Disaster planning for a surgical surge: when mass trauma threatens to overwhelm your operating rooms.

Mass casualty events particularly those requiring multiple simultaneous operating rooms are of increasing concern. Existing literature predominantly focuses on mass casualty care in the emergency department. Hospital disaster plans should include a component focused on preparing for multiple simultaneous operations. When developing this plan, representatives from all segments of the perioperative team should be included. The plan needs to address activation, communication, physical space, staffing, equipment, blood and medications, disposition offloading, special populations, and rehearsal.

Are trauma surgeons prepared? A survey of trauma surgeons' disaster preparedness before and during the COVID-19 pandemic.

Objective: US trauma centers (TCs) must remain prepared for mass casualty incidents (MCIs). However, trauma surgeons may lack formal MCI training. The recent COVID-19 pandemic drove multiple patient surges, overloaded Emergency Medical Services (EMS) agencies, and stressed TCs. This survey assessed trauma surgeons' MCI training, experience, and system and personal preparedness before the pandemic compared with the pandemic's third year. Methods: Survey invitations were emailed to all 1544 members of the American Association for the Surgery of Trauma in 2019, and then resent in 2022 to 1575 members with additional questions regarding the pandemic. Questions assessed practice type, TC characteristics, training, experience, beliefs about personal and hospital preparedness, likelihood of MCI scenarios, interventions desired from membership organizations, and pandemic experiences. Results: The response rate was 16.7% in 2019 and 12% in 2022. In 2022, surgeons felt better prepared than their hospitals for pandemic care, mass shootings, and active shooters, but remained feeling less well prepared for cyberattack and hazardous material events, compared with 2019. Only 35% of the respondents had unintentional MCI response experience in 2019 or 2022, and even fewer had experience with intentional MCI. 78% had completed a Stop the Bleed (STB) course and 63% own an STB kit. 57% had engaged in family preparedness activities; less than 40% had a family action plan if they could not come home during an MCI. 100% of the respondents witnessed pandemic-related adverse events, including colleague and coworker illness, patient surges, and resource limitations, and 17% faced colleague or coworker death. Conclusions: Trauma surgeons thought that they became better at pandemic care and rated themselves as better prepared than their hospitals for MCI care, which is an opportunity for them to take greater leadership roles. Opportunities remain to improve surgeons' family and personal MCI preparedness. Surgeons' most desired professional organization interventions include advocacy, national standards for TC preparedness, and online training. Level of evidence: VII, survey of expert opinion.

The national trauma triage protocol: how EMS perspective can inform the guideline revision.

OBJECTIVES: The Field Triage Guidelines (FTG) support emergency medical service (EMS) decisions regarding the most appropriate transport destination for injured patients. While the components of the algorithm are largely evidenced-based, the stepwise approach was developed with limited input from EMS providers. FTG are only useful if they can easily be applied by the field practitioner. We sought to gather end-user input on the current guidelines from a broad group of EMS stakeholders to inform the next revision of the FTG. METHODS: An expert panel composed an end-user feedback tool. Data collected included: demographics, EMS agency type, geographic area of respondents, use of the current FTG, perceived utility, and importance of each step in the algorithm (1: physiologic, 2: anatomic, 3 mechanistic, 4: special populations). The American College of Surgeons Committee on Trauma (ACS COT), in partnership with several key organizations, distributed the tool to reach as many providers as possible. RESULTS: 3958 responses were received (82% paramedics/emergency medical technicians, 9% physicians, 9% other). 94% responded directly to scene emergency calls and 4% were aeromedical providers. Steps 2 and 3 were used in 95% of local protocols, steps 1 and 4 in 90%. Step 3 was used equally in protocols across all demographics; however, step 1 was used significantly more in the air medical services than ground EMS (96% vs 88%, p<0.05). Geographic variation was demonstrated in FTG use based on the distance to a trauma center, but step 3 (not step 1) drove the majority of the decisions. This point was reinforced in the qualitative data with the comment, "I see the wreck before I see the patient." CONCLUSION: The FTG are widely used by EMS in the USA. The stepwise approach is useful; however, mechanism (not physiological criteria) drives most of the decisions and is evaluated first. Revision of the FTG should consider the experience of the end-users. LEVEL OF EVIDENCE: V.

National Stop the Bleed Day: The impact of a social media campaign on the Stop the Bleed program.

BACKGROUND: National Stop the Bleed Day (NSTBD) was created to increase public awareness of the official Stop-the-Bleed initiative and the Bleeding Control Basic course. The goal was to develop and employ an effective national social media strategy that would encourage and support efforts already in place to train the public in basic bleeding control techniques. METHODS: March 31, 2018, was designated as NSTBD. Analysis focused on a 2-week window centered on NSTBD. The number of courses offered, number of instructors registered and total number of students trained overall during this period was derived from the American College of Surgeons (ACS) website bleedingcontrol.org. Courses not registered with the ACS were not included. Data on overall website activity were also included for analysis. RESULTS: Forty-three states and 18 countries participated in NSTBD. During the study period, there were 1884 courses registered on bleedingcontrol.org. Comparatively, over a 4-month period from August to November 2017, the mean number of registered courses per month was 834. There were 34,699 students trained during the two-week study period as opposed to August to November 2017, the mean number of people trained per month was 9,626. In addition, 576 new B-Con instructors were certified during this time window. Additionally, the international coordinators reported 1500 students were trained during the study period. During this time, the ACS reported a significant increase in website activity. This included 10,530 new visitors, 12,772 visitors overall and 35,342 page views recorded during the study period. CONCLUSION: The NSTBD effort was successful in generating widespread interest for the Stop-the-Bleed initiative. The use of a targeted social media campaign in this context was successful in driving people to available training opportunities while also increasing awareness of the overall effort. While only in its early stages, the NSTBD concept is a good one and should be developed further in coming years. LEVEL OF EVIDENCE: Retrospective, Level V.

Logistics of air medical transport: When and where does helicopter transport reduce prehospital time for trauma?

BACKGROUND: Trauma is a time sensitive disease. Helicopter emergency medical services (HEMS) have shown benefit over ground emergency medical services (GEMS), which may be related to reduced prehospital time. The distance at which this time benefit emerges depends on many factors that can vary across regions. Our objective was to determine the threshold distance at which HEMS has shorter prehospital time than GEMS under different conditions. METHODS: Patients in the Pennsylvania trauma registry 2000 to 2013 were included. Distance between zip centroid and trauma center was calculated using straight-line distance for HEMS and driving distance from geographic information systems network analysis for GEMS. Contrast margins from linear regression identified the threshold distance at which HEMS had a significantly lower prehospital time than GEMS, indicated by nonoverlapping 95% confidence intervals. The effect of peak traffic times and adverse weather on the threshold distance was evaluated. Geographic effects across EMS regions were also evaluated. RESULTS: A total of 144,741 patients were included with 19% transported by HEMS. Overall, HEMS became faster than GEMS at 7.7 miles from the trauma center (p = 0.043). Helicopter emergency medical services became faster at 6.5 miles during peak traffic (p = 0.025) compared with 7.9 miles during off-peak traffic (p = 0.048). Adverse weather increased the distance at which HEMS was faster to 17.1 miles (p = 0.046) from 7.3 miles in clear weather (p = 0.036). Significant variation occurred across EMS regions, with threshold distances ranging from 5.4 to 35.3 miles. There was an inverse but non-significant relationship between urban population and threshold distance across EMS regions (ρ, -0.351, p = 0.28). CONCLUSION: This is the first study to demonstrate that traffic, weather, and geographic region significantly impact the threshold distance at which HEMS are faster than GEMS. Helicopter emergency medical services was faster at shorter distances during peak traffic while adverse weather increased this distance. The threshold distance varied widely across geographic region. These factors must be considered to guide appropriate HEMS triage protocols. LEVEL OF EVIDENCE: Therapeutic, level IV.

Characterizing injury severity in nonaccidental trauma: Does Injury Severity Score miss the mark?

BACKGROUND: Children suffering nonaccidental trauma (NAT) are at high risk of death. It is unclear whether markers of injury severity for trauma center/system benchmarking such as Injury Severity Score (ISS) adequately characterize this. Our objective was to evaluate mortality prediction of ISS in children with NAT compared with accidental trauma (AT). METHODS: Pediatric patients younger than 16 years from the Pennsylvania state trauma registry 2000 to 2013 were included. Logistic regression predicted mortality from ISS for NAT and AT patients. Multilevel logistic regression determined the association between mortality and ISS while adjusting for age, vital signs, and injury pattern in NAT and AT patients. Similar models were performed for head Abbreviated Injury Scale (AIS). Sensitivity analysis examined impaired functional independence at discharge as an alternate outcome. RESULTS: Fifty thousand five hundred seventy-nine patients were included with 1,866 (3.7%) NAT patients. Nonaccidental trauma patients had a similar rate of mortality at an ISS of 13 as an ISS of 25 for AT patients. Nonaccidental trauma patients also have higher mortality for a given head AIS level (range, 1.2-fold to 5.9-fold higher). Injury Severity Score was a significantly greater predictor of mortality in AT patients (adjusted odds rations [AOR], 1.14; 95% confidence interval [CI], 1.13-1.15; p < 0.01) than NAT patients (AOR, 1.09; 95% CI, 1.07-1.12; p < 0.01) per 1-point ISS increase, while head injury was a significantly greater predictor of mortality in NAT patients (AOR, 3.48; 95% CI, 1.54-8.32; p < 0.01) than AT patients (AOR, 1.21; 95% CI, 0.95-1.45; p = 0.12). Nonaccidental trauma patients had a higher rate of impaired functional independence at any given ISS or head AIS level than AT patients. CONCLUSION: Nonaccidental trauma patients have higher mortality and impaired function at a given ISS/head AIS than AT patients. Conventional ISS thresholds may underestimate risk and head injury is a more important predictor of mortality in the NAT population. These findings should be considered in system performance improvement and benchmarking efforts that rely on ISS for injury characterization. LEVEL OF EVIDENCE: Epidemiologic study, level III.

Speed is not everything: Identifying patients who may benefit from helicopter transport despite faster ground transport.

BACKGROUND: Helicopter emergency medical services (HEMS) have demonstrated survival benefits over ground emergency medical services (GEMS) for trauma patient transport. While HEMS speed is often-cited, factors such as provider experience and level of care may also play a role. Our objective was to identify patient groups that may benefit from HEMS even when prehospital time for helicopter utilization is longer than GEMS transport. METHODS: Adult patients transported by HEMS or GEMS from the scene of injury in the Pennsylvania State Trauma Registry were included. Propensity score matching was used to match HEMS and GEMS patients for likelihood of HEMS, keeping only pairs in which the HEMS patient had longer total prehospital time than the matched GEMS patient. Mixed-effects logistic regression evaluated the effect of transport mode on survival while controlling for demographics, admission physiology, transfusions, and procedures. Interaction testing between transport mode and existing trauma triage criteria was conducted and models stratified across significant interactions to determine which criteria identify patients with a significant survival benefit when transported by HEMS even when slower than GEMS. RESULTS: From 153,729 eligible patients, 8,307 pairs were matched. Helicopter emergency medical services total prehospital time was a median of 13 minutes (interquartile range, 6-22) longer than GEMS. Patients with abnormal respiratory rate (odds ratio [OR], 2.39; 95% confidence interval [CI], 1.26-4.55; p = 0.01), Glasgow Coma Scale score of 8 or less (OR, 1.61; 95% CI, 1.16-2.22; p < 0.01), and hemo/pneumothorax (OR, 2.25; 95% CI, 1.06-4.78; p = 0.03) had a significant survival advantage when transported by HEMS even with longer prehospital time than GEMS. Conversely, there was no association between transport mode and survival in patients without these factors (p > 0.05). CONCLUSION: Patients with abnormal respiratory rate, Glasgow Coma Scale score of 8 or less, and hemo/pneumothorax benefit from HEMS transport even when GEMS transport was faster. This may indicate that these patients benefit primarily from HEMS care, such as advanced airway and chest trauma management, rather than simply faster transport to a trauma center. LEVEL OF EVIDENCE: Therapeutic, level III.

The value of the injury severity score in pediatric trauma: Time for a new definition of severe injury?

BACKGROUND: The Injury Severity Score (ISS) is the most commonly used injury scoring system in trauma research and benchmarking. An ISS greater than 15 conventionally defines severe injury; however, no studies evaluate whether ISS performs similarly between adults and children. Our objective was to evaluate ISS and Abbreviated Injury Scale (AIS) to predict mortality and define optimal thresholds of severe injury in pediatric trauma. METHODS: Patients from the Pennsylvania trauma registry 2000-2013 were included. Children were defined as younger than 16 years. Logistic regression predicted mortality from ISS for children and adults. The optimal ISS cutoff for mortality that maximized diagnostic characteristics was determined in children. Regression also evaluated the association between mortality and maximum AIS in each body region, controlling for age, mechanism, and nonaccidental trauma. Analysis was performed in single and multisystem injuries. Sensitivity analyses with alternative outcomes were performed. RESULTS: Included were 352,127 adults and 50,579 children. Children had similar predicted mortality at ISS of 25 as adults at ISS of 15 (5%). The optimal ISS cutoff in children was ISS greater than 25 and had a positive predictive value of 19% and negative predictive value of 99% compared to a positive predictive value of 7% and negative predictive value of 99% for ISS greater than 15 to predict mortality. In single-system-injured children, mortality was associated with head (odds ratio, 4.80; 95% confidence interval, 2.61-8.84; p < 0.01) and chest AIS (odds ratio, 3.55; 95% confidence interval, 1.81-6.97; p < 0.01), but not abdomen, face, neck, spine, or extremity AIS (p > 0.05). For multisystem injury, all body region AIS scores were associated with mortality except extremities. Sensitivity analysis demonstrated ISS greater than 23 to predict need for full trauma activation, and ISS greater than 26 to predict impaired functional independence were optimal thresholds. CONCLUSION: An ISS greater than 25 may be a more appropriate definition of severe injury in children. Pattern of injury is important, as only head and chest injury drive mortality in single-system-injured children. These findings should be considered in benchmarking and performance improvement efforts. LEVEL OF EVIDENCE: Epidemiologic study, level III.

External validation of the Air Medical Prehospital Triage score for identifying trauma patients likely to benefit from scene helicopter transport.

BACKGROUND: The Air Medical Prehospital Triage (AMPT) score was developed to identify injured patients who may benefit from scene helicopter emergency medical services (HEMS) transport. External validation using a different data set is essential to ensure reliable performance. The study objective was to validate the effectiveness of the AMPT score to identify patients with a survival benefit from HEMS using the Pennsylvania Trauma Outcomes Study registry. METHODS: Patients 16 years or older undergoing scene HEMS or ground EMS (GEMS) transport in the Pennsylvania Trauma Outcomes Study registry 2000-2013 were included. Patients with 2 or higher AMPT score points were triaged to HEMS, while those with less than 2 points were triaged to GEMS. Multilevel Poisson regression determined the association of survival with actual transport mode across AMPT score triage assignments, adjusting for demographics, mechanism, vital signs, interventions, and injury severity. Successful validation was defined as no survival benefit for actual HEMS transport in patients triaged to GEMS by the AMPT score, with a survival benefit for actual HEMS transport in patients triaged to HEMS by the AMPT score. Subgroup analyses were performed in patients treated by advanced life support providers and patients with transport times longer than 10 minutes. RESULTS: There were 222,827 patients included. For patients triaged to GEMS by the AMPT score, actual transport mode was not associated with survival (adjusted relative risk, 1.004; 95% confidence interval, 0.999-1.009; p = 0.08). For patients triaged to HEMS by the AMPT score, actual HEMS transport was associated with a 6.7% increase in the relative probability of survival (adjusted relative risk, 1.067; 95% confidence interval, 1.040-1.083, p < 0.001). Similar results were seen in all subgroups. CONCLUSIONS: This study is the first to externally validate the AMPT score, demonstrating the ability of this tool to reliably identify trauma patients most likely to benefit from HEMS transport. The AMPT score should be considered when protocols for HEMS scene transport are developed and reviewed. LEVEL OF EVIDENCE: Epidemiologic/prognostic study, level III; therapeutic/care management study, level IV.

Not all prehospital time is equal: Influence of scene time on mortality.

BACKGROUND: Trauma is time sensitive, and minimizing prehospital (PH) time is appealing. However, most studies have not linked increasing PH time with worse outcomes because raw PH times are highly variable. It is unclear whether specific PH time patterns affect outcomes. Our objective was to evaluate the association of PH time interval distribution with mortality. METHODS: Patients transported by emergency medical services in the Pennsylvania trauma registry from 2000 to 2013 with a total PH time (TPT) of 20 minutes or longer were included. TPT was divided into three PH time intervals: response, scene, and transport time. The number of minutes in each PH time interval was divided by TPT to determine the relative proportion each interval contributed to TPT. A prolonged interval was defined as any one PH interval contributing equal to or greater than 50% of TPT. Patients were classified by prolonged PH interval or no prolonged PH interval (all intervals < 50% of TPT). Patients were matched for TPT, and conditional logistic regression determined the association of mortality with PH time pattern, controlling for confounders. PH interventions were explored as potential mediators, and PH triage criteria used identify patients with time-sensitive injuries. RESULTS: There were 164,471 patients included. Patients with prolonged scene time had increased odds of mortality (odds ratio, 1.21; 95% confidence interval, 1.02-1.44; p = 0.03). Prolonged response, transport, and no prolonged interval were not associated with mortality. When adjusting for mediators including extrication and PH intubation, prolonged scene time was no longer associated with mortality (odds ratio, 1.06; 95% confidence interval, 0.90-1.25; p = 0.50). Together, these factors mediated 61% of the effect between prolonged scene time and mortality. Mortality remained associated with prolonged scene time in patients with hypotension, penetrating injury, and flail chest. CONCLUSION: Prolonged scene time is associated with increased mortality. PH interventions partially mediate this association. Further study should evaluate whether these interventions drive increased mortality because they prolong scene time or by another mechanism, as reducing scene time may be a target for intervention. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level III.

Helicopters and injured kids: Improved survival with scene air medical transport in the pediatric trauma population.

BACKGROUND: Helicopter emergency medical services (HEMS) are frequently used to transport injured children, despite unclear evidence of benefit. The study objective was to evaluate the association of HEMS compared with ground emergency medical services (GEMS) transport with outcomes in a national sample of pediatric trauma patients. METHODS: Patients 15 years or younger undergoing scene transport by HEMS or GEMS in the National Trauma Data Bank from 2007 to 2012 were included. Propensity score matching was used to match HEMS and GEMS patients for likelihood of HEMS transport based on demographics, prehospital physiology and time, injury severity, and geographic region. Absolute standardized differences of less than 0.1 indicated adequate covariate balance between groups after matching. The primary outcome was in-hospital survival, while the secondary outcome was discharge disposition in survivors. Conditional logistic regression determined the association between HEMS versus GEMS transport with outcomes while controlling for demographics, admission physiology, injury severity, nonaccidental trauma, and in-hospital complications not accounted for in the propensity score. Subgroup analysis was performed in patients with a transport time of greater than 15 minutes to capture patients with the potential for HEMS transport. RESULTS: A total of 25,700 HEMS/GEMS pairs were matched from 166,594 patients. Groups were well matched, with all propensity score variables having absolute standardized differences of less than 0.1. In matched patients, HEMS was associated with a 72% increase in odds of survival compared with GEMS (adjusted odds ratio, 1.72; 95% confidence interval, 1.26-2.36; p < 0.01). Transport mode was not associated with discharge disposition (p = 0.47). Subgroup analysis included 17,657 HEMS/GEMS pairs. HEMS was again associated with a significant increase in odds of survival (adjusted odds ratio, 1.81; 95% confidence interval, 1.24-2.65; p < 0.01), while transport mode was not associated with discharge disposition (p = 0.58). CONCLUSION: Scene transport by HEMS was associated with improved odds of survival compared with GEMS in pediatric trauma patients. Further study is warranted to understand the underlying mechanisms and develop specific triage criteria for HEMS transport in this population. LEVEL OF EVIDENCE: Therapeutic study, level III.

Helicopter transport improves survival following injury in the absence of a time-saving advantage.

BACKGROUND: Although survival benefits have been shown at the population level, it remains unclear what drives the outcome benefits for helicopter emergency medical services (HEMS) in trauma. Although speed is often cited as the vital factor of HEMS, we hypothesized a survival benefit would exist in the absence of a time savings over ground emergency medical services (GEMS). The objective was to examine the association of survival with HEMS compared with GEMS transport across similar prehospital transport times. METHODS: We used a retrospective cohort of scene HEMS and GEMS transports in the National Trauma Databank (2007-2012). Propensity score matching was used to match HEMS and GEMS subjects on the likelihood of HEMS transport. Subjects were stratified by prehospital transport times in 5-minute increments. Conditional logistic regression determined the association of HEMS with survival across prehospital transport times strata controlling for confounders. Transport distance was estimated from prehospital transport times and average HEMS/GEMS transport speeds. RESULTS: There were 155,691 HEMS/GEMS pairs matched. HEMS had a survival benefit over GEMS for prehospital transport times between 6 and 30 minutes. This benefit ranged from a 46% increase in odds of survival between 26 and 30 minutes (adjusted odds ratio [AOR], 1.46; 95% CI, 1.11-1.93; P < .01) to an 80% increase in odds of survival between 16 and 20 minutes (AOR, 1.80; 95% CI, 1.51-2.14; P < .01). This prehospital transport times window corresponds to estimated transport distance between 14.3 and 71.3 miles for HEMS and 3.3 and 16.6 miles for GEMS. CONCLUSION: When stratified by prehospital transport times, HEMS had a survival benefit concentrated in a window between 6 and 30 minutes. Because there was no time-savings advantage for HEMS, these findings may reflect care delivered by HEMS providers.

Development and Validation of the Air Medical Prehospital Triage Score for Helicopter Transport of Trauma Patients.

OBJECTIVE: The aim of this study was to develop and internally validate a triage score that can identify trauma patients at the scene who would potentially benefit from helicopter emergency medical services (HEMS). SUMMARY BACKGROUND DATA: Although survival benefits have been shown at the population level, identification of patients most likely to benefit from HEMS transport is imperative to justify the risks and cost of this intervention. METHODS: Retrospective cohort study of subjects undergoing scene HEMS or ground emergency medical services (GEMS) in the National Trauma Databank (2007-2012). Data were split into training and validation sets. Subjects were grouped by triage criteria in the training set and regression used to determine which criteria had a survival benefit associated with HEMS. Points were assigned to these criteria to develop the Air Medical Prehospital Triage (AMPT) score. The score was applied in the validation set to determine whether subjects triaged to HEMS had a survival benefit when actually transported by helicopter. RESULTS: There were 2,086,137 subjects included. Criteria identified for inclusion in the AMPT score included GCS <14, respiratory rate <10 or >29, flail chest, hemo/pneumothorax, paralysis, and multisystem trauma. The optimal cutoff for triage to HEMS was ≥2 points. In subjects triaged to HEMS, actual transport by HEMS was associated with an increased odds of survival (AOR 1.28; 95% confidence interval [CI] 1.21-1.36, P < 0.01). In subjects triaged to GEMS, actual transport mode was not associated with survival (AOR 1.04; 95% CI 0.97-1.11, P = 0.20). CONCLUSIONS: The AMPT score identifies patients with improved survival following HEMS transport and should be considered in air medical triage protocols.

Geographic Variation in Outcome Benefits of Helicopter Transport for Trauma in the United States: A Retrospective Cohort Study.

OBJECTIVE: Evaluate the effect of US geographic region on outcomes of helicopter transport (HT) for trauma. BACKGROUND: HT is an integral component of trauma systems. Evidence suggests that HT is associated with improved outcomes; however, no studies examine the impact of geographic variation on outcomes for HT. METHODS: Retrospective cohort study of patients undergoing scene HT or ground transport in the National Trauma Databank (2009-2012). Subjects were divided by US census region. HT and ground transport subjects were propensity-score matched based on prehospital physiology and injury severity. Conditional logistic regression was used to evaluate the effect of HT on survival and discharge to home in each region. Region-level characteristics were assessed as potential explanatory factors. RESULTS: A total of 193,629 pairs were matched. HT was associated with increased odds of survival and discharge to home; however, the magnitude of these effects varied significantly across regions (P < 0.01). The South had the greatest survival benefit (odds ratio: 1.44; 95% confidence interval: 1.39-1.49, P < 0.01) and the Northeast had the greatest discharge to home benefit (odds ratio: 1.29; 95% confidence interval: 1.18-1.41, P < 0.01). A subset of region-level characteristics influenced the effect of HT on each outcome, including helicopter utilization, injury severity, trauma center and helicopter distribution, trauma center access, traffic congestion, and urbanicity (P < 0.05). CONCLUSIONS: Geographic region impacts the benefits of HT in trauma. Variations in resource allocation partially account for outcome differences. Policy makers should consider regional factors to better assess and allocate resources within trauma systems to optimize the role of HT.