A 21-year-old man is brought in 20 minutes after a high-speed front-impact motor vehicle accident. He was seated in the back seat, wearing only the lap portion of the lap-sash seatbelt. He denies losing consciousness but states that he cannot feel or move his lower limbs now. His medical, surgical, and family histories are unremarkable and he is not on any medications currently.
There is free fluid in the abdomen, in all four compartments.
X-rays of the cervical spine appear normal. X-rays of the chest show no evidence of pneumothorax or diaphragmatic rupture.
The complete blood count is significant for a hemoglobin of 10.2 g/dL (normal: 11-18). Crossmatching reveals his blood group to be O+.
You realize that this investigation will waste valuable time.