Evaluation of the Impact of a Less-Invasive Trunk and Pelvic Trauma Protocol on Mortality in Patients with Severe Injury by Interrupted Time-Series Analysis.

Background and Objectives: Minimally invasive trauma management, including interventional radiology and non-operative approaches, has proven effective. Consequently, our hospital established a trauma IVR protocol called "Ohta Nishinouchi Hospital trauma protocol (ONH trauma protocol) in 2013, mainly for trunk trauma. However, the efficacy of the ONH trauma protocol has remained unverified. We aimed to assess the protocol's impact using interrupted time-series analysis (ITSA). Materials and Methods: This retrospective cohort study was conducted at Ohta Nishinouchi hospital, a tertiary emergency hospital, from January 2004 to December 2019. We included patients aged ≥ 18 years who presented to our institution due to severe trauma characterized by an Abbreviated Injury Scale of ≥3 in any region. The primary outcome was the incidence of in-hospital deaths per 100 transported patients with trauma. Multivariable logistic regression analysis was conducted with in-hospital mortality as the outcome, with no exposure before protocol implementation and with exposure after protocol implementation. Results: Overall, 4558 patients were included in the analysis. The ITSA showed no significant change in in-hospital deaths after protocol induction (level change -1.49, 95% confidence interval (CI) -4.82 to 1.84, p = 0.39; trend change -0.044, 95% CI -0.22 to 0.14, p = 0.63). However, the logistic regression analysis revealed a reduced mortality effect following protocol induction (odds ratio: 0.50, 95% CI: 0.37 to 0.66, p < 0.01, average marginal effects: -3.2%, 95% CI: -4.5 to -2.0, p < 0.01). Conclusions: The ITSA showed no association between the protocol and mortality. However, before-and-after testing revealed a positive impact on mortality. A comprehensive analysis, including ITSA, is recommended over before-and-after comparisons to assess the impact of the protocol.

Sex Disparities in Applied Force on Maxillary Incisors Among Novices During Laryngoscopy Using a High-Fidelity Simulator: A Prospective Observational Study.

Endotracheal intubation (ETI) is a common and crucial intervention. Whether the performance of ETI differs according to the sex of the laryngoscopist remains unclear. The aim of this study was to assess sex disparities in markers of ETI performance among novices using a high-fidelity simulator. This prospective observational study was conducted from April 2017 to March 2019 in a public medical university. In total, 209 medical students (4th and 5th grade) without clinical ETI experience were recruited. Of the 209 students, 64 (30.6%) were female. The participants used either a Macintosh direct laryngoscope or C-MAC video laryngoscope in combination with a stylet or gum-elastic bougie to perform ETI on a high-fidelity simulator. The primary endpoint was the maximum force applied on the maxillary incisors during laryngoscopy. The secondary endpoint was the time to ETI. The implanted sensors in the simulator automatically quantified the force and time to ETI. The maximum force applied on the maxillary incisors was approximately 30% lower in the male than female group for all laryngoscopes and intubation aids examined (all P < 0.001). Similarly, the time to ETI was approximately 10% faster in the male than female group regardless of the types of laryngoscopes and intubation aids used (all P < 0.05). In this study, male sex was associated with a lower maximum force applied on the maxillary incisors during both direct and indirect laryngoscopy performed by novices. A clinical study focusing on sex differences in ETI performance is needed to validate our findings.

Attempted Suicide Is Independently Associated with Increased In-Hospital Mortality and Hospital Length of Stay among Injured Patients at Community Tertiary Hospital in Japan: A Retrospective Study with Propensity Score Matching Analysis.

Suicide is an increasingly important public healthcare concern worldwide. Studies examining the effect of attempted suicide on clinical outcomes among patients with trauma are scarce. We conducted a retrospective cohort study at a community emergency department in Japan. We included all severely injured patients with an Injury Severity Score > 15 from January 2002 to December 2021. The primary outcome measure was in-hospital mortality. The other outcome of interest was hospital length of stay. One-to-one propensity score matching was performed to compare these outcomes between suicide attempt and no suicide attempt groups. Of the 2714 eligible patients, 183 (6.7%) had trauma caused by a suicide attempt. In the propensity score-matched analysis with 139 pairs, the suicide attempt group showed a significant increase in-hospital mortality (20.9% vs. 37.4%; odds ratio 2.27; 95% confidence intervals 1.33-3.87) compared with the no suicide attempt group. Among survivors, the median hospital length of stay was significantly longer in the suicide attempt group than that in the no suicide attempt group (9 days vs. 12 days, p = 0.0076). Because of the unfavorable consequences and potential need for additional healthcare, increased attention should be paid to patients with trauma caused by a suicide attempt.

Concomitant severe traumatic brain injury is not associated with increased red blood cell transfusion volumes in patients with pelvic fractures: A retrospective observational study.

INTRODUCTION: Traumatic brain injury (TBI)-associated coagulopathy significantly influences survival outcomes in patients with multiple injuries. Severe TBI can potentially affect systemic hemostasis due to coagulopathy; however, there is limited evidence regarding whether the risk of hemorrhage increases in patients with pelvic fractures complicated with TBI. Therefore, through multivariable analysis, we aimed to examine the association between severe TBI and increased blood transfusion requirements in patients with pelvic fractures. MATERIALS AND METHODS: This retrospective observational study was conducted at a tertiary care facility in Japan. Patients aged 16 years or older with pelvic fractures who were admitted to our intensive care unit between April 2014 and December 2021 were included in the analysis. The patients were categorized into no to mild and severe TBI groups according to whether the Head Abbreviated Injury Scale (AIS) score was 3 or higher. The primary outcome was the number of red blood cell (RBC) units transfused within 24 h after arrival at the hospital. The primary outcome was analyzed using univariable and multivariable linear regression analyses. The covariates used for the multivariable linear regression analysis were age, sex, antithrombotic therapy, mechanism of injury, Pelvic AIS score, and extravasation on contrast-enhanced computed tomography on admission. RESULTS: We identified 315 eligible patients (221 and 94 in the no to mild and severe TBI groups, respectively). In the univariable analysis, the RBC transfusion volume within 24 h after arrival was significantly higher in the severe TBI group than in the no to mild TBI group (2.53-unit increase; 95 % confidence interval [CI]: 0.46-4.61). However, in the multivariable analysis, no statistically significant association was detected between severe TBI and the RBC transfusion volume within 24 h after arrival at the hospital (0.87-unit increase; 95 % CI: -1.11-2.85). CONCLUSIONS: Concomitant severe TBI was not associated with increased RBC transfusion volumes in patients with pelvic fractures on multivariable analysis.

Gender Disparities in First Authorship at Three Medical Universities in an Area Affected by the Great East Japan Earthquake.

The Great East Japan Earthquake that occurred on March 11, 2011, was one of the largest natural disasters in modern times. Publication in medical journals is important aspects of the academic promotion process, and is thus important for all scientists. However, little is known about whether and how substantial natural disasters affect gender disparities in academic productivity in disaster-affected areas. We hypothesized that the Great East Japan Earthquake widened the existing disparities in scientific publishing between male and female researchers. To test this hypothesis, this retrospective observational study using existing databases was conducted. We extracted from the MEDLINE database all types of biomedical articles published from March 11, 2007, to March 11, 2015, by three medical universities in a disaster-affected area of Japan. Differences in the proportion of female first authorship during the 4 years before and after the Great East Japan Earthquake were compared. A total of 5,873 papers were analyzed. The proportion of female first authors significantly declined after the Great East Japan Earthquake (20.5% vs. 14.1%; odds ratio 0.64; 95% confidence interval 0.56-0.73). A similar trend was identified across all prespecified subgroups, including clinical department; original article; public medical university; and prestigious journal with impact factor >6. Reference data from two medical universities minimally affected by the Great East Japan Earthquake showed the opposite trend. These results collectively suggest that large natural disasters can reinforce existing gender disparities in first authorship in biomedicine.

Long-Term Incidence and Timing of Splenic Pseudoaneurysm Formation after Blunt Splenic Injury: A Descriptive Study.

BACKGROUND: Nonoperative management (NOM) has become a standard strategy for hemodynamically stable patients with blunt splenic injury; however, delayed rupture of splenic pseudoaneurysm (SPA) is a serious complication of NOM. In medical literature, data regarding the long-term incidence of SPA are scarce, and the appropriate timing for performing follow-up contrast-enhanced computed tomography (CT) has not yet been reported. This study aimed to elucidate the long-term incidence and timing of SPA formation after blunt splenic injury in patients treated with NOM. METHODS: This descriptive study was conducted at a tertiary medical center in Japan. Patients with blunt splenic injury who were treated with NOM between April 2014 and August 2020 were included in the analysis. Included patients underwent repeated contrast-enhanced CT to detect SPA formation. The primary outcome was the cumulative incidence of delayed formation of SPA. We also evaluated differences in SPA formation between patients who received transcatheter arterial embolization (TAE; TAE group) and those who did not receive it (non-TAE group) on admission day. RESULTS: Among 49 patients with blunt splenic injury who were treated with NOM, 5 patients (10.2%) had delayed formation of SPA. All cases of SPA formation occurred within 15 days of injury. The incidence of SPA formation was not significantly different between the TAE and non-TAE groups (1/19 vs. 4/30, P = 0.67). CONCLUSIONS: SPA developed in 10% of patients within approximately 2 weeks after blunt splenic injury. Therefore, performing follow-up contrast-enhanced CT in this period after injury may be useful to evaluate delayed formation of SPA. Although our findings are novel, they should be confirmed through future studies with larger sample sizes.

Transcatheter arterial embolization using imipenem/cilastatin sodium and microspheres for traumatic pseudoaneurysm: A case report.

For transcatheter arterial embolization (TAE) of pseudoaneurysms, when the culprit artery is too small or tortuous to be selected with a microcatheter, n-butyl-2-cyanoacrylate (NBCA) may be used as embolic material. Nevertheless, NBCA can cause inadvertent embolization and ischemic complications because liquid adhesives cannot be controlled precisely. In such cases, imipenem/cilastatin sodium (IPM/CS) could be used as an alternative to NBCA for TAE. However, TAE using IPM/CS for traumatic pseudoaneurysms has not been reported previously. Therefore, the possibility of using IPM/CS to embolize refractory traumatic pseudoaneurysms with small culprit arteries remains unknown. A previously healthy 51-year-old man sustained multiple traumatic injuries, including an open pelvic fracture. An emergency TAE for the pelvic fracture, massive blood transfusion, and emergency colostomy and cystostomy were performed on admission day, following which the patient was hemodynamically stable. However, he had repeated episodes of hematochezia due to pelvic pseudoaneurysm on days 18, 53, 60, and 70 after admission despite several TAE attempts using gelatin sponge, coils, and NBCA. During recurrence on day 70, we performed TAE using IPM/CS and microspheres, following which the pseudoaneurysm resolved without rebleeding or obvious ischemic complications. IPM/CS and microspheres could embolize, without rebleeding, the refractory pseudoaneurysm in small and tortuous culprit arteries that could not be embolized with NBCA. For embolization of traumatic pseudoaneurysms with severe tissue damage and small culprit arteries, NBCA might not be able to reach the bleeding point. In such cases, TAE using IPM/CS and microspheres could be a safe and effective procedure.

Right thyrocervical trunk rupture after right internal jugular vein puncture: a case report and systematic review of the literature.

BACKGROUND: Thyrocervical trunk rupture is an unusual, but critical, complication associated with central venous catheter (CVC) placement. The management of this complication has not been fully determined because it is rare. CASE PRESENTATION: A 53-year-old Japanese woman with anorexia nervosa developed refractory ventricular fibrillation. After returning spontaneous circulation, a CVC was successfully placed at the initial attempt in the right internal jugular vein using real-time ultrasound guidance. Immediately after CVC placement, she developed enlarging swelling around the neck. Contrast-enhanced computed tomography showed massive contrast media extravasation around the neck and mediastinum. Brachiocephalic artery angiography showed a "blush" appearance of the ruptured right thyrocervical trunk. After selective arterial embolization with 33% N-butyl-2-cyanoacrylate, the extravasation completely disappeared and hemostasis was achieved. CONCLUSION: Our findings suggest that severe vascular complications arising from CVC placement can occur in patients with a fragile physiological state. Endovascular embolization is an effective treatment for such complications.

Introduction and utility of resuscitative endovascular balloon occlusion of the aorta for cases with a potential high risk of postpartum hemorrhage: A single tertiary care center experience of two cases.

Postpartum hemorrhage is an important obstetric complication and the leading cause of maternal mortality worldwide. Occasionally, we encounter unexpected massive postpartum hemorrhage diagnosed for the first time after delivery. Therefore, it is essential to pay attention to patients with a high risk of postpartum hemorrhage. The authors report two cases of patients at high risk of postpartum hemorrhage that were successfully managed by resuscitative endovascular balloon occlusion of the aorta before cesarean section. Case 1: A 32-year-old woman with a history of cesarean section and who conceived using assisted reproductive technology was diagnosed with partial placenta previa at 25 weeks of gestation. Because of tocolysis failure, emergent cesarean section with resuscitative endovascular balloon occlusion of the aorta was performed at 36 weeks of gestation. Natural placental resorption was observed. She was discharged at 5 days after delivery without significant hemorrhage. Case 2: A 41-year-old woman with suspected placenta accreta spectrum due to a cesarean scar pregnancy was referred to our hospital at 33 weeks of gestation. A planned cesarean section with resuscitative endovascular balloon occlusion of the aorta was conducted at 37 weeks of gestation. There was no visual evidence of abnormal placental invasion of the myometrium, and natural placental resorption was observed. She was discharged at 5 days after delivery without significant hemorrhage.

Impact of emergency physician-staffed ambulances on preoperative time course and survival among injured patients requiring emergency surgery or transarterial embolization: A retrospective cohort study at a community emergency department in Japan.

Injured patients requiring definitive intervention, such as surgery or transarterial embolization (TAE), are an extremely time-sensitive population. The effect of an emergency physician (EP) patient care delivery system in this important trauma subset remains unclear. We aimed to clarify whether the preoperative time course and mortality among injured patients differ between ambulances staffed by EPs and those staffed by emergency life-saving technicians (ELST). This was a retrospective cohort study at a community emergency department (ED) in Japan. We included all injured patients requiring emergency surgery or TAE who were transported directly from the ED to the operating room from January 2002 to December 2019. The primary exposure was dispatch of an EP-staffed ambulance to the prehospital scene. The primary outcome measures were preoperative time course including prehospital length of stay (LOS), ED LOS, and total time to definitive intervention. The other outcome of interest was in-hospital mortality. One-to-one propensity score matching was performed to compare these outcomes between the groups. Of the 1,020 eligible patients, 353 (34.6%) were transported to the ED by an EP-staffed ambulance. In the propensity score-matched analysis with 295 pairs, the EP group showed a significant increase in median prehospital LOS (71.0 min vs. 41.0 min, P < 0.001) and total time to definitive intervention (189.0 min vs. 177.0 min, P = 0.002) in comparison with the ELST group. Conversely, ED LOS was significantly shorter in the EP group than in the ELST group (120.0 min vs. 131.0 min, P = 0.043). There was no significant difference in mortality between the two groups (8.8% vs.9.8%, P = 0.671). At a community hospital in Japan, EP-staffed ambulances were found to be associated with prolonged prehospital time, delay in definitive treatment, and did not improve survival among injured patients needing definitive hemostatic procedures compared with ELST-staffed ambulances.

Impact of closure of the in-house psychiatric care unit on prehospital and emergency ward length of stay and disposition locations in patients who attempted suicide: A retrospective before-and-after cohort study at a community hospital in Japan.

ABSTRACT: Suicide is an increasingly serious public health care concern worldwide. The impact of decreased in-house psychiatric resources on emergency care for suicidal patients has not been thoroughly examined. We evaluated the effects of closing an in-hospital psychiatric ward on the prehospital and emergency ward length of stay (LOS) and disposition location in patients who attempted suicide.This was a retrospective before-and-after study at a community emergency department (ED) in Japan. On March 31, 2014, the hospital closed its 50 psychiatric ward beds and outpatient consultation days were decreased from 5 to 2 days per week. Electronic health record data of suicidal patients who were brought to the ED were collected for 5 years before the decrease in in-hospital psychiatric services (April 1, 2009-March 31, 2014) and 5 years after the decrease (April 1, 2014-March 31, 2019). One-to-one propensity score matching was performed to compare prehospital and emergency ward LOS, and discharge location between the 2 groups.Of the 1083 eligible patients, 449 (41.5%) were brought to the ED after the closure of the psychiatric ward. Patients with older age, burns, and higher comorbidity index values, and those requiring endotracheal intubation, surgery, and emergency ward admission, were more likely to receive ED care after the psychiatric ward closure. In the propensity matched analysis with 418 pairs, the after-closure group showed a significant increase in median prehospital LOS (44.0 minutes vs 51.0 minutes, P < .001) and emergency ward LOS (3.0 days vs 4.0 days, P = .014) compared with the before-closure group. The rate of direct home return was significantly lower in the after-closure group compared with the before-closure group (87.1% vs 81.6%, odds ratio: 0.66; 95% confidence interval: 0.45-0.96).The prehospital and emergency ward LOS for patients who attempted suicide in the study site increased significantly after a decrease in hospital-based mental health services. Conversely, there was significant reduction in direct home discharge after the decrease in in-house psychiatric care. These results have important implications for future policy to address the increasing care needs of patients who attempt suicide.

Intraoperative fluid management in hepato-biliary-pancreatic operation using stroke volume variation monitoring: A single-center, open-label, randomized pilot study.

TRIAL DESIGN: This investigator-initiated, single-center, open-label, parallel-group, randomized-controlled pilot study was designed to compare the intraoperative fluid balance and perioperative complications in patients undergoing hepato-biliary-pancreatic surgery with or without stroke volume variation (SVV)-guided fluid management. METHODS: Patients who were aged >18 years and underwent elective major hepato-biliary-pancreatic surgery between June 30, 2015, and August 31, 2016 at our center were randomly assigned to receive SVV-guided or conventional fluid therapy. The intervention group used SVV to determine the patients' volume status. The primary outcome was the total fluid balance per body weight per operation time, and the secondary outcomes were the total amount of intravenous infusion per body weight per operation time and the Sequential Organ Failure Assessment score on postoperative day 1. Patients were randomized by a two-block computer-generated assignment sequence. Masking of patients and assessors was conducted. The patients and assessors were each blinded to the details of the trial; however, the clinicians were not. RESULTS: Of the 69 patients who were initially eligible, 60 provided informed consent for participation in the study. After randomization, three patients dropped out of the study because of deviations from the protocol or unexpected hypotension, leaving 28 and 29 patients in the intervention and control groups, respectively. Patients in both groups had similar characteristics at baseline. The median (interquartile range [IQR]) intraoperative fluid balance in the control and SVV groups was 6.2 (IQR, 4.9-7.9) and 8.1 (IQR, 5.7-10.5) ml/kg/h, respectively (P = .103). The administered intravenous infusion was significantly higher in the SVV group (median, 10.9; IQR, 8.3-15.3 ml/kg/h) than in the control group (median, 9.5; IQR, 7.7-10.3 ml/kg/h) (P = .011). On postoperative day 1, the PaO2/FiO2 ratio was lower in the SVV group (median, 266; IQR, 261-341) than in the control group (median, 346; IQR, 299-380) (P = .019). CONCLUSIONS: Use of the SVV-guided fluid management protocol did not reduce intraoperative fluid balance but increased the intraoperative fluid administration and might worsen postoperative oxygenation. TRIAL REGISTRATION: UMIN000018111.

Case Report: A Fatal Case of Scrub Typhus Complicated by Heatstroke.

A 76-year-old man who had been bathing in a hot spring was taken to the hospital in a coma. PCR assay performed on the eschar revealed a serotype Hirano/Kuroki of Orientia tsutsugamushi. Coexisted heatstroke superimposed on multiple underlying risk factors likely led to a fatal clinical course.

The use of veno-venous extracorporeal membrane oxygenation for massive hemoptysis following a traumatic lung injury: a case report.

BACKGROUND: Published reports regarding the use of veno-venous extracorporeal membrane oxygenation (V-V ECMO) for massive hemoptysis following a thoracic injury are still scarce. CASE PRESENTATION: A 34-year-old man developed massive hemoptysis from the right lung after a 2 m fall and being compressed with an iron pipe weighing 500 kg. He was immediately intubated using a double-lumen tube, and one-lung ventilation was started. Endotracheal hemorrhage was controlled by sealing the right lumen. V-V ECMO was initiated to endure the lethal hypoxemia while waiting for the right lung to heal. He came off of V-V ECMO after 17 days and was discharged on foot on day 46. CONCLUSION: The strategy of using V-V ECMO in combination with one-lung ventilation is useful and should be strongly considered to save lethal massive hemoptysis cases following traumatic lung injury.

Lower maximum forces on oral structures when using gum-elastic bougie than when using endotracheal tube and stylet during both direct and indirect laryngoscopy by novices: a crossover study using a high-fidelity simulator.

BACKGROUND: Applying excessive force during endotracheal intubation (ETI) is associated with several complications, including dental trauma and hemodynamic alterations. A gum-elastic bougie (GEB), a type of tracheal tube introducer, is a useful airway adjunct for patients with poor laryngoscopic views. However, how the use of a GEB affects the force applied during laryngoscopy is unclear. We compared the force applied on the oral structures during ETI performed by novices using the GEB versus an endotracheal tube + stylet. METHODS: This prospective crossover study was conducted from April 2017 to March 2019 in a public medical university in Japan. In total, 209 medical students (4th and 5th grade, mean age of 23.7 ± 2.0 years) without clinical ETI experience were recruited. The participants used either a Macintosh direct laryngoscope (DL) or C-MAC video laryngoscope (VL) in combination with a GEB or stylet to perform ETI on a high-fidelity airway management simulator. The order of the first ETI method was randomized to minimize the learning curve effect. The outcomes of interest were the maximum forces applied on the maxillary incisors and tongue during laryngoscopy. The implanted sensors in the simulator quantified these forces automatically. RESULTS: The maximum force applied on the maxillary incisors was significantly lower when using a GEB than when using an endotracheal tube + stylet both with the Macintosh DL (39.0 ± 23.3 vs. 47.4 ± 32.6 N, P < 0.001) and C-MAC VL (38.9 ± 18.6 vs. 42.0 ± 22.1 N, P < 0.001). Similarly, the force applied on the tongue was significantly lower when using a GEB than when using an endotracheal tube + stylet both with the Macintosh DL (31.9 ± 20.8 vs. 37.8 ± 22.2 N, P < 0.001) and C-MAC VL (35.2 ± 17.5 vs. 38.4 ± 17.5 N, P < 0.001). CONCLUSIONS: Compared with the use of an endotracheal tube + stylet, the use of a GEB was associated with lower maximum forces on the oral structures during both direct and indirect laryngoscopy performed by novices. Our results suggest the expanded role of a GEB beyond an airway adjunct for difficult airways.

Vehicle configurations associated with anatomical-specific severe injuries resulting from traffic collisions.

Vehicles can be classified by configuration as either bonnet-type or cab-over type according to engine location. Compared to bonnet-type, the front compartment of cab-over type vehicles is considerably shorter; thus, it may be less likely to absorb the energy generated in a collision, and in turn be unable to prevent deformation of the occupant space and protect occupants from injury. This study was a cohort study involving 943 occupants of mini-vehicles who were injured in frontal collision accidents between 2001 and 2015 and transferred to Ohta Nishinouchi Hospital. The vehicle configuration was divided into bonnet-type and cab-over type (i.e., truck-type and wagon-type). The tested outcomes were anatomical-specific severe injury of the pelvis and extremities, the head and neck, the abdomen, and the chest. To estimate adjusted odds ratios (AOR) for associations between vehicle configuration and anatomical-specific severe injury, we fitted generalized estimating equations for each outcome. Compared with bonnet-type vehicles, a greater risk of serious pelvis and extremities injury was found for both truck (AOR: 2.21; 95% Confidence Interval [95% CI]: 1.22-4.00) and wagon-type vehicles (AOR: 3.43; 95%CI 1.60-7.39). For serious head and neck injury, truck-type vehicles were associated with greater risk (AOR: 2.04; 95% CI: 1.10-3.79) than bonnet-type vehicles, whereas wagon-type vehicles were not. Compared with the occupants of bonnet-type vehicles, cab-over type vehicle occupants were more likely to have serious pelvis and extremities injury during frontal collisions. Additionally, truck-type vehicle occupants were more likely to have serious head and neck injury than bonnet-type vehicle occupants. These findings are expected to promote safer behaviors for vehicle occupants and the automobile industry.

Impact of the academic calendar cycle on survival outcome of injured patients: a retrospective cohort study at a community emergency department in Japan.

BACKGROUND: Commencement of a new academic cycle is presumed to be associated with poor patient outcomes. However, supportive evidence is limited for trauma patients treated in under-resourced hospitals, especially those who require specialized interventions and with little physiological reserve. We examined whether a new academic cycle affects the survival outcomes of injured patients in a typical Japanese teaching hospital. METHODS: This historical cohort study was conducted at a Japanese community emergency department (ED). All injured patients brought to the ED from April 2002 to March 2018 were included in the analysis. The primary exposure was presentation to the ED during the first quartile of the academic cycle (April-June). The primary outcome measure was the hospital mortality rate. RESULTS: Of the 20,945 eligible patients, 5282 (25.2%) were admitted during the first quartile. In the univariable analysis, the hospital mortality rate was similar between patients admitted during the first quartile of the academic year and those admitted during the remaining quartiles (4.1% vs. 4.4%, respectively; odds ratio [OR], 0.931; 95% confidence interval [CI] 0.796-1.088). After adjusting for the potential confounding factors of the injury severity score, age, sex, Glasgow coma scale score, systolic blood pressure, trauma etiology (blunt or penetrating), and admission phase (2002-2005, 2006-2009, 2010-2013, and 2014-2018), no statistically significant association was present between first-quartile admission and trauma death (adjusted OR 0.980; 95% CI 0.748-1.284). Likewise, when patients were subgrouped according to age of > 55 years, injury severity score of > 15, Glasgow coma scale score of < 9, systolic blood pressure of < 90 mmHg, requirement for doctor car system dispatches, emergency operation, emergency endotracheal intubation, and weekend and night presentation, no significant associations were present between first-quartile admission and hospital mortality in both the univariable and multivariable analysis. CONCLUSIONS: At a community hospital in Japan, admission at the beginning of the academic year was not associated with an increased risk of hospital mortality among trauma patients, even those requiring specialized interventions and with little physiological reserve. Our results support the uniformity of trauma care provision throughout the academic cycle in a typical Japanese trauma system.