Forensic pathological evaluation of injury severity and fatal outcome in traffic accidents: five illustrative autopsy cases of clinically unexpected death.

In forensic casework, investigation of injury severity in traffic accidents is important for evaluating the mortality, occasionally in terms of the adequacy of clinical management. The present study evaluated 5 cases of clinically unexpected delayed collapse followed by death using the abbreviated injury scale (AIS), injury severity score (ISS), and a clinical trauma care method (trauma and injury severity score, TRISS). In these cases, major injury (AIS = 3-5) was found in the head, chest and/or abdomen at autopsy, and ISS was estimated to be 11-45 (serious to critical but not incompatible with life). By the TRISS method, the probability of survival (P (s)) was estimated to be >0.5 for all cases (0.60-0.99), suggesting that these were preventable deaths. However, the present cases showed several common features: (a) fatality due to closed injury/-ies to the thoracic and/or abdominal viscera, (b) alert and poor symptoms/clinical signs, and (c) poor positive findings in diagnostic imaging at early times after injury, and (d) complications of other evident injuries, suggesting difficulties in the clinical diagnosis of potentially fatal injuries, but (e) possibly predictable fatal injury when typical patterns of traffic accident injury were considered.