Epidemiology of Out-of-Hospital Cardiac Arrest Due to Suffocation Focusing on Suffocation Due to Japanese Rice Cake: A Population-Based Observational Study From the Utstein Osaka Project.

BACKGROUND: Japanese rice cake ("mochi") is a major cause of food-choking accidents in Japan. However, the epidemiology of out-of-hospital cardiac arrests (OHCAs) due to suffocation caused by rice cakes is poorly understood. METHODS: OHCA data from 2005 to 2012 were obtained from the population-based OHCA registry in Osaka Prefecture. Patients aged ≥20 years who experienced OHCA caused by suffocation that occurred before the arrival of emergency-medical-service (EMS) personnel were included. Patient characteristics, prehospital interventions, and outcomes were compared based on the cause of suffocation (rice cake and non-rice-cake). The primary outcome was 1-month survival after OHCA. RESULTS: In total, 46 911 adult OHCAs were observed during the study period. Of the OHCAs, 7.0% (3,294/46,911) were due to suffocation, with choking due to rice cake as the cause in 9.5% of cases (314/3,294), and of these, 24.5% (77/314) occurred during the first 3 days of the New Year. In crude analysis, 1-month survival was 17.2% (54/314) in those with suffocation caused by rice cake and 13.4% (400/2,980) in those with suffocation due to other causes. In the multivariable analysis for all-cause suffocation, younger age, arrest witnessed by bystanders, and earlier EMS response time were significantly related to better 1-month survival. CONCLUSION: Approximately 10% of OHCAs due to suffocation were caused by rice-cake choking, and 25% of these occurred during the first 3 days of the New Year. Further efforts for establishing preventive measures as well as improving the early recognition of choking and encouraging bystanders to call EMS sooner are needed.

The Current Status of Development and Implementation of Medical Emergency Response Plan in Schools.

BACKGROUND: Automated external defibrillators (AEDs) have been widely distributed at schools in Japan. We have demonstrated that ventricular fibrillation accounted for 68% of nontraumatic sudden cardiac arrest (SCA) in schools, suggesting that a well-prepared medical emergency response plan (MERP) for schools would improve the outcomes of SCA patients. However, it is uncertain if the MERP has been well developed or implemented in Japanese schools. METHODS AND RESULTS: We conducted a cross-sectional study of schools in Osaka using a postal questionnaire. Survey items included type of school, number of students, school staff and teaching staff, number of AEDs used and the place of installation, cardiopulmonary resuscitation (CPR) training to school staff, MERP development and implementation, and the number of SCA cases they experienced. The response rate to this survey was 44% (764 of 1728 schools). Every school except for 4 have installed at least 1 AED. Thirty-six percent of schools, however, have not yet developed and implemented a MERP for SCA. Moreover, 49% of schools surveyed have not conducted a rehearsal training session for SCA in the previous 3 years, although 95% of schools provided CPR training courses to school staff. A total of 15 schools have experienced 16 presumed or actual SCA cases in the study period. Of the 15 schools, 6 schools reported that bystanders experienced psychological stress. CONCLUSIONS: A MERP for SCA has not yet been fully developed and implemented in the schools surveyed in our study despite widely distributed AEDs and CPR training.

Variation of current protocols for managing out-of-hospital cardiac arrest in prehospital settings among Asian countries.

BACKGROUND/PURPOSE: Protocols for managing patients with out-of-hospital cardiac arrest (OHCA) may vary due to legal, cultural, or socioeconomic concerns. We sought to assess international variation in policies and protocols related to OHCA. METHODS: A brief survey was developed by consensus. Elicited information included protocols for managing patients with nontraumatic OHCA or traumatic OHCA, policies for using automated external defibrillators (AEDs) during transportation of patients with ongoing resuscitation, and application of terminations of resuscitation (TOR) rules in prehospital settings in the respondent's city or country. The populations of interest were emergency physicians, medical directors of emergency medical services (EMS), and policy makers. RESULTS: Responses were obtained from eight cities in six Asian countries. Only one (12.5%) city applied TOR rules for OHCAs. Do-not-resuscitate (DNR) orders were valid in prehospital settings in five (62.5%) cities. All cities used AEDs for nontraumatic OHCAs; seven (87.5%) cities did not routinely use AEDs for traumatic OHCAs. For nontraumatic OHCAs, four (50%) cities performed 2 minutes of on-scene cardiopulmonary resuscitation (CPR) and then transported the patients with ongoing resuscitation to hospitals; three (37.5%) cities performed 4 minutes of on-scene CPR; one (12.5%) city allowed variation in the duration of on-scene CPR. CONCLUSION: International variation in practices and polices related to OHCAs do exist. Concerns regarding prehospital TOR rules include medical evidence, legal considerations, EMS manpower, public perception, medical oversight, education, EMS characteristics, and cost-effectiveness analysis. Further research is needed to achieve consensus regarding management protocols, especially for EMS that perform resuscitation during transportation of OHCA patients.

Rationale, Methodology, and Implementation of a Dispatcher-assisted Cardiopulmonary Resuscitation Trial in the Asia-Pacific (Pan-Asian Resuscitation Outcomes Study Phase 2).

Abstract Background. Survival outcomes from out-of-hospital cardiac arrest (OHCA) in Asia are poor (2-11%). Bystander cardiopulmonary resuscitation (CPR) rates are relatively low in Asia. Dispatcher-assisted CPR (DA-CPR) has recently emerged as a potentially cost-effective intervention to increase bystander CPR and survival from OHCA. The Pan-Asian Resuscitation Outcomes Study (PAROS), an Asia-Pacific cardiac arrest registry, was set up in 2009, with the aim of understanding OHCA as a disease in Asia and improving OHCA survival. The network has adopted DA-CPR as part of its strategy to improve OHCA survival. Objective. This article aims to describe the conceptualization, study design, potential benefits, and difficulties for implementation of DA-CPR trial in the Asia-Pacific. Methods. Two levels of intervention, basic and comprehensive, will be offered to PAROS participating sites. The basic level consists of implementation of a DA-CPR protocol and training program, while the comprehensive level consists of implementation of the basic level, with the addition of a dispatch quality measurement tool, quality improvement program, and community education program. Sites that are not able to implement the package will contribute control data. The primary outcome of the study is survival to hospital discharge or survival to 30 days post cardiac arrest. DA-CPR and bystander CPR are secondary outcomes. Conclusion. Implementation of DA-CPR requires concerted efforts by EMS leaders and supervisors, dispatchers, hospital stakeholders, policy makers, and the general public. The DA-CPR trial implemented by the PAROS sites, if successful, can serve as a model for other countries considering such an intervention in their EMS systems.

Association between atmospheric conditions and occurrence of out-of-hospital cardiac arrest- 10-year population-based survey in Osaka.

BACKGROUND: Weather conditions affect the occurrence of cardiovascular disease. The aim of this study was to investigate the associations between atmospheric conditions including temperature, pressure, and humidity, and the occurrence of out-of-hospital cardiac arrests (OHCAs) with cardiac etiology. METHODS AND RESULTS: This study was a cross-sectional analysis of a prospective cohort that included all persons aged ≥ 18 years with OHCA in Osaka, from 1998 through 2007. The association between the number of daily OHCA events with various atmospheric conditions was analyzed using Poisson regression. A total of 28,806 adult OHCAs were presumed to be of cardiac etiology. The number of OHCAs in 1 day was inversely correlated with the day's mean atmospheric temperature. The regression coefficient was greater on the days under 18°C (r=-0.317, P<0.001) than on days over 18°C (r=-0.088, P<0.001). A positive linear relation was found between the number of OHCAs in 1 day and the day's mean atmospheric pressure (r=0.321, P<0.001). Under 18°C, every 5°C decrease in the daily mean temperature was associated with an 11% (95% confidence interval [CI]: 8-13%) increase in OHCA occurrence in the non-elderly group, and a 16% increase in the elderly group (95% CI: 14-19%). CONCLUSIONS: The occurrence of adult OHCA with cardiac etiology increases with decreasing temperature of the day. Elderly people are more susceptible to severe weather conditions.

Recommendations on ambulance cardiopulmonary resuscitation in basic life support systems.

AIM: Cardiopulmonary resuscitation (CPR) during ambulance transport can be a safety risk for providers and can affect CPR quality. In many Asian countries with basic life support (BLS) systems, patients experiencing out-of-hospital cardiac arrest (OHCA) are routinely transported in ambulances in which CPR is performed. This paper aims to make recommendations on best practices for CPR during ambulance transport in BLS systems. METHODS: A panel consisting of 20 experts (including 4 North Americans) in emergency medical services (EMS) and resuscitation science was selected, and met over two days. We performed a literature review and selected 33 candidate issues in five core areas. Using Delphi methodology, the issues were classified into dichotomous (yes/no), multiple choice, and ranking questions. Primary consensus between experts was reached when there was more than 70% agreement. Questions with 60-69% agreement were made more specific and were submitted for a second round of voting. RESULTS: The panel agreed upon 24 consensus statements with more than 70% agreement (2 rounds of voting). The recommendations cover the following: length of time on the scene; advanced airway at the scene; CPR prior to transport; rhythm analysis and defibrillation during transport; prehospital interventions; field termination of resuscitation (TOR); consent for TOR; destination hospital; transport protocol; number of staff members; restraint systems; mechanical CPR; turning off of the engine for rhythm analysis; alternative CPR; and feedback for CPR quality. CONCLUSION: Recommendations for CPR during ambulance transport were developed using the Delphi method. These recommendations should be validated in clinical settings.

An association between systolic blood pressure and stroke among patients with impaired consciousness in out-of-hospital emergency settings.

BACKGROUND: Stroke is difficult to diagnose when consciousness is disturbed. However few reports have discussed the clinical predictors of stroke in out-of-hospital emergency settings. This study aims to evaluate the association between initial systolic blood pressure (SBP) value measured by emergency medical service (EMS) and diagnosis of stroke among impaired consciousness patients. METHODS: We included all patients aged 18 years or older who were treated and transported by EMS, and had impaired consciousness (Japan Coma Scale ≧ 1) in Osaka City (2.7 million), Japan from January 1, 1998 through December 31, 2007. Data were prospectively collected by EMS personnel using a study-specific case report form. Multiple logistic regressions assessed the relationship between initial SBP and stroke and its subtypes adjusted for possible confounding factors. RESULTS: During these 10 years, a total of 1,840,784 emergency patients who were treated and transported by EMS were documented during the study period in Osaka City. Out of 128,678 with impaired consciousness, 106,706 who had prehospital SBP measurements in the field were eligible for our analyses. The proportion of patients with severe impaired consciousness significantly increased from 14.5% in the <100 mmHg SBP group to 27.6% in the > =200 mmHg SBP group (P for trend <0.001). The occurrence of stroke significantly increased with increasing SBP (adjusted odd ratio [AOR] 1.34, 95% confidence interval [CI] 1.33 to 1.35), and the AOR of the SBP > =200 mmHg group versus the SBP 101-120 mmHg group was 5.26 (95% CI 4.93 to 5.60). The AOR of the SBP > =200 mmHg group versus the SBP 101-120 mmHg group was 9.76 in subarachnoid hemorrhage (SAH), 16.16 in intracranial hemorrhage (ICH), and 1.52 in ischemic stroke (IS), and the AOR of SAH and ICH was greater than that of IS. CONCLUSIONS: Elevated SBP among emergency patients with impaired consciousness in the field was associated with increased diagnosis of stroke.

Impact of early intravenous epinephrine administration on outcomes following out-of-hospital cardiac arrest.

BACKGROUND: The effectiveness of epinephrine administration for cardiac arrests has been shown in animal models, but the clinical effect is still controversial. METHODS AND RESULTS: A prospective, population-based, observational study in Osaka involved consecutive out-of-hospital cardiac arrest (OHCA) patients from January 2007 through December 2009. We evaluated the outcomes among adult non-traumatic bystander-witnessed OHCA patients for whom the local protocol directed the emergency medical service personnel to administer epinephrine. After stratifying by first documented cardiac rhythm, outcomes were compared among the following groups: non-administration, ≤10, 11-20 and ≥21 min as the time from emergency call to epinephrine administration. A total of 3,161 patients were eligible for our analyses, among whom 1,013 (32.0%) actually received epinephrine. The epinephrine group had a significantly lower rate of neurologically intact 1-month survival than the non-epinephrine group (4.1% vs. 6.1%, P=0.028). In cases of ventricular fibrillation (VF) arrest, patients in the early epinephrine group who received epinephrine administration within 10 min had a significantly higher rate of neurologically intact 1-month survival compared with the non-epinephrine group (66.7% vs. 24.9%), though other epinephrine groups did not. In cases of non-VF arrest, the rate of neurologically intact 1-month survival was low, irrespective of epinephrine administration. CONCLUSIONS: The effectiveness of epinephrine after OHCA depends on the time of administration. When epinephrine is administered in the early phase, there is an improvement in neurological outcome from OHCA with VF.

Comparison of emergency medical services systems across Pan-Asian countries: a Web-based survey.

BACKGROUND: There are great variations in out-of-hospital cardiac arrest (OHCA) survival outcomes among different countries and different emergency medical services (EMS) systems. The impact of different systems and their contribution to enhanced survival are poorly understood. This paper compares the EMS systems of several Asian sites making up the Pan-Asian Resuscitation Outcomes Study (PAROS) network. Some preliminary cardiac arrest outcomes are also reported. METHODS: This is a cross-sectional descriptive survey study addressing population demographics, service levels, provider characteristics, system operations, budget and finance, medical direction (leadership), and oversight. RESULTS: Most of the systems are single-tiered. Fire-based EMS systems are predominant. Bangkok and Kuala Lumpur have hospital-based systems. Service level is relatively low, from basic to intermediate in most of the communities. Korea, Japan, Singapore, and Bangkok have intermediate emergency medical technician (EMT) service levels, while Taiwan and Dubai have paramedic service levels. Medical direction and oversight have not been systemically established, except in some communities. Systems are mostly dependent on public funding. We found variations in available resources in terms of ambulances and providers. The number of ambulances is 0.3 to 3.2 per 100,000 population, and most ambulances are basic life support (BLS) vehicles. The number of human resources ranges from 4.0 per 100,000 population in Singapore to 55.7 per 100,000 population in Taipei. Average response times vary between 5.1 minutes (Tainan) and 22.5 minutes (Kuala Lumpur). CONCLUSION: We found substantial variation in 11 communities across the PAROS EMS systems. This study will provide the foundation for understanding subsequent studies arising from the PAROS effort.

The predictive performance of current termination-of-resuscitation rules in patients following out-of-hospital cardiac arrest in Asian countries: A cross-sectional multicentre study.

BACKGROUND: Termination-of-resuscitation rules (TORRs) in out-of-hospital cardiac arrest (OHCA) patients have been applied in western countries; in Asia, two TORRs were developed and have not been externally validated widely. We aimed to externally validate the TORRs using the registry of Pan-Asian Resuscitation Outcomes Study (PAROS). METHODS: PAROS enrolled 66,780 OHCA patients in seven Asian countries from 1 January 2009 to 31 December 2012. The American Heart Association-Basic Life Support and AHA-ALS (AHA-BLS), AHA-Advanced Life Support (AHA-ALS), Goto, and Shibahashi TORRs were selected. The diagnostic test characteristics and area under the receiver operating characteristic curve (AUC) were calculated. We further determined the most suitable TORR in Asia and analysed the variable differences between subgroups. RESULTS: We included 55,064 patients in the final analysis. The sensitivity, specificity, negative predictive value, positive predictive value, and AUC, respectively, for AHA-BLS, AHA-ALS, Goto, Shibashi TORRs were 79.0%, 80.0%, 19.6%, 98.5%, and 0.80; 48.6%, 88.3%, 9.8%, 98.5%, and 0.60; 53.8%, 91.4%, 11.2%, 99.0%, and 0.73; and 35.0%, 94.2%, 8.4%, 99.0%, and 0.65. In countries using the Goto TORR with PPV<99%, OHCA patients were younger, had more males, a higher rate of shockable rhythm, witnessed collapse, pre-hospital defibrillation, and survival to discharge, compared with countries using the Goto TORR with PPV ≥99%. CONCLUSIONS: There was no single TORR fit for all Asian countries. The Goto TORR can be considered the most suitable; however, a high predictive performance with PPV ≥99% was not achieved in three countries using it (Korea, Malaysia, and Taiwan).

Incidence and outcome of out-of-hospital cardiac arrest with public-access defibrillation. A descriptive epidemiological study in a large urban community.

BACKGROUND: Detailed characteristics of those who experience an out-of-hospital cardiac arrest (OHCA) with public-access defibrillation (PAD) are unknown. METHODS AND RESULTS: A prospective, population-based observational study involving consecutive OHCA patients with emergency responder resuscitation attempts was conducted from July 1, 2004 through December 31, 2008 in Osaka City. We extracted data for OHCA patients shocked by a public-access automated external defibrillator (AED) and evaluated the patients' and rescuers' characteristics. The main outcome measure was neurologically favorable 1-month survival. During the study period, 10,375 OHCA patients were registered and of 908 patients suffering ventricular fibrillation arrest, 53 (6%) received public-access AED shocks by lay-rescuers, with the proportion increasing from 0% in 2004 to 11% in 2008 (P for trend<0.001). Railway stations (34%) were the places where PAD shocks were most frequently delivered, followed by nursing homes (11%), medical facilities (9%), and fitness facilities (7%). In 57% of cases, the subject received public-access AED shocks delivered by non-medical persons, including employees of railway companies (13%), school teachers (6%), employees of fitness facilities (6%), and security guards (6%). The proportion of neurologically favorable 1-month survival tended to increase from 0% in 2005 to 58% in 2008 (P for trend=0.081). CONCLUSIONS: Railway stations are the most common places where shocks by public-access AEDs were delivered in large urban communities of Japan, and among lay-rescuers railway station workers use AEDs more frequently.

Comparison of supraglottic airway versus endotracheal intubation for the pre-hospital treatment of out-of-hospital cardiac arrest.

INTRODUCTION: Both supraglottic airway devices (SGA) and endotracheal intubation (ETI) have been used by emergency life-saving technicians (ELST) in Japan to treat out-of-hospital cardiac arrests (OHCAs). Despite traditional emphasis on airway management during cardiac arrest, its impact on survival from OHCA and time dependent effectiveness remains unclear. METHODS: All adults with witnessed, non-traumatic OHCA, from 1 January 2005 to 31 December 2008, treated by the emergency medical services (EMS) with an advanced airway in Osaka, Japan were studied in a prospective Utstein-style population cohort database. The primary outcome measure was one-month survival with neurologically favorable outcome. The association between type of advanced airway (ETI/SGA), timing of device placement and neurological outcome was assessed by multiple logistic regression. RESULTS: Of 7,517 witnessed non-traumatic OHCAs, 5,377 cases were treated with advanced airways. Of these, 1,679 were ETI while 3,698 were SGA. Favorable neurological outcome was similar between ETI and SGA (3.6% versus 3.6%, P = 0.95). The time interval from collapse to ETI placement was significantly longer than for SGA (17.2 minutes versus 15.8 minutes, P < 0.001). From multivariate analysis, early placement of an advanced airway was significantly associated with better neurological outcome (Adjusted Odds Ratio (AOR) for one minute delay, 0.91, 95% confidence interval (CI) 0.88 to 0.95). ETI was not a significant predictor (AOR 0.71, 95% CI 0.39 to 1.30) but the presence of an ETI certified ELST (AOR, 1.86, 95% CI 1.04 to 3.34) was a significant predictor for favorable neurological outcome. CONCLUSIONS: There was no difference in neurologically favorable outcome from witnessed OHCA for ETI versus SGA. Early airway management with advanced airway regardless of type and rhythm was associated with improved outcomes.

Reduction in incidence and fatality of out-of-hospital cardiac arrest in females of the reproductive age.

AIMS: The aim of this study was to determine relative risk (RR) of incidence and fatality of out-of-hospital cardiac arrest (OHCA) by gender and oestrogen status. METHODS AND RESULTS: In a prospective, population-based observational study from 1998 through 2007, incidence and neurologically intact 1-month survival after OHCA were compared by gender after grouping: 0-12 years, 13-49 years, and > or =50 years according to menarche and menopause age. Among 26 940 cardiac arrests, there were 11 179 females and 15 701 males. Age-adjusted RR of females for OHCA incidence compared with males was 0.72 [95% confidence interval (CI), 0.58-0.91] in age 0-12 years, 0.39 (95% CI, 0.37-0.43) in age 13-49 years, and 0.54 (95% CI, 0.52-0.55) in age > or =50 years. Females aged 13-49 years had a significantly higher good neurological outcome than males [adjusted odds ratio (OR), 2.00 (95% CI 1.21-3.32)]. This sex difference was larger than that in the other age groups [adjusted OR, 0.82 (95% CI, 0.06-12.02) in age 0-12 years and 1.23 (95% CI, 0.98-1.54) in age > or =50 years]. CONCLUSION: Reproductive females had a lower incidence and a better outcome of OHCA than females of other ages and males, which might be explained by cardioprotective effects of endogenous oestrogen on OHCA.

Continuous improvements in "chain of survival" increased survival after out-of-hospital cardiac arrests: a large-scale population-based study.

BACKGROUND: The impact of ongoing efforts to improve the "chain of survival" for out-of-hospital cardiac arrest (OHCA) is unclear. The objective of this study was to evaluate the incremental effect of changes in prehospital emergency care on survival after OHCA. METHODS AND RESULTS: This prospective, population-based observational study involved consecutive patients with OHCA from May 1998 through December 2006. The primary outcome measure was 1-month survival with favorable neurological outcome. Multiple logistic regression analysis was used to assess factors that were potentially associated with better neurological outcome. Among 42,873 resuscitation-attempted adult OHCAs, 8782 bystander-witnessed arrests of presumed cardiac origin were analyzed. The median time interval from collapse to call for medical help, first cardiopulmonary resuscitation, and first shock shortened from 4 (interquartile range [IQR] 2 to 11) to 2 (IQR 1 to 5) minutes, from 9 (IQR 5 to 13) to 7 (IQR 3 to 11) minutes, and from 19 (IQR 13 to 22) to 9 (IQR 7 to 12) minutes, respectively. Neurologically intact 1-month survival after witnessed ventricular fibrillation increased from 6% (6/96) to 16% (49/297; P<0.001). Among all witnessed OHCAs, earlier cardiopulmonary resuscitation (odds ratio per minute 0.89, 95% confidence interval 0.85 to 0.93) and earlier intubation (odds ratio per minute 0.96, 95% confidence interval 0.94 to 0.99) were associated with better neurological outcome. For ventricular fibrillation, only earlier shock was associated with better outcome (odds ratio 0.84, 95% confidence interval 0.80 to 0.88). CONCLUSIONS: Data from a large, population-based cohort demonstrate a continuous increase in OHCA survival with improvement in the chain of survival. The incremental benefit of early advanced care on OHCA survival is also suggested.

Heuristic bias in perception of medical students relating to out-of-hospital cardiac arrests.

AIM: The aim of this study was to assess the perceptions of medical students with respect to out-of-hospital cardiac arrests focusing on the frequency and survival and to identify potential problems in resuscitation education. METHODS: Fourth-year medical students in a six-year undergraduate educational system were asked to guess the number of out-of-hospital cardiac arrests with cardiac etiology per year in Japan, related data such as the one-month survival rate from out-of-hospital cardiac arrests with cardiac etiology and the number of deaths from traffic accidents for comparison. The guesses of students were compared with actual statistical data. RESULTS: The incidence of out-of-hospital cardiac arrests was clearly underestimated by the students compared to the real statistics. The median guessed number of out-of-hospital cardiac arrests ranged from 6000 to 20,000 while the real statistics ranged from 73.023 to 78.302 by year (P â€‹< â€‹0.001 for all years). In contrast, the guessed number of deaths from traffic accidents was markedly overestimated: the median guessed number ranged from 8000 to 20,000 and the real statistics were 3694 to 4438 (P â€‹< â€‹0.001 for all years). The one-month survival rate was also underestimated: the guessed number was 50% and the real rate was 11.5 to 13.5% (P â€‹< â€‹0.001 for all years). CONCLUSIONS: Out-of-hospital cardiac arrests are underestimated in frequency, and survival after an arrest is overestimated by medical students. To recognize and to understand the heuristic bias in perception of learners is needed for resuscitation education in addition to promote resuscitation skills of learners.

Variability in the effects of prehospital advanced airway management on outcomes of patients with out-of-hospital cardiac arrest.

OBJECTIVE: To investigate variations in the effects of prehospital advanced airway management (AAM) on outcomes of out-of-hospital cardiac arrest (OHCA) patients according to regional emergency medical service (EMS) systems in four Asian cities. METHODS: We enrolled adult patients with EMS-treated OHCA of presumed cardiac origin between 2012 and 2014 from Osaka (Japan), Seoul (Republic of Korea), Singapore (Singapore), and Taipei (Taiwan). The main exposure variable was prehospital AAM. The primary endpoint was neurological recovery. We compared outcomes between the prehospital AAM and non-AAM groups using multivariable logistic regression with an interaction term between prehospital AAM and the four Asian cities. RESULTS: A total of 16,510 patients were included in the final analyses. The rates of prehospital AAM varied among Osaka, Seoul, Singapore, and Taipei (65.0%, 19.2%, 84.9%, and 34.1%, respectively). The non-AAM group showed better outcomes than the AAM group (adjusted odds ratio [aOR] for neurological recovery 0.30; 95% confidence interval [CI], 0.24-0.38]). In the interaction model for neurological recovery, the aORs for AAM in Osaka and Singapore were 0.12 (95% CI, 0.06-0.26) and 0.21 (95% CI, 0.16-0.28), respectively. In Seoul and Taipei, the association between prehospital AAM and neurological recovery was not significant (aOR 0.58 [95% CI, 0.31-1.10] and 0.79 [95% CI, 0.52-1.20], respectively). The interaction between prehospital AAM and region was significant (P=0.01). CONCLUSION: The effects of prehospital AAM on outcomes of OHCA patients differed according to regional variability in the EMS systems.

Effectiveness of bystander-initiated cardiac-only resuscitation for patients with out-of-hospital cardiac arrest.

BACKGROUND: Previous animal and clinical studies suggest that bystander-initiated cardiac-only resuscitation may be superior to conventional cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrests. Our hypothesis was that both cardiac-only bystander resuscitation and conventional bystander CPR would improve outcomes from out-of-hospital cardiac arrests of < or = 15 minutes' duration, whereas the addition of rescue breathing would improve outcomes for cardiac arrests lasting > 15 minutes. METHODS AND RESULTS: We carried out a prospective, population-based, observational study involving consecutive patients with emergency responder resuscitation attempts from May 1, 1998, through April 30, 2003. The primary outcome measure was 1-year survival with favorable neurological outcome. Multivariable logistic regression analysis was performed to evaluate the relationship between type of CPR and outcomes. Among the 4902 witnessed cardiac arrests, 783 received conventional CPR, and 544 received cardiac-only resuscitation. Excluding very-long-duration cardiac arrests (> 15 minutes), the cardiac-only resuscitation yielded a higher rate of 1-year survival with favorable neurological outcome than no bystander CPR (4.3% versus 2.5%; odds ratio, 1.72; 95% CI, 1.01 to 2.95), and conventional CPR showed similar effectiveness (4.1%; odds ratio, 1.57; 95% CI, 0.95 to 2.60). For the very-long-duration arrests, neurologically favorable 1-year survival was greater in the conventional CPR group, but there were few survivors regardless of the type of bystander CPR (0.3% [2 of 624], 0% [0 of 92], and 2.2% [3 of 139] in the no bystander CPR, cardiac-only CPR, and conventional CPR groups, respectively; P<0.05). CONCLUSIONS: Bystander-initiated cardiac-only resuscitation and conventional CPR are similarly effective for most adult out-of-hospital cardiac arrests. For very prolonged cardiac arrests, the addition of rescue breathing may be of some help.

Subsequent ventricular fibrillation and survival in out-of-hospital cardiac arrests presenting with PEA or asystole.

BACKGROUND: The prognostic implications of conversion to ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OHCA) patients with an initial non-shockable rhythm are unclear. HYPOTHESIS: Among OHCA patients with an initial non-shockable rhythm, survival is better in individuals who subsequently develop VF and are defibrillated. DESIGN: Utstein style population-based cohort study. SUBJECTS: adults (age>or=18 years) with OHCA of presumed cardiac etiology and initial rhythm of pulseless electrical activity (PEA) or asystole treated by emergency medical services systems in Osaka, Japan from January 1, 2001 to December 31, 2005. Primary outcome measure was one-month neurologically favorable survival (CPC

Survival rate and factors associated with 1-month survival of witnessed out-of-hospital cardiac arrest of cardiac origin with ventricular fibrillation and pulseless ventricular tachycardia: the Utstein Osaka project.

OBJECTIVE: We reassessed 1-month survival of patients with witnessed out-of-hospital cardiac arrest (OHCA) of cardiac origin with ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) in Osaka, Japan, and identified factors associated with 1-month survival using updated data from 1998 to 2004 collected based on the Utstein Style. METHODS: Using the Utstein Osaka Project database, we analyzed 1028 cases which met the following criteria: (1) patient age 18 years or older; (2) presumed cardiac origin based on the definition of the Utstein Style; (3) witnessed by citizens; (4) VF or pulseless VT at the time of arrival of the ambulance. The main outcome measure was survival at 1 month after collapse. Variables to develop a predictive model for 1-month survival were selected by stepwise logistic regression. RESULTS: Survival at 1 month was 19.6%. Factors retained in the final logistic regression were age, sex, type of witness, and time interval from (a) ambulance call receipt to cardiopulmonary resuscitation (CPR) by the ambulance crew; (b) ambulance call to defibrillation; (c) CPR by the ambulance crew to hospital arrival. Area under the receiver-operating characteristic curve for the model developed with the six variables was 0.738 and Hosmer-Lemshow goodness-of-fit p-value was 0.94. CONCLUSION: We successfully developed a model to estimate the probability of 1-month survival using variables easy to collect in the early phase of resuscitation, and this model would help physicians and family members predict the likelihood of 1-month survival of OHCA patients on admission.

Effect of known history of heart disease on survival outcomes after out-of-hospital cardiac arrests.

OBJECTIVE: We aimed to investigate the effect of known heart disease on post-out-of-hospital cardiac arrest (OHCA) survival outcomes, and its association with factors influencing survival. METHODS: This was an observational, retrospective study involving an OHCA database from seven Asian countries in 2009-2012. Heart disease was defined as a documented diagnosis of coronary artery disease or congenital heart disease. Patients with non-traumatic arrests for whom resuscitation was attempted and with known medical histories were included. Differences in demographics, arrest characteristics and survival between patients with and without known heart disease were analysed. Multivariate logistic regression was performed to identify factors influencing survival to discharge. RESULTS: Of 19 044 eligible patients, 5687 had known heart disease. They were older (77 vs 72 years) and had more comorbidities like diabetes (40.9 vs 21.8%), hypertension (60.6 vs 36.0%) and previous stroke (15.2 vs 10.1%). However, they were not more likely to receive bystander cardiopulmonary resuscitation (P = 0.205) or automated external defibrillation (P = 0.980). On univariate analysis, known heart disease was associated with increased survival (unadjusted odds ratio 1.16, 95% confidence interval 1.03-1.30). However, on multivariate analysis, heart disease predicted poorer survival (adjusted odds ratio 0.76, 95% confidence interval 0.58-1.00). Other factors influencing survival corresponded with previous reports. CONCLUSIONS: Known heart disease independently predicted poorer post-OHCA survival. This study may provide information to guide future prospective studies specifically looking at family education for patients with heart disease and the effect on OHCA outcomes.