Impact of pandemic-related movement restriction on public access defibrillation in Japan: a retrospective cohort study.

OBJECTIVES: To analyse monthly changes in public access defibrillation (PAD) incidence and outcomes of out-of-hospital cardiac arrest (OHCA) during the 2020-2021 COVID-19 pandemic compared with those during the 2016-2019 prepandemic period with consideration of pandemic-related movement restriction. DESIGN: Retrospective cohort study. SETTING: An extended database was created by combining and reconciling the nationwide Utstein-style OHCA and the emergency medical service (EMS) transportation databases in Japan. PARTICIPANTS: We analysed 226 182 EMS-witnessed, non-newborn and out-of-home OHCA cases in Japan. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes were the PAD incidence and neurologically favourable 1-month survival rate. The secondary outcomes were bystander cardiopulmonary resuscitation (CPR) provision and dispatcher-assisted CPR attempts. RESULTS: The proportion of out-of-home OHCA cases slightly decreased during the pandemic (from 33.7% to 31.9%). Although the pandemic was associated with a decreased PAD incidence, 2-year trend analyses by an interaction test showed that the PAD incidence was lower during the first nationwide declaration of a state of emergency (p<0.001) and in the pandemic's second year (p<0.01). Regardless of location, delays in basic life support (BLS) actions and EMS contact with patients were more common and the rate of PAD-induced return of spontaneous circulation was lower during the pandemic. PAD incidence reduction was significant only in locations with a recommendation of automated external defibrillator placement (p<0.001). In other locations, a pronounced delay in BLS was found during the pandemic. The neurologically favourable survival rate was reduced in parallel with the reduced PAD incidence during the pandemic (r=0.612, p=0.002). CONCLUSIONS: Prolonged and repeated movement restrictions during the COVID-19 pandemic worsened the OHCA outcomes concurrently with disturbed BLS actions, including the reduced PAD incidence in out-of-home settings. Maintaining BLS training, re-arranging automated external defibrillator placement and establishing a local alert system for recruiting well-trained citizens to the scene are essential.

Association between the COVID-19 pandemic in 2020 and out-of-hospital cardiac arrest outcomes and bystander resuscitation efforts for working-age individuals in Japan: a nationwide observational and epidemiological analysis.

BACKGROUND: Improving out-of-hospital cardiac arrest (OHCA) prognosis within the working-age population is important, but no studies have investigated the effects of COVID-19 pandemic specifically on the working-age population with OHCAs. We aimed to determine the association between the 2020 COVID-19 pandemic and OHCA outcomes and bystander resuscitation efforts among the working-age population. METHODS: Prospectively collected nationwide, population-based records concerning 166 538 working-age individuals (men, 20-68 years; women, 20-62 years) with OHCA between 2017 and 2020 were assessed. We compared characteristics and outcome differences of the arrests between three prepandemic years (2017-2019) and the pandemic year 2020. The primary outcome was neurologically favourable 1-month survival (cerebral performance category 1 or 2). Secondary outcomes were bystander cardiopulmonary resuscitation (BCPR), dispatcher-assisted instruction for cardiopulmonary resuscitation (DAI-CPR), bystander-provided defibrillation (public access defibrillation (PAD)) and 1-month survival. We examined variations in bystander resuscitation efforts and outcomes among pandemic phase and regional classifications. RESULTS: Among 149 300 OHCA cases, 1-month survival (2020, 11.2%; 2017-2019, 11.1% (crude OR (cOR) 1.00, 95% CI 0.97 to 1.05)) and 1-month neurologically favourable survival (7.3%-7.3% (cOR 1.00, 95% CI 0.96 to 1.05)) were unchanged; however, the neurologically favourable 1-month survival rate decreased in 12 of the most COVID-19-affected prefectures (7.2%-7.8% (cOR 0.90, 95% CI 0.85 to 0.96)), whereas it increased in 35 other prefectures (7.5%-6.6% (cOR 1.15, 95% CI 1.07 to 1.23)). Favourable outcomes decreased for OHCAs of presumed cardiac aetiology (10.3%-10.9% (cOR 0.94, 95% CI 0.90 to 0.99)) but increased for OHCAs of non-cardiac aetiology (2.5%-2.0% (cOR 1.27, 95% CI 1.12 to 1.44)). BCPR provision increased from 50.7% of arrests prepandemic to 52.3% (crude OR 1.07, 95% CI 1.04 to 1.09). Compared with 2017-2019, home-based OHCAs in 2020 increased (64.8% vs 62.3% (crude OR 1.12, 95% CI 1.09 to 1.14)), along with DAI-CPR attempts (59.5% vs 56.6% (cOR 1.13, 95% CI 1.10 to 1.15)) and multiple calls to determine a destination hospital (16.4% vs 14.5% (cOR 1.16, 95% CI 1.12 to 1.20)). PAD use decreased from 4.0% to 3.7% but only during the state of emergency period (7 April-24 May 2020) and in prefectures significantly affected by COVID-19. CONCLUSIONS: Reviewing automated external defibrillator (AED) locations and increasing BCPR through DAI-CPR may help prevent pandemic-associated decreases in survival rates for patients with cardiac OHCAs.

Associations between prehospital defibrillation and outcomes of out-of-hospital cardiac arrests presumed to be caused by hypothermia: A nationwide observational study with epidemiological analysis.

This study aimed to clarify the epidemiology of out of-hospital cardiac arrest (OHCA) cases caused by hypothermia. The associations between the presence/absence of shockable initial electrocardiography rhythm, prehospital defibrillation and the outcomes of OHCA were also investigated. This study involved the retrospective analysis of prospectively collected, nationwide, population-based data for OHCA cases caused by hypothermia. One thousand five hundred seventy-five emergency medical service (EMS)-confirmed OHCA cases with hypothermia, recorded between 2013 and 2019, were extracted from the Japanese nationwide database. The primary outcome was neurologically favorable 1-month survival, defined as cerebral performance category 1 or 2. The secondary outcome was 1-month survival. OHCA cases with hypothermia occurred more frequently in the winter. In approximately half (837) of the hypothermic OHCA cases, EMS was activated in the morning (6:00 am to 11:59 am). Shockable initial electrocardiogram rhythms were recorded in 30.8% (483/1570) of cases. prehospital defibrillation was attempted in 96.1% (464/483) of cases with shockable rhythms and 25.8% (280/1087) of cases with non-shockable initial rhythms. EMS-witnessed cases, prolonged transportation time intervals and prehospital epinephrine administration were associated with rhythm conversion in cases with non-shockable initial rhythms. Binominal logit test followed by multivariable logistic regression revealed that shockable initial rhythms were associated with better outcomes. prehospital defibrillation was not significantly associated with better outcomes, regardless of the type of initial rhythm (shockable or non-shockable). Transportation to high-level emergency hospitals was associated with better outcomes (adjusted odds ratio: 2.94, 95% confidence interval: 1.66-5.21). In hypothermic OHCA, shockable initial rhythm but not prehospital defibrillation is likely to be associated with better neurologically favorable outcomes. In addition, transport to a high-level acute care hospital may be appropriately considered despite prolonged transport. Further investigation, including core temperature data in analyses, is necessary to determine the benefit of prehospital defibrillation in hypothermic OHCA.

Impact of the COVID-19 pandemic on prehospital characteristics and outcomes of out-of-hospital cardiac arrest among the elderly in Japan: A nationwide study.

Aim: To assess the impact of the 2020 coronavirus disease (COVID-19) pandemic on the prehospital characteristics and outcomes of out-of-hospital cardiac arrest (OHCA) in the elderly. Methods: In this population-based nationwide observational study in Japan, 563,100 emergency medical service-unwitnessed OHCAs in elderly (≥65 years) patients involving any prehospital resuscitation efforts were analysed (144,756, 140,741, 140,610, and 136,993 cases in 2020, 2019, 2018, and 2017, respectively). The epidemiology, characteristics, and outcomes associated with OHCAs in elderly patients were compared between 3 years pre-pandemic (2017-2019) and the pandemic year (2020). The primary outcome was neurologically favourable one-month survival. The secondary outcomes were the rate of bystander cardiopulmonary resuscitation (CPR), defibrillation by a bystander, dispatcher-assisted (DA)-CPR attempts, and one-month survival. Results: During the pandemic year, the rates of neurologically favourable 1-month survival (crude odds ratio, 95% confidence interval: 1.19, 1.14-1.25), bystander CPR (1.04, 1.03-1.06), and DA-CPR attempts (1.10, 1.08-1.11) increased, whereas the incidence of public access defibrillation (0.88, 0.83-0.93) decreased. Subgroup analyses based on interaction tests showed that the increased rate of neurologically favourable survival during the pandemic year was enhanced in OHCA at care facilities (1.51, 1.36-1.68) and diminished or abolished on state-of-emergency days (0.90, 0.74-1.09), in the mainly affected prefectures (1.08, 1.01-1.15), and in cases with shockable initial rhythms (1.03, 0.96-1.12). Conclusions: The COVID-19 pandemic increased the bystander CPR rate in association with enhanced DA-CPR attempts and improved the outcomes of elderly patients with OHCAs.

Effects of the 2020 COVID-19 pandemic on outcomes of out-of-hospital cardiac arrest and bystander resuscitation efforts: a nationwide cohort study in Japan.

Background and importance There is limited knowledge about the nationwide impact of the 2020 COVID-19 pandemic in Japan on out-of -hospital cardiac arrest (OHCA) outcomes.Objectives The aim of this study was to investigate the impact of the 2020 COVID-19 pandemic on OHCA outcomes and bystander resuscitation efforts in Japan. Design Retrospective analysis of a nationwide population-based registry of OHCA cases. Settings and participants To conduct this study, we created a comprehensive database comprising 821 665 OHCA cases by combining and reconciling the OHCA database for 835 197 OHCA cases between 2017 and 2020 with another database, including location and time records. After applying exclusion and inclusion criteria, we analysed 751 617 cases.Outcome measures and analysis The primary outcome measure for this study was survival with neurologically favourable outcome (cerebral performance category 1 or 2). We compare OHCA characteristics and outcomes between prepandemic and pandemic years, and also investigated differences in factors associated with outcomes. Results We found that survival with neurologically favourable outcome and the rates of bystander cardiopulmonary resuscitation (CPR) slightly increased in the pandemic year [2.8% vs. 2.9%; crude odds ratio (OR), 1.07; 95% confidence interval (CI), 1.03-1.10; 54.1% vs. 55.3%, 1.05 (1.04-1.06), respectively], although the incidence of public access defibrillation (PAD) slightly decreased [1.8% vs. 1.6%, 0.89 (0.86-0.93)]. Calls for hospital selection by emergency medical service (EMS) increased during the pandemic. Subgroup analysis showed that the incidence of neurologically favourable outcome increased in 2020 for OHCA cases that occurred on nonstate of emergency days, in unaffected prefectures, with noncardiac cause, nonshockable initial rhythm, and during daytime hours. Conclusions During the 2020 COVID-19 pandemic in Japan, survival with neurologically favourable outcome of OHCA patients and bystander CPR rate did not negatively change, despite the decrement in PAD incidence. However, these effects varied with the state of emergency, region, and characteristics of OHCA, suggesting an imbalance between medical demand and supply, and raising concerns about the pandemic.

Epidemiology of out-of-hospital cardiac arrests caused by anaphylaxis and factors associated with outcomes: an observational study.

OBJECTIVES: Describe the epidemiologic features of out-of-hospital cardiac arrest (OHCA) caused by anaphylaxis and identify outcome-associated factors. DESIGN: Observational study. SETTING: Data from the Japanese Fire and Disaster Management Agency database. PARTICIPANTS: A total of 292 patients from 879 057 OHCA events between 2013 and 2019 with OHCA caused by anaphylaxis and for whom prehospital resuscitation was attempted were included in the analysis. OUTCOME MEASURES: The incidence of anaphylaxis-induced OHCA, neurologically favourable 1-month survival, defined as cerebral performance category 1 or 2, and 1-month survival. RESULTS: The proportion of OHCAs caused by anaphylaxis was high in non-elderly and male patients from July to September and during business hours. Bystander-witnessed (adjusted OR=4.43; 95% CI 1.84 to 10.7) and emergency medical service-witnessed events (adjusted OR=3.28; 95% CI 1.21 to 8.87) were associated with higher rates of neurologically favourable 1-month survival as well as better 1-month survival. Shockable initial ECG rhythms were recorded in only 19 patients (6.5%), and prehospital defibrillation was attempted in 16 such patients (84.2%). Neither shockable initial rhythms nor prehospital defibrillation was associated with better outcomes. Patients requiring advanced airway management had poor neurological outcomes (adjusted OR=0.17; 95% CI 0.07 to 0.42) and worse 1-month survival (adjusted OR=0.28; 95% CI 0.14 to 0.58). CONCLUSIONS: Few cases of OHCA were attributable to anaphylaxis. Witnessed OHCAs, particularly those witnessed by bystanders, were associated with better neurological outcomes. Airway complications requiring advanced airway management were likely associated with poor outcomes.

Effect of large-scale disasters on bystander-initiated cardiopulmonary resuscitation in family-witnessed, friend-witnessed and colleague-witnessed out-of-hospital cardiac arrest: a retrospective analysis of prospectively collected, nationwide, population-based data.

IMPORTANCE: The effect of large-scale disasters on bystander cardiopulmonary resuscitation (BCPR) performance is unknown. OBJECTIVE: To investigate whether and how large-scale earthquake and tsunami as well as subsequent nuclear pollution influenced BCPR performance for out-of-hospital cardiac arrest (OHCA) witnessed by family and friends/colleagues. DESIGN AND SETTING: Retrospective analysis of prospectively collected, nationwide, population-based data for OHCA cases. PARTICIPANTS: From the nationwide OHCA registry recorded between 11 March 2010 and 1 March 2013, we extracted 74 684 family-witnessed and friend/colleague-witnessed OHCA cases without prehospital physician involvement. EXPOSURE: Earthquake and tsunamis that were followed by nuclear pollution and largely affected the social life of citizens for at least 24 weeks. MAIN OUTCOME AND MEASURE: Neurologically favourable outcome after 1 month, 1-month survival and BCPR. METHODS: We analysed the 4-week average trend of BCPR rates in the years affected and before and after the disaster. We used univariate and multivariate logistic regression analyses to investigate whether these disasters affected BCPR and OHCA results. RESULTS: Multivariable logistic regression for tsunami-affected prefectures revealed that the BCPR rate during the impact phase in 2011 was significantly lower than that in 2010/2012 (42.5% vs 48.2%; adjusted OR; 95% CI 0.82; 0.68 to 0.99). A lower level of bystander compliance with dispatcher-assisted CPR instructions (62.1% vs 69.5%, 0.72; 95% CI 0.57 to 0.92) in the presence of a preserved level of voluntary BCPR performance (23.6% vs 23.8%) was also observed. Both 1-month survival and neurologically favourable outcome rates during the impact phase in 2011 were significantly poorer than those in 2010/2012 (8.5% vs 10.7%, 0.72; 95% CI 0.52 to 0.99, 4.0% vs 5.2%, 0.62; 95% CI 0.38 to 0.98, respectively). CONCLUSION AND RELEVANCE: A large-scale disaster with nuclear pollution influences BCPR performance and clinical outcomes of OHCA witnessed by family and friends/colleagues. Basic life-support training leading to voluntary-initiated BCPR might serve as preparedness for disaster and major accidents.

Association between the types of bystander cardiopulmonary resuscitation and the survival with good neurologic outcome of preschool pediatric out-of-hospital cardiac arrest cases in Japan: A propensity score matching analysis using an extended nationwide database.

Background: Pediatric out-of-hospital cardiac arrests (OHCAs) are frequently associated with a respiratory etiology. Despite the high proportion of preschool children with OHCAs, very few studies on this special population exist. This study characterizes the epidemiologic features of preschool pediatric OHCAs and analyzes the advantage of conventional (ventilations with chest compressions) bystander cardiopulmonary resuscitation (CPR) over compression-only bystander CPR (BCPR) on the one-month post-event neurological status of the patient. Methods: Japanese nationwide databases for all ambulance transport events and OHCAs occurring during a 4-year period between 2016 and 2019 were combined, totalling 3,608 patient events. Children ≤6-years-old were included; physician- and EMS-witnessed events, no prehospital resuscitation effort events, and neonatal patient events were excluded. Neurologically favorable 1-month survival rates were compared among groups using univariate and multivariate analyses before and after propensity score matching. Results: From the combined database, 2,882 pediatric OHCAs meeting selection criteria were categorized as no BCPR (984), compression-only BCPR (1,428), and conventional BCPR (470). The proportion of bystander-witnessed cases was low (22.3%). Most OHCA witnesses were family members (88.5%), and most OHCAs occurred at home (88.0%). The neurologically favorable 1-month survival rates were: no BCPR 2.4%, compression only, 3.2%, and conventional 6.6% (P < 0.01). Multivariate logistic regression analysis before and after matching showed that conventional BCPR was associated with higher neurologically favorable 1-month survival than compression-only BCPR. Subgroup analyses after matching demonstrated that conventional BCPR was associated with better outcomes in nonmedical (adjusted odds ratio; 95% confidence interval, 2.83; 1.09-7.32) and unwitnessed OHCA cases (3.42; 1.09-10.8). Conclusions: Conventional CPR is rarely performed by bystanders in preschool pediatric OHCA. However, conventional BCPR results in neurologically favorable outcomes in nonmedical and unwitnessed cases.

Seizure-like activity at the onset of emergency medical service-witnessed out-of-hospital cardiac arrest: An observational study.

AIMS: Emergency medical service (EMS) may detect seizure-like activity in addition to agonal breathing in out-of-hospital cardiac arrest (OHCA). This study investigates the incidence and predictors of seizure-like activity in nontraumatic, EMS-witnessed OHCA and their association with clinical outcomes. METHODS: This prospective study explored EMS-recorded concomitant signs/symptoms that lead to the requirement of advanced life support in patients with nontraumatic, EMS-witnessed OHCA. Seizure-like activity includes abnormal/tonic movements and eyeball deviation. Sudden OHCA was defined by the absence of signs/symptoms of impending cardiac arrest at EMS contact or progressive circulatory/respiratory depressions after the EMS contact. Neurologically favorable outcomes were defined as the cerebral performance category score of 1 or 2 at discharge. RESULTS: From April 2012 to March 2020, 465 patients were studied. The incidence of seizure-like activity at cardiac arrest onset was 12.7% (59/465) in all patients with nontraumatic, EMS-witnessed OHCA. Seizure-like activity was common during shockable initial rhythm; in patients with "sudden" OHCA; and in patients who were younger, male, or had a presumed cardiac etiology. In a boosting tree, shockable initial rhythm, "sudden" OHCA, and presumed cardiac etiology were major factors that predicted the incidence of seizure-like activity. Multivariate logistic regression models including and excluding OHCA characteristics revealed that both seizure-like activity and agonal breathing recorded during EMS-witnessed OHCA were associated with favorable outcomes. CONCLUSIONS: Seizure-like activity is a major sign/symptom of the onset of "sudden" cardiac arrest of presumed cardiac etiology, particularly in patients with shockable initial rhythms. Such activity were significantly associated with neurologically favorable outcomes.

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

AIM: 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. METHODS: We analysed 1,068 school-age children (6-18 years 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. RESULTS: 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. CONCLUSIONS: 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.

Prehospital Epinephrine as a Potential Factor Associated with Prehospital Rearrest.

Objective: To investigate the impact of epinephrine on prehospital rearrest and re-attainment of prehospital return of spontaneous circulation (ROSC). Methods: Data for 9,292 (≥ 8 years) out-of-hospital cardiac arrest (OHCA) patients transported to hospitals by emergency medical services were collected in Ishikawa Prefecture, Japan during 2010-2018. Univariate and multivariable analyses were retrospectively performed for 1,163 patients with prehospital ROSC. Results: Of 1,163 patients, rearrest occurred in 272 (23.4%) but not in 891 (76.6%). Both single and multiple doses of epinephrine administered before prehospital ROSC (adjusted odds ratio (OR): 3.62, 95% confidence interval (CI): 2.42-5.46 for 1 mg, and 4.27, 2.58-6.79 for ≥ 2 mg) were main factors associated with rearrest. The association between initial and rearrest rhythms was significantly associated with epinephrine administration (p = 0.02). However, the rearrest rhythm was primarily associated with the initial rhythm (p < 0.01). The majority of patients with the non-shockable initial rhythm had pulseless electrical activity (PEA) as the rearrest rhythm, regardless of epinephrine administration (80.4% for administration, 81.6% for no administration). When the initial rhythm was shockable, the primary rearrest rhythms in patients with and without epinephrine administration before prehospital ROSC were PEA (52.2%) and ventricular fibrillation/pulseless ventricular tachycardia (56.8%), respectively. Only epinephrine administration after rearrest was associated with prehospital re-attainment of ROSC (adjusted OR: 2.49, 95% CI: 1.20-5.19). Stepwise multivariable logistic regression analyses revealed that neurologically favorable outcome was poorer in patients with rearrest than those without rearrest (9.9% vs. 25.0%, adjusted OR: 0.42, 95% CI: 0.23-0.73). The total prehospital doses of epinephrine were associated with poorer neurological outcome in a dose-dependent manner (adjusted OR: 0.22, 95% CI: 0.13-0.36 for 1 mg; 0.09, 0.04-0.19 for 2 mg; 0.03, 0.01-0.09 for ≥ 3 mg, no epinephrine as a reference). Transportation to hospitals with a unit for post-resuscitation care was associated with better neurological outcome (adjusted OR: 1.53, 95% CI: 1.02-2.32). Conclusions: The requirement for epinephrine administration before prehospital ROSC was associated with subsequent rearrest. Routine epinephrine administrations and rearrest were associated with poorer neurological outcome of OHCA patients with prehospital ROSC.

Association of school hours with outcomes of out-of-hospital cardiac arrest in schoolchildren.

OBJECTIVE: To investigate the association of school hours with outcomes of schoolchildren with out-of-hospital cardiac arrest (OHCA). METHODS: From the 2005-2014 nationwide databases, we extracted the data for 1660 schoolchildren (6-17 years) with bystander-witnessed OHCA. Univariate analyses followed by propensity-matching procedures and stepwise logistic regression analyses were applied. School hours were defined as 08:00 to 18:00. RESULTS: The neurologically favourable 1-month survival rate during school hours was better than that during non-school hours only on school days: 18.4% and 10.5%, respectively. During school hours on school days, patients with OHCA more frequently received bystander cardiopulmonary resuscitation (CPR) and public access defibrillation (PAD), and had a shockable initial rhythm and presumed cardiac aetiology. The neurologically favourable 1-month survival rate did not significantly differ between school hours on school days and all other times of day after propensity score matching: 16.4% vs 16.1% (unadjusted OR 1.02; 95% CI 0.69 to 1.51). Stepwise logistic regression analysis during school hours on school days revealed that shockable initial rhythm (adjusted OR 2.44; 95% CI 1.12 to 5.42), PAD (adjusted OR 3.32; 95% CI 1.23 to 9.10), non-exogenous causes (adjusted OR 5.88; 95% CI 1.85 to 20.0) and a shorter emergency medical service (EMS) response time (adjusted OR 1.15; 95% CI 1.02 to 1.32) and witness-to-first CPR interval (adjusted OR 1.08; 95% CI 1.01 to 1.15) were major factors associated with an improved neurologically favourable 1-month survival rate. CONCLUSIONS: School hours are not an independent factor associated with improved outcomes of OHCA in schoolchildren. The time delays in CPR and EMS arrival were independently associated with poor outcomes during school hours on school days.

Assessing the efficacy of the new protocol for chest compressions before definitive cardiac arrest in emergency medical service-witnessed adult out-of-hospital cardiac arrests.

AIMS: Japanese emergency medical services (EMS) personnel providing advance life support confirm the absence of a carotid pulse before initiating chest compressions (CCs) in adult out-of-hospital cardiac arrest (OHCA). This study aims to investigate the efficacy of a new protocol facilitating early CCs before definitive cardiac arrest in enhancing the outcomes of OHCA. METHODS: The 2011 new protocol facilitated EMS to initiate CCs when the carotid pulse was weak and/or <50/min in comatose adult patients with respiratory arrest (apnoea or agonal breathing) and loss of the radial pulse. During 2008-2015, we compared the neurologically favourable 1-year survival rate of EMS-witnessed OHCA and EMS-confirmed out-of-hospital respiratory arrest (OHRA) in adults before (N = 257 and 34, respectively) and after (N = 255 and 54, respectively) the implementation of the new protocol. RESULTS: After the new protocol, EMS initiated CCs >1.5 min before definitive cardiac arrest in 31% (80/255) and 33% (18/54) of EMS-witnessed OHCA and EMS-confirmed OHRA, respectively. While the new protocol was not significantly associated with survival of EMS-confirmed OHRA, it was significantly associated with survival of EMS-witnessed OHCA: 9.0% and 14.9%, before and after, P by univariate analysis <0.03; adjusted OR (95% CI) by multivariable logistic regression analysis, 2.01 (1.04-3.90). Neither early start of CCs nor the new protocol was associated with the progression to cardiac arrest in 212 cases with impending cardiac arrest. CONCLUSIONS: A new EMS protocol facilitating early CCs before definitive cardiac arrest was associated with higher survival of EMS-witnessed OHCA.

Temporal variations in dispatcher-assisted and bystander-initiated resuscitation efforts.

PURPOSE: To investigate temporal variations in dispatcher-assisted and bystander-initiated resuscitation efforts and their association with survival after bystander-witnessed out-of-hospital cardiac arrests (OHCAs). METHODS: We retrospectively analyzed the neurologically favorable 1-month survival and the parameters related to dispatcher assisted cardiopulmonary resuscitation (DA-CPR) and bystander CPR (BCPR) for 227,524 OHCA patients between 2007 and 2013 in Japan. DA-CPR sensitivity for OHCAs, bystander's compliance to DA-CPR assessed by the proportion of bystanders who follow DA-CPR, and performance of BCPR measured by the rate of bystander-initiated CPR in patients without DA-CPR were calculated as indices of resuscitation efforts. RESULTS: Performance of BCPR was only similar to temporal variations in the survival (correlation between hourly paired values, R2=0.263, P=0.01): a lower survival rate (3.4% vs 4.2%) and performance of BCPR (23.1% vs 30.8%) during night-time (22:00-5:59) than during non-night-time. In subgroup analyses based on interaction tests, all three indices deteriorated during night-time when OHCAs were witnessed by non-family (adjusted odds ratio, 0.73-0.82), particularly in non-elderly patients. The rate of public access defibrillation for these OHCAs markedly decreased during night-time (adjusted odds ratio, 0.49) with delayed emergency calls and BCPR initiation. Multivariable logistic regression analyses revealed that the survival rate of non-family-witnessed OHCAs was 1.83-fold lower during night-time than during non-night-time. CONCLUSIONS: Dispatcher-assisted and bystander-initiated resuscitation efforts are low during night-time in OHCAs witnessed by non-family. A divisional alert system to recruit well-trained individuals is needed in order to improve the outcomes of night-time OHCAs witnessed by non-family bystanders.

Poor outcomes of out-of-hospital cardiac arrest at dinnertime in the elderly: Diurnal and seasonal variations.

PURPOSE: To investigate differences in chronological variations in characteristics and outcomes of out-of-hospital cardiac arrests (OHCAs) between elderly and non-elderly patients. METHODS: We retrospectively analyzed bystander-witnessed OHCAs without prehospital involvement of physicians between January 2007 and December 2014 in Japan. We considered the following time periods: night-time (23:00-5:59) and non-night-time; we further divided non-night-time into dinnertime (18:00-20:29) and other non-night-time. Subsequently, we analyzed chronological variations in factors associated with OHCA survival using univariate and multivariable logistic regression analyses for unmatched and propensity-matched pairs, respectively. RESULTS: For elderly (≥65 years old, N = 201,073) and non-elderly (≥10, <65 years old, N = 57,124) OHCA patients, survival rates were lower during night-time than during non-night-time (elderly, 2.8% vs 1.6%; non-elderly, 9.8% vs 7.7%). The trend for incidences of bystander-witnessed OHCA in the elderly showed three peaks associated with breakfast-time, lunchtime, and dinnertime. However, a transient but considerable decrease in survival rates was observed at dinnertime (1.9% at dinnertime and 3.0% during other non-night-time). OHCAs in the elderly at dinnertime were characterized by low proportions of presumed cardiac etiologies and shockable initial rhythm. However,even after adjusting for these and other factors associated with survival,survival rates were significantly lower at dinnertime than during other non-night-time for elderly OHCA patients (adjusted odds ratio, 1.29; 95% confidence interval, 1.18-1.41, with dinnertime as reference). This difference was significant even after propensity matching with significant augmentation in winter. CONCLUSIONS: Dinnertime, particularly in winter, is associated with lower survival in elderly OHCA patients.

The impact of prehospital assessment and EMS transport of acute aortic syndrome patients.

BACKGROUND: The quality of acute aortic syndrome (AAS) assessment by emergency medical service (EMS) and the incidence and prehospital factors associated with 1-month survival remain unclear. METHODS: We retrospectively analyzed the data collected for 94,468 patients with non-traumatic medical emergency excluding out-of-hospital cardiac arrest during the period of 2011-2014. RESULTS: Of these transported by EMS, 22,075 had any of the AAS-related symptoms, and 330 had an EMS-assessed risk for AAS; of these, 195 received an in-hospital AAS diagnosis. Of the remaining 21,745 patients without EMS-assessed risk, 166 were diagnosed with AAS. Therefore, the sensitivity and specificity of our EMS-risk assessment for AAS was 54.0% (195/361) and 99.4% (21,579/21,714), respectively. EMS assessed the risk less frequently when patients were elderly and presented with dyspnea and syncope/faintness. Sign of upper extremity ischemia was rarely detected (6.9%) and absence of this sign was associated with lack of EMS-assessed risk. The calculation of modified aortic dissection detection risk score revealed that rigorous assessment based on this score may increase the EMS sensitivity for AAS. The 1-month survival rate was significantly higher in patients admitted to core hospitals with surgical teams for AAS than in those admitted to all other hospitals [87.5% (210/240) vs 69.4% (84/121); P<0.01]. Multiple logistic regression analysis demonstrated that Stanford type A, Glasgow coma scale ≤14, and admission to core hospitals providing emergency cardiovascular surgery were associated with 1-month survival. CONCLUSIONS: Improvement of AAS survival is likely to be affected by rapid admission to appropriate hospitals providing cardiovascular surgery.

Augmented survival of out-of-hospital cardiac arrest victims with the use of mobile phones for emergency communication under the DA-CPR protocol getting information from callers beside the victim.

PURPOSE: To investigate the impacts of emergency calls made using mobile phones on the quality of dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) and survival from out-of-hospital cardiac arrests (OHCAs) that were not witnessed by emergency medical service (EMS). METHODS: In this prospective study, we collected data for 2530 DA-CPR-attempted medical emergency cases (517 using mobile phones and 2013 using landline phones) and 2980 non-EMS-witnessed OHCAs (600 using mobile phones and 2380 using landline phones). Time factors and quality of DA-CPR, backgrounds of callers and outcomes of OHCAs were compared between mobile and landline phone groups. RESULTS: Emergency calls are much more frequently placed beside the arrest victim in mobile phone group (52.7% vs. 17.2%). The positive predictive value and acceptance rate of DA-CPR in mobile phone group (84.7% and 80.6%, respectively) were significantly higher than those in landline group (79.2% and 70.9%). The proportion of good-quality bystander CPR in mobile phone group was significantly higher than that in landline group (53.5% vs. 45.0%). When analysed for all non-EMS-witnessed OHCAs, rates of 1-month survival and 1-year neurologically favourable survival in mobile phone group (7.8% and 3.5%, respectively) were higher than those in landline phone group (4.6% and 1.9%; p<0.05). Multiple logistic regression analysis, including other backgrounds, revealed that mobile phone calls were associated with increased 1-month survival in the subgroup of OHCAs receiving bystander CPR (adjusted odds ratio, 1.84; 95% CI, 1.15-2.92). CONCLUSION: Emergency calls made using mobile phones are likely to augment the survival from OHCAs by improving DA-CPR.

Recruitments of trained citizen volunteering for conventional cardiopulmonary resuscitation are necessary to improve the outcome after out-of-hospital cardiac arrests in remote time-distance area: A nationwide population-based study.

AIMS: To compare the factors associated with survival after out-of-hospital cardiac arrests (OHCAs) among three time-distance areas (defined as interquartile range of time for emergency medical services response to patient's side). METHODS: From a nationwide, prospectively collected data on 716,608 OHCAs between 2007 and 2012, this study analyzed 193,914 bystander-witnessed OHCAs without pre-hospital physician involvement. RESULTS: Overall neurologically favourable 1-month survival rates were 7.4%, 4.1% and 1.7% for close, intermediate and remote areas, respectively. We classified BCPR by type (compression-only vs. conventional) and by dispatcher-assisted CPR (DA-CPR) (with vs. without); the effects on time-distance area survival were analyzed by BCPR classification. Association of each BCPR classification with survival was affected by time-distance area and arrest aetiology (p<0.05). The survival rates in the remote area were much higher with conventional BCPR than with compression-only BCPR (odds ratio; 95% confidence interval, 1.26; 1.05-1.51) and with BCPR without DA-CPR than with BCPR with DA-CPR (1.54; 1.29-1.82). Accordingly, we classified BCPR into five groups (no BCPR, compression-only with DA-CPR, conventional with DA-CPR, compression-only without DA-CPR, and conventional without DA-CPR) and analyzed for associations with survival, both cardiac and non-cardiac related, in each time-distance area by multivariate logistic regression analysis. In the remote area, conventional BCPR without DA-CPR significantly improved survival after OHCAs of cardiac aetiology, compared with all the other BCPR groups. Other correctable factors associated with survival were short collapse-to-call and call-to-first CPR intervals. CONCLUSION: Every effort to recruit trained citizens initiating conventional BCPR should be made in remote time-distance areas.