Association of pediatric firearm injury with neighborhood social deprivation in Philadelphia.

Background: Firearm-related injury is the leading cause of death among children and adolescents. There is a need to clarify the association of neighborhood environment with gun violence affecting children. We evaluated the relative contribution of specific social determinants to observed rates of firearm-related injury in children of different ages. Methods: This was a population-based study of firearm injury in children (age <18 years) that occurred in Philadelphia census tracts (2015-2021). The exposure was neighborhood Social Deprivation Index (SDI) quintile. The outcome was the rate of pediatric firearm injury due to interpersonal violence stratified by age, sex, race, and year. Hierarchical negative binomial regression measured the risk-adjusted association between SDI quintile and pediatric firearm injury rate. The relative contribution of specific components of the SDI to neighborhood risk of pediatric firearm injury was estimated. Effect modification and the role of specific social determinants were evaluated in younger (<15 years old) versus older children. Results: 927 children were injured due to gun violence during the study period. Firearm-injured children were predominantly male (87%), of black race (89%), with a median age of 16 (IQR 15-17). Nearly one-half of all pediatric shootings (47%) occurred in the quintile of highest SDI (Q5). Younger children represented a larger proportion of children shot in neighborhoods within the highest (Q5), compared with the lowest (Q1), SDI quintile (25% vs 5%; p<0.007). After risk adjustment, pediatric firearm-related injury was strongly associated with increasing SDI (Q5 vs Q1; aRR 14; 95% CI 6 to 32). Specific measures of social deprivation (poverty, incomplete schooling, single-parent homes, and rented housing) were associated with significantly greater increases in firearm injury risk for younger, compared with older, children. Component measures of the SDI explained 58% of observed differences between neighborhoods. Conclusions: Neighborhood measures of social deprivation are strongly associated with firearm-related injury in children. Younger children appear to be disproportionately affected by specific adverse social determinants compared with older children. Root cause evaluation is required to clarify the interaction with other factors such as the availability of firearms and interpersonal conflict that place children at risk in neighborhoods where gun violence is common. Level of evidence: Level III - Observational Study.

Changes in payer mix of new and established trauma centers: the new trauma center money grab?

Background: Although timely access to trauma center (TC) care for injured patients is essential, the proliferation of new TCs does not always improve outcomes. Hospitals may seek TC accreditation for financial reasons, rather than to address community or geographic need. Introducing new TCs risks degrading case and payer mix at established TCs. We hypothesized that newly accredited TCs would see a disproportionate share of commercially insured patients. Study design: We collected data from all accredited adult TCs in Pennsylvania using the state trauma registry from 1999 to 2018. As state policy regarding supplemental reimbursement for underinsured patients changed in 2004, we compared patient characteristics and payer mix between TCs established before and after 2004. We used multivariable logistic regression to assess the relationship between payer and presentation to a new versus established TC in recent years. Results: Over time, there was a 40% increase in the number of TCs from 23 to 38. Of 326 204 patients from 2010 to 2018, a total of 43 621 (13.4%) were treated at 15 new TCs. New TCs treated more blunt trauma and less severely injured patients (p<0.001). In multivariable analysis, patients presenting to new TCs were more likely to have Medicare (OR 2.0, 95% CI 1.9 to 2.1) and commercial insurance (OR 1.6, 95% CI 1.5 to 1.6) compared with Medicaid. Over time, fewer patients at established TCs and more patients at new TCs had private insurance. Conclusions: With the opening of new centers, payer mix changed unfavorably at established TCs. Trauma system development should consider community and regional needs, as well as impact on existing centers to ensure financial sustainability of TCs caring for vulnerable patients. Level of evidence: Level III, prognostic/epidemiological.

High-Fidelity Bleeding Control Simulation Scenario During Medical Student Orientation Improves Students' Self-Reported Ability to Identify and Treat Life-Threatening Bleeding with 3-year Follow-up.

OBJECTIVE: Increasingly, medical schools integrate clinical skills into early didactic coursework. The Stop the Bleed® Campaign emphasizes prehospital hemorrhage control to reduce preventable deaths; however, this course overlooks team interactions. We assessed the impact of high-fidelity simulation during medical student orientation on identification and treatment of life-threatening hemorrhage in a team setting. DESIGN: In this mixed method, prospective pre-, post-, and follow-up survey analysis assessing student knowledge and attitudes, student teams encountered a standardized patient in a prehospital environment with pulsatile bleeding from an extremity wound. Individual students completed surveys assessing previous experience, willingness and ability to assist bleeding person(s), and knowledge and attitudes about tourniquets. Postscenario, faculty preceptors made qualitative observations on teamwork. SETTING: Medical student orientation at a tertiary care academic medical center with long-term follow-up. PARTICIPANTS: Medical students (N = 150). RESULTS: Ninety students (60%) completed both pre- and postsimulation questionnaires. Sixteen (17%) students had previous tourniquet training experience although none had applied a tourniquet outside of training. Postsimulation, students reported increased likelihood of providing treatment until additional help arrived (p = 0.035), improved ability to identify life-threatening hemorrhage (p < 0.001), and more favorable opinions about tourniquet use (p < 0.001) and potential for limb-salvage (p = 0.018). Long-term follow-up respondents (n = 34, 23%) reported increased ability to identify life-threatening hemorrhage (p = 0.010) and universal willingness to intervene until additional help arrived. Follow-up survey responses elicited themes in hemorrhage control including recognition of the importance of continuous pressure, appropriate use of tourniquets, a desire for repeated team training, and the recognition of clerkship rotations as an optimal setting for skill reinforcement. Preceptors noted variable team responses but uniformly endorsed the exercise. CONCLUSIONS: High-fidelity bleeding simulation during medical student orientation improved students' knowledge and attitudes about treating life-threatening hemorrhage and served as an introduction to team-based emergency care. Future studies should further explore team training and hemorrhage control education.

Solid Metal Chemical and Thermal Injury Management.

INTRODUCTION: Solid metals may create a variety of injuries. White phosphorous (WP) is a metal that causes both caustic and thermal injuries. Because of its broad use in munitions and smoke screens during conflicts and wars, all military clinicians should be competent at WP injury identification and acute therapy, as well as long-term consequence recognition. MATERIALS AND METHODS: English-language manuscripts addressing WP injuries were curated from PubMed and Medline from inception to January 31, 2024. Data regarding WP injury identification, management, and sequelae were abstracted to construct a Scale for the Assessment of Narrative Review Articles guideline-consistent narrative review. RESULTS: White phosphorous appears to be ubiquitous in military conflicts. White phosphorous creates a characteristic wound appearance accompanied by smoke, a garlic aroma, and spontaneous combustion on contact with air. Decontamination and burning prevention or cessation are key and may rely on aqueous irrigation and submersion or immersion in substances that prevent air contact. Topical cooling is a key aspect of preventing spontaneous ignition as well. Disposal of all contaminated clothing and gear is essential to prevent additional injury, especially to rescuers. Long-term sequelae relate to phosphorous absorption and may lead to death. Chronic or repeated exposure may induce jaw osteonecrosis. Tactical Combat Casualty Care recommendations do not currently address WP injury management. CONCLUSIONS: Education and management regarding WP acute injury and late sequelae is essential for acute battlefield and definitive facility care. Resource-replete and resource-limited settings may use related approaches for acute management and ignition prevention. Current burn wound management recommendations should incorporate specific WP management principles and actions for military clinicians at every level of skill and environment.

Real-time performance improvement optimizes damage control resuscitation best practice adherence: Results of a pilot prospective observational study.

BACKGROUND: Maintaining balanced blood product ratios during damage control resuscitation (DCR) is independently associated with improved survival. We hypothesized that real-time performance improvement (RT-PI) would increase adherence to DCR best practice. STUDY DESIGN AND METHODS: From December 2020-August 2021, we prospectively used a bedside RT-PI tool to guide DCR in severely injured patients surviving at least 30 min. RT-PI study patients were compared to contemporary control patients at our institution and historic PROMMTT study patients. A subset of patients transfused ≥6 U red blood cells (RBC) in 6 h (MT+) was also identified. The primary endpoint was percentage time in a high ratio range (≥3:4) of plasma (PLAS):RBC and platelet (PLT):RBC over 6 h. Secondary endpoints included time to massive transfusion protocol activation, time to calcium and tranexamic acid (TXA) dosing, and cumulative 6-h ratios. RESULTS: Included patients (n = 772) were 35 (24-51) years old with an Injury Severity Score of 27 (17-38) and 42% had penetrating injuries. RT-PI (n = 10) patients spent 96% of the 6-h resuscitation in a high PLAS:RBC range, no different versus CONTROL (n = 87) (96%) but more than PROMMTT (n = 675) (25%, p < .001). In the MT+ subgroup, optimal PLAS:RBC and PLT:RBC were maintained for the entire 6 h in RT-PI (n = 4) versus PROMMTT (n = 391) patients for both PLAS (p < .001) and PLT ratios (p < .001). Time to TXA also improved significantly in RT-PI versus CONTROL patients (27 min [22-31] vs. 51 min [29-98], p = .035). CONCLUSION: In this prospective study, RT-PI was associated with optimized DCR. Multicenter validation of this novel approach to optimizing DCR implementation is warranted.

Early GFAP and UCH-L1 point-of-care biomarker measurements for the prediction of traumatic brain injury and progression in patients with polytrauma and hemorrhagic shock.

OBJECTIVE: Traumatic brain injury (TBI) and hemorrhage are responsible for the largest proportion of all trauma-related deaths. In polytrauma patients at risk of hemorrhage and TBI, the diagnosis, prognosis, and management of TBI remain poorly characterized. The authors sought to characterize the predictive capabilities of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCH-L1) measurements in patients with hemorrhagic shock with and without concomitant TBI. METHODS: The authors performed a secondary analysis on serial blood samples derived from a prospective observational cohort study that focused on comparing early whole-blood and component resuscitation. A convenience sample of patients was used in which samples were collected at three time points and the presence of TBI or no TBI via CT imaging was documented. GFAP and UCH-L1 measurements were performed on plasma samples using the i-STAT Alinity point-of-care platform. Using classification tree recursive partitioning, the authors determined the measurement cut points for each biomarker to maximize the abilities for predicting the diagnosis of TBI, Rotterdam CT imaging scores, and 6-month Glasgow Outcome Scale-Extended (GOSE) scores. RESULTS: Biomarker comparisons demonstrated that GFAP and UCH-L1 measurements were associated with the presence of TBI at all time points. Classification tree analyses demonstrated that a GFAP level > 286 pg/ml for the sample taken upon the patient's arrival had an area under the receiver operating characteristic curve of 0.77 for predicting the presence of TBI. The classification tree results demonstrated that a cut point of 3094 pg/ml for the arrival GFAP measurement was the most predictive for an elevated Rotterdam score on the initial and second CT scans and for TBI progression between scans. No significant associations between any of the most predictive cut points for UCH-L1 and Rotterdam CT scores or TBI progression were found. The predictive capabilities of UCH-L1 were limited by the range allowed by the point-of-care platform. Arrival GFAP cut points remained strong independent predictors after controlling for all potential polytrauma confounders, including injury characteristics, shock severity, and resuscitation. CONCLUSIONS: Early measurements of GFAP and UCH-L1 on a point-of-care device are significantly associated with CT-diagnosed TBI in patients with polytrauma and shock. Early elevated GFAP measurements are associated with worse head CT scan Rotterdam scores, TBI progression, and worse GOSE scores, and these associations are independent of other injury attributes, shock severity, and early resuscitation characteristics.

Digital twin mathematical models suggest individualized hemorrhagic shock resuscitation strategies.

BACKGROUND: Optimizing resuscitation to reduce inflammation and organ dysfunction following human trauma-associated hemorrhagic shock is a major clinical hurdle. This is limited by the short duration of pre-clinical studies and the sparsity of early data in the clinical setting. METHODS: We sought to bridge this gap by linking preclinical data in a porcine model with clinical data from patients from the Prospective, Observational, Multicenter, Major Trauma Transfusion (PROMMTT) study via a three-compartment ordinary differential equation model of inflammation and coagulation. RESULTS: The mathematical model accurately predicts physiologic, inflammatory, and laboratory measures in both the porcine model and patients, as well as the outcome and time of death in the PROMMTT cohort. Model simulation suggests that resuscitation with plasma and red blood cells outperformed resuscitation with crystalloid or plasma alone, and that earlier plasma resuscitation reduced injury severity and increased survival time. CONCLUSIONS: This workflow may serve as a translational bridge from pre-clinical to clinical studies in trauma-associated hemorrhagic shock and other complex disease settings.

Research to improve survival in patients with severe bleeding after major trauma presents many challenges. Here, we created a computer model to simulate the effects of severe bleeding. We refined this model using data from existing animal studies to ensure our simulations were accurate. We also used patient data to further refine the simulations to accurately predict which patients would live and which would not. We studied the effects of different treatment protocols on these simulated patients and show that treatment with plasma (the fluid portion of blood that helps form blood clots) and red blood cells jointly, gave better results than treatment with intravenous fluid or plasma alone. Early treatment with plasma reduced injury severity and increased survival time. This modelling approach may improve our ability to evaluate new treatments for trauma-associated bleeding and other acute conditions.

Missing in action: A bibliometric analysis of military research in the medical literature since 1950.

BACKGROUND: Top-tier general and specialty scientific journals serve as a bellwether for national research priorities. We hypothesize that military-relevant publications are underrepresented in the scientific literature and that such publications decrease significantly during peacetime. METHODS: We identified high impact journals in the fields of Medicine, Surgery and Critical Care and developed Boolean searches for military-focused topics using National Library of Medicine Subject Headings terms. A PubMed search from 1950 to 2020 returned the number of research publications in relevant journals and the rate of military-focused publications by year. Rates of military publications were compared between peacetime and wartime. Publication rate trends were modeled with a quadratic function controlling for the start of active conflict and total casualty numbers. Baseline proportions of military physicians relative to the civilian sector served to estimate expected publication rates. Comparisons were performed using Pearson's χ 2 and Mann-Whitney U test, with p < 0.05 considered a significant difference. RESULTS: From 1950 to 2020, a total of 716,340 manuscripts were published in the journals queried. Of these, military-relevant manuscripts totaled 4,052 (0.57%). We found a significant difference in the rate of publication during times of peace and times of war (0.40% vs. 0.69%, p < 0.001). Subgroup analysis found significantly reduced rates of publication in medical and critical care journals during peacetime. For each conflict, the percentage of military-focused publications peaked during periods of war but then receded below baseline levels within a median of 2.5 years (interquartile range, 1.5-3.8 years) during peacetime. The proportion of military-focused publications never reached the current proportion of military physicians in the workforce. CONCLUSION: There is marked reduction in rates of publication for military-focused articles in high impact journals during peacetime. Military-focused articles are underrepresented in high-impact journals. Investigators of military-relevant topics and editors of high-impact journals should seek to close this gap.

Hemodynamic Deterioration of Trauma Patients Undergoing Interhospital Transfer.

INTRODUCTION: Organized trauma systems reduce morbidity and mortality after serious injury. Rapid transport to high-level trauma centers is ideal, but not always feasible. Thus, interhospital transfers are an important component of trauma systems. However, transferring a seriously injured patient carries the risk of worsening condition before reaching definitive care. In this study, we evaluated characteristics and outcomes of patients whose hemodynamic status worsened during the transfer process. METHODS: We conducted a retrospective cohort study using data from the Pennsylvania Trauma Outcomes Study database from 2011 to 2018. Patients were included if they had a heart rate ≤ 100 and systolic blood pressure ≥ 100 at presentation to the referring hospital and were transferred within 24 h. We defined hemodynamic deterioration (HDD) as admitting heart rate > 100 or systolic blood pressure < 100 at the receiving center. We compared demographics, mechanism of injury, injury severity, management, and outcomes between patients with and without HDD using descriptive statistics and multivariable regression analysis. RESULTS: Of 52,919 included patients, 5331 (10.1%) had HDD. HDD patients were more often moderately-severely injured (injury severity score 9-15; 40.4% versus 39.4%, P < 0.001) and injured via motor vehicle collision (23.2% versus 16.6%, P < 0.001) or gunshot wound (2.1% versus 1.3%, P < 0.001). HDD patients more often had extremity or torso injuries and after transfer were more likely to be transferred to the intensive care unit (35% versus 28.5%, P < 0.001), go directly to surgery (8.4% versus 5.9%, P < 0.001), or interventional radiology (0.8% versus 0.3%, P < 0.001). Overall mortality in the HDD group was 4.9% versus 2.1% in the group who remained stable. These results were confirmed using multivariable analysis. CONCLUSIONS: Interhospital transfers are essential in trauma, but one in 10 transferred patients deteriorated hemodynamically in that process. This high-risk component of the trauma system requires close attention to the important aspects of transfer such as patient selection, pretransfer management/stabilization, and communication between facilities.

What's new in whole blood resuscitation? In the trauma bay and beyond.

PURPOSE OF REVIEW: Transfusion therapy commonly supports patient care during life-threatening injury and critical illness. Herein we examine the recent resurgence of whole blood (WB) resuscitation for patients in hemorrhagic shock following trauma and other causes of severe bleeding. RECENT FINDINGS: A growing body of literature supports the use of various forms of WB for hemostatic resuscitation in military and civilian trauma practice. Different types of WB include warm fresh whole blood (FWB) principally used in the military and low titer O cold stored whole blood (LTOWB) used in a variety of military and civilian settings. Incorporating WB initial resuscitation alongside subsequent component therapy reduces aggregate blood product utilization and improves early mortality without adversely impacting intensive care unit length of stay or infection rate. Applications outside the trauma bay include prehospital WB and use in patients with nontraumatic hemorrhagic shock. SUMMARY: Whole blood may be transfused as FWB or LTOWB to support a hemostatic approach to hemorrhagic shock management. Although the bulk of WB resuscitation literature has appropriately focused on hemorrhagic shock following injury, extension to other etiologies of severe hemorrhage will benefit from focused inquiry to address cost, efficacy, approach, and patient-centered outcomes.

Percutaneous thoracostomy with thoracic lavage for traumatic hemothorax: a performance improvement initiative.

Objectives: Percutaneously placed small-bore (14 Fr) catheters and pleural lavage have emerged independently as innovative approaches to hemothorax management. This report describes techniques for combining percutaneous thoracostomy with pleural lavage and presents results from a performance improvement series of patients managed with percutaneous thoracostomy with immediate lavage. Methods: This was a prospective performance improvement series of patients treated at a level 1 trauma center with percutaneous thoracostomy and immediate lavage between April 2021 and May 2023. Results: Percutaneous thoracostomy with immediate lavage was used to treat nine hemodynamically normal patients with acute hemothorax. Injuries included both blunt and penetrating mechanisms. 56% of patients presented immediately after injury, and 44% presented in a delayed fashion ranging from 2 to 26 days after injury. Median length of stay was 6 days (IQR 6, 9). Seven patients were discharged home in stable condition, one was discharged to an acute rehabilitation facility, and one was discharged to a skilled nursing facility. Conclusions: Percutaneous thoracostomy with pleural lavage is clinically feasible and effective and warrants further evaluation with a multicenter clinical trial. Level of evidence: Therapeutic/care management, level V.

Treatment approach for coexisting chest wall fractures and unstable thoracolumbar spine fractures in polytrauma patients requiring prone spine surgery.

Concomitant chest wall fractures (sternal and/or rib fractures) with unstable thoracolumbar fractures that require surgical fixation are rare but highly morbid injuries that mandate a multidisciplinary approach to treatment. There is limited evidence in the literature regarding optimal timing and order of surgical fixation of these patients with multiple injuries. Here, we present our experience with two patients at a single institution that demonstrates the challenges that present with this patient population. We advocate for earlier fixation of the chest wall fractures in the appropriately indicated patients, prior to prone positioning for spinal fixation.

The role of emergency department thoracotomy in patients with cranial gunshot wounds.

BACKGROUND: Although several society guidelines exist regarding emergency department thoracotomy (EDT), there is a lack of data upon which to base guidance for multiple gunshot wound (GSW) patients whose injuries include a cranial GSW. We hypothesized that survival in these patients would be exceedingly low. METHODS: We used Pennsylvania Trauma Outcomes Study data, 2002 to 2021, and included EDTs for GSWs. We defined EDT by International Classification of Diseases codes for thoracotomy or procedures requiring one, with a location flagged as emergency department. We defined head injuries as any head Abbreviated Injury Scale (AIS) score of ≥1 and severe head injuries as head AIS score of ≥4. Head injuries were "isolated" if all other body regions have an AIS score of <2. Descriptive statistics were performed. Discharge functional status was measured in five domains. RESULTS: Over 20 years in Pennsylvania, 3,546 EDTs were performed; 2,771 (78.1%) were for penetrating injuries. Most penetrating EDTs (2,003 [72.3%]) had suffered GSWs. Survival among patients with isolated head wounds (n = 25) was 0%. Survival was 5.3% for the non-head injured (n = 94 of 1,787). In patients with combined head and other injuries, survival was driven by the severity of the head wound-0% (0 of 81) with a severe head injury ( p = 0.035 vs. no severe head injury) and 4.5% (5 of 110) with a nonsevere head injury. Of the five head-injured survivors, two were fully dependent for transfer mobility, and three were partially or fully dependent for locomotion. Of 211 patients with a cranial injury who expired, 2 (0.9%) went on to organ donation. CONCLUSION: Although there is clearly no role for EDT in patients with isolated head GSWs, EDT may be considered in patients with combined injuries, as most of these patients have minor head injuries and survival is not different from the non-head injured. However, if a severe head injury is clinically apparent, even in the presence of other body cavity injuries, EDT should not be pursued. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Thoracic Lavage for Traumatic Hemothorax.

This Surgical Innovation discusses thoracic lavage for traumatic hemothorax.

ECMO in trauma care: What you need to know.

ABSTRACT: Over the past 10 years, extracorporeal membrane oxygenation (ECMO) use in trauma patients has increased significantly. This includes adult and pediatric trauma patients and even combat casualties. Most ECMO applications are in a venovenous (VV ECMO) configuration for acute hypoxemic respiratory failure or anatomic injuries that require pneumonectomy or extreme lung rest in a patient with insufficient respiratory reserve. In this narrative review, we summarize the most common indications for VV ECMO and other forms of ECMO support used in critically injured patients, underscore the importance of early ECMO consultation or regional referral, review the technical aspects of ECMO cannulation and management, and examine the expected outcomes for these patients. In addition, we evaluate the data where it exists to try to debunk some common myths surrounding ECMO management.

CT-based pleural effusion volume estimation formula demonstrates low accuracy and reproducibility for traumatic hemothorax.

PURPOSE: We aimed to evaluate the accuracy and reproducibility of the CT-based volume estimation formula V = d2 * h, where d and h represent the maximum depth and height of the effusion, for acute traumatic hemothorax. MATERIALS & METHODS: Prospectively identified patients with CT showing acute traumatic hemothorax were considered. Volumes were retrospectively estimated using d2 * h, then manually measured on axial images. Subgroup analysis was performed on borderline-sized hemothorax (200-400 mL). Measurements were repeated by three non-radiologists. Bland-Altman analysis was used to assess agreement between the two methods and agreement between raters for each method. RESULTS: A total of 46 patients (median age 34; 36 men) with hemothorax volume 23-1622 mL (median 191 mL, IQR 99-324 mL) were evaluated. Limits of agreement between estimates and measured volumes were -718 - +842 mL (± 202 mL). Borderline-sized hemothorax (n = 13) limits of agreement were -300 - +121 mL (± 114 mL). Of all hemothorax, 85 % (n = 39/46) were correctly stratified as over or under 300 mL, and of borderline-sized hemothorax, 54 % (n = 7/13). Inter-rater limits of agreement were -251 - +350, -694 - +1019, and -696 - +957 for the estimation formula, respectively, and -124 - +190, -97 - +111, and -96 - +46 for the measured volume. DISCUSSION: An estimation formula varies with actual hemothorax volume by hundreds of mL. There is low accuracy in stratifying hemothorax volumes close to 300 mL. Variability between raters was substantially higher with the estimation formula than with manual measurements.

Optimizing Mass Casualty Triage: Using Discrete Event Simulation to Minimize Time to Resuscitation.

BACKGROUND: Urban areas in the US are increasingly focused on mass casualty incident (MCI) response. We simulated prehospital triage scenarios and hypothesized that using hospital-based blood product inventories for on-scene triage decisions would minimize time to treatment. STUDY DESIGN: Discrete event simulations modeled MCI casualty injury and patient flow after a simulated blast event in Boston, MA. Casualties were divided into moderate (Injury Severity Score 9 to 15) and severe (Injury Severity Score >15) based on injury patterns. Blood product inventories were collected from all hospitals (n = 6). The primary endpoint was the proportion of casualties managed with 1:1:1 balanced resuscitation in a target timeframe (moderate, 3.5 U red blood cells in 6 hours; severe, 10 U red blood cells in 1 hour). Three triage scenarios were compared, including unimpeded casualty movement to proximate hospitals (Nearest), equal distribution among hospitals (Equal), and blood product inventory-based triage (Supply-Guided). RESULTS: Simulated MCIs generated a mean ± SD of 302 ± 7 casualties, including 57 ± 2 moderate and 15 ± 2 severe casualties. Nearest triage resulted in significantly fewer overall casualties treated in the target time (55% vs Equal 86% vs Supply-Guided 91%, p < 0.001). These differences were principally due to fewer moderate casualties treated, but there was no difference among strategies for severe casualties. CONCLUSIONS: In this simulation study comparing different triage strategies, including one based on actual blood product inventories, nearest hospital triage was inferior to equal distribution or a Supply-Guided strategy. Disaster response leaders in US urban areas should consider modeling different MCI scenarios and casualty numbers to determine optimal triage strategies for their area given hospital numbers and blood product availability.