Medicine at mass gatherings: current progress of preparedness of emergency medical services and disaster medical response during 2020 Tokyo Olympic and Paralympic Games from the perspective of the Academic Consortium (AC2020).

Mass gatherings are events characterized by "the concentration of people at a specific location for a specific purpose over a set period of time that have the potential to strain the planning and response resources of the host country or community." Previous reports showed that, as a result of the concentration of people in the limited area, injury and illness occurred due to several factors. The response plan should aim to provide timely medical care to the patients and to reduce the burden on emergency hospitals, and to maintain a daily emergency medical services system for residents of the local area. Although a mass gathering event will place a significant burden on the local health-care system, it can provide the opportunity for long-term benefits of public health-care and improvement of daily medical service systems after the end of the event. The next Olympic and Paralympic Games will be held in Tokyo, during which mass gatherings will occur on a daily basis in the context of the coronavirus disease (COVID-19) epidemic. The Academic Consortium on Emergency Medical Services and Disaster Medical Response Plan during the Tokyo Olympic and Paralympic Games in 2020 (AC2020) was launched 2016, consisting of 28 academic societies in Japan, it has released statements based on assessments of medical risk and publishing guidelines and manuals on its website. This paper outlines the issues and countermeasures for emergency and disaster medical care related to the holding of this big event, focusing on the activities of the academic consortium.

JAAM Nationwide Survey on the response to the first wave of COVID-19 in Japan. Part I: How to set up a treatment system in each hospital.

AIM: To clarify how the medical institutions overcame the first wave of coronavirus disease 2019 (COVID-19) in Japan and to discuss its impact on the medical labor force. METHODS: We analyzed questionnaire data from the end of May 2020 from 180 hospitals (102,578 beds) certified by the Japanese Association for Acute Medicine. RESULTS: Acute (emergency) medicine physicians treated severe COVID-19 patients in more than half of hospitals. Emergency medical teams consisted of acute medicine physicians and other specialists. Frontline acute care physicians were concerned about their risk of infection in 80% of hospitals, and experienced stress due to a lack of personal protective equipment. Twenty-six of the 143 hospitals that had a mental health check/consultation system in place indicated that there was a doctor who experienced mental health problems. Of the 37 hospitals without a system, only one hospital was aware of the presence of a doctor complaining of mental health problems. CONCLUSION: Acute care physicians and physicians in other departments experienced high levels of stress as they fought to arrange COVID-19 treatment teams and inpatient COVID-19 wards for infected patients. Medical materials and equipment may be sufficient for a second or third wave; however, active support is needed for the physical and mental care of medical staff. Mental health problems may be missed in facilities without mental check and consultation system.

JAAM nationwide survey on the response to the first wave of COVID-19 in Japan. Part II: how did medical institutions overcome the first wave and how should they prepare for the future?

Aim: To investigate and clarify the surge capacity of staff/equipment/space, and patient outcome in the first wave of coronavirus disease (COVID-19) in Japan. Methods: We analyzed questionnaire data from the end of May 2020 from 180 hospitals (total of 102,578 beds) with acute medical centers. Results: A total of 4,938 hospitalized patients with COVID-19 were confirmed. Of 1,100 severe COVID-19 inpatients, 112 remained hospitalized and 138 died. There were 4,852 patients presumed to be severe COVID-19 patients who were confirmed later to be not infected. Twenty-seven hospitals (15% of 180 hospitals) converted their intensive care unit (ICU) to a unit for COVID-19 patients only, and 107 (59%) had to manage both severe COVID-19 patients and others in the same ICU. Restriction of ICU admission occurred in one of the former 27 hospitals and 21 of the latter 107 hospitals. Shortage of N95 masks was the most serious concern regarding personal protective equipment. As for issues that raised ICU bed occupancy, difficulty undertaking or progressing rehabilitation for severe patients (42%), and the improved patients (28%), long-lasting severely ill patients (36%), and unclear isolation criteria (34%) were mentioned. Many acute medicine physicians assisted regional governmental agencies, functioning as advisors and volunteer coordinators. Conclusion: The mortality rate of COVID-19 in this study was 4.1% of all hospitalized patients and 12.5% (one in eight) severe patients. The hospitals with dedicated COVID-19 ICUs accepted more patients with severe COVID-19 and had lower ICU admission restrictions, which could be helpful as a strategy in the next pandemic.

Evaluating quality indicators of tertiary care hospitals for trauma care in Japan.

OBJECTIVE: This study examined the associations between trauma mortality and quality of care indicators currently used in Japan. DESIGN: This is a retrospective two-level discrete-time survival analysis. Quality indicators were derived from the 2012-2013 annual hospital survey conducted by the Ministry of Health, Labour and Welfare. Trauma mortality data were derived from the Japan Trauma Data Bank for the period of April 2012 to March 2013. SETTING: Tertiary care centers designated as emergency and critical care centers (ECCCs) in Japan. PARTICIPANTS: The analysis included 12 378 patients aged ≥15 years with blunt trauma and an Injury Severity Score ≥9, registered to the data bank from 91 ECCCs. INTERVENTION: Quality of care indicators examined in the annual hospital survey. MAIN OUTCOME MEASURES: Deaths within 30 days. RESULTS: Of the 12 378 patients, 660 (5%) died within 30 days. Higher indicator score was significantly associated with lower mortality risk (hazard ratio [HR] for the second, third and fourth quartiles vs. lowest quartile 0.61, 0.55 and 0.52, respectively). Factors significantly associated with lower mortality risk were, higher patient volume (HR for the highest vs. lowest quartile, 0.74), director's qualification as specialist (HR 0.57) or consultant (HR 0.58), review of patient arrival process (HR 0.68), triage functions (HR 0.69), availability of psychiatrists (HR 0.75) and operating room being ready 24-h (HR 0.81). CONCLUSIONS: The study identified certain indicators associated with trauma patient mortality. Further refinement of indicators is required to specifically identify what needs changing.

Comparison of registry and government evaluation data to ascertain severe trauma cases in Japan.

Aims: Accurate evaluation of health care quality requires high-quality data, and case ascertainment (confirming eligible cases and deaths) is a foundation for accurate data collection. This study examined the accuracy of case ascertainment from two Japanese data sources. Methods: Using hospital-level data, we investigated the concordance in ascertaining trauma cases between a nationwide trauma registry (the Japan Trauma Data Bank) and annual government evaluations of tertiary hospitals between April 2012 and March 2013. We compared the median values for trauma case volumes, numbers of deaths, and case fatality rates from both data sources, and also evaluated the variability in discrepancies for the intrahospital differences of these outcomes. Results: The analyses included 136 hospitals. In the registry and annual evaluation data, the median case volumes were 120.5 cases and 180.5 cases, respectively; the median numbers of deaths were 11 and 12, respectively; and the median case fatality rates were 8.1% and 6.4%, respectively. There was broad variability in the intrahospital differences in these outcomes. Conclusions: The observed discordance between the two data sources implies that these data sources may have inaccuracies in case ascertainment. Measures are needed to evaluate and improve the accuracy of data from these sources.

[Pre-hospital medicine and medical control system in Japan].

It is necessary to treat the patient from the site of the emergency to raise a lifesaving rate of the patient. As a prime example would be out-of-hospital cardiac arrest. Once you start the treatment after hospital arrival, cardiac arrest patient can't be life-saving. It is necessary to start the chest compression, etc. from the site of the emergency. Medical care to be carried out on the scene of emergency is the pre-hospital care. In recent years, improvement of the pre-hospital care is remarkable in Japan. It is because of that the quantity and quality of the emergency life-saving technician are being enhanced. And also doctor-helicopter system have been enhanced. Medical control is a critical component of the improvement.

Characteristics and outcomes of pediatric out-of-hospital cardiac arrest by scholastic age category.

OBJECTIVES: There is a paucity of data examining nationwide population-based incidences and outcomes of pediatric out-of-hospital cardiac arrest. The objective of this study is to describe the detailed characteristics of pediatric out-of-hospital cardiac arrest by scholastic age category and to evaluate the impact of bystander cardiopulmonary resuscitation and public access-automated external defibrillators on the 1-month survival and favorable neurological status of pediatric out-of-hospital cardiac arrest patients. DESIGN: A nationwide, population-based, observational study. SETTING: Nationwide emergency medical system in Japan. PATIENTS: Out-of-hospital cardiac arrest patients aged ≤ 18 yr. MEASUREMENTS AND MAIN RESULTS: We identified 7,624 pediatric out-of-hospital cardiac arrest patients (≤ 18 yr old) from a nationwide population-based out-of-hospital cardiac arrest database in Japan from 2005 to 2008 and stratified them into five categories by scholastic age. The overall rates of 1-month survival and favorable neurological outcomes were 11.0% and 5.1%, respectively. Bystander cardiopulmonary resuscitation resulted in a significant improvement in both 1-month survival (odds ratio 2.81; 95% confidence interval 2.30-3.44) and favorable neurological outcomes (odds ratio 4.55; 95% confidence interval 3.35-6.18). Performing public access-automated external defibrillators had a significant effect on the 1-month survival rate (odds ratio 3.51; 95% confidence interval 1.81-6.81) and favorable neurological outcomes (odds ratio 5.13; 95% confidence interval 2.64-9.96). CONCLUSIONS: This study demonstrated that bystander cardiopulmonary resuscitation and public access-automated external defibrillators had a significant impact on the outcomes of pediatric out-of-hospital cardiac arrest. The improved survival associated with bystander cardiopulmonary resuscitation and public access-automated external defibrillators are clinically important and are of major public health importance for school-aged out-of-hospital cardiac arrest patients.

Comparison of neurological outcome between tracheal intubation and supraglottic airway device insertion of out-of-hospital cardiac arrest patients: a nationwide, population-based, observational study.

BACKGROUND: The effect of prehospital use of supraglottic airway devices as an alternative to tracheal intubation on long-term outcomes of patients with out-of-hospital cardiac arrest is unclear. STUDY OBJECTIVES: We compared the neurological outcomes of patients who underwent supraglottic airway device insertion with those who underwent tracheal intubation. METHODS: We conducted a nationwide population-based observational study using a national database containing all out-of-hospital cardiac arrest cases in Japan over a 3-year period (2005-2007). The rates of neurologically favorable 1-month survival (primary outcome) and of 1-month survival and return of spontaneous circulation before hospital arrival (secondary outcomes) were examined. Multiple logistic regression analyses were performed to adjust for potential confounders. Advanced airway devices were used in 138,248 of 318,141 patients, including an endotracheal tube (ETT) in 16,054 patients (12%), a laryngeal mask airway (LMA) in 34,125 patients (25%), and an esophageal obturator airway (EOA) in 88,069 patients (63%). RESULTS: The overall rate of neurologically favorable 1-month survival was 1.03% (1426/137,880). The rates of neurologically favorable 1-month survival were 1.14% (183/16,028) in the ETT group, 0.98% (333/34,059) in the LMA group, and 1.04% (910/87,793) in the EOA group. Compared with the ETT group, the rates were significantly lower in the LMA group (adjusted odds ratio 0.77, 95% confidence interval [CI] 0.64-0.94) and EOA group (adjusted odds ratio 0.81, 95% CI 0.68-0.96). CONCLUSIONS: Prehospital use of supraglottic airway devices was associated with slightly, but significantly, poorer neurological outcomes compared with tracheal intubation, but neurological outcomes remained poor overall.

Monophasic versus biphasic defibrillation for pediatric out-of-hospital cardiac arrest patients: a nationwide population-based study in Japan.

INTRODUCTION: Conventional monophasic defibrillators for out-of-hospital cardiac-arrest patients have been replaced with biphasic defibrillators. However, the advantage of biphasic over monophasic defibrillation for pediatric out-of-hospital cardiac-arrest patients remains unknown. This study aimed to compare the survival outcomes of pediatric out-of-hospital cardiac-arrest patients who underwent monophasic defibrillation with those who underwent biphasic defibrillation. METHODS: This prospective, nationwide, population-based observational study included pediatric out-of-hospital cardiac-arrest patients from January 1, 2005, to December 31, 2009. The primary outcome measure was survival at 1 month with minimal neurologic impairment. The secondary outcome measures were survival at 1 month and the return of spontaneous circulation before hospital arrival. Multivariable logistic regression analysis was performed to identify the independent association between defibrillator type (monophasic or biphasic) and outcomes. RESULTS: Among 5,628 pediatric out-of-hospital cardiac-arrest patients (1 through 17 years old), 430 who received defibrillation shock with monophasic or biphasic defibrillator were analyzed. The number of patients who received defibrillation shock with monophasic defibrillator was 127 (30%), and 303 (70%) received defibrillation shock with biphasic defibrillator. The survival rates at 1 month with minimal neurologic impairment were 17.5% and 24.4%, the survival rates at 1 month were 32.3% and 35.6%, and the rates of return of spontaneous circulation before hospital arrival were 24.4% and 27.4% in the monophasic and biphasic defibrillator groups, respectively. Hierarchic logistic regression analyses by using generalized estimation equations found no significant difference between the two groups in terms of 1-month survival with minimal neurologic impairment (odds ratio (OR), 1.57; 95% confidence interval (CI), 0.87 to 2.83; P = 0.14) and 1-month survival (OR, 1.38; 95% CI, 0.87 to 2.18; P = 0.17). CONCLUSIONS: The present nationwide population-based observational study could not confirm an advantage of biphasic over monophasic defibrillators for pediatric OHCA patients.

Elderly out-of-hospital cardiac arrest has worse outcomes with a family bystander than a non-family bystander.

BACKGROUND: A growing elderly population along with advances in equipment and approaches for pre-hospital resuscitation necessitates up-to-date information when developing policies to improve elderly out-of-hospital cardiac arrest (OHCA) outcomes. We examined the effects of bystander type (family or non-family) intervention on 1-month outcomes of witnessed elderly OHCA patients. METHODS: Data from a total of 85,588 witnessed OHCA events in patients aged ≥65 years, which occurred from 2005 to 2008, were obtained from a nationwide population-based database. Patients were stratified into three age categories (65-74, 75-84, ≥85 years), and the effects of bystander type (family or non-family) on initial cardiac rhythm, rate of bystander cardiopulmonary resuscitation (CPR), and 1-month outcomes were assessed. RESULTS: The overall survival rate was 6.9% (65-74 years: 9.8%, 75-84 years: 6.9%, ≥85 years: 4.6%). Initial VF/VT was recorded in 11.1% of cases with a family bystander and 12.9% of cases with a non-family bystander. The rate of bystander CPR was constant across the age categories in patients with a family bystander and increased with advancing age categories in patients with a non-family bystander. Patients having a non-family bystander were associated with significantly higher 1-month rates of survival (OR: 1.26; 95% CI: 1.19-1.33) and favorable neurological status (OR: 1.47; 95% CI: 1.34-1.60). CONCLUSIONS: Elderly patient OHCA events witnessed by a family bystander were associated with worse 1-month outcomes than those witnessed by a non-family bystander. Healthcare providers should consider targeting potential family bystanders for CPR education to increase the rate and quality of bystander CPR.

Comparison of outcomes after use of biphasic or monophasic defibrillators among out-of-hospital cardiac arrest patients: a nationwide population-based observational study.

BACKGROUND: The use and popularity of the biphasic waveform defibrillator as a replacement for the monophasic waveform defibrillator are increasing, but it is unclear whether this can improve the rate of survival among out-of-hospital cardiac arrest patients. This study aimed to verify the hypothesis that the outcome of out-of-hospital cardiac arrest patients who received defibrillation shock with the biphasic waveform defibrillator was better than that of patients who received defibrillation shock with the monophasic defibrillator. METHODS AND RESULTS: This prospective, nationwide, population-based, observational study included 21 172 out-of-hospital cardiac arrest patients with initial ventricular fibrillation or pulseless ventricular tachycardia from January 1, 2005, through December 31, 2007. Defibrillation shock was performed by monophasic defibrillator on 8224 (39%) patients and by biphasic defibrillator on 12 948 (61%) patients. The rate of survival at 1 month with minimal neurological impairment was 11.6% (951/8192) in the monophasic defibrillator group and 12.8% (1653/12 928) in the biphasic defibrillator group. Hierarchical logistic regression analysis using a generalized estimation equation showed no significant difference between the biphasic and monophasic groups in 1-month survival with minimal neurological impairment (adjusted odds ratio, 1.07; 95% confidence interval, 0.91-1.26; P=0.42). Confirmatory propensity score analyses showed similar results. CONCLUSIONS: Although monophasic defibrillators are being replaced by biphasic defibrillators, our nationwide population-based observational study failed to demonstrate a statistically significant association between defibrillation waveform and 1-month survival rate with minimal neurological impairment.

Impact of telephone dispatcher assistance on the outcomes of pediatric out-of-hospital cardiac arrest.

OBJECTIVE: Most previous studies of pediatric out-of-hospital cardiac arrest have typically examined relatively small datasets from small study regions. Although several studies have reported the impact on adult out-of-hospital cardiac arrest, little information is available on the impact of telephone dispatcher assistance on the outcomes of pediatric out-of-hospital cardiac arrest. We set out to examine the impact of cardiopulmonary resuscitation instruction by telephone dispatcher on the outcomes of pediatric out-of-hospital cardiac arrest. DESIGN: Population-based, observational study. SETTING: Japan-wide population-based setting. PATIENTS: We identified 1,780 pediatric out-of-hospital cardiac arrest patients (67.8% male) with witnessed collapse from a nationwide, population-based, out-of-hospital cardiac arrest database. INTERVENTION: None. MEASUREMENT AND MAIN RESULTS: We assessed the impact of telephone dispatcher assistance on the outcomes of 1-month survival rates and favorable neurologic status among the groups. The overall rate of bystander-performed chest compression and mouth-to-mouth ventilation among the witnessed pediatric out-of-hospital cardiac arrests were 39.5% and 25.6%, respectively. Telephone dispatcher assistance was offered in 28.4% of the witnessed pediatric out-of-hospital cardiac arrest cases and resulted in a significant increase in both chest compression (adjusted odds ratio 6.04; 95% confidence interval 4.72-7.72) and mouth-to-mouth ventilation (adjusted odds ratio 3.10; 95% confidence interval 2.44-3.95), and a significant improvement in 1-month survival rate (adjusted odds ratio 1.46; 95% confidence interval 1.05-2.03), but no significant effect on favorable neurologic outcomes at 1 month (adjusted odds ratio 1.15; 95% confidence interval 0.70-1.88). Potential confounding factors included age categories, sex, bystander type, cause of cardiac arrest, bystander cardiopulmonary resuscitation, and attempted defibrillation. CONCLUSIONS: Telephone dispatcher assistance could significantly increase bystander cardiopulmonary resuscitation among witnessed pediatric out-of-hospital cardiac arrests. Although there was only a small, nonsignificant effect on the improvement in favorable neurologic outcome at 1 month, the improved survival associated with telephone dispatcher assistance in pediatric out-of-hospital cardiac arrest is clinically important, and is of major public health importance. In cases where cardiac arrest was uncertain from the bystander's replies during the call to emergency medical services, telephone dispatcher assistance was not offered, which could affect the adjusted odds ratio of the present study.

Traumatic renal artery occlusion treated with an endovascular stent--the limitations of surgical revascularization: report of a case.

When renal artery occlusion occurs secondary to blunt trauma, the recovery rate of renal function after open revascularization is varied and far from satisfactory. Although the optimal treatment for this type of injury has not been established, percutaneous revascularization by endovascular stenting has recently been advocated for patients with unilateral renal artery occlusion. We herein report a case of blunt renal artery occlusion treated with an endovascular stent. After the placement of the stent, renal arteriography showed multiple nonflow-limiting contrast defects in the distal renal arteries, suggesting peripheral thrombosis. Although the duration of warm renal ischemia appears to be the crucial determinant of renal function, multiple thrombi in the distal renal arteries, which would be undetectable during open surgery, could also affect the functional outcome. The presence of these thrombi may explain the limited success of surgical revascularization in such cases.

Population density, call-response interval, and survival of out-of-hospital cardiac arrest.

BACKGROUND: Little is known about the effects of geographic variation on outcomes of out-of-hospital cardiac arrest (OHCA). The present study investigated the relationship between population density, time between emergency call and ambulance arrival, and survival of OHCA, using the All-Japan Utstein-style registry database, coupled with geographic information system (GIS) data. METHODS: We examined data from 101,287 bystander-witnessed OHCA patients who received emergency medical services (EMS) through 4,729 ambulatory centers in Japan between 2005 and 2007. Latitudes and longitudes of each center were determined with address-match geocoding, and linked with the Population Census data using GIS. The endpoints were 1-month survival and neurologically favorable 1-month survival defined as Glasgow-Pittsburgh cerebral performance categories 1 or 2. RESULTS: Overall 1-month survival was 7.8%. Neurologically favorable 1-month survival was 3.6%. In very low-density (<250/km(2)) and very high-density (≥10,000/km(2)) areas, the mean call-response intervals were 9.3 and 6.2 minutes, 1-month survival rates were 5.4% and 9.1%, and neurologically favorable 1-month survival rates were 2.7% and 4.3%, respectively. After adjustment for age, sex, cause of arrest, first aid by bystander and the proportion of neighborhood elderly people ≥65 yrs, patients in very high-density areas had a significantly higher survival rate (odds ratio (OR), 1.64; 95% confidence interval (CI), 1.44 - 1.87; p < 0.001) and neurologically favorable 1-month survival rate (OR, 1.47; 95%CI, 1.22 - 1.77; p < 0.001) compared with those in very low-density areas. CONCLUSION: Living in a low-density area was associated with an independent risk of delay in ambulance response, and a low survival rate in cases of OHCA. Distribution of EMS centers according to population size may lead to inequality in health outcomes between urban and rural areas.

Immediate defibrillation or defibrillation after cardiopulmonary resuscitation.

OBJECTIVES: This study aimed to determine whether short cardiopulmonary resuscitation (CPR) by emergency medical services before defibrillation (CPR first) has a better outcome than immediate defibrillation followed by CPR (shock first) in patients with ventricular fibrillation/pulseless ventricular tachycardia (VF/pulseless VT) out-of-hospital cardiac arrest. METHODS: We analyzed a national database between 2006 and 2008, and included patients aged 18 years or more who had witnessed cardiac arrests and whose first recorded rhythm was VF/pulseless VT. Those study subjects were divided into five groups in accordance with the CPR/defibrillation intervention sequence. Each group was subdivided into call-to-response intervals of <5 minutes and ≥ 5 minutes. We identified 267 patients in the shock-first group and 6,407 patients in the CPR-first group. One-month survival and neurologically favorable one-month survival rates were used for outcome measures. The association of intervention type on outcomes (one-month survival or neurologically favorable one-month survival) was analyzed using multivariate logistic regression analyses by adjusting potential confounding factors such as survey year, gender, age (years), bystander CPR, intubation, and call-to-response interval (min). RESULTS: The overall one-month survival rate was 26.2% (3,125/11,941) and the neurologically favorable one-month survival rate was 16.6% (1,983/11,934). The CPR-first group had a one-month survival rate of 27.8% (1,780/6,407) and a neurologically favorable one-month survival rate of 17.8% (1,140/6,404), and the shock-first group had survival rates of 24.7% (66/267) and 18.4% (49/267), respectively. There were no significant differences in one-month survival and neurologically favorable one-month survival in these two primary comparison groups (odds ratio [95% confidence interval], 0.85 [0.64-1.13] and 1.04 [0.76-1.42], respectively). Logistic regression analysis showed that neither CPR first nor shock first was associated with the rate of one-month survival or neurologically favorable one-month survival, after adjusting for potential confounders. CONCLUSIONS: In our study, CPR prior to attempted defibrillation did not present a better outcome compared with shock first as measured by either one-month survival or neurologically favorable one-month survival, after adjusting for potential confounders. Further studies are required to determine whether CPR first has an advantage over shock first.

Effect of time and day of admission on 1-month survival and neurologically favourable 1-month survival in out-of-hospital cardiopulmonary arrest patients.

AIM: We sought to examine whether the outcomes of out-of-hospital cardiopulmonary arrest (OHCA) patients differed between weekday and weekend/holiday admissions, or between daytime and nighttime admissions. METHODS: From a national registry of OHCA events in Japan between 2005 and 2008, 173,137 cases where the call-to-hospital admission interval was shorter than 120 min and collapse was witnessed by a bystander were included in this study. One-month survival rate and neurologically favourable 1-month survival rate were used as outcome measures. Logistic regression was used to adjust for potential confounding factors. RESULTS: No significant differences in outcome were found between weekday and holiday/weekend admissions in rates of 1-month survival or neurologically favourable 1-month survival (p=0.78 and p=0.80, respectively). In contrast, patients admitted in the daytime exhibited significantly better outcomes than those admitted at night, on both outcome measures (p<0.001 and p<0.001). After adjusting for possible confounding factors, outcomes were significantly better for daytime admissions, with odds ratios of 1.26 (95% confidence interval (CI) 1.22-1.31; p<0.001) for 1-month survival, and 1.26 (95% CI 1.20-1.32; p<0.001) for neurologically favourable 1-month survival. In contrast, no significant differences on either outcome measure were found between weekday and weekend/holiday cases, with odds ratios of 1.00 (95% CI 0.96-1.04; p=0.96) for 1-month survival and 0.99 (95% CI 0.94-1.04; p=0.78) for neurologically favourable 1-month survival. CONCLUSIONS: Even after adjusting for confounding factors, admission day (weekday vs. weekend/holiday) had no effect on 1-month survival or neurologically favourable 1-month survival. In contrast, daytime admission was associated with significantly better outcomes than nighttime admissions.

The effects of sex on out-of-hospital cardiac arrest outcomes.

OBJECTIVE: We examined the effects of sex on out-of-hospital cardiac arrest outcomes. There is evidence that women are more likely to survive cardiac arrest than men. However, few large studies have examined these sex differences in detail. It is unknown whether the female survival advantage is age-specific or whether sex affects neurologic outcomes after cardiac arrest events. METHODS: Data were analyzed from a nationwide population-based out-of-hospital cardiac arrest database (between January 2005 and December 2007) involving 318,123 patients (male: 188,357, female: 129,766) to assess the effects of sex on out-of-hospital cardiac arrest outcomes in Japan. We selected 276,590 patients aged 20 to 89 years with out-of-hospital cardiac arrest and compared the frequencies of initial cardiac rhythms, 1-month survival rates, and favorable neurologic outcome rates between sexes. RESULTS: The incidence of out-of-hospital cardiac arrest was higher in men than in women (men: 0.12%; women: 0.07%). Men were witnessed more often while out-of-hospital cardiac arrest was occurring (men: 42.1% and women: 36.9%), typically presented with initial ventricular fibrillation/ventricular tachycardia rhythms, and had a higher 1-month survival rate overall after out-of-hospital cardiac arrest events (men: 5.2% and women: 4.3%). However, the rate of survival with a favorable neurologic outcome for women aged 30 to 49 years was significantly higher than that for men within the same age range. Among patients initially presenting with ventricular fibrillation/ventricular tachycardia, the rate of survival with favorable neurologic outcome was higher for women than men in the group aged 40 to 59 years. CONCLUSION: Our results suggest that men have a higher 1-month survival rate after out-of-hospital cardiac arrest because of a higher frequency of ventricular fibrillation/ventricular tachycardia presentation compared with women. Although patients of both sexes with out-of-hospital cardiac arrest initially presenting with ventricular fibrillation/ventricular tachycardia exhibited similar overall survival rates, the rate of survival with favorable neurologic outcome was significantly higher for women than men in the group aged 40 to 59 years.

Outcomes of chest compression only CPR versus conventional CPR conducted by lay people in patients with out of hospital cardiopulmonary arrest witnessed by bystanders: nationwide population based observational study.

OBJECTIVE: To compare the effectiveness of cardiopulmonary resuscitation (CPR) with chest compression only and conventional CPR on outcomes after cardiopulmonary arrest out of hospital. DESIGN: Nationwide population based observational study. SETTING: A nationwide emergency medical service system in Japan. Population All consecutive patients with out of hospital cardiopulmonary arrest, January 2005 to December 2007 in Japan, witnessed at the moment of collapse. Lay people attempted chest compression only CPR (n = 20,707) or conventional CPR (mouth to mouth ventilation and chest compression) (n = 19,328), and patients were transferred to hospital by ambulance. MAIN OUTCOME MEASURES: Factors associated with better outcomes (assessed with χ(2), multiple logistic regression analysis, odds ratios and their 95% confidence intervals): one month survival and neurologically favourable one month survival rates defined as category one (good cerebral performance) or two (moderate cerebral disability) of the cerebral performance categories. RESULTS: Conventional CPR was associated with better outcomes than chest compression only CPR, for both one month survival (adjusted odds ratio 1.17, 95% confidence interval 1.06 to 1.29) and neurologically favourable one month survival (1.17, 1.01 to 1.35). Neurologically favourable one month survival decreased with increasing age and with delays of up to 10 minutes in starting CPR for both conventional and chest compression only CPR. The benefit of conventional CPR over chest compression only CPR was significantly greater in younger people in non-cardiac cases (P = 0.025) and with a delay in start of CPR after the event was witnessed in non-cardiac cases (P = 0.015) and all cases combined (P = 0.037). CONCLUSIONS: Conventional CPR is associated with better outcomes than chest compression only CPR for selected patients with out of hospital cardiopulmonary arrest, such as those with arrests of non-cardiac origin and younger people, and people in whom there was delay in the start of CPR.

Collaborative effects of bystander-initiated cardiopulmonary resuscitation and prehospital advanced cardiac life support by physicians on survival of out-of-hospital cardiac arrest: a nationwide population-based observational study.

INTRODUCTION: There are inconsistent data about the effectiveness of prehospital physician-staffed advanced cardiac life support (ACLS) on the outcomes of out-of-hospital cardiac arrest (OHCA). Furthermore, the relative importance of bystander-initiated cardiopulmonary resuscitation (BCPR) and ACLS and the effectiveness of their combination have not been clearly demonstrated. METHODS: Using a prospective, nationwide, population-based registry of all OHCA patients in Japan, we enrolled 95,072 patients whose arrests were witnessed by bystanders and 23,127 patients witnessed by emergency medical service providers between 2005 and 2007. We divided the bystander-witnessed arrest patients into Group A (ACLS by emergency life-saving technicians without BCPR), Group B (ACLS by emergency life-saving technicians with BCPR), Group C (ACLS by physicians without BCPR) and Group D (ACLS by physicians with BCPR). The outcome data included 1-month survival and neurological outcomes determined by the cerebral performance category. RESULTS: Among the 95,072 bystander-witnessed arrest patients, 7,722 (8.1%) were alive at 1 month, including 2,754 (2.9%) with good performance and 3,171 (3.3%) with vegetative status or worse. BCPR occurred in 42% of bystander-witnessed arrests. In comparison with Group A, the rates of good-performance survival were significantly higher in Group B (odds ratio (OR), 2.23; 95% confidence interval, 2.05 to 2.42; P < 0.01) and Group D (OR, 2.80; 95% confidence interval, 2.28 to 3.43; P < 0.01), while no significant difference was seen for Group C (OR, 1.18; 95% confidence interval, 0.86 to 1.61; P = 0.32). The occurrence of vegetative status or worse at 1 month was highest in Group C (OR, 1.92; 95% confidence interval, 1.55 to 2.37; P < 0.01). CONCLUSIONS: In this registry-based study, BCPR significantly improved the survival of OHCA with good cerebral outcome. The groups with BCPR and ACLS by physicians had the best outcomes. However, receiving ACLS by physicians without preceding BCPR significantly increased the number of patients with neurologically unfavorable outcomes.