Aim : This review discusses the efficacy of tranexamic acid (TXA) administration for patients with hemorrhage. In particular, we examined the impact of early TXA administration on mortality in trauma patients and the potential for prehospital administration for the treatment of trauma in Japan.

　　Method : A narrative review of the literature on TXA administration was conducted using Igaku Chuo Zasshi, PubMed, and Google Scholar. Through this review of the literature, the effects and challenges of TXA for trauma patients were explored.

　　Results : Early administration of TXA with antifibrinolytic activity was reported to reduce mortality under several conditions associated with hemorrhage. In particular, prehospital administration of TXA for trauma patients was shown to markedly reduce mortality. However, prehospital use in Japan is still insufficient, and establishing appropriate timing of administration and management systems were identified as challenges.

　　Conclusion : This review suggests the merits of introducing prehospital TXA to treat trauma patients in Japan. The availability of prehospital TXA administration could improve the quality of emergency care and save more lives. Further policy and emergency care system reforms are needed to make this a reality.

　　Digital technology is rapidly advancing, and virtual reality is making marked progress. Cameras, viewers, and editing software that used to be expensive have become commonplace, and equipment sold at retail stores has become sufficiently practical. The immersive experience of a head-mounted display (HMD) is completely different from that of existing video as it creates the illusion of being present in the projected virtual reality. Once a video is created, it is possible to experience advanced emergency procedures involving any time, place, or person. In this study, we created a video simulator of initial trauma treatment that could be projected on HMD using inexpensive equipment available at general retail stores, and verified its effectiveness through a survey. Ten hospital staff members and residents used the video simulator and completed a questionnaire. All participants confirmed that the experience was effective and made interesting by the novelty of HMD, perceiving the simulation as realistic and active. The simulator may be useful in the emergency field, facilitating effective training on interventions necessary in life-threatening cases, such as those related to COVID-19, critical illnesses, rare diseases, infectious diseases, and radiation.

　　This study was aimed at providing epidemiological descriptions of head injuries according to the site and type of injury.

　　The analysis included 105,867 patients with head injuries and an abbreviated injury scale (AIS) severity score of ≥2 who were registered in the Japan Trauma Data Bank between 2004 and 2019. The injuries were categorized by site and type using AIS codes, and the frequency of injury, patient age distribution, injury outcome, percentage of in-hospital deaths, and concurrent injuries were determined.

　　By site, cerebral hemorrhage accounted for 90% of head injuries, and by type, subarachnoid hemorrhage accounted for 50%. Young patients comprised a relatively large proportion of patients with axonal injuries and epidural hematomas. Older patients accounted for a relatively large proportion of patients with subdural, intracerebral, and subarachnoid hematomas. Falls were the most common cause of injury. Patients with brainstem and brain swelling injuries had the highest in-hospital fatality rates. Concurrent injuries to the chest and upper limbs were common among those with head injuries.

　　The distributions of patient age, injury severity and mechanisms, and concurrent injuries differed depending on the site and type of head injury.

　　Accessory renal arteries commonly cause vascular anomalies ; however, reports of blunt trauma injuries to these vessels are rare. Herein, we present a case of accessory renal artery injury in a 24-year-old man who sustained an abdominal injury from a piece of wood. Contrast-enhanced computed tomography revealed an inferior pole infarction of the right kidney, a retroperitoneal hematoma spanning zones 1 and 2, and a vessel branching off from the abdominal aorta distal to the main trunk of the right renal artery. Angiography confirmed rupture of the vessel. The patient was diagnosed with accessory renal artery injury, presenting challenges for embolization due to its complexity. Therefore, the central stump was ligated via laparotomy. Accessory renal artery injury should be considered when a retroperitoneal hematoma is detected at a localized site that does not correspond to the renal infarction site, as in the present case. Moreover, revascularization may not always be necessary.