Hyperfibrinolysis is a critical complication in severe trauma. Hyperfibrinolysis is traditionally diagnosed via elevated D-dimer or fibrin/fibrinogen degradation product levels, and recently, using thromboelastometry. Although hyperfibrinolysis is observed in patients with severe isolated traumatic brain injury (TBI) on arrival at the emergency department (ED), it is unclear which factors induce hyperfibrinolysis. The present study aimed to investigate the factors associated with hyperfibrinolysis in patients with isolated severe TBI. We conducted a multicentre retrospective review of data for adult trauma patients with an injury severity score ≥ 16, and selected patients with isolated TBI (TBI group) and extra-cranial trauma (non-TBI group). The TBI group included patients with an abbreviated injury score (AIS) for the head ≥ 4 and an extra-cranial AIS < 2. The non-TBI group included patients with an extra-cranial AIS ≥ 3 and head AIS < 2. Hyperfibrinolysis was defined as a D-dimer level ≥ 38 mg/L on arrival at the ED. We evaluated the relationships between hyperfibrinolysis and injury severity/tissue injury/tissue perfusion in TBI patients by comparing them with non-TBI patients. We enrolled 111 patients in the TBI group and 126 in the non-TBI group. In both groups, patients with hyperfibrinolysis had more severe injuries and received transfusion more frequently than patients without hyperfibrinolysis. Tissue injury, evaluated on the basis of lactate dehydrogenase and creatine kinase levels, was associated with hyperfibrinolysis in both groups. Among patients with TBI, the mortality rate was higher in those with hyperfibrinolysis than in those without hyperfibrinolysis. Tissue hypoperfusion, evaluated on the basis of lactate level, was associated with hyperfibrinolysis in only the non-TBI group. Although the increase in lactate level was correlated with the deterioration of coagulofibrinolytic variables (prolonged prothrombin time and activated partial thromboplastin time, decreased fibrinogen levels, and increased D-dimer levels) in the non-TBI group, no such correlation was observed in the TBI group. Hyperfibrinolysis is associated with tissue injury and trauma severity in TBI and non-TBI patients. However, tissue hypoperfusion is associated with hyperfibrinolysis in non-TBI patients, but not in TBI patients. Tissue hypoperfusion may not be a prerequisite for the occurrence of hyperfibrinolysis in patients with isolated TBI.

Aim: To describe the registry design of the Osaka Emergency Information Research Intelligent Operation Network system (ORION) and its profile of hospital information, patient and emergency medical service characteristics, and in‐hospital outcomes among all patients transported to critical care centers and emergency hospitals in Osaka Prefecture, Japan.Methods: The Osaka Prefecture Government has developed and introduced an information system for emergency patients (the ORION system) that uses a smartphone application (app) for hospital selection by on‐scene emergency medical service personnel and has been accumulating all ambulance records. Since January 2015, medical institutions have obtained information on the diagnosis and outcome of patients transported to medical institutions, and the ORION system merged these data with ambulance records including smartphone app data.Results: From January 2015 to December 2016, 753,301 eligible patients were registered. The mean age was 58.7 years, and 51.5% of patients were male. After hospital arrival, 39.7% were hospitalized, 58.2% were discharged from hospital, 1.1% changed hospital, and 1.0% died. The most common diagnoses were injury, poisoning, and certain other consequences of external causes. Among the hospitalized patients, 29.2% were continuously hospitalized, 59.0% discharged, 5.2% changed hospital, and 5.8% were dead at 21 days after hospitalization. The most common confirmed diagnosis was diseases of the circulatory system.Conclusion: Using the ORION system developed and operated by Osaka Prefecture since January 2015, we described the epidemiological data of all emergency patients transported to emergency hospitals. Analysis using the ORION database in the future could lead to improvements in the emergency transport system and patient outcomes.

Acute coagulopathy is a well-known predictor of poor outcomes in patients with severe trauma. However, using coagulation and fibrinolytic markers, how one can best predict mortality to find out potential candidates for treatment of coagulopathy remains unclear. This study aimed to determine preferential markers and their optimal cut-off values for mortality prediction. We conducted a retrospective observational study of patients with severe blunt trauma (injury severity score ≥ 16) transferred directly from the scene to emergency departments at two trauma centres in Japan from January 2013 to December 2015. We investigated the impact and optimal cut-off values of initial coagulation (platelet counts, fibrinogen and prothrombin time-international normalised ratio) and a fibrinolytic marker (D-dimer) on 28-day mortality via classification and regression tree (CART) analysis. Multivariate logistic regression analysis confirmed the importance of these markers. Receiver operating characteristic curve analyses were used to examine the prediction accuracy for mortality. Totally 666 patients with severe blunt trauma were analysed. CART analysis revealed that the initial discriminator was fibrinogen (cut-off, 130 mg/dL) and the second discriminator was D-dimer (cut-off, 110 μg/mL in the lower fibrinogen subgroup; 118 μg/mL in the higher fibrinogen subgroup). The 28-day mortality was 90.0% (lower fibrinogen, higher D-dimer), 27.8% (lower fibrinogen, lower D-dimer), 27.7% (higher fibrinogen, higher D-dimer) and 3.4% (higher fibrinogen, lower D-dimer). Multivariate logistic regression demonstrated that fibrinogen levels < 130 mg/dL (adjusted odds ratio [aOR], 9.55; 95% confidence interval [CI], 4.50–22.60) and D-dimer ≥110 μg/mL (aOR, 5.89; 95% CI, 2.78–12.70) were independently associated with 28-day mortality after adjusting for probability of survival by the trauma and injury severity score (TRISS Ps). Compared with the TRISS Ps alone (0.900; 95% CI, 0.870–0.931), TRISS Ps with fibrinogen and D-dimer yielded a significantly higher area under the curve (0.942; 95% CI, 0.920–0.964; p < 0.001). Fibrinogen and D-dimer were the principal markers for stratification of mortality in patients with severe blunt trauma. These markers could function as therapeutic targets because they were significant predictors of mortality, independent from severity of injury.

Aim: The impact of the coronavirus disease (COVID‐19) pandemic on the emergency medical service system in Japan has not been fully revealed. The purpose of this study was to determine the impact of the COVID‐19 pandemic in 2021 on the difficulty in hospital acceptance of patients and patient outcome in Osaka Prefecture.Methods: This study was a descriptive epidemiological study with a 3‐year study period from January 2019 to December 2021. We included patients who were transported by ambulance and had registered in the Osaka Emergency Information Research Intelligent Operation Network (ORION) system. The primary end‐point of this study was the difficulty in hospital acceptance by month, and the secondary outcome was the mortality of patients who experience difficulty in hospital acceptance in each year.Results: We included 1,302,646 cases in this study. The proportion of cases with difficulty in hospital acceptance was 2.74% (12,829/468,709) in 2019, 3.74% (15,527/414,987) in 2020, and 5.09% (21,311/418,950) in 2021. The crude odds ratio for 2020 was 1.38 (95% confidence interval, 1.35–1.41) and for 2021 was 1.90 (95% confidence interval, 1.86–1.95). In 2019, 218 patients with difficulty in hospital acceptance had died by 21 days after hospitalization, whereas the number increased to 405 in 2020 and 750 in 2021.Conclusion: The number of patients experiencing difficulty in hospital acceptance during the COVID‐19 pandemic in Osaka Prefecture increased, and patient outcomes were worse than before the pandemic.

Although the COVID-19 pandemic affects the emergency medical service (EMS) system, little is known about the impact of the COVID-19 pandemic on the prognosis of emergency patients. This study aimed to reveal the impact of the COVID-19 pandemic on the EMS system and patient outcomes. We included patients transported by ambulance who were registered in a population-based registry of patients transported by ambulance. The endpoints of this study were the incident number of patients transported by ambulance each month and the number of deaths among these patients admitted to hospital each month. The incidence rate ratio (IRR) and 95% confidence interval (CI) using a Poisson regression model with the year 2019 as the reference were calculated. A total of 500,194 patients were transported in 2019, whereas 443,321 patients were transported in 2020, indicating a significant decrease in the number of emergency patients transported by ambulance (IRR: 0.89, 95% CI: 0.88–0.89). The number of deaths of emergency patients admitted to hospital was 11,931 in 2019 and remained unchanged at 11,963 in 2020 (IRR: 1.00, 95% CI: 0.98–1.03). The incidence of emergency patients transported by ambulance decreased during the COVID-19 pandemic in 2020, but the mortality of emergency patients admitted to hospital did not change in this study.