All-Japan Utstein Registry Research Articles

Intra-day change in occurrence of out-of-hospital ventricular fibrillation in Japan: The JCS-ReSS study

BackgroundReal-world evidence of out-of-hospital ventricular fibrillation (VF), especially regarding intra-day change, remains unclear. We aimed to investigate that age- and gender-dependent difference of intra-day change of VF occurrence. MethodWe enrolled 71,692 patients (males: 56,419 [78.7%], females: 15,273 [21.3%]) in whom cardiac VF had been documented from the 2005–2015 All-Japan Utstein Registry data. Subjects were divided into four groups: group-I (<18 years old), group-II (18–39), group-III (40–69), and group-IV (≥70). Among four groups in each of male and female, we compared the intra-day change of VF occurrence, and evaluated the risk factors of the unfavorable neurologic outcomes at 1 month after VF. ResultsRegardless of age, the incidence of VF was significantly greater in male than in female subjects. In male subjects, VF in group-I, III and IV occurred higher at daytime, however, group-II had no intra-day difference because group-II had a higher VF events at midnight~ early morning compared with other aged groups (Poisson regression analysis, p = .03). While in female, each group showed similar intra-day pattern of VF occurrence. Logistic regression analysis revealed that some of the clinical parameters such as time periods from call receipt to first shock and the presence of bystander cardiopulmonary resuscitation were important for risk of 30-day neurologically unfavorable outcomes. ConclusionsThe intra-day change of VF occurrence was age-dependently different in males but not in females, suggesting age- and gender-dependent differences in underlying cardiac diseases. These might affect the significant difference in unfavorable neurologic outcome.

P498External validation of a field termination-of-resuscitation rule for refractory out-of-hospital cardiac arrests in Japan

Abstract Background A universal basic life support termination-of-resuscitation (BLS-TOR) rule was developed to identify patients with out-of-hospital cardiac arrest (OHCA) eligible for field termination of cardiopulmonary resuscitation (CPR). In Japan, however, emergency medical service (EMS) providers are not allowed field termination of CPR and must transport all patients with OHCA to hospitals, regardless of return of spontaneous circulation (ROSC). Therefore, we previously developed a Japanese TOR (JP-TOR) rule in the field for refractory OHCAs using data from the All-Japan Utstein registry between 2011 and 2015, when CPR was performed according to the 2010 guidelines. The JP-TOR rule recommends CPR termination when patients meet all the following criteria: initial asystole, unwitnessed arrest, age ≥81 years, no bystander interventions before EMS arrival, and no ROSC after EMS-initiated CPR for 14 min. Purpose To validate the JP-TOR rule using more recent data where CPR was performed according to the 2015 guidelines, comparing the relevance of JP-TOR rule with the BLS-TOR rule, which consists of the following criteria: no prehospital ROSC after 6-min EMS-initiated CPR, arrest unwitnessed by EMS providers, and no shock received. Methods We analysed the records of 242,184 patients (age ≥18 years) who experienced OHCA treated by EMS providers. Data were obtained from a prospectively recorded Japanese nationwide Utstein-style database from 2016 to 2017. The primary endpoints were specificity and positive predictive value (PPV) for predicting the 1-month mortality after OHCA with the JP-TOR and BLS-TOR rules. Results The overall 1-month survival rate was 5.3% (12,847/242,184). The proportions of patients with OHCA fulfilled the JP-TOR and BLS-TOR criteria were 10.4% and 89.3%, respectively. The specificity and PPV of the JP-TOR and BLS-TOR rules for predicting 1-month mortality were 99.5% (95% confidence interval [CI], 99.4%–99.5%) and 99.8% (95% CI, 99.7%–99.8%) and 44.7% (95% CI, 43.8%–45.5%) and 96.7% (95% CI, 96.6%–96.8%), respectively. Conclusions The JP-TOR rule for EMS providers treating patients with OHCA in the field was successfully validated using more recent data from a Japanese registry where CPR was performed according to the 2015 guidelines. The JP-TOR rule was superior to the BLS-TOR rule in Japanese EMS systems, having both high specificity and PPV of &amp;gt;99% for predicting 1-month mortality. The JP-TOR rule may help EMS providers decide whether to terminate resuscitation efforts for unresuscitable patients with OHCA in the field. Prospective validation studies and establishment of prehospital EMS protocol are required before implementing this rule in Japan.

Neurologically favourable outcomes of cardiogenic out-of-hospital cardiac arrest with relation to the type of witness in Japan

AimTo assess the current situation and neurologically favourable outcomes after out-of-hospital cardiac arrest (OHCA) with respect to the type of witness. MethodsThis retrospective observational study used data from the All-Japan Utstein Registry of the Fire and Disaster Management Agency collected between January 1, 2016, and December 31, 2016. Patients with cardiogenic OHCA aged ≥18 years who were witnessed by bystanders were included. The primary outcome measure was a neurologically favourable outcome 1 month after the OHCA. ResultsAmong the 123,554 patients with OHCA registered between January 1, 2016, and December 31, 2016, 24,856 patients were included. Of them, 15,139 were witnessed by family, and 9717 were witnessed by non-family (friends, 1306; colleagues, 951; passers-by, 997; others, 6463). When witnessed by family, the rate of neurologically favourable outcomes was significantly lower than that when witnessed by non-family (odds ratio [OR] = 0.45, 95% confidence interval [CI] = 0.41–0.49, P < 0.001). After adjusting for potential confounders, the rate of neurologically favourable outcomes remained lower when OHCA was witnessed by family (OR = 0.88, 95% CI = 0.79–0.99, P = 0.03). However, in subgroup analysis, adjusted ORs for neurologically favourable outcomes were slightly greater for 65–84-year-old women and ≥85-year-old women with family witnesses than for those with non-family witnesses. For all other groups, non-family witnesses outperformed family witnesses. ConclusionFamily-witnessed OHCA events had fewer neurologically favourable outcomes before and after adjusting for confounders. BLS education for family members may lead to improved prognosis of witnessed cardiogenic OHCAs.

Association of Fine Particulate Matter Exposure With Bystander-Witnessed Out-of-Hospital Cardiac Arrest of Cardiac Origin in Japan

Out-of-hospital cardiac arrests (OHCAs) are a major public health concern and a leading cause of death worldwide. Exposure to ambient air pollution is associated with increases in morbidity and mortality and has been recognized as a leading contributor to global disease burden. To examine the association between short-term exposure to particulate matter with a diameter of 2.5 μm or smaller (PM2.5) and the incidence of OHCAs of cardiac origin and with the development of initial cardiac arrest rhythm. This case-control study used data from cases registered between January 1, 2005, and December 31, 2016, in the All-Japan Utstein Registry, a prospective, nationwide, population-based database for OHCAs across all 47 Japanese prefectures. These OHCA cases included patients who had bystander-witnessed OHCAs and for whom emergency medical services responders initiated resuscitation before hospital transfer. A case-crossover design was employed for the study analyses. A prefecture-specific, conditional logistic regression model to estimate odds ratios was applied, and a random-effects meta-analysis was used to obtain prefecture-specific pooled estimates. All analyses were performed from May 7, 2019, to January 23, 2020. The main outcome was the association of short-term PM2.5 exposure with the incidence of bystander-witnessed OHCAs of cardiac origin. The differences in the distribution of initial cardiac arrest rhythm in OHCAs among those with exposure to PM2.5 were also examined. In total, 103 189 OHCAs witnessed by bystanders were included in the final analysis. Among the patients who experienced such OHCAs, the mean (SD) age was 75 (15.5) years, and 62 795 (60.9%) were men. Point estimates of the percentage increase for a 10-μg/m3 increase in PM2.5 at lag0-1 (difference in mean PM2.5 concentrations measured on the case day and 1 day before) demonstrated a statistically significantly higher incidence of OHCA across most of the 47 prefectures, without significant heterogeneity (I2 = 20.1%; P = .12). A stratified analysis found an association between PM2.5 exposure and OHCAs (% increase, 1.6; 95% CI, 0.1%-3.1%). An initial shockable rhythm, such as ventricular fibrillation or pulseless ventricular tachycardia (% increase, 0.6; 95% CI, -2.0% to 3.2%), was not associated with PM2.5 exposure. However, an initial nonshockable rhythm, such as pulseless electrical activity and asystole, was associated with PM2.5 exposure (% increase, 1.4; 95% CI, 0.1%-2.7%). Findings from this study suggest that increased PM2.5 concentration is associated with bystander-witnessed OHCA of cardiac origin that commonly presents with nonshockable rhythm. The results support measures to reduce PM2.5 exposure to prevent OHCAs of cardiac origin.

Characteristics and Outcomes of Out-of-Hospital Cardiac Arrest in Educational Institutions in Japan - All-Japan Utstein Registry.

Although schools are key places that conduct cardiopulmonary resuscitation (CPR) and public-access defibrillation (PAD) programs, out-of-hospital cardiac arrest (OHCA) in educational institutions is poorly understood. This study describes the characteristics and outcomes of such OHCAs.Methods and Results:Data for OHCAs of any cause occurring in educational institutions between 2013 and 2015 were extracted from the All-Japan Utstein Registry. Patient characteristics and outcomes were documented. Subjects were divided into 6 age groups (0-1, 2-5, 6-11, 12-14, 15-17, and ≥18 years). Among the 783 eligible OHCA patients, most received bystander CPR regardless of age, ranging from 73.9% in those aged ≥18 years to 90.0% in those aged 2-5 years. However, the proportion receiving PAD differed by age group, ranging from 2.9% in those aged 0-1 years to 66.7% in those aged 12-14 years. The proportion of patients with 1-month survival with favorable neurological outcome differed significantly by age group, being extremely low among patients aged 0-1 years (zero for OHCA of cardiac origin), but high among patients aged 6-11, 12-14, and 15-17 years (69.2%, 77.5%, and 70.0%, respectively) for OHCA of cardiac origin. The outcomes of OHCA occurring in educational institutions, where PAD is available, differed significantly by age.

Patient outcomes of school-age, out-of-hospital cardiac arrest in Japan: A nationwide study of schoolchildren as witnesses.

Using the data from the All-Japan Utstein Registry, this study evaluates the neurologically favourable patient outcomes and associated factors of out-of-hospital cardiac arrest (OHCA) with Japanese schoolchildren as witnesses. We analysed 1,068 school-age children (6-18years old) who underwent OHCA from 2011 to 2016. Among the 1,068 cases, 179 were witnessed by schoolchildren and 889 were witnessed by other bystanders. Propensity score-matched and logistic regression analyses were used to evaluate the outcomes and associated factors. The crude neurologically favourable outcome in the schoolchildren-witnessed group was considerably higher than that in the other-bystander-witnessed group (19.6% versus 12.3%; P<0.010). However, the difference was not significant in the propensity score-matched analysis (19.6% versus 21.8%; P=0.602). The multivariable logistic regression analyses of school-age OHCA with schoolchildren as witnesses demonstrated that bystander cardiopulmonary resuscitation (CPR) provision (odds ratio [OR] 4.12, 95% confidence interval [CI] 1.44-11.75), shockable initial rhythm (OR 3.39, 95% CI 1.43-8.04), and defibrillation (OR 4.58, 95% CI 1.65-12.71) provided by any bystander were positively associated with favourable outcomes. By contrast, dispatcher-assisted CPR provision (OR 0.28, 95% CI 0.11-0.70), exogenous cause (OR 0.16, 95% CI 0.03-0.86), adrenaline administration (0.25; 95% CI 0.07-0.92), and prolonged response time (OR 0.86; 95% CI 0.75-0.98) were negatively associated with favourable outcomes. Patient outcomes did not differ significantly between schoolchildren- and other-bystander-witnessed cases of school-age OHCA. Although schoolchildren as witnesses might not be inferior to other bystanders in school-age OHCA, further studies are needed to examine the effect of bystander CPR by schoolchildren and basic life support education in schools.

Abstract 141: Defibrillation Protocol Update Neurologically Intact Survival for Patients With Out-Of-Hospital Shockable Cardiac Arrest

Background: A series of cardiopulmonary resuscitation (CPR) maneuvers of the CoSTR has been updated since first international guidelines was published in 2000. We investigated whether CPR, especially defibrillation protocol, based on the CoSTR update improves neurologically intact survival after shockable out-of-hospital cardiac arrest (OHCA). Methods: From the All-Japan Utstein Registry between 2005 and 2015, we enrolled adult patients with witnessed shockable OHCA. Study patients were divided into 3 groups according to each CPR recommendation era (the Guidelines 2000 group in 2005; 3-stacked-shock protocol era, CoSTR 2005 group between 2006 and 2010; 1-shock protocol [1 shock immediately followed by 2 minutes of CPR] era, and the CoSTR 2010 group between 2006 and 2010; simplified dispatcher chest compressions instruction and 1-shock protocol era). Primary endpoint was favorable 30-day neurological outcome after OHCA. Results: Of the 73,578 study patients, 5,575 (7.6%) received CPR based on the Guidelines 2000, 32,749 (44.5%) the CoSTR 2005, and 35,255 (47.9%) the CoSTR 2010. Crude frequency of favorable 30-day neurological outcome increased significantly whenever the CPR maneuvers were updated (12.3% in the Guidelines 2000 group vs. 19.3% in the CoSTR 2005 group vs. 23.3% in the CoSTR 2010 group, p&lt;0.001). Multivariable logistic-regression analysis for favorable 30-day neurological outcome showed that adjusted odds ratio (reference, the Guidelines 2000 group) was 1.89 (95% CI, 1.72-2.07) in the CoSTR 2005 group and 2.71 (95% CI, 2.47-2.97) in the CoSTR 2010 group. Other independent predictors were age, sex, collapse-to-CPR interval, call-to-scene interval, witnessed and/or bystander CPR status, and cause of cardiac arrest. On the other hand, some advanced life support maneuvers were not acceptable; adjusted odds ratio of 0.37 (95%CI, 0.35-0.39) in advanced airway management (reference, bug-mask ventilation) and 0.36 (95%CI, 0.33-0.38) in intravenous epinephrine (reference, no epinephrine). Conclusions: Defibrillation protocol update based on the CoSTR was the preferable approach to resuscitation for adult patients with witnessed shockable OHCA. However, prehospital epinephrine and advanced airway management were not helpful.

Abstract 323: Time to Specialized Prehospital Care and Neurologically Favorable Survival After Traumatic Out-Of-Hospital Cardiac Arrest: Results From a Japanese Registry-Based Study

Introduction: Specialized care is essential for successful resuscitation after traumatic out-of-hospital cardiac arrest (OHCA). However, the effect of early specialized care by healthcare professional for traumatic OHCA in the prehospital setting is unknown. Hypothesis: We sought to determine whether time to specialized prehospital care by healthcare professional is associated with a neurological status after traumatic OHCA. Methods: This was a nationwide population-based study of traumatic OHCA based on data from the All-Japan Utstein Registry. We included patients who experienced traumatic OHCA in Japan from 2013 to 2016. The primary outcome was 1-month neurologically favorable survival. Results: A total of 8,470 patients were included. Among these patients, 50 (0.6%) survived with a favorable neurological status one month after OHCA. The median time to specialized prehospital care by healthcare professional was 9 minutes (IQR, 7-13; mean [SD], 10.7 [6.3] minutes). Longer time to specialized prehospital care was associated with a decreased chance of neurologically favorable survival: 2.6, 1.2, 0.9, 0.5, 0.2, and 0.0%, respectively, when time to specialized prehospital care was treated as a categorical variable categorized into ≤2, 3-5, 6-8, 9-11, 12-14, and ≥15 minutes (P for trend &lt;0.0001), and multivariable-adjusted OR per minute delay 0.79 (95%CI 0.70-0.89, P&lt;0.0001) when time to specialized prehospital care was treated as a linear and continuous variable. In subgroup analyses, longer time to specialized care was associated with a decreased chance of neurologically favorable survival when ALS was provided in the prehospital setting (adjusted OR 0.73, 95%CI 0.61-0.87, P=0.0007), especially when prehospital ALS was performed by physician (adjusted OR 0.72, 95%CI 0.56-0.93, P=0.0119), whereas there was no significant association between time to specialized care and neurologically favorable survival when only BLS was provided in the prehospital setting (adjusted OR 0.86, 95%CI 0.74-1.01, P=0.0734). Conclusion: In traumatic OHCA, delayed specialized prehospital care by healthcare professional was associated with a decreased chance of neurologically favorable survival, especially when a physician was involved in prehospital ALS.

Abstract 27: Machine Learning Models for Outcome Prediction of Out-Of-Hospital Cardiac Arrest of Presumed Cardiac Cause Using the All-Japan Utstein Registry

Background: Outcome prediction for patients with out-of-hospital cardiac arrest (OHCA) using prehospital information has been one of the major challenges in resuscitation medicine. Recently, machine learning techniques have been shown to be highly effective in predicting outcomes using clinical registries. In this study, we aimed to establish a prediction model for outcomes of OHCA of presumed cardiac cause using machine learning techniques. Methods: We analyzed data from the All-Japan Utstein Registry of the Fire and Disaster Management Agency between 2005 and 2016. Of 1,423,338 cases, data of OHCA patients aged ≥18 years with presumed cardiac etiology were retrieved and divided into two groups: training set, n = 584,748 (between 2005 and 2013) and test set, n = 223,314 (between 2014 and 2016). The endpoints were neurologic outcome at 1-month and survival at 1-month. Of 47 variables evaluated during the prehospital course, 19 variables (e.g.,sex, age, ECG waveform, and practice of bystander CPR) were used for outcome prediction. Performances of logistic regression, random forests, and deep neural network were examined in this study. Results: For prediction of neurologic outcomes (cerebral performance category 1 or 2) using the test set, the generated models showed area under the receiver operating characteristic curve (AUROC) values of 0.942 (95% confidence interval [CI] 0.941-0.943), 0.947 (95% CI 0.946-0.948), and 0.948 (95% CI 0.948-0.950) in logistic regression, random forest, and deep neural network, respectively. For survival prediction, the generated models showed AUROC values of 0.901 (95% CI 0.900-0.902), 0.913 (95% CI 0.912-0.914), and 0.912 (95% CI 0.911-0.913) in logistic regression, random forest, and deep neural network, respectively. Conclusions: Machine learning techniques using prehospital variables showed favorable prediction capability for 1-month neurologic outcome and survival in OHCA of presumed cardiac cause.

Abstract 340: Effect of the 2015 CPR Guidelines for Patients With Out-Of-Hospital Cardiac Arrest Due to Non-Shockable Rhythm: Results From the All-Japan Utstein Registry

Background: The 2015 cardiopulmonary resuscitation (CPR) guidelines have stressed that high-quality CPR improves survival from cardiac arrest (CA). In particular, the guidelines recommended that it is reasonable for rescuers to perform chest compressions at a rate of 100 to 120/min in adult CA patients. However, it is unknown whether the 2015 guidelines contributed to favorable neurological outcome in adult CA patients. The present study aimed to clarify the effects of the 2015 guidelines in adult CA patients, using the data of the All-Japan Utstein Registry, a prospective, nationwide, population-based registry of out-of-hospital CA (OHCA). Methods: From the data of this registry between 2011 and 2016, we included adult witnessed OHCA patients due to cardiac etiology, who had non-shockable rhythm, PEA and asystole, as an initial rhythm. Study patients were divided into two groups based on the different CPR guidelines; the era of the 2010 guidelines (2010G), and the era of the 2015 guidelines (2015G). The endpoint was the favorable neurological outcome at 30 days after OHCA. Results: The 109,175 patients who met the inclusion criteria comprised 18,764 who received CPR based on 2015G and 90,411 who received CPR based on 2010G. The figure showed favorable neurological outcomes at 30 days in the two groups. In the multivariate analysis, the adjusted odds ratio for 30-day favorable neurological outcome in 2015G patients as compared to 2010G patients was 1.28 (95%CI 1.11-1.46, p&lt;0.001). Conclusion: In the OHCA patients with non-shockable rhythm, the 2015 guidelines were superior to the 2010 guidelines, in terms of neurological benefits.

Abstract 165: Impact of Prehospital Epinephrine for Patients Treated With Extracorporeal Cardiopulmonary Resuscitation After Refractory Out-Of-Hospital Shockable Cardiac Arrest

Background: The 2015 CoSTR recommended that standard-dose epinephrine (SDE) was reasonable for patients with out-of-hospital cardiac arrest (OHCA) and extracorporeal cardiopulmonary resuscitation (ECPR) was reasonable rescue therapy for selected patients with ongoing cardiac arrest when initial conventional CPR was unsuccessful. We investigated the effect of prehospital SDE for patients who met the criteria of ECPR. Methods: From the All-Japan OHCA Utstein Registry between 2007 and 2015, we included 22,552 patients who met the criteria of ECPR of the SAVE-J study (age between 20 and 75, witnessed shockable OHCA, cardiac arrest on hospital arrival, cardiac etiology, and collapse-to-ECPR interval within 60 minutes). Study patients were divided into two groups according to prehospital SDE or not. Primary endpoint was favorable 30-day neurological outcome after OHCA. Results: Of the 22,552 study patients, 5,659 (25%) received prehospital SDE and 16,893 (75%) did not. The SDE group resulted in lower proportion of favorable 30-day neurological outcome than the no-SDE group (5.6% versus 8.4%, p&lt;0.001) with longer collapse-to-hospital-arrival interval (36.7±9.8 min vs. 29.6±11.3 min, p&lt;0.001). After adjustment for independent predictors of resuscitation, prehospital SDE did not impact on neurological benifit (adjusted OR,1.13; 95%CI,0.98-1.29), but the collapse-to-hospital-arrival interval was associated with neurological benefit (adjusted OR, 0.94; 95% CI, 0.93-0.95). In curve estimation of the SDE group, when collapse-to-hospital-arrival interval was delayed, proportion of the favorable neurological outcome decreased to about 25% at 1 minute and about 0% at 54 minutes (R=0.14). In the 274 patients undergoing ECPR of the SAVE-J study, however, it was about 43% at 1 minute and about 0% at 96 minutes (R=0.17). Conclusions: Prehospital SDE did not improve likelihood of favorable neurological outcome for patients who met the criteria of ECPR (age between 20 and 75, witnessed shockable OHCA, cardiac arrest on hospital arrival, cardiac etiology and collapse-to-ECPR interval within 60 minutes), because SED administration delayed the collapse-to-hospital-arrival interval which was closely related to the neurologically intact survival on ECPR.

Abstract 475: Association Between Bystander Delay in Activating the Emergency Response System and Outcomes Following Out-Of-Hospital Cardiac Arrest: All-Japan National Utstein Registry

Introduction: An emphasis on the chain of survival has contributed to improved outcomes of out-of-hospital cardiac arrest (OHCA). Although immediate recognition of cardiac arrest (CA) and activation of the emergency response system are the first links in the chain of survival, their impact on outcomes is unclear. Hypothesis: Delayed time from collapse to activation of the emergency response system (bystander delay) is associated with an unfavorable neurological outcome after adult OHCA. Methods: Data from the prospective, nationwide, population-based All-Japan Utstein Registry of the Fire and Disaster Management Agency between January 1, 2012 and December 31, 2016 were analyzed. Of the 625,916 eligible cases, 164,256 adult, non-traumatic, witnessed OHCA including bystander delay times (age, 79 [IQR, 67-86] years; 60% male) were studied. The primary outcome measure was favorable neurological outcome 1 month after an OHCA, defined as a score of 1 or 2 on the Cerebral Performance Category Scale. Results: The median bystander delay time of 2.0 [1.0-4.0] min was shorter among patients who achieved a favorable outcome as compared to 3.0 [1.0-6.0] min (P &lt; 0.001) for patients with an unfavorable outcome. In multivariable logistic regression analyses, bystander delay had an OR for favorable neurological outcome of 0.94 [95% CI, 0.93-0.97] after adjusting for age, sex, etiology of arrest, first documented rhythm, provision of bystander CPR, use of public access automated external defibrillator, epinephrine administration, time intervals of activation of the emergency response system and hospital arrival, and collapse to initiation of CPR, and regional location. Similarly, bystander delay was independently associated with reduced neurologically favorable survival among patients who received bystander CPR within one minute of collapse (adjusted OR, 0.97 [0.97-0.98]). Conclusions: Bystander delay was independently associated with decreased odds of neurologically favorable survival, even among patients for whom bystander CPR was immediately performed.

P2666Association of out-of-hospital cardiac arrest occurrence time and the survival in all-Japan utstein registry: difference between international resuscitation guidelines 2005 and 2010

Abstract Background/Introduction Previous studies have shown that out-of-hospital cardiac arrest (OHCA) occurring at night have poor outcomes compared with OHCA occurring during daytime. On the other hand, nationwide OHCA outcomes have gradually improved in Japan. Purpose We sought to examine whether one-month survival of OHCA differed between daytime and nighttime occurrences, and they differed between the periods of International Resuscitation Guidelines 2005 and 2010. Methods Using the All-Japan Utstein Registry between 2005 and 2015, adult OHCA patients whose collapse was witnessed by a bystander and the call-to-hospital admission interval was shorter than 120 min were included in this study. OHCA patients were divided by period of the International Resuscitation Guideline 2005 and 2010. Guideline 2005 included years from 2006 to 2010, while Guideline 2010 included years from 2011 to 2015. The primary outcome was one-month survival with favorable neurological outcome, defined as Cerebral Performance Category scale of 1 or 2. Daytime, evening, and night were defined as 0700 to 1459 h, 1500 to 2259 h, and 2300 to 0659 h, respectively. Results Among 479,046 cases, 20.3% revealed OHCA occurring at night. OHCA patients occurring at night had lower rate of bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator use than those occurring at both daytime and evening. In addition, of those who received bystander CPR, higher rate of patients received CPR by family members. OHCA patients occurring at night in both guideline periods had significantly worse one-month survival than those occurring during daytime (reference) (adjusted odds ratio, 0.69, 0.64; 95% confidence interval 0.65–0.72, 0.61–0.67; P&lt;0.001, P&lt;0.001, Guideline 2005 and 2010 respectively). OHCA patients occurring during daytime in Guideline 2010 had better one-month survival than those in Guideline 2005 (adjusted odds ratio, 1.29; 95% confidence interval 1.24–1.34; P&lt;0.001). Conclusions One-month survival with favorable neurological outcome in OHCA patients occurring at night remains to be significantly worse than those occurring during daytime, even improved by the periods during daytime. CPR training for the family members should be more expanded and strengthened against the night time imperfection.

P1707Non-business hours and cold exposure independently worsen neurological outcome after out-of-hospital cardiac arrest

Abstract Background It has been known that survival rates after out-of-hospital cardiac arrest (OHCA) are lower at night than during the day. It may be explained by diurnal temperature changes. Purpose The purpose of the present study was to test our hypothesis that diurnal variation of the prognosis after OHCA would be independent from the ambient temperature changes. Methods We used the All-Japan Utstein Registry (2005–2010) combined with atmospheric temperature from the Automated Meteorological Data Acquisition System, and enrolled adult OHCA patients who had suffered from a witnessed cardiac arrest and who had been resuscitated. The primary outcome was a favorable neurological outcome one month after OHCA and the secondary outcome was the presence of return of spontaneous circulation (ROSC) before hospital admission. Effects of business vs. non-business hours and ambient temperature on the primary and secondary outcomes were assessed with adjustment for factors that are known to potentially affect OHCA outcomes. Sub-group analysis based on the initial cardiac rhythm (VT/Vf, PEA and Asystole) was also performed. Results Among the 263,750 witnessed OHCA patients, neurological survival and ROSC rates were significantly increased with an adjusted odds ratio (OR) of 1.13 (95% CI 1.08–1.18) and hazard ratio (HR) of 1.06 (95% CI 1.04–1.09) for non-business hours, and OR of 1.11 (95% CI 1.05–1.17) and HR of 1.05 (95% CI 1.02–1.08) for each 20°C increase in temperature. The effects were different between business vs. non-business hours and ambient temperature dependent on the initial cardiac rhythm. Conclusions These findings suggest that both the outdoor temperature and business hours are independent factors for predicting neurological outcomes after OHCA with different characteristics based on the initial cardiac rhythms. Diurnal variability of prognosis after OHCA is likely to be attributable to diurnal variation of medical resources.

1271Short-term effects of exposure to ambient fine particulate matter on out-of-hospital cardiac arrest: a nationwide case-crossover study in Japan

Abstract Introduction The cardiovascular health consequences of ambient air pollution generally equal or exceed those due to pulmonary diseases and cancers. Particulate matter less than 2.5μm in aerodynamic diameter (PM2.5) has become a major focus of research on the short-term exposure to air pollution and cardiovascular disease. However, the evidence regarding the association between several air pollutants and out-of-hospital cardiac arrest (OHCA), has been inconsistent, which could be due to limited sample sizes (∼11,000). Thus, a larger study may assist in characterising possible associations. Purpose This study aimed to identify the associations between exposure to ambient air pollution and the incidence of OHCA in Japan. Methods A case-crossover design was used to determine the odds ratio (OR) of OHCA across Japan with daily exposure of PM2.5, carbon monoxide (CO), photochemical oxidants (Ox), and sulfur dioxide (SO2) on the day of the arrest or 1–3 days before it (lag 0–3). OHCA cases were identified through the All-Japan Utstein registry of the Fire and Disaster Management Agency from January 1, 2014 to December 31, 2015. All cause OHCAs were investigated by conditional logistic regression adjusted for daily temperature and relative humidity. Results A total of 249,372 OHCAs were included during study period. Each 10 μg/m3 increase in daily PM2.5 exposure over 4 days was associated with all cause OHCA risk (lag 0: OR 1.017, 95% confidence interval (CI) 1.010, 1.024; lag 1: OR 1.015, 95% CI 1.008, 1.022; lag 2: OR 1.018, 95% CI 1.011, 1.025; lag 3: OR 1.021, 95% CI 1.014, 1.028; lag 0–1: OR 1.022, 95% CI 1.014, 1.030). CO, Ox and SO2 also showed significant associations with OHCAs. In the multi-pollutant model, the effects of PM2.5 remained independent of CO, Ox and SO2 (Table). Conclusion Short-term exposure to PM2.5 was independently associated with an increased risk of OHCA.

2284Sex and age differences in short-term exposure to ambient fine particulate matter and out-of-hospital cardiac arrest: a nationwide case-crossover study in Japan

Abstract Introduction Accumulating evidence has shown the elevated risk for cardiovascular diseases (CVD) with exposure to air pollution, such as fine particles &lt;2.5μm in aerodynamic diameter (PM2.5). A bi-directional relationship exists between air pollution and traditional CV risk factors like obesity, diabetes, and hypertension. However, little is known about the effect of age and sex on association between ambient air pollution and out-of-hospital cardiac arrest (OHCA). Purpose This study aimed to identify sex and age differences in the associations between exposure to PM2.5 and OHCA in Japan. Methods A case-crossover design was used to determine the odds ratio (OR) of OHCA across Japan with daily PM2.5 exposure on the day of the arrest or 1–3 days before it (lag 0–3). OHCA cases were identified through the All-Japan Utstein registry of the Fire and Disaster Management Agency from January 1, 2014 to December 31, 2015. OHCAs were investigated by conditional logistic regression adjusted for daily temperature and relative humidity with stratification by sex and age. Results A total of 249,372 OHCAs were included during study period. Their mean age was 75 years and 57% were male. Each 10 μg/m3 increase in daily PM2.5 exposure over 4 days was associated with all cause OHCA risk for male (lag 0: OR 1.022, 95% confidence interval (CI) 1.013, 1.031; lag 1: OR 1.016, 95% CI 1.007, 1.025; lag 2: OR 1.016, 95% CI 1.007, 1.026; lag 3: OR 1.017, 95% CI 1.008, 1.027; lag 0–1: OR 1.025, 95% CI 1.015, 1.036). Increased risk in OHCA was also found with lag 1 to lag 3 PM2.5 exposure among women. Lag 0 to lag 3 PM2.5 exposures were significantly associated with OHCA among patients older than 65 years. Among 35 to 64 years, only lag 3 PM2.5 exposure was associated with an increased risk in OHCA. No significant association was observed between PM2.5 exposure and OHCA among patients less than 35 years. Conclusions Short-term exposure to PM2.5 is associated with an increased risk of OHCA in both sexes. Patients older than 65 years were more susceptible to PM2.5 exposure than younger age group.

Prehospital advanced airway management for paediatric patients with out-of-hospital cardiac arrest: A nationwide cohort study

BackgroundAlthough prehospital advanced airway management (AAM) (i.e., endotracheal intubation [ETI] and insertion of supraglottic airways [SGA]) has been performed for paediatric out-of-hospital cardiac arrest (OHCA), the effect of AAM has not been fully studied. We evaluated the association between prehospital AAM for paediatric OHCA and patient outcomes. MethodsWe conducted an observational cohort study, using the All-Japan Utstein Registry between 2014 and 2016. We included paediatric patients (age <18 years) with OHCA. We calculated time-dependent propensity score at each minute after initiation of cardiopulmonary resuscitation by EMS providers, using a Fine-Gray regression model. We sequentially matched patients who received AAM during cardiac arrest to patients at risk of receiving AAM within the same minute (risk-set matching). The primary outcome was 1-month survival. Secondary outcome was 1-month survival with favourable functional status, defined as Cerebral Performance Category score of 1 or 2. ResultsWe analysed 3801 paediatric patients with OHCA. 481 patients (12.7%) received AAM and 3320 (87.3%) did not. Among the 3801 analysed patients, 912 patients underwent risk-set matching. In the matched cohort, AAM was not associated with 1-month survival (AAM: 52/456 [11.4%] vs. no AAM: 44/456 [9.6%]; risk ratio [RR], 1.15 [95% CI, 0.76–1.73]; risk difference [RD], 1.5% [−3.0 to 6.1%]) or favourable functional status (AAM: 9/456 [2.0%] vs. no AAM: 10/456 [2.2%]; RR, 0.69 [95% CI, 0.26–1.79]; RD, −0.8% [−2.9 to 1.3%]). ConclusionAmong paediatric patients with OHCA, we found that prehospital AAM was not associated with 1-month survival or favourable functional status.

Relationship between Fine Particulate Matter Exposure and Out-of-Hospital Cardiac Arrest of Cardiac Origin: A Nationwide Registry-Based Japanese Study

Background: Sudden cardiac arrest is a leading cause of cardiovascular death. We aimed to examine the association of short-term exposure to particulate matter of diameter ≤2·5 μm (PM2·5) with factors including incidence of out-of-hospital cardiac arrests (OHCAs) of cardiac origin, efficacy of basic life support measures, and eventual prognosis. Methods: We utilised data from the prospective, nationwide, population-based All-Japan Utstein Registry of OHCAs occurring throughout all 47 Japanese prefectures. We obtained PM2·5 concentrations and other air pollutants from atmospheric environmental database of the National Institute for Environmental Studies. A time-stratified, case-crossover design was applied to study the association of prefecture-specific estimates of PM2·5 with OHCA-related factors using a conditional logistic regression analysis. Estimations were combined with a random-effects meta-analysis for higher accuracy. Findings: The study included 103 189 bystander-witnessed OHCAs of cardiac origin that occurred from April 2011 to December 2016. A 10-μg/m3 increase in the average PM2·5 concentration on the day of OHCA over that on the day prior was associated with a 1·6 (95% CI, 0·1-3·1)% increase. PM2·5-exposure was closely associated with OHCAs presenting with asystole (2·1 [0·2-4·1]%) as compared to those with other initial cardiac rhythms. Occurrence of unfavourable prognosis such as 1-month mortality (1·5 [0·0-3·2]%) was estimated, and both chest compressions and rescue breathing were associated with higher 1-month mortality (4·6 [0·4-9·0]%) than chest-compression-only type of cardiopulmonary resuscitation (1·2 [-0·7-3·1]%) in OHCA patients with PM2·5-exposure. Interpretation: Increase in PM2·5 concentrations triggers OHCAs of cardiac origin, which commonly present with initial asystole, leading to poor outcomes. The impact of rescue breathing for cardiac origin-OHCA patients affected by short-term exposure to PM2·5, requires further study. Funding: Environment Research and Technology Development Fund (5-1751) of the Ministry of Environment, Japan, and Grants-in-Aid for Scientific Research (17K19821) of the Japan Society for Promotion of Science. Declaration of Interest: None. Ethical Approval: They conducted the study with approval from the Ethics Committee of Kawasaki Medical School (Approved Number: 3383).

Association of Prehospital Epinephrine Administration With Survival Among Patients With Traumatic Cardiac Arrest Caused By Traffic Collisions

For traumatic cardiac arrest (TCA), the effect of prehospital epinephrine administration was unclear. The aim of this study was to evaluate the relationship between prehospital epinephrine administration and survival in patients with TCA caused by traffic collisions. We conducted a nationwide, prospective, population-based observational study involving patients who experienced out-of-hospital cardiac arrest (OHCA) by using the All-Japan Utstein Registry. Blunt trauma patients with TCA who received prehospital epinephrine were compared with those who did not receive prehospital epinephrine. The primary outcome was 1-month survival of patients. The secondary outcome was prehospital return of spontaneous circulation (ROSC). A total of 5,204 patients with TCA were analyzed. Of those, 758 patients (14.6%) received prehospital epinephrine (Epinephrine group), whereas the remaining 4,446 patients (85.4%) did not receive prehospital epinephrine (No epinephrine group). Eleven (1.5%) and 41 (0.9%) patients in the Epinephrine and No epinephrine groups, respectively, survived for 1 month. In addition, 74 (9.8%) and 40 (0.9%) patients achieved prehospital ROSC in the Epinephrine and No epinephrine groups, respectively. In multivariable logistic regression models, prehospital epinephrine administration was not associated with 1-month survival (odds ratio [OR] 1.495, 95% confidence interval [CI] 0.758 to 2.946) and was associated with prehospital ROSC (OR 3.784, 95% CI 2.102 to 6.812). A propensity score-matched analysis showed similar results for 1-month survival (OR 2.363, 95% CI 0.606 to 9,223) and prehospital ROSC (OR 6.870, 95% CI 3.326 to 14.192). Prehospital epinephrine administration in patients with TCA was not associated with 1-month survival, but was beneficial in regard to prehospital ROSC.

Citizen bystander–patient relationship and 1-month outcomes after out-of-hospital cardiac arrest of cardiac origin from the All-Japan Utstein Registry: a prospective, nationwide, population-based, observational study

ObjectivesThe presence of a bystander witness is a crucial predictor of patient survival after out-of-hospital cardiac arrest (OHCA). However, the differences in survival and neurological outcomes among different types of...