You are working at a tertiary care center and a 55-year-old woman is transferred to you from an outside hospital for severe persistent thrombocytopenia of unknown origin. On arrival, she is mildly confused and tachycardic. The platelet count is 7K and the hemoglobin is 5.8. Peripheral blood smear demonstrates schistocytes consistent with microangiopathic hemolytic anemia. The diagnosis of thrombotic thrombocytopenic purpura (TTP) is suspected. TTP is a hematologic emergency: what are the next steps in management?