<prompt> A 70-year-old man is brought to the emergency department following a car crash. X-rays revealed a fractured rib on the left and a fracture of the right femur. A CT scan of the abdomen showed a left-sided retroperitoneal hematoma adjacent to the left kidney and no evidence of urine extravasation. The hematoma should be managed by which of the following?ObservationExploratory laparotomy through a midline incisionCT scan-guided aspirationSurgical exploration through a left-flank retroperitoneal approach  <response>: A small nonexpanding hematoma with no associated urine extravasation can be managed by observation with repeat CT scan or ultrasound. If the patient becomes hypotensive, exploration through a midline incision would be indicated. 