A 60-year-old man is hit by a pickup truck and brought to the emergency department with a blood pressure of 70/0 mm Hg. Peritoneal lavage showed no blood in the abdomen. The blood pressure is elevated to 85 systolic following the administration of 2 L of Ringer's lactate. An x-ray showed a pelvic fracture. What is the next step in management?

Early external fixation of the pelvis has been shown to reduce bleeding and mortality in patients in shock consequent to pelvic fractures. An unstable patient should not be sent for a CT scan. Selective angiography with embolization of the bleeding vessel may also be helpful in these patients. Laparotomy usually results in uncontrollable pelvic bleeding.