A 70-year-old intensive care unit patient complains of fever and shaking chills. The patient develops hypotension, and blood cultures are positive for gram-negative bacilli. The patient begins bleeding from venipuncture sites and around his Foley catheter. Laboratory studies are as follows:Hct: 38%WBC: 15,000/mLPlatelet count: 40,000/mL (normal 150,000-400,000)Peripheral blood smear: fragmented RBCsPT: elevated PTT: elevatedPlasma fibrinogen: 70 mg/dL (normal 200-400)Which of the following is the best course of therapy in this patient?