Thursday, August 04, 2005

Seatbelts and Trauma

This is an interesting case my partner had recently. A young man was traveling in the back seat of his family's large SUV (gross weight 9200 pounds) when it was struck head on at about 70 mph by a much smaller vehicle. In a stunning display of the laws of physics, the SUV flattened the smaller car, as well as its passenger. All of the family members in the SUV were wearing their seatbelts, except for this young man, who was wearing only the lap belt portion, slinging the shoulder harness behind him. He arrived here with a classic "seat belt sign" on the abdominal wall, and had this impressive CT scan (click on pictures for a larger view):

The arrow on the right side of the image points to a normal abdominal wall contour, with normal musculature. On the left side, the circle shows complete loss of the abdominal wall, with bowel laying up against the skin.

A few cuts lower, the edges of the muscle can be seen (arrows). The whole abdominal wall musculature had been divided in two, indicative of massive force.

In this scenario, a whole host of other injuries can be found, including a ruptured diaphragm, small and large bowel perforation or devascularization, spinal fracture, liver fracture, and pancreatic injury. Upon exploration, he was found to have a completely disrupted abdominal wall, but no solid organ injury. The right diaphragm had been torn fairly significantly and had to be reattached to the ribs; most of the liver attachments had been ripped as well, but fortunately there was no liver injury. He had one unstable spinal fracture which was stabilized the following day.

This case illustrates the forces that are applied to torsos in auto accidents, as well as the reason that modern seatbelts were invented. Without a seatbelt, this young man would be yet another auto crash fatality statistic. With half a seatbelt, he suffered significant injuries. With a full seatbelt, he may have been less severely injured.

Buckle up.