Long-Awaited Evidence on Back Blows Versus Abdominal Thrusts.

This is a commentary on the study conducted by Dunne et al. from Alberta, Canada, which retrospectively analyzed data from patients with foreign body airway obstruction (FBAO) in the region. By linking the region's prehospital data with hospital data, the authors were able to report not only the FBAO relief of each intervention, but also patient survival outcomes and complications associated with the interventions. By analyzing the 709 patient encounters that received BLS interventions from bystanders, paramedics, or both, and adjusting for potential confounders, the study showed that abdominal thrusts and chest compressions were associated with decreased odds of FBAO relief compared to back blows as the first intervention. The commentary summarizes the study findings and discusses the importance of the study in the context of FBAO research, which has been choked for too many years.

The effects of bystander interventions for foreign body airway obstruction on survival and neurological outcomes: Findings of the MOCHI registry.

INTRODUCTION: Foreign body airway obstruction (FBAO) is a life-threatening condition. We aimed to quantify the impact of bystander FBAO interventions on survival and neurological outcomes. METHODS: We conducted a Japan-wide prospective, multi-center, observational study including all FBAO patients who presented to the Emergency Department from April 2020 to March 2023. Information on bystander FBAO interventions was collected through interviews with emergency medical services personnel. Primary outcomes included 1-month survival and favorable neurologic outcome defined as Cerebral Performance Category 1 or 2. We performed a multivariable logistic regression and a Cox proportional hazards modeling to adjust for confounders. RESULTS: We analyzed a total of 407 patients in the registry who had the median age of 82 years old (IQR 73-88). The FBAO incidents were often witnessed (86.5%, n = 352/407) and the witnesses intervened in just over half of the cases (54.5%, n = 192/352). The incidents frequently occurred at home (54.3%, n = 221/407) and nursing home (21.6%, n = 88/407). Common first interventions included suction (24.8%, n = 101/407) and back blow (20.9%, n = 85/407). The overall success rate of bystander interventions was 48.4% (n = 93/192). About half (48.2%, n = 196/407) survived to 1-month and 23.8% patients (n = 97/407) had a favorable neurological outcome. Adjusting for pre-specified confounders, bystander interventions were independently associated with survival (hazard ratio, 0.55; 95% CI, 0.39-0.77) and a favorable neurological outcome (adjusted OR, 2.18; 95% CI, 1.23-3.95). CONCLUSION: Bystander interventions were independently associated with survival and favorable neurological outcome, however, they were performed only in the half of patients.

Performance of a Large Language Model on Japanese Emergency Medicine Board Certification Examinations.

BACKGROUND: Emergency physicians need a broad range of knowledge and skills to address critical medical, traumatic, and environmental conditions. Artificial intelligence (AI), including large language models (LLMs), has potential applications in healthcare settings; however, the performance of LLMs in emergency medicine remains unclear. METHODS: To evaluate the reliability of information provided by ChatGPT, an LLM was given the questions set by the Japanese Association of Acute Medicine in its board certification examinations over a period of 5 years (2018-2022) and programmed to answer them twice. Statistical analysis was used to assess agreement of the two responses. RESULTS: The LLM successfully answered 465 of the 475 text-based questions, achieving an overall correct response rate of 62.3%. For questions without images, the rate of correct answers was 65.9%. For questions with images that were not explained to the LLM, the rate of correct answers was only 52.0%. The annual rates of correct answers to questions without images ranged from 56.3% to 78.8%. Accuracy was better for scenario-based questions (69.1%) than for stand-alone questions (62.1%). Agreement between the two responses was substantial (kappa = 0.70). Factual error accounted for 82% of the incorrectly answered questions. CONCLUSION: An LLM performed satisfactorily on an emergency medicine board certification examination in Japanese and without images. However, factual errors in the responses highlight the need for physician oversight when using LLMs.

Ambulance Traffic Crashes in Japan: Characteristics of Casualties and Efforts to Improve Ambulance Safety.

BACKGROUND: An ambulance traffic crash not only leads to injuries among emergency medical service (EMS) professionals but also injures patients or their companions during transportation. We aimed to describe the incidence of ambulance crashes, seating location, seatbelt use for casualties (ie, both fatal and nonfatal injuries), ambulance safety efforts, and to identify factors affecting the number of ambulance crashes in Japan. METHODS: We conducted a nationwide survey of all fire departments in Japan. The survey queried each fire department about the number of ambulance crashes between January 1, 2017, and December 31, 2019, the number of casualties, their locations, and seatbelt usage. Additionally, the survey collected information on fire department characteristics, including the number of ambulance dispatches, and their safety efforts including emergency vehicle operation training and seatbelt policies. We used regression methods including a zero-inflated negative binomial model to identify factors associated with the number of crashes. RESULTS: Among the 726 fire departments in Japan, 553 (76.2%) responded to the survey, reporting a total of 11,901,210 ambulance dispatches with 1,659 ambulance crashes (13.9 for every 100,000 ambulance dispatches) that resulted in a total of 130 casualties during the 3-year study period (1.1 in every 100,000 dispatches). Among the rear cabin occupants, seatbelt use was limited for both EMS professionals (n = 3/29, 10.3%) and patients/companions (n = 3/26, 11.5%). Only 46.7% of the fire departments had an internal policy regarding seatbelt use. About three-fourths of fire departments (76.3%) conducted emergency vehicle operation training internally. The output of the regression model revealed that fire departments that conduct internal emergency vehicle operation training had fewer ambulance crashes compared to those that do not (odds of being an excessive zero -2.20, 95% CI: -3.6 to -0.8). CONCLUSION: Two-thirds of fire departments experienced at least one crash during the study period. The majority of rear cabin occupants who were injured in ambulance crashes were not wearing a seatbelt. Although efforts to ascertain seatbelt compliance were limited, Japanese fire departments have attempted a variety of methods to reduce ambulance crashes including internal emergency vehicle operation training, which was associated with fewer ambulance crashes.

Effect of prehospital advanced airway management on out-of-hospital cardiac arrest due to asphyxia: A JAAM-OHCA registry-based observational study in Japan.

Aim: To investigate the relationship between prehospital advanced airway management (AAM) and neurological outcomes in patients with asphyxia-related out-of-hospital cardiac arrest (OHCA). Methods: We retrospectively analyzed data from the Japanese Association for Acute Medicine OHCA registry between June 2014 and December 2017. Patients with asphyxia-related cardiac arrest aged ≥18 years were included. The primary outcome was a 1-month favorable neurological outcome (cerebral performance category [CPC] 1-2). Results: Of the 34,754 patients in the 2014-2017 JAAM-OHCA Registry, 1956 were included in our analysis. Cerebral performance category 1-2 was observed in 31 patients (1.6%), while CPC 3-5 was observed in 1925 patients (98.4%). Although prehospital AAM was associated with unfavorable neurological outcomes (odds ratio [OR], 0.269; 95% confidence interval [CI], 0.114-0.633; p = 0.003) in the univariate analysis, the association was not significant in the multivariate analysis. Compared with the AAM group, the non-AAM group showed increased rates of cardiac arrest after emergency medical service contact (4.3 vs. 7.2%, p = 0.009) and Glasgow Coma Scale ≥4 at hospital admission (1.9% vs. 4.7%, p = 0.004). Among the 903 patients for whom the time to return of spontaneous circulation (ROSC) could be calculated, the time from witnessed cardiac arrest to ROSC was significantly shorter (median, 8.5 vs. 37.0 min; p < 0.001) for those with favorable neurological outcomes than for those without. Conclusion: Prehospital AAM is not associated with improved neurological outcomes among those with asphyxia-related OHCA. However, the time from cardiac arrest to the first ROSC was significantly shorter among those with favorable outcomes.

Association between capnography and recovery time after procedural sedation and analgesia in the emergency department.

Aim: Capnography is recommended for use in procedural sedation and analgesia (PSA); however, limited studies assess its impact on recovery time. We investigated the association between capnography and the recovery time of PSA in the emergency department (ED). Methods: This study was a secondary analysis of a multicenter PSA patient registry including eight hospitals in Japan. We included all patients who received PSA in the ED between May 2017 and May 2021 and divided the patients into capnography and no-capnography groups. The primary outcome was recovery time, defined as the time from the end of the procedure to the cessation of monitoring. The log-rank test and multivariable analysis using clustering for institutions were performed. Results: Of the 1265 screened patients, 943 patients who received PSA were enrolled and categorized into the capnography (n = 150, 16%) and no-capnography (n = 793, 84%) groups. The median recovery time was 40 (interquartile range [IQR]: 25-63) min in the capnography group and 30 (IQR: 14-55) min in the no-capnography group. In the log-rank test, the recovery time was significantly longer in the capnography group (p = 0.03) than in the no-capnography group. In the multivariable analysis, recovery time did not differ between the two groups (adjusted hazard ratio, 0.95; 95% confidence interval, 0.77-1.17; p = 0.61). Conclusion: In this secondary analysis of the multicenter registry of PSA in Japan, capnography use did not associate with shorter recovery time in the ED.

Efficact of Supplemental Oxygen During Procedural Sedation and Analgesia in Elderly Patients in the Emergency Department.

BACKGROUND: The use of supplemental oxygen (SO) for procedural sedation and analgesia (PSA) is recommended in many guidelines, but the evidence of SO for the elderly is limited. OBJECTIVES: This study aimed to compare the incidence of hypoxia with or without SO in PSA for the elderly patients. METHODS: We prospectively collected data on all patients undergoing PSA in the emergency department (ED) from May 2017 through December 2021. These data are from the Japanese Procedural SedaTion and Analgesia Registry. We included all elderly patients (65 years and older) who received PSA in the ED. We performed propensity score analysis for inverse probability of treatment weighting (IPTW) to balance the baseline characteristics. The primary outcome was the incidence of hypoxia (SpO2 < 90%), and the secondary outcome was the incidence of bag-valve mask ventilation. RESULTS: Among 1465 patients in the registry, we included 816 (55.7%) patients in the analysis. After propensity score method for IPTW, the distributions of confounders were closely balanced between the two groups. The incidence of hypoxia was significantly lower in the SO group compared with the non-SO group (6.2% vs. 19.3%; difference -13.1%; 95% confidence interval [CI] -9.8 to -16.4; p < 0.001). SO was also associated with a lower incidence of bag-valve mask ventilation (5.2% vs. 15.4%; difference -10.2%; 95% CI -7.1 to -13.2; p < 0.001). CONCLUSIONS: In a propensity-matched analysis, SO was associated with a lower incidence of hypoxia in elderly patients during ED PSA.

Food choking incidents in the hospital: Incidents, characteristics, effectiveness of interventions, and mortality and morbidity outcomes.

AIM: Foreign body airway obstruction (FBAO) due to food can occur wherever people eat, including in hospitals. We characterized in-hospital FBAO incidents and their outcomes. METHODS: We searched the Japan Council for Quality Health Care nationwide in-hospital adverse events database for relevant events from 1,549 institutions. We included all patients with FBAO incidents due to food in the hospital from January 2010 to June 2021 and collected data on the characteristics, interventions, and outcomes. FBAO from non-food materials were excluded. Our primary outcomes were mortality and morbidity from FBAO incidents. RESULTS: We identified 300 patients who had a FBAO incident from food. The most common age group was 80-89 years old (32.3%, n = 97/300). One-half (50.0%, n = 150/300) were witnessed events. Suction was the most common first intervention (31.3%, n = 94/300) and resulted in successful removal of foreign body in 17.0% of cases (n = 16/94). Back blows (16.0%, n = 48/300) and abdominal thrusts (8.1%, n = 24/300) were less frequently performed as the first intervention and the success rates were 10.4% (n = 5/48) and 20.8% (n = 5/24), respectively. About one-third of the patients (31%, n = 93/300) died and 26.7% (n = 80/300) had a high potential of residual disability from these incidents. CONCLUSION: FBAO from food in the hospital is an uncommon but life-threatening event. The majority of patients who suffered from in-hospital FBAO incidents did not receive effective interventions initially and many of them died or suffered residual disability.

An unbroken ring of the chain of survival.

This is a commentary on the study conducted by Kennedy et al. from Victoria, Australia, that analyzed the cohort of all adult EMS-witnessed out-of-hospital cardiac arrest (OHCA) patients in the region and compared patients treated during the COVID-19 period to a historical comparator period. The commentary summarizes the study findings and discusses the importance of the study in the context of the chain of survival and changes in airway management for OHCA patients during the COVID-19 pandemic.

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.

Incidence of adverse events for procedural sedation and analgesia for cardioversion using thiopental in elderly patients: a multicenter prospective observational study.

Aim: The incidence and characteristics of thiopental-related adverse events (AEs) in elderly patients during procedural sedation and analgesia (PSA) have not been well studied. We aimed to characterize thiopental-related AE in elderly patients during PSA and compare the incidence of AE in elderly patients with non-elderly adults. Methods: This is a secondary analysis of the Japanese Procedural Sedation and Analgesia Registry (JPSTAR). We included all adult patients who received thiopental for PSA in the emergency departments and excluded patients who received concomitant sedative(s) in addition to thiopental or patients with missing body weight data. We compared the incidence of AE between the non-elderly (18-64 years) and elderly groups (≥65 years). Results: The JPSTAR had data on 379 patients who received thiopental for PSA and included 311 patients for analysis. Most (222/311, 71.3%) were elderly. Cardioversion was the most common reason for PSA (96.1%). The AE incidence between groups overall was similar, however, hypoxia was significantly more frequent in the elderly compared with the non-elderly group (10.3% versus 2.2%; adjusted odds 5.63, 95% confidence interval 1.27-25.0). The initial and total doses of thiopental were significantly lower in the elderly group than in the non-elderly group (1.95 mg/kg versus 2.21 mg/kg and 2.33 mg/kg versus 2.93 mg/kg, respectively). Conclusions: Although elderly patients received lower doses of thiopental, hypoxic events were significantly more frequent in this group compared with the non-elderly patients. However, the AE incidence was similar.

Driving Ambulances Safely: Findings of Ten Years of Japanese Ambulance Crash Data.

OBJECTIVE: Rules and regulations for ambulance operations differ across countries and regions, however, little is known about ambulance crashes outside of the United States. Japan is unique in several aspects, for example, routine use of lights and sirens during response and transport regardless of the urgency of the case and low speed limits for ambulances. The aim of this study was to describe the incidence and characteristics of ambulance crashes in Japan. METHODS: We retrospectively analyzed data from the Institute for Traffic Accident Research and Data Analysis (ITARDA) that include all traffic crashes resulting in injury or death in Japan. The study included all ambulance crashes from 2009 to 2018. We compared crashes that occurred during emergency operations with lights and sirens (i.e., when responding to a call or transporting a patient) to those that occurred during non-emergency operations without lights or sirens. We also used data on total number of ambulance dispatches from the Japanese Fire and Disaster Management Agency to calculate ambulance crash risk. RESULTS: During the 10-year period, we identified a total of 486 ambulance crashes out of 59,208,761 ambulance dispatches (0.82 in every 100,000 dispatches or one crash for every 121,829 dispatches) that included two fatal crashes. Among all ambulance crashes, 142 (29.2%) occurred during emergency operations. The incidence of ambulance crashes decreased significantly over the 10-year period. Ambulance crashes at an intersection occurred more frequently during emergency operations than during non-emergency operations (72.5% vs. 58.1%; 14.4% difference, 95% CI 5.0-22.9). CONCLUSIONS: Ambulance crashes occurred infrequently in Japan with crash rates much lower than previously reported crash rates in the United States. Ambulance crashes during emergency operations occurred more frequently at intersections compared to non-emergency operations. Further investigation of the low Japanese ambulance crash rates could provide opportunities to improve ambulance safety in other countries.

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.

Antibiotic Prescribing in Adults Presenting with Pharyngitis Pre- and Post-Implementation of a Rapid Group A Streptococcus Test.

Background: Group A Streptococcus (GAS) pharyngitis is the most common bacterial cause of acute pharyngitis and is often over treated with unnecessary antibiotics. The purpose was to evaluate if implementation of a rapid antigen detection test (RADT) for GAS would reduce the number of inappropriately prescribed antibiotics for adult patients presenting with symptoms of pharyngitis. Methods: This was a retrospective cohort study of adult urgent care clinic patients pre- and post-implementation of a GAS RADT. We included patients who had a diagnosis of GAS identified via ICD-10 codes and either a throat culture, GAS RADT, or antibiotic prescribed for GAS. Antibiotic prescribing was assessed as appropriate or inappropriate based on testing and IDSA guideline recommendations. Thirty-day follow-up visits related to pharyngitis or the prescribed antibiotics was also evaluated. Results: A total of 1734 patients were included; 912 and 822 in the pre- and post-implementation groups, respectively. Following implementation of the GAS RADT, there was an increase in the number of antibiotics prescribed for GAS (43.4% vs 59.1%, P < .001) as well as an increase in appropriate prescribing (67.6% vs 77.5%, P < .001). More 30-day pharyngitis-related follow-up visits were seen in the pre-intervention group (12.5% vs 9.3%, P = .03). Conclusion: Implementation of a RADT for GAS pharyngitis was associated with an increase in both the overall number of antibiotic prescriptions for GAS and the proportion of appropriately prescribed antibiotics. There was also a reduction in follow up visits related to GAS pharyngitis, however educational efforts to further increase appropriate prescribing is needed.

Airway obstruction time and outcomes in patients with foreign body airway obstruction: multicenter observational choking investigation.

Aim: Foreign body airway obstruction (FBAO) is a major public health concern worldwide for infants and older adults. This study determines the association between airway obstruction time and neurological outcomes to plan an effective response for patients with FBAO. Methods: This multicenter retrospective observational study was carried out among patients with life-threatening FBAO in Japan over a period of 4 years. The duration of airway obstruction was calculated from the time of the accident to the time of foreign body removal. The study examined the relationship between airway obstruction time and outcome. The primary outcome was vegetative state or death at hospital discharge. Results: Among 119 patients, 68 were in the category of vegetative state or death. Logistic regression analysis showed that longer airway obstruction time (adjusted odds ratio 1.04; 95% confidence interval 1.01-1.07) was associated with vegetative state or death. When the cut-off value was set at 10, the sensitivity was 0.88, the specificity 0.47, with the area under the curve 0.69. Using the other cut-off value of 4 min, the negative predictive value was 1.00. Conclusion: Longer airway obstruction time was associated with vegetative state or death for patients with FBAO. The incidence of vegetative state or death increased when the airway obstruction time exceeded 10 min. Meanwhile, 4 min or less may be set as a target time for foreign body removal in order to prevent vegetative state or death and plan an effective response.

A core outcome set for resuscitative endovascular balloon occlusion of the aorta: A consensus based approach using a modified Delphi method.

BACKGROUND: The utilization of resuscitative endovascular balloon occlusion of the aorta (REBOA) in trauma has grown exponentially in recent years. However, inconsistency in reporting of outcome metrics related to this intervention has inhibited the development of evidence-based guidelines for REBOA application. This study sought to attain consensus on a core outcome set (COS) for REBOA. METHODS: A review of "landmark" REBOA articles was performed, and panelists (first and senior authors) were contacted for participation in a modified Delphi study. In round 1, panelists provided a list of potential core outcomes. In round 2, using a Likert scale (1 [not important] to 9 [very important]), panelists scored the importance of each potential outcome. Consensus for core outcomes was defined a priori as greater than 70% of scores receiving 7 to 9 and less than 15% of scores receiving 1 to 3. Feedback was provided after round 2, and a third round was performed to reevaluate variables not achieving consensus and allow a final "write-in" round by the experts. RESULTS: From 17 identified panelists, 12 participated. All panelists (12 of 12, 100%) participated in each subsequent round. Panelists initially identified 34 unique outcomes, with two outcomes later added upon write-in request after round 2. From 36 total potential outcomes, 20 achieved consensus as core outcomes, and this was endorsed by 100% of the participants. CONCLUSION: Panelists successfully achieved consensus on a COS for REBOA-related research. This REBOA-COS is recommended for all clinical trials related to REBOA and should help enable higher-quality study designs, valid aggregation of published data, and development of evidence-based practice management guidelines. LEVEL OF EVIDENCE: Diagnostic test or criteria, level V. TRIAL REGISTRATION: Core Outcomes in Trauma Surgery: Development of a Core Outcome Set for Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) http://www.comet-initiative.org/Studies/Details/1709.

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.