Kanna Ota

Background/Objectives: Comprehensive epidemiological studies of bicycle crashes involving all ages in Japan are limited, particularly regarding multiple-rider incidents. This study investigated the epidemiology of single- and multiple-rider bicycle crashes in a Japanese core regional city. Methods: Ambulance transport data from Takatsuki City (1 January 2014 to 31 July 2024) were retrospectively analyzed, including demographics, crash characteristics, and severity of injury for bicycle crash patients. The primary outcome was examination of the epidemiology of bicycle crashes with moderate and severe severity or severe and fatal severity, encompassing both single- and multiple-rider incidents. Statistical tests and logistic regression analysis were used. Results: For 6683 transported patients, 6377 (95.4%) involved single-rider crashes and 306 (4.6%) involved multiple riders. Single-rider crash patients were older and more often male. Moderate or greater injuries occurred in 625 single-rider and 11 multiple-rider crash patients. No severe or fatal injuries occurred in multiple-rider crashes. General roadways and intersections were common crash locations. Male sex and older age predicted greater injury severity in single-rider crashes. Fifty single-rider bicycle crashes resulted in severe or greater severity injuries, and four fatal crashes were recorded. Conclusions: This study uniquely details multiple-rider bicycle crashes in Japan, revealing a lower severity of injuries compared to single-rider crashes.

Background: A Morel–Lavallée lesion (MLL) is a traumatic, internal closed degloving injury that results from shearing of subcutaneous tissue away from underlying fascia, usually associated with high-velocity trauma. Case presentation: A 52-year-old man was transported to hospital for further follow-up of a superficial femoral artery injury. Examination on admission showed bruising seen around the left thigh. Contrast-enhanced computed tomography of the left thigh revealed hematoma with extravasation from a branch of the left superficial femoral artery, but no apparent aneurysms or femoral fractures. The patient was treated with compression bandages and discharged on hospital day 6. He left hospital able to walk unaided. He subsequently complained of left thigh pain with swelling and visited the hospital several times. He was treated at another outpatient clinic and was diagnosed with MLL. Single-use disposable portable negative pressure wound therapy (NPWT) was applied for about 2 months, achieving a stable wound site. Conclusion: We encountered a case of MLL successfully treated with single-use portable NPWT. This report presents the case of a patient with isolated MLL without fracture in the left thigh, in which the diagnosis was missed on initial admission. Finally, the patient received minor interventions including drainage along with tissue debridement and portable NPWT. We reviewed the relevant literature and summarize the pathogenesis, clinical manifestations, and treatment strategies for MLL. Emergency physicians require an increased understanding of MLL to avoid misdiagnosis and missed diagnosis.

Rationale: Low-velocity penetrating head injury (PHI) is rare, comprising 0.2% to 0.4% of head traumas, but can be devastating and is associated with significant morbidity and mortality. No previous case of very-low-velocity PHI due to self-inflicted stabbing with a gimlet has been reported. Patient concerns: A 62-year-old man was admitted to the hospital with bleeding head and abdominal wounds after stabbing his abdomen with a gimlet, and then hammering the same gimlet into his forehead and removing the gimlet himself. Diagnoses: Upon examination at admission, stab wounds were present on the forehead and the right upper quadrant. Computed tomography (CT) of the head revealed a bone defect in the left frontal bone and showed the intracranial path of the gimlet surrounded by mild hemorrhage and pneumocephalus. Magnetic resonance imaging (MRI) confirmed a small amount of hemorrhage with pneumocephalus but no vascular injury. Interventions: Conservative treatment without surgery. Outcomes: Follow-up MRI on hospital day 58 showed no abscess or traumatic intracranial aneurysm. The patient achieved full recovery of motor and mental functions with conservative treatment and was discharged on hospital day 69. Lessons: Very-low-velocity PHI might be successfully treated with conservative treatment.

Background: New-onset anisocoria is an important clinical clue to life-threatening intracranial injury. Anisocoria alone without impairment of extraocular muscles is a rare presentation of moderate traumatic brain injury (TBI). Case presentation: A 79-year-old woman was transported to hospital soon after falling off a bicycle. Glasgow Coma Scale score on arrival was 11 (E3V3M5). On examination at admission, she was found to be drowsy. Bruising was seen around the right eye and pupil diameters differed (right, 4.5 mm; left, 3.0 mm; both reactive to light). Computed tomography of the head revealed hemorrhagic contusion in the left temporal lobe and left pretectal area of the midbrain, right clavicular fracture, and pulmonary contusion with fractures of the 3rd and 4th ribs. Magnetic resonance imaging confirmed hemorrhagic contusion of the midbrain. The patient achieved full recovery of motor and mental functions with conservative treatment and was discharged on hospital day 17. Conclusion: We encountered a case of anisocoria without major extraocular muscle impairment due to moderate TBI with midbrain contusion.

Background: Coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2, has spread rapidly around the world. Objective: To assess the effect of the COVID-19 pandemic on the emergency medical service (EMS) and hospital admission course for children transported by ambulance. Methods: This study was a retrospective, descriptive study with a study period from January 1, 2018 to December 31, 2020 using the Osaka Emergency Information Research Intelligent Operation Network (ORION) system. All children who were transported by ambulance in Osaka Prefecture were included. The main outcome of this study was the rate of difficult-to-transfer cases, which was calculated by univariate and multivariate Poisson regression analyses. Results: Over the 3 years between January 1, 2018 and December 31 2020, 1,436,212 patients were transported to hospitals by ambulances in Osaka Prefecture, with children accounting for 102,473 (37,064, 39,590, and 25,819, in 2018, 2019, and 2020, respectively). Poisson regression analysis showed that children were negatively associated with difficult-to-transfer cases (risk ratio (RR) 0.35, 95% CI 0.33 to 0.37). With reference to 2018, 2020 was not significantly associated with difficult-to-transfer cases in children (RR 1.14, 95% CI 0.99 to 1.32, P = 0.075), but was significantly related (RR 1.24, 95% CI 1.21 to 1.27, P < 0.001) to difficult-to-transfer cases in the general population. Conclusion: Children were consistently associated with a reduced RR for difficult-to-transfer cases, even in the COVID-19 pandemic in 2020.

Introduction: Sudden-onset quadriplegia is a neurologic emergency that requires immediate management. Anterior spinal artery syndrome (ASAS) is rare, but can cause sudden-onset quadriplegia. Magnetic resonance imaging (MRI) is an essential imaging modality for diagnosing ASAS. Case Presentation: A 31-year-old woman without previous medical history was transferred to our facility for further workup of sudden-onset neck pain with quadriplegia. Diffusion-weighted imaging (DWI) revealed hyperintense signals predominantly in grey matter with a decreased apparent diffusion coefficient (ADC). These findings strongly suggested ASAS with spinal cord infarction. Edaravone, heparin, and aspirin with steroid pulse therapy were immediately initiated. Twelve days in an intensive care unit was required for dyspnea. Symptoms gradually resolved with rehabilitation, but the patient was wheelchair-bound without bladder control and was transferred to a rehabilitation facility on hospital day 48. Conclusion: A combination of DWI with ADC mapping of the spine should proceed as soon as possible to ensure appropriate management. Early treatment with edaravone, aspirin, and steroid pulse therapy may prove beneficial for ASAS.

Background: Edwardsiella tarda is a motile, facultatively anaerobic gram-negative bacillus that is isolated from a wide spectrum of animals in aquatic environments but rarely causes infection in humans. Here, we describe the case of a gastric submucosal abscess caused by E. tarda infection. Case presentation: The patient was a 74-year-old man with a history of hypertension and chronic alcohol consumption who was admitted to our hospital for abdominal pain, appetite loss and vomiting. Contrast-enhanced computed tomography (CT) revealed choledocholithiasis in the common bile duct, a gastric wall abscess and an intra-abdominal abscess. Endoscopic ultrasound (EUS)-guided drainage with antibiotics successfully cured the patient. Conclusion: The combination of CT, endoscopy and EUS-guided drainage with antibiotic therapy might be effective for diagnosis and treatment of a gastric submucosal abscess caused by E. tarda infection.

Massive hemothorax resulting from a minor injury mechanism is considered to be rare particularly when the diaphragm is injured. We report a case of massive hemothorax with bleeding from the intercostal artery and diaphragmatic damage caused by minor blunt trauma. An 83-year-old Japanese man was transported to our hospital 3 hours after falling out of bed. Computed tomography revealed hemothorax and multiple rib fractures. He underwent fluid resuscitation and a tube thoracostomy, but he became hemodynamically unstable. Contrast-enhanced computed tomography revealed worsening hemothorax with contrast extravasation 4 hours after arrival at the hospital. Emergency angiography indicated hemorrhage in the area supplied by the tenth intercostal artery. Transcatheter arterial embolization stabilized his vital signs for a short period. However, further hemodynamic stabilization required a thoracotomy, which revealed diaphragmatic trauma, which was removed and sutured before fixing his fractured ribs. His postoperative course was uneventful, and he was transferred to another hospital for rehabilitation without complications on hospital day 29. Minor mechanisms of blunt trauma can cause rib fractures and massive hemothorax. Traumatic diaphragm injury should be considered a differential diagnosis if hemodynamic instability persists after transcatheter arterial embolization in patients with lower level rib fractures.