What estimated impact speed indicates an automatic mechanism of injury for a major trauma victim?

In the context of trauma assessment, an automatic mechanism of injury refers to circumstances that are likely to result in significant injury due to the forces involved. For major trauma victims, a higher estimated impact speed serves as an important indicator.

When the impact speed exceeds 40 mph, the forces exerted on the body can lead to more severe trauma due to the increased energy transfer during a collision. At these higher speeds, even with the most advanced safety measures in vehicles, the likelihood of sustaining serious injuries rises significantly. Factors such as deformation of the vehicle, blunt force trauma, and secondary impacts (e.g., from occupants striking interior parts of the vehicle) are amplified, making severe outcomes more probable.

In contrast, lower impact speeds (like 20 mph or 30 mph) are generally associated with a reduced risk of major trauma, as they tend to produce less energy transfer and fewer critical injuries. Therefore, the threshold of more than 40 mph is a recognized benchmark within EMS protocols indicating that the potential for severe or life-threatening injuries is substantial, warranting immediate and comprehensive medical assessment and intervention.