A 27-year-old G2P1 woman at 34 weeks' gestation presents to the emergency depament following a motor vehicle collision. In the trauma bay her hea rate is 130/min and blood pressure is 150/90 mm Hg. She is ale and oriented to person, place, and time. She complains of severe abdominal pain that began immediately after the collision. Physical examination reveals bruising over her abdomen, along with a hypeonic uterus and dark vaginal bleeding. A sonogram reveals a placental abruption, and the fetal hea tracing reveals some decelerations. Emergency laboratory tests reveal an International Normalized Ratio of 2.5, with elevated fibrin degradation products. Which of the following is the most appropriate first step in'management?