An obviously pregnant female is brought to the emergency department by EMT on a stretcher. They report that she had been driving erratically on the highway, where she grazed another vehicle and screeched to a halt against a median fence. She was extricated with difficulty. She is now minimally coherent, thrashing, moaning, and trying to hold her belly. Vital signs reveal a blood pressure of 210/160 mmHg, a heart rate of 110/min, and a respiratory rate of 30/min. Rapid evaluation confirms a pregnancy of 6 to 8 months. Earlier evaluation was negative for orthopedic and nonobstetric trauma. The most appropriate initial step is to