In the emergency department (ED), activation of the trauma team immediately draws human resources—physicians and nurses, as well as radiology, laboratory, and respiratory technicians—away from other patients all over the hospital. In addition, access by other patients to hard resources such as beds, the computed tomography scanner, and the operating room may be delayed while the trauma patient is evaluated. In the situation where the trauma patient is both the sickest person in the department and the one with the greatest potential to benefit from all these resources, activating the trauma team is appropriate. However, the criteria we currently use to determine who needs the “trauma team” after blunt trauma are flawed. Across the country, as many as 50% of blunt trauma patients initially thought to be seriously injured are not admitted or discharged from the hospital within 24 hours.1, 2 Through the view of the “retrospectoscope,” it is unlikely that these patients should have jumped the line to access resources that could have been allocated to others perhaps more critically ill.
The criteria for trauma team activation have traditionally been based on maximizing sensitivity—meaning that we are willing to accept overtriage of patients as simply the cost of not missing anyone who is severely injured and in need of immediate intervention. As EDs become more crowded, our willingness and ability to tolerate this degree of overtriage may decline. Most systems use a combination of physiologic data and mechanistic criteria to determine the need for trauma team activation, and many systems use a tiered approach where the sickest patients draw the most resources. Physiologic abnormalities speak for themselves in demonstrating injury severity; patients who are obtunded, hypotensive, or in respiratory distress after blunt trauma are believed to need the entire trauma team to optimize outcome. The difficulty is accurately identifying the few patients with serious or life-threatening injuries from the group that arrives in the ED awake, alert, and with normal vital signs.
For this group, “mechanistic” criteria for transportation to a trauma center and trauma team activation were created by the American College of Surgeons in 1990 and have been revisited and revised since that time. Initially, these were based on little evidence, but with the belief that mechanism must play some role in increasing the risk of serious injury.3 Injuries are caused when energy above the failure threshold is transferred into human tissue, so it makes sense that higher energy situations should be more likely to result in serious injury. For motor vehicle crashes, crash characteristics that are thought to identify higher energy situations include rollover events or the presence of a fatality in the same vehicle, and these are often mechanistic criteria for trauma team activation. However, recent work suggests some of these criteria, particularly in regard to motor vehicle crashes, add little to the process of correctly choosing which patients should become a “trauma code” (evidenced by death in the ED, admission directly to the operating room or ICU) and which may safely be seen in the normal routine of the ED.2
What we want are readily available, on-scene data points that improve both the sensitivity and specificity of trauma team activation for victims of motor vehicle crashes who do not otherwise meet physiologic criteria. The work reported by Newgard et al4 in this issue of Annals is a first step toward improving our understanding of the effect of mechanism in determining injury severity and upgrading our ability to accurately identify those apparently “stable” motor vehicle occupants who need the resources of trauma team activation.
This work used data from the National Automotive Sampling System; these data are complex and often missing. Newgard and his team made good use of the statistical option of imputing missing data.4 This process greatly strengthens the final conclusions, particularly after being held to a stringent sensitivity analysis. The results suggest about a 30% increase in risk for serious (Abbreviated Injury Score ≥3) thoracic injury for the driver and about a 50% increase in risk for serious thoracic or abdominal injury for the right front seat passenger for each 5-cm increase in steering wheel deformity. Of course, the baseline risk is very low, partly because this study included crashes in which no injury occurred. It remains to be seen whether the amount of steering wheel deformity adds to our ability to identify seriously injured occupants from among those who were injured.
Other crash characteristics, including increased ΔV (change in velocity at the time of impact), side impact on the same side as the occupant (“near-side” impact), and ejection, were also associated with significant increase in the risk of torso injury for the front occupants. In the future, emergency medical services personnel may be readily able to download the data from the vehicle's event data recorder (the “black box”), and we may have real-time access to information such as ΔV and restraint use at the time of the crash. The technology already exists for transmitting these data from some vehicles to emergency medical services and ED personnel (advanced automatic crash notification). These data could be combined with an algorithm for predicting serious injury (“urgency”),5 but the significance of the result in the care of the injured patient and its utility in discriminating serious injuries from the group of patients without major physiologic signs still need to be studied.
Finally, to be truly useful, crash scene information must be accurately determined at the scene and then communicated to the correct treating clinicians without information loss. This is not a minor detail. In my ED, there is always confusion about “what happened to whom” when 5 victims from 3 vehicles involved in 2 separate crashes arrive nearly simultaneously. Having more information could increase the confusion rather than improve patient care; this is another area for future research.
In summary, crash characteristics such as steering wheel deformity, compartment intrusion, and near side impacts may significantly improve the accuracy of trauma triage for victims of motor vehicle crashes. The work presented by Newgard et al4 is not the end of the discussion; hopefully, it is just the beginning.
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