Transfusion Therapy - Special Considerations
Hemophilia A and B are rare, sex-linked diseases affecting males almost exclusively. Hemophilia A is due to an abnormality in factor VIII, while hemophilia B (Christmas disease) is due to a factor IX abnormality. The incidence in the United States is 1:10,000 males for hemophilia A and 1:100,000 males for hemophilia.
- Clinical features. Patients usually present early in childhood with hemarthroses and soft tissue hematomas after minor trauma. Laboratory tests demonstrate a markedly prolonged PTT with normal PT and platelet count.
- Treatment with the appropriate factor (of either recombinant or lyophilized concentrate source) should be coordinated with the patient's hematologist. Hemophilia A is treated with factor VIII to achieve preoperative activity levels of 25% to 100%, depending on the extent of the procedure. Some patients with mild hemophilia A may respond to DDAVP therapy. In an emergency, if factor VIII is unavailable, cryoprecipitate transfusion can provide the deficient factor. Hemophilia B is treated with factor IX to achieve at least 30% to 50% activity before surgery.
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