Change in Velocity and Energy Dissipation on Impact in Motor Vehicle Crashes as a Function of the Direction of Crash: Key Factors in the Production of Thoracic Aortic Injuries, Their Pattern of Associated Injuries and Patient Survival A Crash Injury Research Engineering Network (CIREN) Study

Abstract

To examine the effect of change in velocity (MV) and energy dissipation (IE) on impact, above and below the test levels for federal motor vehicle crash (MVC) safety standards, on the incidence of aortic injury (AI) and its mortality and associated injury patterns in frontal (F) and lateral (L) MVCs. Comparison of 80 AI and 796 non-AI patients of AIS = 3. Eight hundred seventy-six MVC adult drivers or front-seat passengers (552 F and 324 L) evaluated by 10 Level I CIREN study Trauma Centers together with vehicle and crash scene engineering reconstruction. Patient seatbelt and/or airbag use correlated with clinical or autopsy findings. In AI, 63% of cases were dead at the scene and only 16% survived to leave hospital. The relation between IE dissipated in the MVC and the ΔV on impact was exponen-tial as ΔV increased, but the rise in IE for a given ΔV was greater in LMVC than in FMVC (p p The implications for AI of the focused IE at the upper chest suggest a probable mechanism for MVC AI with the pressurized aortic arch acting as the long arm of a lever system with the fulcrum at the subclavian artery, producing maximum torsional strain at the short arm of the isthmus where 75% of the AIs occurred. AI mortality is also influenced by the associated injuries. To develop more effective safety systems to prevent AI, MVC safety testing with airbags and seatbelts should be carried out at ΔVs of 1 SD above means for FMVC and LMVC.