Injury patterns in motor vehicle collision-youth pedestrian deaths.

OBJECTIVE: The objective of this study was to describe fatal pedestrian injury patterns in youth aged 15 to 24 years old and correlate them with motor vehicle collision (MVC) dynamics and pedestrian kinematics using data from medicolegal death investigations of MVCs occurring in the current Canadian motor vehicle (MV) fleet. METHODS: Based on a systematic literature review, MVC-pedestrian injuries were collated in an injury data collection form (IDCF). The IDCF was coded using the Abbreviated Injury Scale (AIS) 2015 revision. The AIS of the most frequent severe injury was noted for individual body regions. The Maximum AIS (MAIS) was used to define the most severe injury to the body overall and by body regions (MAISBR). This study focused on serious to maximal injuries (AIS 3-6) that had an increasing likelihood of causing death. The IDCF was used to extract collision and injury data from the Office of the Chief Coroner for Ontario (OCCO) database of postmortem examinations done at the Provincial Forensic Pathology Unit (PFPU) in Toronto, Canada, and other provincial facilities between 2013 and 2019. Injury data were correlated with data about the MVs and MV dynamics and pedestrian kinematics.The study was approved by the Western University Health Science Research Ethics Board (Project ID: 113440; Lawson Health Research Institute Approval No. R-19-066). RESULTS: There were 88 youth, including 54 (61.4%) males and 34 (38.6%) females. Youth pedestrians comprised 13.1% (88/670) of all autopsied pedestrians. Cars (n = 25/88, 28.4%) were the most frequent type of vehicle in single-vehicle impacts, but collectively vehicles with high hood edges (i.e., greater distance between the ground and hood edge) were in the majority. Forward projection (n = 34/88, 38.6%) was the most frequent type of pedestrian kinematics. Regardless of the type of vehicle, there was a tendency in most cases for the median MAISBR ≥ 3 to involve the head and thorax. A similar trend was seen in most of the pedestrian kinematics involving the various frontal impacts. Of the 88 cases, at least 63 (71.6%) were known to be engaged in risk-taking behaviors (e.g., activity on roadway). At least 12 deaths were nonaccidental (8 suicides and 4 homicides). Some activities may have been impairment related, because 26/63 (41.3%) pedestrians undertaking risk-taking behavior on the roadway were impaired. Toxicological analyses revealed that over half of the cases (47/88, 53.4%) tested positive for a drug that could have affected behavior. Ethanol was the most common. Thirty-one had positive blood results. CONCLUSION: A fatal dyad of head and thorax trauma was observed for pedestrians struck by cars. For those pedestrians hit by vehicles with high hood edges, which were involved in the majority of cases, a fatal triad of injuries to the head, thorax, and abdomen/retroperitoneum was observed. Most deaths occurred from frontal collisions and at speeds more than 35 km/h.

Predicting Outcomes in Patients with Diffuse Axonal Injury: External Validation of the Widely Used Prognostic Instruments.

AIM: Accurate prognosis of diffuse axonal injury (DAI) is important in directing clinical care, allocating resources appropriately, and communicating with families and surrogate decision-makers. METHODS: A study was conducted on patients with clinical DAI due to closed-head traumatic brain injury treated at a trauma center in Brazil from July 2013 to September 2015.  The objective efficacy of the Glasgow Coma Scale (GCS), Trauma and Injury Severity Scoring system (TRISS), New Trauma and Injury Severity Scoring system (NTRISS), Abbreviated Injury Scale (AIS)/head, Corticosteroid Randomization After Significant Head Injury (CRASH), and International Mission on Prognosis and Analysis of Clinical Trials (IMPACT) models in the prediction of mortality at 14 days and 6-months and unfavorable outcomes at 6 months was tested. RESULTS: Our cohort comprised 95 prospectively recruited adults (85 males, 10 females, mean age 30.3 ± 10.9 years) admitted with DAI. Model efficacy was assessed through discrimination (area under the curve [AUC]), and Cox calibration. The AIS/head, TRISS, NTRISS, CRASH, and IMPACT models were able to discriminate both mortality and unfavorable outcomes (AUC 0.78-0.87). IMPACT models resulted in a statistically perfect calibration for both 6-month outcome variables; mortality and 6-month unfavorable outcome. Calibration also revealed that TRISS, NTRISS, and CRASH systematically overpredicted both outcomes, except for 6-month unfavorable outcome with TRISS. CONCLUSIONS: The results of this study suggest that TRISS, NTRISS, CRASH, and IMPACT models satisfactorily discriminate between mortality and unfavorable outcomes. However, only the TRISS and IMPACT models showed accurate calibration when predicting 6-month unfavorable outcome.

An Analysis of Tube Thoracostomy in Combat Implications for Improved Prehospital Recognition and Treatment.

BACKGROUND: Thoracic trauma occurs frequently in combat and is associated with high mortality. Tube thoracostomy (chest tube) is the treatment for pneumothorax resulting from thoracic trauma, but little data exist to characterize combat casualties undergoing this intervention. We sought to describe the incidence of these injuries and procedures to inform training and materiel development priorities. METHODS: This is a secondary analysis of a Department of Defense Trauma Registry (DoDTR) data set from 2007 to 2020 describing prehospital care within all theaters in the registry. We described all casualties who received a tube thoracostomy within 24 hours of admission to a military treatment facility. Variables described included casualty demographics; abbreviated injury scale (AIS) score by body region, presented as binary serious (=3) or not serious (<3); and prehospital interventions. RESULTS: The database identified 25,897 casualties, 2,178 (8.4%) of whom received a tube thoracostomy within 24 hours of admission. Of those casualties, the body regions with the highest proportions of common serious injury (AIS >3) were thorax 62% (1,351), extremities 29% (629), abdomen 22% (473), and head/neck 22% (473). Of those casualties, 13% (276) had prehospital needle thoracostomies performed, and 19% (416) had limb tourniquets placed. Most of the patients were male (97%), partner forces members or humanitarian casualties (70%), and survived to discharge (87%). CONCLUSIONS: Combat casualties with chest trauma often have multiple injuries complicating prehospital and hospital care. Explosions and gunshot wounds are common mechanisms of injury associated with the need for tube thoracostomy, and these interventions are often performed by enlisted medical personnel. Future efforts should be made to provide a correlation between chest interventions and pneumothorax management in prehospital thoracic trauma.

Resuscitative Endovascular Balloon Occlusion of The Aorta (REBOA) And Mortality in Hemorrhagic Shock Associated with Severe Pelvic Fracture: a National Data Analysis.

BACKGROUND: The purpose of the study was to evaluate the mortality of patients who received Resuscitative Endovascular Balloon Occlusion of The Aorta (REBOA) in severe pelvic fracture with hemorrhagic shock. METHODS: The American College of Surgeon Trauma Quality Improvement Program (ACS-TQIP) database for the calendar years 2017-2019 was accessed for the study. The study included all patients aged 15 years and older who sustained severe pelvic fractures, defined as an injury with an abbreviated injury scale (AIS) score of ≥ 3, and who presented with the lowest systolic blood pressure (SBP) of < 90 mmHg. Patients with severe brain injury were excluded from the study. Propensity score matching was used to compare the patients who received REBOA with similar characteristics to patients who did not receive REBOA. RESULTS: Out of 3,186 patients who qualified for the study, 35(1.1%) patients received REBOA for an ongoing hemorrhagic shock with severe pelvic fracture. The propensity matching created 35 pairs of patients. The pair-matched analysis showed no significant differences between the group who received REBOA and the group that did not receive REBOA regarding patients' demography, injury severity, severity of pelvic fractures, lowest blood pressure at initial assessment and laparotomies. There was no significant difference found between REBOA versus no REBOA group in overall in-hospital mortality (34.3% vs. 28.6, P = 0.789). CONCLUSION: Our study did not identify any mortality advantage in patients who received REBOA in hemorrhagic shock associated with severe pelvic fracture compared to a similar cohort of patients who did not receive REBOA. A larger sample size prospective study is needed to validate our results. CASE-CONTROL RETROSPECTIVE STUDY: Level of Evidence IV.

An evaluation of the "Obesity Paradox" in isolated blunt abdominal trauma in the United States.

BACKGROUND: The obesity paradox theorizes a survival benefit in trauma patients secondary to the cushioning effect of adiposity. We aim to evaluate the impact of body mass index (BMI) on abdominal injury severity, morbidity, and mortality in adults with isolated, blunt abdominal trauma in the United States. METHODS: We reviewed the National Trauma Data Bank (2013-2021) for adults sustaining isolated, blunt abdominal trauma stratified by BMI. We performed a doubly robust, augmented inverse-propensity weighted multivariable logistic regression to estimate the average treatment effect (ATE) of BMI on mortality and the presence of abdominal organ injury. RESULTS: 36,350 patients met the inclusion criteria. In our study, 41.4 % of patients were normal-weight (BMI 18.5-24.9), 20.6 % were obese (BMI 30-39.9), and 4.7 % were severely obese (BMI≥40). In these cohorts, the abdominal abbreviated injury scale (AIS) was 2 (2 -3). Obese and severely obese patients had significantly reduced presence of pancreas, spleen, liver, kidney, and small bowel injuries. The predicted probability of abdominal AIS severity decreased significantly with increasing BMI. Crude mortality was significantly higher in obese (1.3 %) and severely obese patients (1.3 %) compared to normal-weight patients (0.7 %). Obese and severely obese patients demonstrated non-statistically significant changes in the mortality of +26.4 % (ATE 0.264, 95 %CI -0.108-0.637, p = 0.164) and +55.5 % (ATE 0.555, 95 %CI -0.284-1.394, p = 0.195) respectively, compared to normal weight patients. CONCLUSION: BMI may protect against abdominal injury in adults with isolated, blunt abdominal trauma. Mortality did not decrease in association with increasing BMI, as this may be offset by the increase in co-morbidities in this population.

Obesity as a Risk Factor for Adverse Outcomes After Pedestrian Trauma Accidents in the Pediatric Population.

OBJECTIVE: The aim of the study is to determine whether overweight or obese children are at an increased risk for injury and adverse outcomes following pedestrian motor vehicle accidents. METHODS: We performed a retrospective study of patients between the ages of 2 and 17 who were pedestrians injured in a collision with a motorized vehicle, presenting to a level 1 trauma center, between January 1, 2010, to December 31, 2021. Patients with admission weights falling above the 90th percentile of the Centers for Disease Control and Prevention's sex-specific growth charts were identified as overweight/obese, those below the cutoff were categorized as nonobese. Groups were compared regarding demographics, mechanism of injury, Injury Severity Score, and Abbreviated Injury Scale by body region of injury. Outcome measures included hospital admission, length of hospital stay, intensive care unit (ICU) admission, ICU length of stay, and mortality. RESULTS: Of the 306 patients included, 72 (23.5%) were overweight/obese and 234 (76.5%) were nonobese. The mean Injury Severity Score scores were higher among overweight/obese patients (5.37 vs 8.74, P = 0.008). Overweight/obese children were more likely to sustain severe abdominal injuries (Abbreviated Injury Scale ≥ 3) (12.2% vs 5.1%; odds ratio [OR], 2.64; 95% CI, 1.07-6.56; P = 0.030), be admitted to the hospital (94.5% vs 74.3%; OR, 12.07; 95% CI, 2.87-50.72; P < 0.001), require ICU admission (31.0% vs 20.0%, OR, 1.87; 95% CI, 1.03-3.36; P = 0.036), and require a longer ICU stay (0.9 vs 0.4 days, P = 0.014) compared with nonobese patients. CONCLUSIONS: Obese and overweight children are at increased risk for higher injury severity scores, severe abdominal injuries, and ICU admission after pedestrian motor vehicle accidents.

Examination of Crash Injury Risk as a Function of Occupant Demographics.

The objectives of this study were to provide insights on how injury risk is influenced by occupant demographics such as sex, age, and size; and to quantify differences within the context of commonly-occurring real-world crashes. The analyses were confined to either single-event collisions or collisions that were judged to be well-defined based on the absence of any significant secondary impacts. These analyses, including both logistic regression and descriptive statistics, were conducted using the Crash Investigation Sampling System for calendar years 2017 to 2021. In the case of occupant sex, the findings agree with those of many recent investigations that have attempted to quantify the circumstances in which females show elevated rates of injury relative to their male counterparts given the same level bodily insult. This study, like others, provides evidence of certain female-specific injuries. The most problematic of these are AIS 2+ and AIS 3+ upper-extremity and lower-extremity injuries. These are among the most frequently observed injuries for females, and their incidence is consistently greater than for males. Overall, the odds of females sustaining MAIS 3+ (or fatality) are 4.5% higher than the odds for males, while the odds of females sustaining MAIS 2+ (or fatality) are 33.9% higher than those for males. The analyses highlight the need to carefully control for both the vehicle occupied, and the other involved vehicle, when calculating risk ratios by occupant sex. Female driver preferences in terms of vehicle class/size differ significantly from those of males, with females favoring smaller, lighter vehicles.

Accuracy of Trauma Surgeons Prospective Estimation of the Injury Severity Score: A Pilot Study.

Injury Severity Score (ISS) has limited utility as a prospective predictor of trauma outcomes as it is currently scored by abstractors post-discharge. This study aimed to determine accuracy of ISS estimation at time of admission. Attending trauma surgeons assessed the Abbreviated Injury Scale of each body region for patients admitted during their call, from which estimated ISS (eISS) was calculated. The eISS was considered concordant to abstracted ISS (aISS) if both were in the same category: mild (<9), moderate (9-15), severe (16-25), or critical (>25). Ten surgeons completed 132 surveys. Overall ISS concordance was 52.2%; 87.5%, 30.8%, 34.8%, and 61.7% for patients with mild, moderate, severe, and critical aISS, respectively; unweighted k = .36, weighted k = .69. This preliminarily supports attending trauma surgeons' ability to predict severity of injury in real time, which has important clinical and research implications.

Utilizing ultra-early continuous physiologic data to develop automated measures of clinical severity in a traumatic brain injury population.

Determination of prognosis in the triage process after traumatic brain injury (TBI) is difficult to achieve. Current severity measures like the Trauma and injury severity score (TRISS) and revised trauma score (RTS) rely on additional information from the Glasgow Coma Scale (GCS) and the Injury Severity Score (ISS) which may be inaccurate or delayed, limiting their usefulness in the rapid triage setting. We hypothesized that machine learning based estimations of GCS and ISS obtained through modeling of continuous vital sign features could be used to rapidly derive an automated RTS and TRISS. We derived variables from electrocardiograms (ECG), photoplethysmography (PPG), and blood pressure using continuous data obtained in the first 15 min of admission to build machine learning models of GCS and ISS (ML-GCS and ML-ISS). We compared the TRISS and RTS using ML-ISS and ML-GCS and its value using the actual ISS and GCS in predicting in-hospital mortality. Models were tested in TBI with systemic injury (head abbreviated injury scale (AIS) ≥ 1), and isolated TBI (head AIS ≥ 1 and other AIS ≤ 1). The area under the receiver operating characteristic curve (AUROC) was used to evaluate model performance. A total of 21,077 cases (2009-2015) were in the training set. 6057 cases from 2016 to 2017 were used for testing, with 472 (7.8%) severe TBI (GCS 3-8), 223 (3.7%) moderate TBI (GCS 9-12), and 5913 (88.5%) mild TBI (GCS 13-15). In the TBI with systemic injury group, ML-TRISS had similar AUROC (0.963) to TRISS (0.965) in predicting mortality. ML-RTS had AUROC (0.823) and RTS had AUROC 0.928. In the isolated TBI group, ML-TRISS had AUROC 0.977, and TRISS had AUROC 0.983. ML-RTS had AUROC 0.790 and RTS had AUROC 0.957. Estimation of ISS and GCS from machine learning based modeling of vital sign features can be utilized to provide accurate assessments of the RTS and TRISS in a population of TBI patients. Automation of these scores could be utilized to enhance triage and resource allocation during the ultra-early phase of resuscitation.

Comparison of injury severity scores derived from ICD-10-AM codes with trauma registry derived scores: A study from New Zealand.

INTRODUCTION: Various attempts at automation have been made to reduce the administrative burden of manually assigning Abbreviated Injury Severity (AIS) codes to derive Injury Severity Scores (ISS) in trauma registry data. The accuracy of the resulting measures remains unclear, especially in the New Zealand (NZ) context. The aim of this study was to compare ISS derived from hospital discharge International Classification of Diseases Australian Modification (ICD-10-AM) codes with ISS recorded in the NZ Trauma Registry (NZTR). METHODS: Individuals admitted to hospital and enrolled in the NZTR between 1 December 2016 and 30 November 2018 were included. ISS were calculated using a modified ICD to AIS mapping tool. The agreement between both methods for raw scores was assessed by the Intraclass Correlation Coefficient (ICC), and for categorical scores the Kappa and weighted Kappa index were used. Analysis was conducted by gender, age, ethnicity, and mechanism of injury. RESULTS: 3,156 patients fulfilled the inclusion criteria. The ICC for agreement between the methods was poor (0.40, 95 % CI: 0.37-0.43). The Kappa index indicated slight agreement between both methods when using a cut-off value of 12 (0.06; 95 % CI: 0.01-0.12) and 15 (0.13 6; 95 % CI: 0.09-0.17). CONCLUSION: Although the overall agreement between NZTR-ISS and ICD-ISS was slight, ICD-derived scores may be useful to describe injury patterns and for body region-specific estimations when manually coded ISS are not available.

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.

[Consistency of injury severity score in severe trauma patients].

OBJECTIVE: To determine the accuracy of injury severity score (ISS)in the assessment of patients with severe trauma by the consistency analysis of the patients'ISS with severe trauma scored by three clinicians, and to guide the allocation of medical resource. METHODS: Through retrospective analysis of 100 patients with serious or severe trauma admitted to Peking University People's Hospital since September 2020 to December 2021 (ISS≥16 points), we conducted a consistency analysis of ISS within different evaluators. The general information (gender, age), vital signs, physical examination, imaging, laboratory examination and other associated data of the patients after admission were retrospectively diagnosed by 3 clinicians specializing in trauma surgery and ISS was determined. SPSS 22.0 software was used for statistical analysis, descriptive reports were made on the observed values of each set of data, and Fleiss kappa test was used for consistency analysis of the credibility of the ISS within three clinicians. RESULTS: Through the consistency analysis of the ISS in 100 patients with severe trauma scored by 3 eva-luators, the total Fleiss kappa value was 0.581, and the overall consistency was medium. Consistency analysis of the different scores was conducted according to the calculation rules of ISS. Among the patients with single-site severe trauma, abbreviated injury scale (AIS) was 4 or 5 points, ISS was 16 or 25 points, and Fleiss kappa value was 0.756 and 0.712 within the three evaluators, showing a relatively high consistency. AIS of each part was more than 4 points, and total ISS was more than 41 points in the severe trauma patients, Fleiss kappa values are higher than 0.8 within the 3 evaluators, showing a high consistency. CONCLUSION: According to the consistency analysis of severe trauma patients ISS within the three evaluators, when the severe trauma patients with ISS≥16 points are treated or transported, there is a certain accuracy error when the score is used for inter-department communication or inter-hospital transportation, and the consistency of different evaluators for the same injury is moderate. It may lead to misjudgment of the severity of trauma and misallocation of medical resources. However, for trauma patients with single or multiple site AIS≥4 points, ISS is highly consistent among different evaluators, which can accurately indicate the severity of the patient's condition.

History of airbag safety benefits and risks.

OBJECTIVE: The history of airbags was reviewed for benefits and risks as they became a supplement to lap-shoulder belts. Sled and crash tests were evaluated and field data was analyzed for airbag effectiveness. Field data on airbag deaths and studies on mechanisms of deployment injury were analyzed. The history was reviewed as airbags evolved from the early 1970s to today. METHODS: Airbag benefits were determined from NHTSA crash tests with unbelted and belted dummies in 40, 48, and 56 km/h (25, 30, and 35 mph) frontal impacts with and without airbags. The literature was reviewed for testing of passive restraints with and without airbags. Recent NCAP tests were compared with earlier tests to determine the change in occupant responses with seatbelts and supplemental airbags in modern vehicles. 1994-2015 NASS-CDS field data was analyzed for MAIS 4 + F injury. Risks were compared for belted and unbelted occupants in frontal impacts by delta V. Airbag risks were identified from field deployments and research. The 1973-76 GM fleet had two deaths due to the occupant being out-of-position (OOP). The mechanisms of injury were determined. From 1989-2003, NHTSA investigated 93 driver, 184 child passenger, and 13 adult passenger airbag deaths. The data was reviewed for injury mechanisms. Second generation airbags essentially eliminated OOP airbag deaths. More recently, three suppliers were linked to airbag rupture deaths. The circumstances for ruptures were reviewed. RESULTS: The risk for serious head injury was 5.495% in drivers and 4.435% passengers in 40-48 km/h (25-30 mph) frontal crash tests without belts or airbags. It was 80.5% lower at 1.073% in drivers and 82.0% at 0.797% in passengers with belts and airbags in 35 mph NCAP crash tests of 2012-20 MY vehicles. NASS-CDS field data showed a 15.45% risk for severe injury (MAIS 4 + F) to unbelted occupants and 4.68% with belted occupants in 30-35 mph frontal crash delta V with airbags, as deployed. The reduction in risk was 69.7% with belt use and airbags deploying in 96.1% of crashes. There were benefits over the range of delta V. Two airbag deaths were studied from the 1970s GM fleet of airbags. The unbelted driver death was caused by punchout force with the airbag cover blocked by the occupant and membrane forces as the airbag wrapped around the head, neck or chest with the occupant close to the inflating airbag. The unbelted child death was from airbag inflation forces from pre-impact braking causing the child to slide forward into the deploying airbag. Research showed that unrestrained children may have 13 different positions near the passenger airbag at deployment. NHTSA investigation of first generation airbag deaths found most driver deaths were females (75.3%) sitting forward on the seat track, close to the driver airbag. Seatbelt use was only 30%. Most child deaths (138, 75.4%) involved no or improper use of the lap-shoulder belts. Of these, 115 deaths involved pre-impact braking. Only 37 (20.2%) children were in child seats with 29 in rear-facing and 8 in forward-facing child seats. Eight child deaths (4.4%) occurred with lap-shoulder belt use. Airbag designs changed. More recently, Takata airbags were related to at least 24 deaths by airbag rupture prompting a recall; the successor company Joyson had an airbag recall. ARC airbags have experienced a chunk of the inflator propelled into the driver during deployment with several deaths leading to a recall. CONCLUSIONS: Airbags are effective in preventing death and injury in crashes. They provide the greatest protection in combination with seatbelt use. NHTSA estimated airbags saved 28,244 lives through 1-1-09 while causing at least 320 deployment deaths, which has prompted improved designs, testing, and recalls.

Investigation on the dynamic characteristic of occupant during the frontal collision between high-speed train and obstacle.

High-speed train may collide with many obstacles, which can cause serious occupant injury. This study aims to investigate the dynamic characteristic of occupant during the frontal collision between high-speed train and obstacle. The finite element method was used to establish the collision model between the head vehicle of the train and obstacle. The frontal collision simulation tests under three collision conditions were established. The dynamic characteristics of occupants under different collision speeds and collision angles were explored. According to the above research, the influences of collision angle and speed on occupant injuries were systematically studied, and the risk boundaries for Railway Group Standard GMRT2100: Rail Vehicle Structures and Passive Safety (GM/RT2100) and Abbreviated injury scale ≥ 3 (AIS 3 + ) injury risk ≤ 5 % were finally proposed. The results show that the occupant injuries increased with the increase of collision speed, and most of the injury values at the collision angle of 20° were the minimum. The risk boundary for AIS 3 + injury risk ≤ 5 % was higher than that for GM/RT2100. The findings in this study are helpful to understand the occupant injury mechanism during the frontal collision between high-speed train and obstacle.

Hemorrhagic Shock in Isolated and Non-Isolated Pelvic Fractures: A Registries-Based Study.

BACKGROUND: Pelvic fractures resulting from high-energy trauma can frequently present with life-threatening hemodynamic instability that is associated with high mortality rates. The role of pelvic exsanguination in causing hemorrhagic shock is unclear, as associated injuries frequently accompany pelvic fractures. This study aims to compare the incidence of hemorrhagic shock and in-hospital outcomes in patients with isolated and non-isolated pelvic fractures. METHODS: Registries-based study of trauma patients hospitalized following pelvic fractures. Data from 1997 to 2021 were cross-referenced between the Israel Defense Forces Trauma Registry (IDF-TR), documenting prehospital care, and Israel National Trauma Registry (INTR) recording hospitalization data. Patients with isolated pelvic fractures were defined as having an Abbreviated Injury Scale (AIS) <3 in other anatomical regions, and compared with patients sustaining pelvic fracture and at least one associated injury (AIS ≥ 3). Signs of profound shock upon emergency department (ED) arrival were defined as either a systolic blood pressure <90 mmHg and/or a heart rate >130 beats per min. RESULTS: Overall, 244 hospitalized trauma patients with pelvic fractures were included, most of whom were males (84.4%) with a median age of 21 years. The most common injury mechanisms were motor vehicle collisions (64.8%), falls from height (13.1%) and gunshot wounds (11.5%). Of these, 68 (27.9%) patients sustained isolated pelvic fractures. In patients with non-isolated fractures, the most common regions with a severe associated injury were the thorax and abdomen. Signs of shock were recorded for 50 (20.5%) patients upon ED arrival, but only four of these had isolated pelvic fractures. In-hospital mortality occurred among 18 (7.4%) patients, all with non-isolated fractures. CONCLUSION: In young patients with pelvic fractures, severe associated injuries were common, but isolated pelvic fractures rarely presented with profound shock upon arrival. Prehospital management protocols for pelvic fractures should prioritize prompt evacuation and resuscitative measures aimed at addressing associated injuries.

"Blunt adrenal injury does not affect outcomes in the pediatric population with isolated abdominal injury- a National Trauma Data Bank Review®."

BACKGROUND: The incidence of blunt abdominal injury (BAI) in the adult population has been estimated to be between 0.03% and 4.95%. However, the impact of BAI on the pediatric population remains unknown. METHODS: We conducted a retrospective review of National Trauma Data Bank datasets for the years 2017-2019. We included patients under the age of 18 who experienced blunt trauma and had suffered a blunt abdominal injury with an Abbreviated Injury Scale (AIS) severity score of 2 or higher. RESULTS: Out of the 8064 pediatric patients with isolated abdominal trauma, 134 patients also suffered from BAI. We found no difference in the outcomes of patients with blunt adrenal injury in terms of mortality, length of stay in the intensive care unit (ICU) and hospital, and the number of ventilator days. Within poly-trauma patients BAI was associated with worst patient outcomes. CONCLUSIONS: This study demonstrates that BAI has minimal clinical impact on patient outcomes in isolation. However it is associated with worst outcomes in poly trauma patients suggesting correlation with increased trauma burden. LEVEL OF EVIDENCE: III.

Reality of treatment for severely injured patients: are there age-specific differences?

BACKGROUND: Major trauma and its consequences are one of the leading causes of death worldwide across all age groups. Few studies have conducted comparative age-specific investigations. It is well known that children respond differently to major trauma than elderly patients due to physiological differences. The aim of this study was to analyze the actual reality of treatment and outcomes by using a matched triplet analysis of severely injured patients of different age groups. METHODS: Data from the TraumaRegister DGU® were analyzed. A total of 56,115 patients met the following inclusion criteria: individuals with Maximum Abbreviated Injury Scale > 2 and < 6, primary admission, from German-speaking countries, and treated from 2011-2020. Furthermore, three age groups were defined (child: 3-15 years; adult: 20-50 years; and elderly: 70-90 years). The matched triplets were defined based on the following criteria: 1. exact injury severity of the body regions according to the Abbreviated Injury Scale (head, thorax, abdomen, extremities [including pelvis], and spine) and 2. level of the receiving hospital. RESULTS: A total of 2,590 matched triplets could be defined. Traffic accidents were the main cause of severe injury in younger patients (child: 59.2%; adult: 57.9%). In contrast, low falls (from < 3 m) were the most frequent cause of accidents in the elderly group (47.2%). Elderly patients were least likely to be resuscitated at the scene. Both children and elderly patients received fewer therapeutic interventions on average than adults. More elderly patients died during the clinical course, and their outcome was worse overall, whereas the children had the lowest mortality rate. CONCLUSIONS: For the first time, a large patient population was used to demonstrate that both elderly patients and children may have received less invasive treatment compared with adults who were injured with exactly the same severity (with the outcomes of these two groups being opposite to each other). Future studies and recommendations should urgently consider the different age groups.

A Lightweight Pre-Crash Occupant Injury Prediction Model Distills Knowledge From Its Post-Crash Counterpart.

Accurate occupant injury prediction in near-collision scenarios is vital in guiding intelligent vehicles to find the optimal collision condition with minimal injury risks. Existing studies focused on boosting prediction performance by introducing deep-learning models but encountered computational burdens due to the inherent high model complexity. To better balance these two traditionally contradictory factors, this study proposed a training method for pre-crash injury prediction models, namely, knowledge distillation (KD)-based training. This method was inspired by the idea of knowledge distillation, an emerging model compression method. Technically, we first trained a high-accuracy injury prediction model using informative post-crash sequence inputs (i.e., vehicle crash pulses) and a relatively complex network architecture as an experienced "teacher". Following this, a lightweight pre-crash injury prediction model ("student") learned both from the ground truth in output layers (i.e., conventional prediction loss) and its teacher in intermediate layers (i.e., distillation loss). In such a step-by-step teaching framework, the pre-crash model significantly improved the prediction accuracy of occupant's head abbreviated injury scale (AIS) (i.e., from 77.2% to 83.2%) without sacrificing computational efficiency. Multiple validation experiments proved the effectiveness of the proposed KD-based training framework. This study is expected to provide reference to balancing prediction accuracy and computational efficiency of pre-crash injury prediction models, promoting the further safety improvement of next-generation intelligent vehicles.

Internal and external validation of an updated ICD-10-CA to AIS-2005 update 2008 algorithm.

BACKGROUND: Administrative data are a powerful tool for population-level trauma research but lack the trauma-specific diagnostic and injury severity codes needed for risk-adjusted comparative analyses. The objective of this study was to validate an algorithm to derive Abbreviated Injury Scale (AIS-2005 update 2008) severity scores from Canadian International Classification of Diseases (ICD-10-CA) diagnostic codes in administrative data. METHODS: This was a retrospective cohort study using data from the 2009 to 2017 Ontario Trauma Registry for the internal validation of the algorithm. This registry includes all patients treated at a trauma center who sustained a moderate or severe injury or were assessed by a trauma team. It contains both ICD-10-CA codes and injury scores assigned by expert abstractors. We used Cohen's kappa (𝜅) coefficient to compare AIS-2005 Update 2008 scores assigned by expert abstractors to those derived using the algorithm and the intraclass correlation coefficient to compare assigned and derived Injury Severity Scores. Sensitivity and specificity for detection of a severe injury (AIS score, ≥ 3) were then calculated. For the external validation of the algorithm, we used administration data to identify adults who either died in an emergency department or were admitted to hospital in Ontario secondary to a traumatic injury (2009-2017). Logistic regression was used to evaluate the discriminative ability and calibration of the algorithm. RESULTS: Of 41,869 patients in the Ontario Trauma Registry, 41,793 (99.8%) had at least one diagnosis matched to the algorithm. Evaluation of AIS scores assigned by expert abstractors and those derived using the algorithm demonstrated a high degree of agreement in identification of patients with at least one severe injury (𝜅 = 0.75; 95% confidence interval [CI], 0.74-0.76). Likewise, algorithm-derived scores had a strong ability to rule in or out injury with AIS ≥ 3 (specificity, 78.5%; 95% CI, 77.7-79.4; sensitivity, 95.1; 95% CI, 94.8-95.3). There was strong correlation between expert abstractor-assigned and crosswalk-derived Injury Severity Score (intraclass correlation coefficient, 0.80; 95% CI, 0.80-0.81). Among the 130,542 patients identified using administrative data, the algorithm retained its discriminative properties. CONCLUSION: Our ICD-10-CA to AIS-2005 update 2008 algorithm produces reliable estimates of injury severity and retains its discriminative properties with administrative data. Our findings suggest that this algorithm can be used for risk adjustment of injury outcomes when using population-based administrative data. LEVEL OF EVIDENCE: Diagnostic Tests/Criteria; Level II.

Injury comparisons between paired drivers and front-seat passengers in frontal collisions using publicly available crash and injury data.

Forensic engineers and crash safety researchers sometimes use the injuries of a seatbelted occupant to infer the injury risk of an unbelted occupant in the same crash, had they instead been wearing a seatbelt. It is unclear, however, whether this inference is valid or how often two occupants in the same collision have similar injuries. Here, we sought to compare the injury outcomes between drivers and front-seat passengers in frontal collisions using real-world collision data. We compared the injury severity, quantified using the Abbreviated Injury Scale (AIS), of 22 injury categories between front-seat occupants with matching seatbelt use and airbag deployment in single-event frontal collisions recorded in the publicly available National Automotive Sampling System, Crashworthiness Data System (years 1993-2015) database to assess whether they had similar severity injuries. We analyzed the four combinations of seatbelt use and airbag deployment and all seatbelt/airbag conditions combined. In only 3 of 88 combinations of injuries and seatbelt/airbag conditions did more than 50% of occupant pairs have the same AIS score, although the related confidence intervals showed these proportions were not significantly greater than 50%. In contrast, we found 19 combinations of injuries and seatbelt/airbag conditions where one occupant was consistently injured more severely than the other. Our findings show that injury outcome is not similar for both front-seat occupants in the same frontal collision with similar seatbelt and airbag conditions; however, one may be able to predict that one occupant would be more severely injured than their fellow occupant.