Objective: We sought to identify potential measurable on-scene information that would assist clinicians in the identification of patients at risk for thoracic aortic tear (AT) after vehicular trauma. Methods: Data were prospectively collected at the scene of 295 motor vehicle crashes from 1995 to 1999, There were 34 cases (12%) with AT. Scene data consisted of vehicle maximal crush, maximal intrusion into the occupant compartment, change in velocity (Delta V) and principal direction of force. Thoracic aortic injuries were confirmed radiographically or at autopsy. Crash factors were analyzed for correlation with AT by logistic regression, Results: Delta V greater than or equal to 20 mph and near-side impact were the factors having the strongest correlation with thoracic aortic injury. Delta V greater than or equal to 20 mph (n = 32 with AT) had an odds ratio = 6.4, (p < 0,01), Near impact (n = 20 with AT) had an odds ratio = 2,3, (p < 0.05) and intrusion greater than or equal to 15 inches had an odds ratio = 3.2, p < 0,05, The sensitivity, specificity, and accuracy of the presence of near impact, Delta V greater than or equal to 20 mph, or both, were 100%, 34%, and 64%. The positive and negative predictive values were 16% and 100%, respectively. There was no relationship of AT to use of seat belts or airbags. Conclusion: Thoracic aortic: injury after vehicular collision can be reliably excluded if near-impact, Delta V greater than or equal to 20 mph, or intrusion greater than or equal to 15 inches are not present. Mechanism of injury in the form of crash scene information may aid clinicians in identifying individuals at risk for thoracic aortic tear after vehicular trauma.
