who require emergency surgery (in whom functional deficiencies of factors II, VII, IX, and X cannot be rapidly reversed by vitamin K). Results of screening coagulation tests (prothrombin, activated partial thromboplastin, and thrombin times) should not be assumed by themselves to reflect the integrity of the coagulation system or regarded as indications for plasma transfusions. To justify plasma transfusion, coagulation test results must be related to the patient’s clinical condition. Transfusion of plasma in patients with chronic liver disease and prolonged clotting times is not recommended unless bleeding is present or an invasive procedure is planned, because correction of the clotting factor deficiencies is brief.

Plasma also contains several anticoagulant proteins (antithrombin III, protein C, and protein S) whose deficiencies have been associated with thrombosis. In selected situations, plasma may be appropriate as replacement therapy, along with anticoagulant treatment, in patients with these disorders. However, when available, purified concentrates are preferred. Other indications for plasma include replacement fluid during plasma exchange in patients with thrombotic thrombocytopenic purpura (i.e., thrombotic microangiopathies) or other disorders for which plasma is likely to be beneficial (plasma exchange in a patient with bleeding and severe coagulopathy). Plasma is not indicated for correction of hypovolemia or as immunoglobulin replacement therapy, because safer alternatives exist (albumin or crystalloid solutions and IV immunoglobulin, respectively).

In neonates, plasma transfusion merits special consideration. Clotting times are “physiologically” prolonged owing to developmental deficiency of clotting proteins, and plasma should be transfused only after reference to normal values adjusted for the birthweight and age of the infant (i.e., not to normal ranges for older children and adults). The indications for plasma in neonates include: (1) reconstitution of red blood cell (RBC) concentrates to simulate whole blood for use in massive transfusions (exchange transfusion or cardiovascular surgery); (2) hemorrhage secondary to vitamin K deficiency; (3) disseminated intravascular coagulation with bleeding; and (4) bleeding in congenital coagulation factor deficiency when more specific treatment is either unavailable or inappropriate. The use of prophylactic plasma transfusion to prevent intraventricular hemorrhage in premature infants is not recommended, as efficacy has not been proven. Plasma should not be used as a suspending agent to adjust the hematocrit values of RBC concentrates before small-volume RBC transfusions to neonates because it offers no apparent medical benefit over the use of sterile solutions such as crystalloid and albumin. Similarly, the use of plasma in partial exchange transfusion for the treatment of neonatal hyperviscosity syndrome is unnecessary, because safer crystalloid or colloid solutions (e.g., albumin) are available.

In the treatment of bleeding infants, cryoprecipitate is often considered because of its small infusion volume. However, cryoprecipitate contains significant quantities of only fibrinogen, von Willebrand factor, and factors VIII and XIII. Thus, it is not effective for treating the usual clinical situation in bleeding infants with multiple clotting factor deficiencies, despite the appeal and convenience of a small infusion volume. In preliminary studies, infusions of very small volumes of recombinant activated factor VII have been lifesaving in patients with hemorrhage due to several mechanisms. Because the efficacy and toxicity of factor VIIa have not been fully defined in these “off-label” (not approved by the U.S. Food and Drug Administration) uses, it must be considered experimental therapy at this time.

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