Abstract
Automobile collisions with driver side intrusion >12 inches or >18 elsewhere meet criteria for trauma activation. However, vehicle safety features have improved since this inception. We hypothesized vehicle intrusion (VI) alone as mechanism-of-injury (MOI) criteria inadequately predicts trauma center activation. A retrospective, single-center chart review of adult patients involved in motor vehicle collisions presenting to a level 1 trauma center from July 2016 to March 2022 was performed. Patients were divided by MOI criteria: VI vs. multiple MOI criteria. 2940 patients met inclusion criteria. The VI group reported lower injury severity scores (P = 0.004), higher incidence of ED discharge (P = 0.001), lower ICU admissions (P = 0.004), and fewer in-hospital procedures (P = 0.03). Vehicle intrusion was found to have a positive likelihood ratio of 0.889 for predicting trauma center need. According to current guidelines, these results suggest that VI criteria alone may not be an accurate predictor for trauma center transport and require further investigation.
Keywords
The National Guidelines for the Field Triage of Injured Patients were developed in 1976 and have undergone periodic revisions, with the latest modification occurring in 2021. Traditionally, the guidelines were formulated in a stepwise manner evaluating triage criteria through the categories of injury patterns (“Anatomic Criteria”), mental status and vital signs (“Physiologic Criteria”), mechanism of injury (MOI), and EMS Judgement (“Special Considerations”) to assist providers with preferential trauma center transport. However, the recent 2021 guidelines included significant structural changes to improve the ease of use for field providers. 1
The threshold to add new triage criteria previously was a positive predictive value of at least 20%. The 2021 guidelines changed this to a positive likelihood ratio (+LR) ≥ 2 or area under the receiver operating characteristic curves (AUROC) ≥ .60. 1 Additionally, in order to remove triage criteria, it must be found to have either no evidence or a + LR 1.0-1.5 or AUROC .50-.55 across multiple studies. 1 Recommendations for vehicle intrusion as a component of MOI previously indicated patients involved in automobile collisions with greater than 12 inches of intrusion or 18 inches at any site meet criteria for trauma activation and should be preferentially transported to a trauma center. The recent edition did not alter these intrusion criteria but rather include the re-addition of need for extrication of the entrapped patient that was removed in the 2006 guidelines.
While these vehicle intrusion criteria have not been adjusted and have been generally accepted for 35 years, it has been shown to result in high rates of overtriage. 2 Additionally, a previous study suggested that vehicle intrusion as MOI criteria is only a moderate predictor for patients who require trauma center resources with a positive likelihood ratio of 2.9 with criteria of ISS greater than 15. 3 The evaluation of MOI criteria is important to help reduce overtriage rates that create unnecessary burdens on the health care system that drain available resources and increase costs. Given the introduction of “crumple zones” and additional modern safety features that have been incorporated into modern vehicle design, this study aimed to evaluate the use of vehicle intrusion alone as a mechanism of action for trauma center transport. We hypothesize that vehicle intrusion alone is not an adequate predictor of trauma center need.
A retrospective, single-center chart review of adult patients involved in motor vehicle collisions (MVCs) presenting to an urban level 1 trauma center from July 2016 to March 2022 was performed. The study population included all adult blunt trauma patients presenting with the mechanism of injury as the reason for transport. Standardized data was collected for each patient and included demographics, presenting vital signs, and injury information. Patients were separated into cohorts based on MOI criteria. The VI group consisted of patients with isolated vehicle intrusion as the mechanism of injury. The MOI + group included those with an isolated mechanism of injury that was not vehicle intrusion, multiple mechanisms of injury, or EMS provider judgment. Trauma center need was defined as an Injury Severity Score (ISS) greater than 15. The primary outcome was the need for hospital admission following activation. Secondary outcomes included operative intervention, intubation, mortality, and imaging modalities obtained. Univariate analyses, using the Student’s t-test on GraphPad Prism Version 9, were conducted to evaluate clinical outcomes with statistical significance set at P < .05. This study was approved by the Institutional Review Board, and a waiver of informed consent was obtained.
Patient Characteristics by Group.
SD = standard deviation; CT = computed tomography; ED = emergency department; GCS = Glasgow Coma Scale; SBP = systolic blood pressure; HR = heart rate; ICU = intensive care unit.
Mechanism of injury has been a part of the field triage guidelines for trauma center activation since its inception with the goal of preferentially transporting critically injured patients to designated trauma centers. Trauma centers are under continual pressure to both reduce undertriage and overtriage rates, with current triage guidelines aiming for less than or equal to 5% and 35%, respectively. 1 This study evaluated the efficacy of vehicle intrusion alone as an indication for trauma activation.
A previous study by Stuke et al found selectively admitting only patients meeting anatomic and physiology criteria (high risk) reduced overtriage from 66% to 9%, while Brown et al report an undertriage rate of 51% selectively using the anatomic and physiologic (A&P) criteria.2,4 Our study found an overtriage rate of 72.1% and an undertriage rate of 55.9%, which does not meet the goal standards by the new guideline standards. Furthermore, the low positive likelihood ratio suggested further evaluation of the validity of vehicle intrusion alone as an MOI should be considered according to guidelines evaluating criteria of positive LR 1.0-1.5 or less. 1
This study is an expansion of the previous literature evaluating the efficacy of vehicle intrusion as a component of MOI but evaluated under the 2011 guidelines. However, it has inherent limitations due to the retrospective, single-center design, and small sample size. Prospective multi-center studies are needed to further evaluate the role of VI as criteria for trauma activation.
In conclusion, this study suggests vehicle intrusion alone may not be an adequate predictor of trauma center need. The evolution of trauma triage guidelines to improve resource utilization without compromising patient care remains an important area of further investigation.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.