Traumatic asphyxia death in a bicyclist: an autopsy case

We report an autopsy case of fatal traumatic asphyxia in a bicyclist. A 15-year-old female bicyclist fell from her bike after collision with the rear end of a truck that was backing up. Her body was pinned between the ground and a spare tire attached to the bottom of the truck. Autopsy revealed congestion of the head, face, neck, upper anterior aspect of the chest, and bilateral arms, and many petechial hemorrhages in the oral mucosa and bilateral palpebral conjunctivae. Internal examination revealed hemorrhage of the intercostal muscles with a rib fracture, mild liver laceration, and pelvic fracture resulting from compression of the thoracoabdominal region, and the findings of acute death. The cause of death was diagnosed as traumatic asphyxia. Known mechanisms of traumatic asphyxia in motor vehicle collisions include crushing of pedestrians or ejected occupants by the vehicle and crushing of occupants by intrusion into the passenger compartment; traumatic asphyxia resulting from vehicle collision involving in a bicyclist has not been reported. The present case indicates that forensic pathologists should consider the possibility of traumatic asphyxia when investigating vehicle collision deaths, especially in bicyclists.