Injuries and illness of athletes at the Tokyo 2020 Olympic and Paralympic summer games visiting outside facilities.

This study aimed to identify the reasons for transferring athletes to local medical facilities during the Olympic and Paralympic Games. Data on 567 injuries and other illnesses of athletes treated at the on-site clinics were collected from the Tokyo 2020 Organizing Committee. Of these, 84 athletes who required outpatient care during the Games were registered for this survey. During the Olympic and Paralympic Games, 66 (8.3/1 000) and 18 (7.2/1 000) athletes, respectively, consulted external medical facilities. In the Olympic Games, the reasons for these visits included 48 cases (72.7%) of injuries, 13 (19.7%) cases of illnesses, and 5 (7.6%) cases of heat stroke illness (HSI). Of these patients, 56 (84.9%) were treated as outpatients and 10 (15.1%) were hospitalized, while three of these patients required hospitalization for > 7 days. On the other hand, in the Paralympics Games, there were 7 (38.8%) cases of injuries, 9 (50.0%) other illnesses, 1 (5.6%) case of HSI, and 1 (5.6%) other cases, of which 11 (61.1%) were treated as outpatients and 7 (38.9%) were hospitalized, but none was hospitalized for > 7 days. Injuries accounted for 70% of the total cases at the 2021 Olympic Games, but only three (0.05%) were severe cases that required hospitalization for more than 1 week. In contrast, in the Paralympic Games, other illnesses accounted for approximately half of the total cases. This study provides details on the extent of injuries and other illnesses that were transferred to outside facilities, which has not been documented in previous games.

Idarucizumab for Emergency Reversal of the Anticoagulant Effects of Dabigatran: Final Results of a Japanese Postmarketing Surveillance Study.

INTRODUCTION: Idarucizumab, a monoclonal antibody fragment that rapidly reverses the anticoagulant effects of dabigatran, was approved in Japan in September 2016, at which time an all-case, postmarketing surveillance (PMS) study was initiated to collect data on idarucizumab in Japanese patients. Interim results were published previously, and the final results are reported herein. METHODS: This multicenter, open-label, uncontrolled, non-interventional PMS study was conducted in Japanese patients who received idarucizumab at the approved dose (2 × 2.5 g/50 ml) and had uncontrolled bleeding (group A) or required an emergency procedure (group B). The primary endpoint was the frequency of adverse drug reactions (ADRs). The secondary endpoint was the maximum extent of reversal of the anticoagulant effects of dabigatran, within 4 h of idarucizumab administration, based on activated partial thromboplastin time (aPTT). RESULTS: The final analysis included 804 patients. ADRs during the idarucizumab treatment and post-treatment periods were reported in 17 of 542 patients (3.1%) in group A and 12 of 240 patients (5.0%) in group B. Thrombotic events were reported in 22 patients (4.1%) in group A and 15 patients (6.3%) in group B, and hypersensitivity occurred in four (0.7%) and five patients (2.1%), respectively. Among 793 patients evaluated for effectiveness, 78 in group A and 26 in group B had aPTT data at baseline (immediately before idarucizumab administration) and within 4 h of idarucizumab administration; in these patients, median maximum percentage reversal within 4 h of idarucizumab administration was 100%. CONCLUSIONS: The final analysis from the PMS study confirms previous findings suggesting that idarucizumab can safely and effectively reverse the anticoagulant effects of dabigatran in Japanese patients in clinical practice. The results support the continued use of idarucizumab in Japan. TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov (NCT02946931).

Atrial fibrillation is an irregular heart rhythm (arrhythmia), and the type of atrial fibrillation not caused by a heart valve problem is known as "non-valvular atrial fibrillation" or NVAF. People with NVAF have an increased risk of ischemic stroke, in which a blood clot (thrombus) blocks an artery in the brain. Drugs that inhibit blood clots, known as anticoagulants, are prescribed to people with NVAF to prevent ischemic stroke. Historically, warfarin has been one of the most prescribed anticoagulant drugs. However, a novel anticoagulant drug, known as dabigatran, has clinical advantages over warfarin and is approved in many countries for people with NVAF. People who take anticoagulants may experience life-threatening bleeding or need urgent surgery, and thus rapid and effective reversal of the anticoagulant effects is critical. The drug idarucizumab specifically binds to dabigatran to reverse its anticoagulant effects in people with uncontrolled bleeding or who require an urgent procedure. Idarucizumab was approved for use in Japan in September 2016. In Japan, drug companies are obligated to collect data after a new drug is launched as an approval condition, which is done through a postmarketing surveillance study. Here, we report the final results of a postmarketing surveillance study conducted between September 2016 and November 2020 to evaluate the safety and effectiveness of idarucizumab in Japanese patients receiving dabigatran. The results of our study show that idarucizumab can safely and effectively reverse the anticoagulant effects of dabigatran in Japanese patients, and support the continued use of idarucizumab in Japan in clinical practice.

Incidence and factor analysis for the heat-related illness on the Tokyo 2020 Olympic and Paralympic Games.

Introduction: Among the 43 venues of Tokyo 2020 Olympic Games (OG) and 33 venues of Paralympic Games (PG) were held, the heat island effect was highly expected to cause heat-related illnesses in the outdoor venues with maximum temperatures exceeding 35°C. However, the actual number of heat-related illness cases during the competition was lower than that was initially expected, and it was unclear under what conditions or environment-related heat illnesses occurred among athletes. Object: To clarify the cause and factors contributing to the occurrence of heat-related illness among athletes participating in the Tokyo 2020 Olympic and Paralympic Games. Method: This retrospective descriptive study included 15 820 athletes from 206 countries. From 21 July 2021 to 8 August 2021 for the Olympics, and from 24 August 2021 to 5 September 2021 for the Paralympics. The number of heat-related illness cases at each venue, the incidence rate for each event, gender, home continent, as well as the type of competition, environmental factors (such as venue, time, location and wet-bulb globe temperature (WBGT)), treatment factor and the type of competition were analysed. Results: More number of heat-related illnesses among athletes occurred at the OG (n=110, 76.3%) than at the PG (n=36, 23.7%). A total of 100 cases (100%) at the OG and 31 cases (86.1%) at the PG occurred at the outdoors venues. In the OG, a total of 50 cases (57.9%) occurred during the competition of marathon running and race walking at Sapporo Odori Park. Six of those, were diagnosed with exertional heat illness and treated with cold water immersion (CWI) at OG and one case at PG. Another 20 cases occurred in athletics (track and field) competitions at Tokyo National Olympic Stadium. In total, 10 cases (10.0%) were diagnosed with severe heat illness in the OG and 3 cases (8.3%) in the PG. Ten cases were transferred to outside medical facilities for further treatment, but no case has been hospitalised due to severe condition. In the factor analysis, venue zone, outdoor game, high WBGT (<28°C) and endurance sports have been found to have a higher risk of moderate and severe heat-related illness (p<0.05). The incidence rate and severity could be attenuated by proper heat-related illness treatment (CWI, ice towel, cold IV transfusion and oral hydration) reduced the severity of the illness, providing summer hot environment sports. Conclusion: The Tokyo 2020 Olympic and Paralympic summer games were held. Contrary to expectations, we calculated that about 1 in 100 Olympic athletes suffered heat-related illness. We believe this was due to the risk reduction of heat-related illness, such as adequate prevention and proper treatment. Our experience in avoiding heat-related illness will provide valuable data for future Olympic summer Games.

Clinical Characteristics and Prognosis of Life-Threatening Acute Myocardial Infarction in Patients Transferred to an Emergency Medical Care Center.

Patients with acute myocardial infarction (AMI) triaged as life-threatening are transferred to our emergency medical care center (EMCC). However, data on these patients remain limited. We aimed to compare the characteristics and AMI prognosis of patients transferred to our EMCC with those transferred to our cardiovascular intensive care unit (CICU) using whole and propensity-matched cohorts.We analyzed the data of 256 consecutive AMI patients transferred from the scene to our hospital by ambulance between 2014 and 2017. The EMCC and CICU groups comprised 77 and 179 patients, respectively. There were no significant between-group age or sex differences. Patients in the EMCC group had more disease severity score and had the left main trunk identified as the culprit more frequently (12% versus 0.6%, P < 0.001) than those in the CICU group; however, the number of patients with multiple culprit vessels did not differ. The EMCC group had a longer door-to-reperfusion time (75 [60, 109] minutes versus 60 [40, 86] minutes, P< 0.001) and a higher in-hospital mortality (19% versus 4.5%, P < 0.001), especially from non-cardiac causes (10% versus 0.6%, P < 0.001), than the CICU group. However, peak myocardial creatine phosphokinase did not significantly differ between the groups. The EMCC group had a significantly higher 1-year post-discharge mortality than the CICU group (log-rank, P = 0.032); this trend was maintained after propensity score matching, although the difference was not statistically significant (log-rank, P = 0.094).AMI patients transferred to the EMCC exhibited more severe disease and worse overall in-hospital and non-cardiac mortality than those transferred to the CICU.

Acute in-competition medical care at the Tokyo 2020 Olympics: a retrospective analysis.

OBJECTIVE: To analyse injuries and illnesses during the 2020 Tokyo Olympic Summer Games. METHODS: This retrospective descriptive study included 11 420 athletes from 206 National Olympic Committees and 312 883 non-athletes. Incidences of injuries and illnesses during the competition period from 21 July to 8 August 2021 were analysed. RESULTS: A total of 567 athletes (416 injuries, 51 non-heat-related illnesses and 100 heat-related illnesses) and 541 non-athletes (255 injuries, 161 non-heat-related illnesses and 125 heat-related illnesses) were treated at the competition venue clinic. Patient presentation and hospital transportation rates per 1000 athletes were 50 and 5.8, respectively. Marathons and race walking had the highest incidence of injury and illness overall (17.9%; n=66). The highest incidence of injury (per participant) was noted in boxing (13.8%; n=40), sport climbing (12.5%; n=5) and skateboarding (11.3%; n=9), excluding golf, with the highest incidence of minor injuries. Fewer infectious illnesses than previous Summer Olympics were reported among the participants. Of the 100 heat-related illnesses in athletes, 50 occurred in the marathon and race walking events. Only six individuals were transported to a hospital due to heat-related illness, and none required hospital admission. CONCLUSION: Injuries and heat-related illnesses were lower than expected at the 2020 Tokyo Olympic Summer Games. No catastrophic events occurred. Appropriate preparation including illness prevention protocols, and treatment and transport decisions at each venue by participating medical personnel may have contributed to these positive results.

Characteristics and Outcomes of Emergency Transferred Patients with Foreign Body Airway Obstruction in Tokyo, Japan.

INTRODUCTION: Foreign body airway obstruction (FBAO) is a life-threatening emergency, and the prognosis of patients with FBAO is greatly affected by the prehospital process. There are only a few large-scale studies analyzing prehospital process databases of the fire department. STUDY OBJECTIVE: The aim of this study was to investigate whether characteristics of patients with FBAO were associated with prehospital factors and outcomes. METHODS: In this retrospective observational study, patients transferred to the hospital by the Tokyo, Japan Fire Department for FBAO from 2017 through 2019 were included. The association between neurologically favorable survival among the characteristics of patients with FBAO and prehospital factors affecting the outcomes was evaluated. RESULTS: Of the 2,429,175 patients, 3,807 (0.2%) patients had FBAO. The highest number of FBAO cases was 99 (2.6%), which occurred on January 1 (New Year's Day), followed by 40 cases (1.1%) on January 2, and 28 cases (0.7%) on January 3. The number of patients who experienced out-of-hospital cardiac arrest (OHCA) caused by FBAO was 1,644 (43.2%). Comparing the OHCA and non-OHCA groups, there were significant differences in age, sex, time spent at the site, and distance between the site and hospital. Cardiac arrest was significantly lower in infants after FBAO (P < .001). In total, 98.2% of patients who did not have return of spontaneous circulation (ROSC) before hospital arrival died within 30 days, a significantly higher mortality rate than that in patients who had ROSC (98.2% versus 65.8%; P < .001). CONCLUSIONS: Among patients who did not have ROSC following FBAO upon arrival at the hospital, 98.2% died within 30 days. Thus, it is important to remove foreign bodies promptly and provide sufficient ventilation to the patient at the scene to increase the potential for ROSC. Further, more precautions should be exercised to prevent FBAO at the beginning of the year.

Current status of active cooling, deep body temperature measurement, and face mask wearing in heat stroke and heat exhaustion patients in Japan: a nationwide observational study based on the Heatstroke STUDY 2020 and 2021.

Aim: The study aimed to determine the current status of face mask use, deep body temperature measurement, and active cooling in patients suffering from heat stroke and heat exhaustion in Japan. Methods: This was a prospective, observational, multicenter study using data from the Heatstroke STUDY 2020-2021, a nationwide periodical registry of heat stroke and heat exhaustion patients. Based on the Bouchama heatstroke criteria, we classified the patients into two groups: severe and mild-to-moderate. We compared the outcomes between the two groups and reclassified them into two subgroups according to the severity of the illness, deep body temperature measurements, and face mask use. Cramer's V was used to determine the effect sizes for a comparison between groups. Results: Almost all patients in this study were categorized as having degree III based on the Japanese Association for Acute Medicine heatstroke criteria (JAAM-HS). However, the severe group was significantly worse than the mild-to-moderate group in outcomes like in-hospital death and modified Rankin Scale scores, when discharged. Heat strokes had significantly higher rates of active cooling and lower mortality rates than heat stroke-like illnesses. Patients using face masks often use them during labor, sports, and other exertions, had less severe conditions, and were less likely to be young male individuals. Conclusions: It is suggested that severe cases require a more detailed classification of degree III in the JAAM-HS criteria, and not measuring deep body temperature could have been a factor in the nonperformance of active cooling and worse outcomes.

Development of a Machine Learning Model to Predict Cardiac Arrest during Transport of Trauma Patients.

BACKGROUND: Trauma is a serious medical and economic burden worldwide, and patients with traumatic injuries have a poor survival rate after cardiac arrest. The authors developed a prediction model specific to prehospital trauma care and used machine learning techniques to increase its accuracy. METHODS: This retrospective observational study analyzed data from patients with blunt trauma injuries due to traffic accidents and falls from January 1, 2018, to December 31, 2019. The data were collected from the National Emergency Medical Services Information System, which stores emergency medical service activity records nationwide in the United States. A random forest algorithm was used to develop a machine learning model. RESULTS: The prediction model had an area under the curve of 0.95 and a negative predictive value of 0.99. The feature importance of the predictive model was highest for the AVPU (Alert, Verbal, Pain, Unresponsive) scale, followed by oxygen saturation (SpO2). Among patients who were progressing to cardiac arrest, the cutoff value was 89% for SpO2 in nonalert patients. CONCLUSIONS: The machine learning model was highly accurate in identifying patients who did not develop cardiac arrest.

Accuracy of breathing and radial pulse assessment by non-medical persons: an observational cross-sectional study.

Early recognition of cardiopulmonary arrest (CPA) expedites emergency calls and resuscitation and improves the survival rate of unresponsive individuals. However, the accuracy of breathing and radial artery pulse assessment by non-medical persons is poorly understood. The aim of this study was to determine the accuracy of breathing assessment and radial pulse palpation among 450 non-medical personnel using a high-fidelity simulator. We examined the accuracy of 10 second's assessment for breathing and radial pulse using a high-fidelity mannequin simulator, included 496 non-medical participants (school teachers) between 2016-2018. For a primary results, the sensitivity for the detection of the presence of the breathing and radial pulse was 96.2% (97.5% for sensitivity and 92.0% for specificity) and 91.7% (99.1% for sensitivity and 56.8% for specificity), respectively. Futher, breathing rate and radial pulse rate were strongly correlated with the assessments, with Spearman's correlation coefficients of 0.813 (P < 0.001) and 0.719 (P < 0.001), respectively. In contrast, radial pulse strength was weakly correlated with the assessment (coefficient of 0.288, P < 0.001). Our results suggested that non-medical persons would show high accuracy in detecting and measuring respiration and radial pulse, although they did not accurately determine radial pulse strength for the early recognition of CPA.

Prehospital ABC (Age, Bystander and Cardiogram) scoring system to predict neurological outcomes of cardiopulmonary arrest on arrival: post hoc analysis of a multicentre prospective observational study.

BACKGROUND: There is currently limited evidence to guide prehospital identification of patients with cardiopulmonary arrest on arrival (CPAOA) to hospital who have potentially favourable neurological function. This study aimed to develop a simple scoring system that can be determined at the contact point with emergency medical services to predict neurological outcomes. METHODS: We analysed data from patients with CPAOA using a regional Japanese database (SOS-KANTO), from January 2012 to March 2013. Patients were randomly assigned into derivation and validation cohorts. Favourable neurological outcomes were defined as cerebral performance category 1 or 2. We developed a new scoring system using logistic regression analysis with the following predictors: age, no-flow time, initial cardiac rhythm and arrest place. The model was internally validated by assessing discrimination and calibration. RESULTS: Among 4907 patients in the derivation cohort and 4908 patients in the validation cohort, the probabilities of favourable outcome were 0.9% and 0.8%, respectively. In the derivation cohort, age ≤70 years (OR 5.11; 95% CI 2.35 to 11.14), no-flow time ≤5 min (OR 4.06; 95% CI 2.06 to 8.01) and ventricular tachycardia or fibrillation as initial cardiac rhythm (OR 6.66; 95% CI 3.45 to 12.88) were identified as predictors of favourable outcome. The ABC score consisting of Age, information from Bystander and Cardiogram was created. The areas under the receiver operating characteristic curves of this score were 0.863 in the derivation and 0.885 in the validation cohorts. Positive likelihood ratios were 6.15 and 6.39 in patients with scores >2 points and were 11.06 and 17.75 in those with 3 points. CONCLUSION: The ABC score showed good accuracy for predicting favourable neurological outcomes in patients with CPAOA. This simple scoring system could potentially be used to select patients for extracorporeal cardiopulmonary resuscitation and minimise low-flow time.

Water-Dispersible Carboxymethyl Dextran-Coated Melamine Nanoparticles for Biosensing Applications.

In this study, we developed a simple method for preparing highly dispersed, stable, and streptavidin (SA)-functionalized carboxymethyl dextran (CMD)-coated melamine nanoparticles (MNPs) in an aqueous buffer at neutral pH. Dynamic light scattering (DLS) revealed the agglomeration of MNPs in an aqueous buffer at neutral pH. When CMD, N-hydroxysuccinimide (NHS), and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were simultaneously mixed with the MNPs, CMD was bound to the MNPs, promoting their dispersibility. Preparation of SA-CMD-MNPs was accomplished simply by adding SA solution to the CMD-MNPs. The amount of SA bound to the CMD-MNPs was quantified by the bicinchoninic assay, and the amount of SA molecules bound to each CMD-MNP was 417 ± 4. SA-CMD-MNPs exhibited high dispersity (polydispersity index = 0.058) in a neutral phosphate buffer and maintained it for 182 days with dispersion using a probe sonicator (5 s) before DLS characterization. The performance of the SA-CMD-MNPs in biosensing was evaluated by immunohistochemistry, which revealed that the nanoparticles could specifically stain MCF-7 cells derived from breast cancer cells with low HER2 expression. This study provides an effective method for synthesizing highly dispersible nanoparticles for biosensing.

Do Video Calls Improve Dispatcher-Assisted First Aid for Infants with Foreign Body Airway Obstruction? A Randomized Controlled Trial/Simulation Study.

BACKGROUND: Because choking quickly leads to cardiopulmonary arrest, it is crucial that bystanders remove foreign bodies effectively. Although oral instructions in video calls by dispatchers have improved the quality of cardiopulmonary resuscitation, it is unclear whether video calls improve the quality of first aid for choking infants. Therefore, this simulation study aimed to determine whether video calls with dispatchers improve the quality of first aid for infants with foreign body airway obstruction (FBAO). METHODS: Seventy first-year college students randomly assigned in pairs to communicate by video or audio calls participated in simulated emergency calls for infants with FBAO. Both groups began with oral instruction in voice calls until the transition was made to video calls in the video group. The primary outcome was quality of first aid performance, which was categorized as excellent, acceptable, or poor on the basis of existing guidelines. RESULTS: There were 17 simulations in the video-call groups and 16 in the voice-call groups. After initial oral instruction, the proportion of rescuers that received an evaluation of excellent or acceptable did not differ significantly between the groups (video, 41% vs. voice, 50%; P=0.61); however, evaluations for seven rescuers improved after transitioning to video calls. Ultimately, the proportion receiving a poor evaluation was significantly lower in the video-call group than in the voice-call group (50% vs. 82%, P=0.049). CONCLUSION: Oral instruction communicated by video calls improved the quality of first aid for infants with FBAO.

Hyperfibrinolysis and fibrinolysis shutdown in patients with traumatic brain injury.

Traumatic brain injury (TBI) is associated with coagulation/fibrinolysis disorders. We retrospectively evaluated 61 TBI cases transported to hospital within 1 h post-injury. Levels of thrombin-antithrombin III complex (TAT), D-dimer, and plasminogen activator inhibitor-1 (PAI-1) were measured on arrival and 3 h, 6 h, 12 h, 1 day, 3 days and 7 days after injury. Multivariate logistic regression analysis was performed to identify prognostic factors for coagulation and fibrinolysis. Plasma TAT levels peaked at admission and decreased until 1 day after injury. Plasma D-dimer levels increased, peaking up to 3 h after injury, and decreasing up to 3 days after injury. Plasma PAI-1 levels increased up to 3 h after injury, the upward trend continuing until 6 h after injury, followed by a decrease until 3 days after injury. TAT, D-dimer, and PAI-1 were elevated in the acute phase of TBI in cases with poor outcome. Multivariate logistic regression analysis showed that D-dimer elevation from admission to 3 h after injury and PAI-1 elevation from 6 h to 1 day after injury were significant negative prognostic indicators. Post-TBI hypercoagulation, fibrinolysis, and fibrinolysis shutdown were activated consecutively. Hyperfibrinolysis immediately after injury and subsequent fibrinolysis shutdown were associated with poor outcome.

Neurointensive Care of Traumatic Brain Injury Patients Based on Coagulation and Fibrinolytic Parameter Monitoring.

Coagulopathy, a common complication of traumatic brain injury (TBI), is characterized by a hypercoagulable state developing immediately after injury, with hyperfibrinolysis and bleeding tendency peaking 3 h after injury, followed by fibrinolysis shutdown. Reflecting this timeframe, the coagulation factor fibrinogen is first consumed and then degraded after TBI, its concentration rapidly decreasing by 3 h post-TBI. The fibrinolytic marker D-dimer reaches its maximum concentration at the same time. Hyperfibrinolysis in the acute phase of TBI is associated with poor prognosis via hematoma expansion. In the acute phase, the coagulation and fibrinolysis parameters must be monitored to determine the treatment strategy. The combination of D-dimer plasma level at admission and the level of consciousness upon arrival at the hospital can be used to predict the patients who will "talk and deteriorate." Fibrinogen and D-dimer levels should determine case selection and the amount of fresh frozen plasma required for transfusion. Surgery around 3 h after injury, when fibrinolysis and bleeding diathesis peak, should be avoided if possible. In recent years, attempts have been made to estimate the time of injury from the time course of coagulation and fibrinolysis parameter levels, which has been particularly useful in some cases of pediatric abusive head trauma patients.

Influence of the coronavirus disease 2019 (COVID-19) pandemic on the incidence of heat stroke and heat exhaustion in Japan: a nationwide observational study based on the Heatstroke STUDY 2019 (without COVID-19) and 2020 (with COVID-19).

AIM: To assess heat stroke and heat exhaustion occurrence and response during the coronavirus disease 2019 pandemic in Japan. METHODS: This retrospective, multicenter, registry-based study describes and compares the characteristics of patients between the months of July and September in 2019 and 2020. Factors affecting heat stroke and heat exhaustion were statistically analyzed. Cramér's V was calculated to determine the effect size for group comparisons. We also investigated the prevalence of mask wearing and details of different cooling methods. RESULTS: No significant differences were observed between 2019 and 2020. In both years, in-hospital mortality rates just exceeded 8%. Individuals >65 years old comprised 50% of cases and non-exertional onset (office work and everyday life) comprised 60%-70%, respectively. The recommendations from the Working Group on Heat Stroke Medicine given during the coronavirus disease pandemic in 2019 had a significant impact on the choice of cooling methods. The percentage of cases, for which intravascular temperature management was performed and cooling blankets were used increased, whereas the percentage of cases in which evaporative plus convective cooling was performed decreased. A total of 49 cases of heat stroke in mask wearing were reported. CONCLUSION: Epidemiological assessments of heat stroke and heat exhaustion did not reveal significant changes between 2019 and 2020. The findings suggest that awareness campaigns regarding heat stroke prevention among the elderly in daily life should be continued in the coronavirus disease 2019 pandemic. In the future, it is also necessary to validate the recommendations of the Working Group on Heatstroke Medicine.

Prevalence and Characteristics of Earthquake-Related Head Injuries: A Systematic Review.

OBJECTIVE: We conducted a systematic review to determine the prevalence and characteristics of earthquake-associated head injuries for better disaster preparedness and management. METHODS: We searched for all publications related to head injuries and earthquakes from 1985 to 2018 in MEDLINE and other major databases. A search was conducted using "earthquakes," "wounds and injuries," and "cranio-cerebral trauma" as a medical subject headings. RESULTS: Included in the analysis were 34 articles. With regard to the commonly occurring injuries, earthquake-related head injury ranks third among patients with earthquake-related injuries. The most common trauma is lower extremity (36.2%) followed by upper extremity (19.9%), head (16.6%), spine (13.1%), chest (11.3%), and abdomen (3.8%). The most common earthquake-related head injury was laceration or contusion (59.1%), while epidural hematoma was the most common among inpatients with intracranial hemorrhage (9.5%) followed by intracerebral hematoma (7.0%), and subdural hematoma (6.8%). Mortality rate was 5.6%. CONCLUSION: Head injuries were found to be a commonly occurring trauma along with extremity injuries. This knowledge is important for determining the demands for neurosurgery and for adequately managing patients, especially in resource-limited conditions.

Evaluation of outcomes after EMS-witnessed traumatic out-of-hospital cardiac arrest caused by traffic collisions.

AIM: The survival rate of patients with traumatic cardiac arrest is 3% or lower. Cardiac arrest witnessed by emergency medical services (EMS) accounts for approximately 16% of prehospital traumatic cardiac arrests, but the prognosis is unknown. We aimed to compare the 1-month survival rate of cardiac arrest witnessed by EMS with that of cardiac arrest witnessed by bystanders and unwitnessed cardiac arrest in traffic trauma victims; further, the time from injury to cardiac arrest was assessed. METHODS: This analysis used the Utstein Registry in Japan and included data of 3883 patients with traumatic cardiac arrest caused by traffic collisions registered between 2014 and 2019 in Japan. RESULTS: The 1-month survival rate was 10.9% in the EMS-witnessed cardiac arrest group; this was significantly higher than that in the bystander-witnessed (7.2%) and unwitnessed (5.6%) cardiac arrest groups (P < 0.01). The median time from injury to cardiac arrest was 18 min (25% quartile: 12, 75% quartile: 26). CONCLUSION: The 1-month survival rate was significantly higher in the EMS-witnessed cardiac arrest group than in the bystander-witnessed and unwitnessed cardiac arrest groups. It is important to prevent progression to cardiac arrest in trauma patients with intact respiratory function and pulse rate at the time of contact with EMS. A system for early recognition of severe trauma is needed, and a doctor's car or helicopter can be requested as needed. We believe that early recognition and prompt intervention will improve the prognosis of prehospital traumatic cardiac arrest.

Wearing a face mask during controlled-intensity exercise is not a risk factor for exertional heatstroke: A pilot study.

AIM: This study aimed to measure the influence of wearing face masks on individuals' physical status in a hot and humid environment. METHODS: Each participant experienced different physical situations: (i) not wearing a mask (control), (ii) wearing a surgical mask, (iii) wearing a sport mask. An ingestible capsule thermometer was used to measure internal core body temperature during different exercises (standing, walking, and running, each for 20 min) in an artificial weather room with the internal wet-bulb globe temperature set at 28°C. The change in the participants' physical status and urinary liver fatty acid-binding protein (L-FABP) were measured. RESULTS: Six healthy male volunteers were enrolled in the study. In each participant, significant changes were observed in the heart rate and internal core temperatures after increased exercise intensity; however, no significant differences were observed between these parameters and urinary L-FABP among the three intervention groups. CONCLUSION: Mask wearing is not a risk factor for heatstroke during increased exercise intensity.

Quantitative analysis of the impact of COVID-19 on the emergency medical services system in Tokyo.

AIM: The coronavirus disease 2019 (COVID-19) pandemic has imposed a heavy burden on emergency medical services (EMS) systems. Therefore, we quantitatively analyzed impacts of COVID-19 on the EMS system in Tokyo. METHODS: In this retrospective observational study, we used publicly available data, including the daily number of newly diagnosed patients with COVID-19, the weekly number of transport difficulties, and the field activity time, from March 2, 2020, to January 25, 2021. Data for the same period in the previous year were used as controls. RESULTS: The total number of EMS calls decreased by 12.7% in 2020 compared with that in 2019. The number of daily transport difficulties significantly increased in 2020 compared with that in 2019 (89 [72-120] vs 57 [49-63]; P < 0.001). Additionally, the field activity time significantly increased in 2020 compared with that in 2019 (22.7 [22.3-23.8] min vs 20.7 [20.6-21.2] min; P < 0.001). Furthermore, the daily number of new patients with COVID-19 was positively correlated with the number of transport difficulties (R = 0.76) and the field activity time on the scene (R = 0.74). With an increase in the number of people infected with COVID-19 by 1,000, the number of daily transport difficulties increased by 86.4. Per 1,000 infected patients per day, the field activity time increased by 3.48 min. CONCLUSION: This study revealed that the increase in the number of patients with COVID-19 indirectly affected the EMS system in Tokyo.