Association Between Emergency Medical Service Agency Volume and Mortality in Trauma Patients.

OBJECTIVE: The aim of this study was to evaluate the association of annual trauma patient volume on outcomes for emergency medical services (EMS) agencies. BACKGROUND: Regionalization of trauma care saves lives. The underlying concept driving this is a volume-outcome relationship. EMS are the entry point to the trauma system, yet it is unknown if a volume-outcome relationship exists for EMS. METHODS: A retrospective analysis of prospective cohort including 8 trauma centers and 20 EMS air medical and metropolitan ground transport agencies. Patients 18 to 90 years old with injury severity scores ≥9 transported from the scene were included. Patient and agency-level risk-adjusted regression determined the association between EMS agency trauma patient volume and early mortality. RESULTS: A total of 33,511 were included with a median EMS agency volume of 374 patients annually (interquartile range: 90-580). Each 50-patient increase in EMS agency volume was associated with 5% decreased odds of 6-hour mortality (adjusted odds ratio=0.95; 95% CI: 0.92-0.99, P =0.03) and 3% decreased odds of 24-hour mortality (adjusted odds ratio=0.97; 95% CI: 0.95-0.99, P =0.04). Prespecified subgroup analysis showed EMS agency volume was associated with reduced odds of mortality for patients with prehospital shock, requiring prehospital airway placement, undergoing air medical transport, and those with traumatic brain injury. Agency-level analysis demonstrated that high-volume (>374 patients/year) EMS agencies had a significantly lower risk-standardized 6-hour mortality rate than low-volume (<374 patients/year) EMS agencies (1.9% vs 4.8%, P <0.01). CONCLUSIONS: A higher volume of trauma patients transported at the EMS agency level is associated with improved early mortality. Further investigation of this volume-outcome relationship is necessary to leverage quality improvement, benchmarking, and educational initiatives.

Impact of patient, system, and environmental factors on utilization of air medical transport after trauma.

BACKGROUND: Air medical transport (AMT) improves outcomes for severely injured patients. The decision to fly patients is complex and must consider multiple factors. Our objective was to evaluate the interaction between geography, patient and environmental factors, and emergency medical services (EMS) system resources on AMT after trauma. We hypothesize that significant geographic variation in AMT utilization will be associated with varying levels of patient, environmental, and EMS resources. METHODS: Patients transported by EMS in the Pennsylvania state trauma registry 2000 to 2017 were included. We used our previously developed Air Medical Prehospital Triage (AMPT; ≥2 points triage to AMT) score and Geographic Emergency Medical Services Index (GEMSI; higher indicates more system resources) as measures for patient factors and EMS resources, respectively. A mixed-effects logistic regression model determined the association of AMT utilization with patient, system, and environmental variables. RESULTS: There were 195,354 patients included. Fifty-five percent of variation in AMT utilization was attributed to geographic differences. Triage to AMT by the AMPT score was associated with nearly twice the odds of AMT utilization (adjusted odds ratio, 1.894; 95% confidence interval, 1.765-2.032; p < 0.001). Each 1-point increase in GEMSI was associated with a 6.1% reduction in odds of AMT (0.939; 0.922-0.957; p < 0.001). Younger age, rural location, and more severe injuries were also associated with increased odds of AMT ( p < 0.05). When categorized by GEMSI level, the AMPT score and patient factors were more important for predicting AMT utilization in the middle tercile (moderate EMS resources) compared with the lower (low EMS resources) and higher tercile (high EMS resources). Weather, season, time-of-day, and traffic were all associated with AMT utilization ( p < 0.05). CONCLUSION: Patient, system, and environmental factors are associated with AMT utilization, which varies geographically and by EMS/trauma system resource availability. A more comprehensive approach to AMT triage could reduce variation and allow more tailored efforts toward optimizing resource allocation and outcomes. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III.

Evaluating potential disparities in geospatial access to American College of Surgeons/American Association for the Surgery of Trauma-verified emergency general surgery centers.

BACKGROUND: The American Association for the Surgery of Trauma and the American College of Surgeons have recently introduced emergency general surgery (EGS) center verification, which could enhance patient outcomes. Distance and resource availability may affect access to these centers, which has been linked to higher mortality. Although many patients can receive adequate care at community centers, those with critical conditions may require specialized treatment at EGS-verified centers. We aimed to evaluate geospatial access to potential EGS-verified centers and identify disparities across different scenarios of EGS verification program uptake in the United States. METHODS: We used hospital capabilities and verified pilot centers to estimate potential patterns of which centers would become EGS verified under four scenarios (EGS centers, high-volume EGS centers, high-volume EGS plus level 1 trauma centers, and quaternary referral centers). We calculated the spatial accessibility index using an enhanced two-step floating catchment technique to determine geospatial access for each scenario. We also evaluated social determinants of health across geospatial access using the Area Deprivation Index (ADI). RESULTS: A total of 1,932 hospitals were categorized as EGS centers, 307 as high-volume EGS centers, 401 as high-volume EGS plus level 1trauma centers, and 146 as quaternary centers. Spatial accessibility index decreased as the stringency of EGS verification increased in each scenario (226.6 [111.7-330.7], 51.8 [0-126.1], 71.52 [3.34-164.56], 6.2 [0-62.2]; p < 0.001). Within each scenario, spatial accessibility index also declined as the ADI quartile increased ( p < 0.001). The high-volume EGS plus level 1trauma center scenario had the most significant disparity in access between the first and fourth ADI quartiles (-54.68). CONCLUSION: Access to EGS-verified centers may vary considerably based on the program's implementation. Disadvantaged communities may be disproportionately affected by limited access. Further work to study regional needs can allow a strategic implementation of the EGS verification program to optimize outcomes while minimizing disparities. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

The Geography of Injuries in Trauma Systems: Using Home as a Proxy for Incident Location.

INTRODUCTION: Effective trauma system organization is crucial to timely access to care and requires accurate understanding of injury and resource locations. Many systems rely on home zip codes to evaluate geographic distribution of injury; however, few studies have evaluated the reliability of home as a proxy for incident location after injury. METHODS: We analyzed data from a multicenter prospective cohort collected from 2017 to 2021. Injured patients with both home and incident zip codes were included. Outcomes included discordance and differential distance between home and incident zip code. Associations of discordance with patient characteristics were determined by logistic regression. We also assessed trauma center catchment areas based on home versus incident zip codes and variation regionally at each center. RESULTS: Fifty thousand one hundred seventy-five patients were included in the analysis. Home and incident zip codes were discordant in 21,635 patients (43.1%). Injuries related to motor vehicles (aOR: 4.76 [95% CI 4.50-5.04]) and younger adults 16-64 (aOR: 2.46 [95% CI 2.28-2.65]) were most likely to be discordant. Additionally, as injury severity score increased, discordance increased. Trauma center catchment area differed up to two-thirds of zip codes when using home versus incident location. Discordance rate, discordant distance, and catchment area overlap between home and incident zip codes all varied significantly by geographic region. CONCLUSIONS: Home location as proxy for injury location should be used with caution and may impact trauma system planning and policy, especially in certain populations. More accurate geolocation data are warranted to further optimize trauma system design.

Direct Trauma Center Access by Helicopter Emergency Medical Services is Associated With Improved Survival After Severe Injury.

OBJECTIVE: Evaluate the association of survival with helicopter transport directly to a trauma center compared with ground transport to a non-trauma center (NTC) and subsequent transfer. SUMMARY BACKGROUND DATA: Helicopter transport improves survival after injury. One potential mechanism is direct transport to a trauma center when the patient would otherwise be transported to an NTC for subsequent transfer. METHODS: Scene patients 16 years and above with positive physiological or anatomic triage criteria within PTOS 2000-2017 were included. Patients transported directly to level I/II trauma centers by helicopter were compared with patients initially transported to an NTC by ground with a subsequent helicopter transfer to a level I/II trauma center. Propensity score matching was used to evaluate the association between direct helicopter transport and survival. Individual triage criteria were evaluated to identify patients most likely to benefit from direct helicopter transport. RESULTS: In all, 36,830 patients were included. Direct helicopter transport was associated with a nearly 2-fold increase in odds of survival compared with NTC ground transport and subsequent transfer by helicopter (aOR 2.78; 95% CI 2.24-3.44, P <0.01). Triage criteria identifying patients with a survival benefit from direct helicopter transport included GCS≤13 (1.71; 1.22-2.41, P <0.01), hypotension (2.56; 1.39-4.71, P <0.01), abnormal respiratory rate (2.30; 1.36-3.89, P <0.01), paralysis (8.01; 2.03-31.69, P <0.01), hemothorax/pneumothorax (2.34; 1.36-4.05, P <0.01), and multisystem trauma (2.29; 1.08-4.84, P =0.03). CONCLUSIONS: Direct trauma center access is a mechanism driving the survival benefit of helicopter transport. First responders should consider helicopter transport for patients meeting these criteria who would otherwise be transported to an NTC.

Review of Diet Protocols Following Orthognathic Surgery and Analysis of Postoperative Weight Loss.

INTRODUCTION: Orthognathic surgery is routinely practiced, yet little comparative data exists to evaluate post-orthognathic surgery diet protocols. OBJECTIVE: To evaluate which postoperative diet protocols are recommended and to quantify post-orthognathic surgery weight changes in our institutional cohort. METHODS: An internet search was carried out on Google for "orthognathic surgery diet" and the postoperative diet recommendations from centers worldwide were quantified. Additionally, a retrospective analysis of patients that underwent orthognathic surgery at our institution was performed, and their preoperative and postoperative weights were recorded. RESULTS: The internet search yielded 58 centers that met our inclusion criteria. Most centers were in the United States (n = 37, 63.8%) and were oral and maxillofacial surgeon (OMFS)-led centers (n = 39, 67.2%). Postoperative diets were categorized into 7 distinct protocols, ranging from most to least restrictive-the most popular was liquid diet for 2 to 4 weeks followed by soft diet for 2 to 6 weeks. There were no significant patterns observed across different geographical regions or specialties.In our institution, 135 patients were identified. Overall, there was an average maximum weight loss of 4.1 kg by week 4, followed by a gradual increase in weight. Linear regression analysis showed that patients with greater preoperative body mass index (BMI) lost more weight postoperatively than patients with lower BMI (R2 = 0.25, P < .001). CONCLUSION: There is a significant variability in recommended postoperative diets following orthognathic surgery. Following a moderately restrictive diet at our institution, patients returned to their preoperative weight after approximately 4 months.

The Subventricular Zone in Glioblastoma: Genesis, Maintenance, and Modeling.

Glioblastoma (GBM) is a malignant tumor with a median survival rate of 15-16 months with standard care; however, cases of successful treatment offer hope that an enhanced understanding of the pathology will improve the prognosis. The cell of origin in GBM remains controversial. Recent evidence has implicated stem cells as cells of origin in many cancers. Neural stem/precursor cells (NSCs) are being evaluated as potential initiators of GBM tumorigenesis. The NSCs in the subventricular zone (SVZ) have demonstrated similar molecular profiles and share several distinctive characteristics to proliferative glioblastoma stem cells (GSCs) in GBM. Genomic and proteomic studies comparing the SVZ and GBM support the hypothesis that the tumor cells and SVZ cells are related. Animal models corroborate this connection, demonstrating migratory patterns from the SVZ to the tumor. Along with laboratory and animal research, clinical studies have demonstrated improved progression-free survival in patients with GBM after radiation to the ipsilateral SVZ. Additionally, key genetic mutations in GBM for the most part carry regulatory roles in the SVZ as well. An exciting avenue towards SVZ modeling and determining its role in gliomagenesis in the human context is human brain organoids. Here we comprehensively discuss and review the role of the SVZ in GBM genesis, maintenance, and modeling.