Source

The protocol of this retrospective study was approved by the institutional review board at Juntendo University (approval number 298), and examinations were conducted according to the standards of good clinical practice and the Declaration of Helsinki.

This study utilized electronic medical records from Juntendo University Shizuoka Hospital and Numazu City Hospital (Numazu, Shizuoka Prefecture, Japan)—the hospital to which the critical patients were initially transported and another hospital for less critical patients—as its information sources.

Observation

At approximately 16:15 on December 26, 2025 – when many workplaces in Japan were wrapping up for the year – at a factory in Mishima City, a man clad in protective gear and wielding a spear-like survival knife attached to a pole carried a backpack rigged with needles. He sprayed an alkaline chlorine bleach solution (pH 11.0-12.0; primarily sodium hypochlorite) using a sprayer while repeatedly attacking others with the blade. ⁹ The first call, made at 16:28 to Mount Fuji Southeast Fire Department (Mishima, Shizuoka Prefecture Japan), reported a possible chemical terrorist attack involving the dispersal of a liquid. A subsequent report stated that five or six people had been stabbed by an unknown assailant. The male suspect was subdued by employees at the same factory and was arrested in the act. Juntendo University Shizuoka Hospital received the initial report at 16:42. As the doctor helicopter had ceased operations due to sunset, four physicians were deployed to the disaster site via the doctor car. One physician was assigned to the command post while the other three provided initial medical care to the injured.

Meanwhile, the hospital assembled all on-site staff, secured operating rooms and the intensive care unit (ICU), mobilized the hospital’s Disaster Medical Assistance Team (DMAT), and established a temporary disaster response headquarters adjacent to the doctor helicopter operations room to prepare for patient reception. Following triage at the scene by emergency medical technicians, a total of eight patients – three severely injured (red tags) and five moderately injured (yellow tags) – all with stab wounds to the torso, were transported to this hospital. Seven patients deemed less severely injured (green tags) – six cases of chemical corneal injury and one case of chemical pharyngeal injury – were transported to another emergency center. The first case of traumatic abdominal evisceration was transported to Shizuoka Hospital at 17:53, and the eighth and final moderate-severity patient (yellow tag) arrived at 18:19. The list of patients is shown in Table 1. The results of triage based on vital signs and anatomical severity as determined by physical examination was adopted at the scene, and triage based on changes in trend of vital signs and anatomical severity as determined by computed tomographic (CT) scans was adopted at the hospital. Among them, three of the five moderate-severity (yellow tag) patients developed hemorrhagic shock and were re-classified as severe. Six patients in total with hemorrhagic shock received blood transfusions after arrival, and four of these patients required endotracheal intubation. Contrast-enhanced CTs were performed in seven cases, excluding one case requiring emergency surgery due to traumatic abdominal evisceration, to assess anatomical severity (Figure 1). The time from arrival at the hospital to the start of CT ranged from six to 76 minutes, with a mean of 43 minutes. Initially, a single CT was used; however, because all cases required contrast-enhanced CT, two scanners were subsequently operated. Emergency surgery was performed in three cases, emergency interventional radiology (IVR) in two cases, and chest drains were placed in two cases. The time from arrival at the hospital to open hemostasis and embolization ranged from 19 to 129 minutes. The surgical team initially managed the traumatic abdominal evisceration; however, because the arrival of the other surgical team was slightly delayed and only one operating room was available, the team that arrived later performed hemostasis under general anesthesia in the emergency room. The delay in starting embolization was due to the time required to stabilize the circulation of the patient in cardiac arrest. One patient with a yellow tag sustained a stab wound to the back. His vital signs were stable and ocular symptoms had resolved. Due to an inability to secure a bed at the hospital, he was transferred to another facility. Of the remaining seven patients, six were admitted to the ICU and one to a general ward. Ultimately, all patients survived and were discharged.

Table 1.

Patient List

Table 1. Long description

A table with 15 rows and 13 columns detailing patient information, including diagnosis, triage status, vital signs, treatments, and hospitalization data. Columns include Case No., Sex, Age, Diagnosis, Triage at Scene, Final Triage, Minimum BP, Transfusion, Tracheal Intubation, Emergency Treatment, Corneal Injury, Skin Burn, Hospitalization, From Arrival to CT, and From Arrival to Intervention. Each row lists specific patient data under these headers.

Abbreviations: CA, cardiac arrest; BP, blood pressure; TOH, transferred to hospital; IVR, interventional radiology; ?, no evaluation; N/A, not applicable.

Figure 1.

Enhanced Computed Tomography (CT) Scans Taken Upon Arrival for Seven Cases (Case 5 was Post-Operative).

Note: Contrast-enhanced CT clearly identified the location and depth of penetrating injuries, as well as the extent of organ and vascular damage in each case (star), playing a crucial role in determining treatment strategies.

No.1: 28-year-old man with a right lumbar back stab wound (star) and an alkaline corneal injury underwent irrigation and wound suturing.

No. 2: 51-year-old man with stab wounds to the left forearm and lumbar back (star), as well as an alkaline corneal injury and a neck burn, underwent irrigation.

No. 3: 26-year-old man with a left iliac wing fracture and a gluteal hematoma (star) underwent emergency transfusion, irrigation, and wound suturing.

No. 4: 28-year-old man with right intra-abdominal hemorrhage and a right perirenal retroperitoneal hematoma (star) underwent emergency transfusion, tracheal intubation, hemostasis, irrigation, and wound suturing.

No. 5: 44-year-old man with two left back stab wounds, a left lumbar artery injury (star), and a mandibular contusion experienced transient cardiac arrest and underwent emergency tracheal intubation, transfusion, embolization, irrigation, and wound suturing.

No. 6: 25-year-old man with an abdominal stab wound (star) and traumatic abdominal evisceration underwent emergency laparotomy. Computed tomography was performed after the operation.

No. 7: 34-year-old man with right traumatic hemopneumothorax and a liver injury (star) underwent emergency tracheal intubation, transfusion, thoracocentesis, embolization, and laparotomy.

No. 8: 45-year-old man with a left traumatic hemothorax (star), a left adrenal injury, and a retroperitoneal hemorrhage (star) underwent emergency transfusion, thoracocentesis, irrigation, and wound suturing.

Among the cases judged as mild (green tag) and transferred to other hospitals, five patients who continued to experience eye pain after initial eye irrigation were transferred to Shizuoka Hospital at approximately 22:00. Following examination by an ophthalmologist, they were diagnosed with superficial punctate keratitis (Figure 2) and were discharged to return home. Concerning the psychosocial impact of the incident on both casualties and responders, medical staff underwent psychological evaluations as part of the post-incident review, and no particular issues were identified. However, one critically ill patient developed posttraumatic stress disorder, for which psychiatric intervention was initiated.

Figure 2.

Corneal Staining Examination (Fluorescein) at Presentation for Cases 9-13 (Cases 12 and 13 Include Slit-Lamp Evaluation).

Note: According to the Roper-Hall classification of chemical eye injury, each case showed Grade II.

Analysis

This case involved multiple stab wounds inflicted by a perpetrator with a strong intent to kill, combined with the use of chemical agents in a pre-meditated incident. The present case is not commensurate with the standard of care typically provided by Shizuoka Hospital. A comprehensive evaluation of the hospital’s activities will be conducted. This evaluation will encompass prehospital care.

Regarding command and control, through regular verification meetings between the hospital and surrounding fire departments, fundamental principles for preliminary medical intervention through the utilization of physician helicopters and medical vehicles have been firmly established. Specifically, when the fire department suspects a potentially critical case based on the call details, they request the immediate dispatch of medical personnel to the scene without waiting for information from the fire department’s on-site personnel. This contributes to the enhancement of patient survival rates. ⁹ In this case, a similar request was promptly issued to the hospital from the fire department. The command-and-control structure for mass-casualty reception within the hospital was established with the department taking the initiative, supported by nurses, to secure intensive care beds for critically ill patients and operating rooms. Additionally, as it was the shift change between day and night shifts, many medical staff were present. Beyond surgeons and radiologists, internists were also placed under the command and participated in the initial treatment of patients.

Concurrently, the hospital inaugurated its DMAT and Disaster Response Headquarters. Centered around administrative staff, a system was also established for the purpose of creating incident chronologies, compiling patient lists, and contacting local governments and other relevant parties. ^{Reference Yanagawa, Takeuchi and Nagasawa10}

Regarding safety, the factory employees physically subdued the perpetrator, eliminating the risk of harm to rescuers. Meanwhile, the alkaline agent had been sprayed at the scene, and its odor suggested the possible use of a household detergent. The dispatched team members determined that the contamination was caused by an alkaline detergent and therefore responded using standard protective gear (Level D), consisting of gloves, goggles, a mask, and protective clothing. Furthermore, since chemical burns caused by alkaline detergents are typically treated in the standard manner, they did not consult a toxicologist, a poison control center, or a chemical hazard expert. However, it is standard practice to seek such consultation if the chemical agent used is not a common one. Regarding on-site response to the differing mechanisms of stab wounds and chemical agents, this was the first such experience in this region. Consequently, the primary focus was on addressing the stab wounds, which directly threatened lives. Fortunately, no staff members at this hospital, including the medical personnel involved in the on-site activities, suffered secondary injuries from the alkaline agent.

Regarding triage, there are limitations to assessing severity and urgency at the scene using various triage methods, including the Simple Triage and Rapid Treatment (START) method. ^{Reference Tan and Wong11} Furthermore, when limited to stab wounds, determining depth, directionality, and organ/vascular damage at the scene is difficult even based on bloodstain patterns from the weapon or statements from the patient or perpetrator. Moreover, in cases like this one where multiple individuals were stabbed in the back with the single weapon, determining depth and direction based on bloodstains or testimony was impossible. While physical examination and physician-performed ultrasound might diagnose pneumothorax or cardiac tamponade, when penetration depth is unknown and vascular or organ injury is impossible to determine, prompt hospital-based contrast-enhanced CT imaging is essential. ^{Reference Bazyar, Farrokhi and Khankeh12,Reference Durso, Caban and Penetrating Thoracic Injury13} On the hospital side, it will be necessary to devise methods for performing early CT diagnoses on multiple casualties using multiple CT imaging devices. In this case, the decision made by the doctors dispatched to the scene to transport all patients with torso stab wounds to Shizuoka Hospital for treatment was appropriate, considering that three yellow-tag patients experienced changes in their condition en route. Furthermore, it was also significant to assess the patients’ conditions, relay that information to the hospital, and initiate prompt and appropriate treatment at the hospital. Furthermore, this incident also served to enhance the disaster response experience of the physicians who attended the scene. Accordingly, the practical value of physician presence at the scene may have been less about procedures and more about advanced assessment, destination decision making, triage refinement, and early hospital communication.

This time, a case of alkaline corneal injury was assessed as mild and transferred to another facility. Under normal circumstances, this would have been a chemical eye injury accepted at Shizuoka Hospital. This condition is also a high-urgency disease. ^{Reference Lozano, Munera, Anderson, Soto, Menias and Caban14} This hospital was the only facility capable of providing ophthalmological care during nighttime and holidays. Although the patients were ultimately transferred back to Shizuoka Hospital, where initial treatment to the eight patients with severe and moderate puncture injuries had already been provided, this would have placed a significant burden on the hospital resources. Consequently, a decision was made to transfer this patient as a minor injury (green tag) case, with the objective of reducing the institution’s workload on a temporary basis. The examination results showed this case was Grade II according to the Roper-Hall classification of chemical eye injury, ^{Reference Xie and Jie15} making an ophthalmology visit the following day acceptable. Given the high public attention surrounding the incident, there may have been value in an earlier diagnosis. All ocular injuries have fully healed.

This study has several limitations, including its retrospective design, the single-event and single-region setting, and the lack of a comparator. In addition, the absence of a protocol for prehospital blood transfusions for mass-casualty incidents at the hospital may limit the generalizability of the findings.

Ultimately, the most important lesson derived from this experience appears to be that, within an emergency medical system in a resource–limited region, a deliberate mass-casualty incident involving multiple intertwined factors should be managed under a single, explicitly defined decision–making framework – specifically, the decision to centralize patients with torso stab wounds at a single facility to enable rapid imaging and definitive treatment, while simultaneously dispersing patients with minor, chemically-induced injuries.