Six Square Miles of Urban America: Association Between Firearm Discharge, Injury, and Fatality.

BACKGROUND: Despite the increase in firearm injury observed across the country, significant gaps remain relevant to our understanding of how firearm exposure translates to injury. Using acoustic gunshot detection and a collaborative hospital and law enforcement firearm injury database, we sought to identify the relationship between firearm discharge and injury over time. STUDY DESIGN: From 2018-2021, instances of firearm discharge captured via acoustic detection in six-square miles of Louisville, KY was merged with data from the collaborative firearm injury database. Key outcomes included the total number of rounds fired, injury and fatality rates per round, and the percentage of rounds discharged from automatic weapons and high-capacity magazines. RESULTS: Over the study period, 54,397 rounds of ammunition were discharged resulting in 914 injuries, 435 hospital admissions, 2,442 hospital days, 155 emergent operations, and 180 fatalities. For each round of ammunition fired, the risk of injury and fatality was 1.7% and 0.3% respectively. The total number of rounds fired per month nearly tripled (614 vs. 1,623, p < 0.001) leading to increased injury (15 vs. 37, p < 0.001) and fatality (3 vs. 7, p < 0.001). The percentage of rounds fired from automatic weapons (0 vs. 6.8%, p < 0.001) and high-capacity magazines (7.6 vs. 28.9%, p < 0.001) increased over time. CONCLUSIONS: The increased burden of firearm injury is related to an overall increase in firearm exposure as measured by the total number of rounds discharged. High-capacity magazines and automatic weaponry are being used with increasing frequency in urban American.

Mechanism matters: mortality and endothelial cell damage marker differences between blunt and penetrating traumatic injuries across three prehospital clinical trials.

Injury mechanism is an important consideration when conducting clinical trials in trauma. Mechanisms of injury may be associated with differences in mortality risk and immune response to injury, impacting the potential success of the trial. We sought to characterize clinical and endothelial cell damage marker differences across blunt and penetrating injured patients enrolled in three large, prehospital randomized trials which focused on hemorrhagic shock. In this secondary analysis, patients with systolic blood pressure < 70 or systolic blood pressure < 90 and heart rate > 108 were included. In addition, patients with both blunt and penetrating injuries were excluded. The primary outcome was 30-day mortality. Mortality was characterized using Kaplan-Meier and Cox proportional-hazards models. Generalized linear models were used to compare biomarkers. Chi squared tests and Wilcoxon rank-sum were used to compare secondary outcomes. We characterized data of 696 enrolled patients that met all secondary analysis inclusion criteria. Blunt injured patients had significantly greater 24-h (18.6% vs. 10.7%, log rank p = 0.048) and 30-day mortality rates (29.7% vs. 14.0%, log rank p = 0.001) relative to penetrating injured patients with a different time course. After adjusting for confounders, blunt mechanism of injury was independently predictive of mortality at 30-days (HR 1.84, 95% CI 1.06-3.20, p = 0.029), but not 24-h (HR 1.65, 95% CI 0.86-3.18, p = 0.133). Elevated admission levels of endothelial cell damage markers, VEGF, syndecan-1, TM, S100A10, suPAR and HcDNA were associated with blunt mechanism of injury. Although there was no difference in multiple organ failure (MOF) rates across injury mechanism (48.4% vs. 42.98%, p = 0.275), blunt injured patients had higher Denver MOF score (p < 0.01). The significant increase in 30-day mortality and endothelial cell damage markers in blunt injury relative to penetrating injured patients highlights the importance of considering mechanism of injury within the inclusion and exclusion criteria of future clinical trials.

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.

Predictors of oliguria in post-traumatic acute kidney injury.

BACKGROUND: Acute kidney injury is classified by urine output into non-oliguric and oliguric variants. Non-oliguric acute kidney injury has lower morbidity and mortality and accounts for up to 64% of acute kidney injury in hospitalized patients. However, the incidence of non-oliguric acute kidney injury in the trauma population and whether the 2 variants of acute kidney injury share the same risk factors is unknown. We hypothesized that oliguria would be present in the majority of acute kidney injury in severely injured trauma patients and that unique risk factors would predispose patients to the development of oliguria. METHODS: Patients admitted to the trauma intensive care unit and diagnosed with an acute kidney injury between 2016 to 2021 were identified. Cases were categorized based on urine output into oliguric (<400 mL per day) and non-oliguric (>400 mL per day) disease. Risk factors, management, and outcomes were compared. Logistic regression was used to identify risk factors associated with oliguria. RESULTS: A total of 227 patients met inclusion criteria. Non-oliguric acute kidney injury accounted for 74% of all cases and was associated with greater survival (78% vs 35.6%, P < .001). Using logistic regression, female sex, vasopressor use, and a greater net fluid balance at 48 hours were all predictive of oliguria (while controlling for age, race, shock index, massive transfusion, operative intervention, cardiac arrest, and nephrotoxic medication exposure). CONCLUSION: Non-oliguria accounts for the majority of post-traumatic acute kidney injury and is associated with improved survival. Specific risk factors for the development of oliguric acute kidney injury include female sex, vasopressor use, and a higher net fluid balance at 48 hours.

Persistent long-term opioid use after trauma: Incidence and risk factors.

BACKGROUND: The opioid epidemic in the United States continues to lead to a substantial number of preventable deaths and disability. The development of opioid dependence has been strongly linked to previous opioid exposure. Trauma patients are at particular risk since opioids are frequently required to control pain after injury. The purpose to this study was to examine the prevalence of opioid use before and after injury and to identify risk factors for persistent long-term opioid use after trauma. METHODS: Records for all patients admitted to a Level 1 trauma center over a 1-year period were analyzed. Demographics, injury characteristics, and hospital course were recorded. A multistate Prescription Drug Monitoring Program database was queried to obtain records of all controlled substances prescribed from 6 months before the date of injury to 12 months after hospital discharge. Patients still receiving narcotics at 1 year were defined as persistent long-term users and were compared against those who were not. RESULTS: A total of 2,992 patients were analyzed. Of all patients, 20.4% had filled a narcotic prescription within the 6 months before injury, 53.5% received opioids at hospital discharge, and 12.5% had persistent long-term use after trauma with the majority demonstrating preinjury use. Univariate risk factors for long-term use included female sex, longer length of stay, higher Injury Severity Score, anxiety, depression, orthopedic surgeries, spine injuries, multiple surgical locations, discharge to acute inpatient rehab, and preinjury opioid use. On multivariate analysis, the only significant predictors of persistent long-term prescription opioid use were preinjury use and a much smaller effect associated with use at discharge. CONCLUSION: During a sustained opioid epidemic, concerns and caution are warranted in the use of prescription narcotics for trauma patients. However, persistent long-term opioid use among opioid-naive patients is rare and difficult to predict after trauma. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III.

Applying the antecedent, behaviour, and consequence taxonomy to unintentional firearm injury as determined by a collaborative firearm injury database.

BACKGROUND: Unintentional firearm injury (UFI) remains a significant problem in the USA with respect to preventable injury and death. The antecedent, behaviour and consequence (ABC) taxonomy has been used by law enforcement agencies to evaluate unintentional firearm discharge. Using an adapted ABC taxonomy, we sought to categorise civilian UFI in our community to identify modifiable behaviours. METHODS: Using a collaborative firearm injury database (containing both a university-based level 1 trauma registry and a metropolitan law enforcement database), all UFIs from August 2008 through December 2021 were identified. Perceived threat (antecedent), behaviour and injured party (consequence) were identified for each incident. RESULTS: During the study period, 937 incidents of UFI were identified with 64.2% of incidents occurring during routine firearm tasks. 30.4% of UFI occurred during neglectful firearm behaviour such as inappropriate storage. Most injuries occurred under situations of low perceived threat. UFI involving children was most often due to inappropriate storage of weapons, while cleaning a firearm was the most common behaviour in adults. Overall, 16.5% of UFI involved injury to persons other than the one handling the weapon and approximately 1.3% of UFI resulted in mortality. CONCLUSIONS: The majority of UFI occurred during routine and expected firearm tasks such as firearm cleaning. Prevention programmes should not overlook these modifiable behaviours in an effort to reduce UFIs, complications and deaths.

Prehospital Time Following Traumatic Injury Is Independently Associated With the Need for In-Hospital Blood and Early Mortality for Specific Injury Types.

OBJECTIVE: Treating traumatic hemorrhage is time sensitive. Prehospital care and transport modes (eg, helicopter and ground) may influence in-hospital events. We hypothesized that prehospital time (on-scene time [OST] and total prehospital time [TPT]) and transport mode are associated with same-day transfusion and mortality. Furthermore, we sought to identify regions of anatomic injury that modify the relationship between prehospital time and outcomes in strata corresponding to transport types. METHODS: We obtained prehospital, in-hospital, and trauma registry data from an 8-center cohort of adult nonburn trauma patients from 2017 to 2022 directly transported from the scene to the hospital and having an Injury Severity Score (ISS) > 9 for the Task Order 1 project of the Linking Investigators in Trauma and Emergency Services research network. We excluded patients missing prehospital times, patients < 18 years of age, patients from interfacility transfers, and recipients of prehospital blood. Our same-day outcomes were in-hospital transfusions within 4 hours and 24-hour mortality. Each outcome was adjusted using multivariable logistic regression for covariates of prehospital phases (OST and TPT), mode of transport (helicopter and ground), age, sex, ISS, Glasgow Coma Scale motor subscale score < 6, and field hypotension (systolic blood pressure < 90 mm Hg). We evaluated the association of prehospital time on outcomes for scene missions by transport mode across severe injury patterns defined by Abbreviated Injury Scale > 2 body regions. RESULTS: Of 78,198 subjects, 34,504 were eligible for the study with a mean age of 47.6 ± 20.3 years, ISS of 18 ± 11, OST of 15.9 ± 9.5 minutes, and TPT of 48.7 ± 20.3 minutes. Adjusted for injury severity and demographic factors, transport type significantly modified the relationship between prehospital time and outcomes. The association of OST and TPT with the odds of 4-hour transfusion was absent for the ground emergency medical services (GEMS) cohort and present for the helicopter emergency medical services (HEMS) ambulance cohort, whereas these times were associated with decreased 24-hour mortality for both transport types. When stratifying by injury to most anatomic regions, OST and TPT were associated with a decreased need for 4-hour transfusions in the GEMS cohort. However, OST was associated with increased early transfusion only among patients with severe injuries of the thorax, and this association persisted after adjusting additionally for injury type (odds ratio [OR] = 1.03; 95% confidence interval [CI], 1.00-1.05; P = .02). The presence of polytrauma supported an association between prehospital time and decreased 24-hour mortality for the GEMS cohort (OST: OR = 0.97; 95% CI, 0.95-0.99; P < .01; TPT: OR = 0.99; 95% CI, 0.98-0.99; P = .02), whereas no injuries showed significant association of helicopter prehospital time on mortality after adjustment. CONCLUSION: We determined that transport type affects the relationship between prehospital time and hospital outcomes (4-hour transfusion: positive relationship for HEMS and negative for GEMS, 24-hour mortality: negative for both transport types). Furthermore, we identified regions of anatomic injury that modify the relationship between prehospital time and outcomes in strata corresponding to transport types. Of these regions, most notable were severe isolated injuries to the thorax that supported a positive relationship between HEMS OST and 4-hour transfusions and polytrauma that showed a negative relationship between GEMS OST or TPT and 24-hour mortality after adjustment.

A Decade of Analysis of Unplanned Extubation Etiology in Trauma Patients Including the Impact of the COVID Pandemic.

BACKGROUND: Unplanned extubations (UEs) in injured patients are potentially fatal, but etiology and patient characteristics are not well described. We have been prospectively characterizing the etiology of UEs after we identified a high rate of UEs and implemented an educational program to address it. This period of monitoring included the years of the COVID-19 pandemic that produced high rates of workforce turnover in many hospitals, dramatically affecting nursing and respiratory therapy services. We hypothesized that frequency of UEs would depend on the etiology and that the workforce changes produced by the COVID-19 pandemic would increase UEs. METHODS: This study was a prospective tracking and retrospective review of trauma registry and performance improvement data from 2012-2021. RESULTS: UE subjects were younger, were more frequently male, were diagnosed more frequently with pneumonia (38% vs 27%), and had longer hospital (19 d vs 15 d) and ICU length of stay (LOS) (12 d vs 10 d) (all P < .05). Most UEs were due to patient factors (self-extubation) that decreased after education, while UEs from other etiologies (mechanical, provider) were stable. Subjects with UEs from mechanical or provider etiologies had longer ICU LOS, higher mortality, and were less likely to be discharged home. The COVID-19 pandemic was associated with more total patient admissions and more days of ventilator use, but the rate of UEs was not changed. CONCLUSIONS: UEs were decreased by education with ongoing tracking, and UEs from patient factors were associated with better outcome than other etiologies. Workforce changes produced by the COVID-19 pandemic did not change the rate of UEs.

Plasma resuscitation improves and restores intestinal microcirculatory physiology following haemorrhagic shock.

BACKGROUND AND OBJECTIVES: Intestinal ischaemia-reperfusion injury following resuscitated haemorrhagic shock (HS) leads to endothelial and microcirculatory dysfunction and intestinal barrier breakdown. Although vascular smooth muscle machinery remains intact, microvascular vasoconstriction occurs secondary to endothelial cell dysfunction, resulting in further ischaemia and organ injury. Resuscitation with fresh frozen plasma (FFP) improves blood flow, stabilizes the endothelial glycocalyx and alleviates organ injury. We postulate these improvements correlate with decreased tissue CO2 concentrations, improved microvascular oxygenation and attenuation of intestinal microvascular endothelial dysfunction. MATERIALS AND METHODS: Male Sprague-Dawley rats were randomly assigned to groups (n = 8/group): (1) sham, (2) HS (40% mean arterial blood pressure [MAP], 60 min) + crystalloid resuscitation (CR) (shed blood saline) and (3) HS + FFP (shed blood + FFP). MAP, heart rate (HR), ileal perfusion, pO2 and pCO2 were measured at intervals until 4 h post-resuscitation (post-RES). At 4 h post-RES, the ileum was rinsed in situ with Krebs solution. Topical acetylcholine and then nitroprusside were applied for 10 min each. Serum was obtained, and after euthanasia, tissues were harvested and snap-frozen in liquid N2 and stored at -80°C. RESULTS: FFP resuscitation resulted in sustained ileal perfusion as well as rapid sustained return to baseline microvascular pO2 and pCO2 values when compared to CR (p < 0.05). Endothelial function was preserved relative to sham in the FFP group but not in the CR group (p < 0.05). CONCLUSION: FFP-based resuscitation improves intestinal perfusion immediately following resuscitation, which correlates with improved tissue oxygenation and decreased tissue CO2 levels. CR resulted in significant damage to endothelial vasodilation response to acetylcholine, while FFP preserved this function.

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.

Optimal Prehospital Crystalloid Resuscitation Volume in Trauma Patients at Risk for Hemorrhagic Shock.

BACKGROUND: Prehospital resuscitation guidelines vary widely, and blood products, although likely superior, are not available for most patients in the prehospital setting. Our objective was to determine the prehospital crystalloid volume associated with the lowest mortality among patients in hemorrhagic shock. STUDY DESIGN: This is a secondary analysis of the Prehospital Air Medical Plasma trial. Injured patients from the scene with hypotension and tachycardia or severe hypotension were included. Segmented regression and generalized additive models were used to evaluate nonlinear effects of prehospital crystalloid volume on 24-hour mortality. Logistic regression evaluated the association between risk-adjusted mortality and prehospital crystalloid volume ranges to identify optimal target volumes. Inverse propensity weighting was performed to account for patient heterogeneity. RESULTS: There were 405 patients included. Segmented regression suggested the nadir of 24-hour mortality lay within 377 to 1,419 mL prehospital crystalloid. Generalized additive models suggested the nadir of 24-hour mortality lay within 242 to 1,333 mL prehospital crystalloid. A clinically operationalized range of 250 to 1,250 mL was selected based on these findings. Odds of 24-hour mortality were higher for patients receiving less than 250 mL (adjusted odds ratio [aOR] 2.46; 95% CI 1.31 to 4.83; p = 0.007) and greater than 1,250 mL (aOR 2.57; 95% CI 1.24 to 5.45; p = 0.012) compared with 250 to 1,250 mL. Propensity-weighted regression similarly demonstrated odds of 24-hour mortality were higher for patients receiving less than 250 mL (aOR 2.62; 95% CI 1.34 to 5.12; p = 0.005) and greater than 1,250 mL (aOR 2.93; 95% CI 1.36 to 6.29; p = 0.006) compared with 250 to 1,250 mL. CONCLUSIONS: Prehospital crystalloid volumes between 250 and 1,250 mL are associated with lower mortality compared with lower or higher volumes. Further work to validate these finding may provide practical volume targets for prehospital crystalloid resuscitation.

Ogilvie's syndrome after paddle spinal cord stimulator implantation: An experience report.

Spinal cord stimulation (SCS) is an emerging technology to treat chronic pain from complex regional pain syndrome (CPRS) neuropathy and post-laminectomy syndrome. A rarely reported postoperative complication of SCS paddle implantation is abdominal pain that can result from thoracic radiculopathy. Ogilvie's syndrome (OS) is a disorder characterized by acute dilatation of the colon in the absence of an anatomic lesion that obstructs the flow of intestinal contents, which has seldom been observed after spine surgery. Here, we describe the case of a 70-year-old male who developed OS after SCS paddle implantation resulting in cecal perforation and multi-system organ failure with lethal outcome. We discuss the pathophysiology, present a method measuring the spinal canal to cord ratio (CCR) to prevent the risk of thoracic radiculopathy and OS after paddle SCS implantation, and propose suggestions for management and treatment of this condition.

Time to early resuscitative intervention association with mortality in trauma patients at risk for hemorrhage.

BACKGROUND: Hemorrhage is the leading cause of preventable death after injury. Others have shown that delays in massive transfusion cooler arrival increase mortality, while prehospital blood product resuscitation can reduce mortality. Our objective was to evaluate if time to resuscitation initiation impacts mortality. METHODS: We combined data from the Prehospital Air Medical Plasma (PAMPer) trial in which patients received prehospital plasma or standard care and the Study of Tranexamic Acid during Air and ground Medical Prehospital transport (STAAMP) trial in which patients received prehospital tranexamic acid or placebo. We evaluated the time to early resuscitative intervention (TERI) as time from emergency medical services arrival to packed red blood cells, plasma, or tranexamic acid initiation in the field or within 90 minutes of trauma center arrival. For patients not receiving an early resuscitative intervention, the TERI was calculated based on trauma center arrival as earliest opportunity to receive a resuscitative intervention and were propensity matched to those that did to account for selection bias. Mixed-effects logistic regression assessed the association of 30-day and 24-hour mortality with TERI adjusting for confounders. We also evaluated a subgroup of only patients receiving an early resuscitative intervention as defined above. RESULTS: Among the 1,504 propensity-matched patients, every 1-minute delay in TERI was associated with 2% increase in the odds of 30-day mortality (adjusted odds ratio [aOR], 1.020; 95% confidence interval [CI], 1.006-1.033; p < 0.01) and 1.5% increase in odds of 24-hour mortality (aOR, 1.015; 95% CI, 1.001-1.029; p = 0.03). Among the 799 patients receiving an early resuscitative intervention, every 1-minute increase in TERI was associated with a 2% increase in the odds of 30-day mortality (aOR, 1.021; 95% CI, 1.005-1.038; p = 0.01) and 24-hour mortality (aOR, 1.023; 95% CI, 1.005-1.042; p = 0.01). CONCLUSION: Time to early resuscitative intervention is associated with morality in trauma patients with hemorrhagic shock. Bleeding patients need resuscitation initiated early, whether at the trauma center in systems with short prehospital times or in the field when prehospital time is prolonged. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

Evaluation of critical care burden following traumatic injury from two randomized controlled trials.

Trauma resuscitation practices have continued to improve with new advances targeting prehospital interventions. The critical care burden associated with severely injured patients at risk of hemorrhage has been poorly characterized. We aim to describe the individual and additive effects of multiorgan failure (MOF) and nosocomial infection (NI) on delayed mortality and resource utilization. A secondary analysis of harmonized data from two large prehospital randomized controlled trials (Prehospital Air Medical Plasma (PAMPer) Trial and Study of Tranexamic Acid during Air and Ground Medical Prehospital Transport (STAAMP) Trial) was conducted. Only those patients who survived beyond the first 24 hours post-injury and spent at least one day in the ICU were included. Patients were stratified by development of MOF only, NI only, both, or neither and diagnosis of early (≤ 3 days) versus late MOF (> 3 days). Risk factors of NI and MOF, time course of these ICU complications, associated mortality, and hospital resource utilization were evaluated. Of the 869 patients who were enrolled in PAMPer and STAAMP and who met study criteria, 27.4% developed MOF only (n = 238), 10.9% developed NI only (n = 95), and 15.3% were diagnosed with both MOF and NI (n = 133). Patients developing NI and/or MOF compared to those who had an uncomplicated ICU course had greater injury severity, lower GCS, and greater shock indexes. Early MOF occurred in isolation, while late MOF more often followed NI. MOF was associated with 65% higher independent risk of 30-day mortality when adjusting for cofounders (OR 1.65; 95% CI 1.04-2.6; p = 0.03), however NI did not significantly affect odds of mortality. NI was individually associated with longer mechanical ventilation, ICU stay, hospital stay, and rehabilitation requirements, and the addition of MOF further increased the burden of inpatient and post-discharge care. MOF and NI remain common complications for those who survive traumatic injury. MOF is a robust independent predictor of mortality following injury in this cohort, and NI is associated with higher resource utilization. Timing of these ICU complications may reveal differences in pathophysiology and offer targets for continued advancements in treatment.

Fall, Crush, Kick: Mechanisms and Outcomes in a Cohort of Equine-Related Injuries.

INTRODUCTION: The potential for significant traumatic injury to individuals who interact with horses remains high due to animal size, forces applied, and unpredictability. Despite an estimated 30 million riders in the United States annually, few recent publications have addressed this patient population. OBJECTIVES: This study describes characteristics of patients injured in interactions with horses, focusing on mechanism of injury and use of protective equipment. METHODS: We queried our institution's trauma registry for all patients admitted for equine-related injuries (ERI) between January 1, 2013 and December 31, 2017. We categorized by specific mechanism of injury (fall, crush, kick, fall + crush, and fall + kick) and presence or absence of protective devices. RESULTS: We discovered 143 patients admitted for injuries in equine-related accidents. Patients averaged 49.2 years old, and 62.2% were female. Crush injuries resulted in a high rate of rib fractures. Riders who were kicked had an increased chance of solid organ and facial injuries and falls most commonly led to rib fractures and extremity trauma. Despite lack of documentation on most subjects, protective devices were associated with less severe injuries in those with data (n = 36). CONCLUSIONS: In this relatively large series of patients with ERI, we found mechanism differences within injury groups. Providers should more carefully document specific circumstances of ERIs. All individuals working with or around horses should exercise prudence and consider using protective equipment.

Lipidomic signatures align with inflammatory patterns and outcomes in critical illness.

Alterations in lipid metabolism have the potential to be markers as well as drivers of pathobiology of acute critical illness. Here, we took advantage of the temporal precision offered by trauma as a common cause of critical illness to identify the dynamic patterns in the circulating lipidome in critically ill humans. The major findings include an early loss of all classes of circulating lipids followed by a delayed and selective lipogenesis in patients destined to remain critically ill. The previously reported survival benefit of early thawed plasma administration was associated with preserved lipid levels that related to favorable changes in coagulation and inflammation biomarkers in causal modelling. Phosphatidylethanolamines (PE) were elevated in patients with persistent critical illness and PE levels were prognostic for worse outcomes not only in trauma but also severe COVID-19 patients. Here we show selective rise in systemic PE as a common prognostic feature of critical illness.

Effect of Plasma Resuscitation with Adjunctive Peritoneal Resuscitation on Hepatic Blood Flow and End-Organ Damage after Hemorrhagic Shock.

BACKGROUND: Intestinal injury from resuscitated hemorrhagic shock (HS) disrupts intestinal microvascular flow and causes enterocyte apoptosis, intestinal barrier breakdown, and injury to multiple organs. Fresh frozen plasma (FFP) resuscitation or directed peritoneal (DPR) resuscitation protect endothelial glycocalyx, improve intestinal blood flow, and alleviate intestinal injury. We postulated that FFP plus DPR might improve effective hepatic blood flow (EHBF) and prevent associated organ injury (liver, heart). STUDY DESIGN: Anesthetized Sprague-Dawley rats underwent HS (40% mean arterial pressure, 60 minutes) and were randomly assigned to groups (n = 8 per group): Sham; crystalloid resuscitation (CR; shed blood + 2 volumes CR); DPR (intraperitoneal 2.5% peritoneal dialysis fluid); FFP (shed blood + 1 vol IV FFP); FFP + DPR. EHBF was measured at postresuscitation timepoints. Organ injury was evaluated by serum ELISA (fatty acid-binding protein [FABP]-1 [liver], FABP-3 [heart], Troponin-I [heart], and Troponin-C [heart]) and hematoxylin and eosin. Differences were evaluated by 1-way ANOVA and 2-way repeated-measures ANOVA. RESULTS: CR resuscitation alone did not sustain EHBF. FFP resuscitation restored EHBF after resuscitation (2 hours, 3 hours, and 4 hours). DPR resuscitation restored EHBF throughout the postresuscitation period but failed to restore serum FABP-1 VS other groups. Combination FFP + DPR rapidly and sustainably restored EHBF and decreased organ injury. CR and DPR alone had elevated organ injury (FABP-1 [hepatocyte], FABP-3 [cardiac], and Troponin-I/C), whereas FFP or FFP + DPR demonstrated reduced injury at 4 hours after resuscitation. CONCLUSION: HS decreased EHBF, hepatocyte injury, and cardiac injury as evidenced by serology. FFP resuscitation improved EHBF and decreased organ damage. Although DPR resuscitation resulted in sustained EHBF, this alone failed to decrease hepatocyte or cardiac injury. Combination therapy with DPR and FFP may be a novel method to improve intestinal and hepatic blood flow and decrease organ injury after HS/resuscitation.

A new pandemic and an old epidemic: The impact of COVID-19 and gun violence as measured by years of potential life lost in a US city.

BACKGROUND: The COVID-19 pandemic has altered daily life on a global scale and has resulted in significant mortality with >985,000 lives lost in the United States alone. Superimposed on the COVID-19 pandemic has been a concurrent worsening of longstanding urban gun violence. We sought to evaluate the impact attributable to these 2 major public health issues on the greater Louisville region as determined by years of potential life lost. METHODS: Using the Collaborative Jefferson County Firearm Injury Database, all firearm injuries from January 1, 2011 to December 31, 2021 were examined. The COVID-19 data was compiled from the Louisville Metro Department of Public Health and Wellness. Pre-COVID (March 1, 2019-February 29, 2020) and COVID (March 1, 2020-February 28, 2021) time intervals were examined. The demographics, outcomes data, and years of potential life lost were determined for the groups, and injury locations were geocoded. RESULTS: From 2011 to 2021, there were 6,043 firearm injuries in Jefferson County, Kentucky. During the COVID time interval, there were 4,574 years of potential life lost due to the SARS-CoV-2 virus and 9,722 years of potential life lost due to all-cause gun violence. In the pre-COVID time interval, there were 5,723 years of potential life lost due to all-cause gun violence. CONCLUSION: In Louisville, greater years of potential life lost were attributable to firearm fatalities than the SARS-CoV-2 virus. Given the impact of COVID-19, the robust response has been proportionate and appropriate. The lack of response to firearm injury and fatality is striking in comparison. Additional resources to combat the sequelae of gun violence are needed.

Safety of De-Escalating Empiric Antimicrobial Agents in Trauma Patients with Indigenous Oral Flora Ventilator-Associated Pneumonia.

Background: Ventilator-associated pneumonia (VAP) is a frequently occurring nosocomial infection in critically ill trauma patients. When bronchoalveolar lavage (BAL) returns with indigenous oral flora (IOF), de-escalating antimicrobial therapy is challenging. Patients and Methods: This is a retrospective review of trauma patients who received broad-spectrum empiric antimicrobial therapy for clinical VAP, and whose BAL culture resulted with >100,000 CFU/mL of IOF from September 1, 2017 to September 1, 2020. Patients were identified using the trauma database and microbiology reports of BALs with IOF. This review evaluated the effect of antibiotic de-escalation on recurrent or persistent pneumonia. Results: Of 51 trauma patients with clinical VAP and IOF, 18 patients (35.3%) had antimicrobial agents de-escalated. De-escalation was driven primarily by the discontinuation of vancomycin, with the continuation of a ß-lactam antibiotic as monotherapy for the remainder of the treatment course (n = 15; 86.7%). The overall rate of either persistent or recurrent VAP in the cohort was 10%, and this did not differ statistically between those who received de-escalation therapy after isolation of IOF and those who did not (16.7% vs. 6.1%; p = 0.224), however, the incidence of acute kidney injury (AKI) was higher in the non-de-escalation group (39.4% vs. 11.1%; p = 0.034). There was no statistical difference in ventilator days, intensive care unit (ICU) length of stay, or hospital length of stay between treatment groups. Conclusions: Trauma patients who develop VAP with isolated BAL cultures of IOF or mixed flora can safely have anti-methicilllin-resistant Staphylococcus aureus (MRSA) antimicrobial agents discontinued, and this may result in decreased rates of AKI.

High Dimensional Multiomics Reveals Unique Characteristics of Early Plasma Administration in Polytrauma Patients With TBI.

OBJECTIVES: The authors sought to identify causal factors that explain the selective benefit of prehospital administration of thawed plasma (TP) in traumatic brain injury (TBI) patients using mediation analysis of a multiomic database. BACKGROUND: The Prehospital Air Medical Plasma (PAMPer) Trial showed that patients with TBI and a pronounced systemic response to injury [defined as endotype 2 (E2)], have a survival benefit from prehospital administration of TP. An interrogation of high dimensional proteomics, lipidomics and metabolomics previously demonstrated unique patterns in circulating biomarkers in patients receiving prehospital TP, suggesting that a deeper analysis could reveal causal features specific to TBI patients. METHODS: A novel proteomic database (SomaLogic Inc., aptamer-based assay, 7K platform) was generated using admission blood samples from a subset of patients (n=149) from the PAMPer Trial. This proteomic dataset was combined with previously reported metabolomic and lipidomic datasets from these same patients. A 2-step analysis was performed to identify factors that promote survival in E2-TBI patients who had received early TP. First, features were selected using both linear and multivariate-latent-factor regression analyses. Then, the selected features were entered into the causal mediation analysis. RESULTS: Causal mediation analysis of observable features identified 16 proteins and 41 lipids with a high proportion of mediated effect (>50%) to explain the survival benefit of early TP in E2-TBI patients. The multivariate latent-factor regression analyses also uncovered 5 latent clusters of features with a proportion effect >30%, many in common with the observable features. Among the observable and latent features were protease inhibitors known to inhibit activated protein C and block fibrinolysis (SERPINA5 and CPB2), a clotting factor (factor XI), as well as proteins involved in lipid transport and metabolism (APOE3 and sPLA(2)-XIIA). CONCLUSIONS: These findings suggest that severely injured patients with TBI process exogenous plasma differently than those without TBI. The beneficial effects of early TP in E2-TBI patients may be the result of improved blood clotting and the effect of brain protective factors independent of coagulation.