Nationwide public-access defibrillation in Japan

Early versus late administration of adrenaline in pediatric patients with out-of-hospital cardiac arrest

OBJECTIVES

Optimal timing of adrenaline administration in pediatric out-of-hospital cardiac arrest (OHCA) is unclear. We aimed to evaluate the impact of early versus late adrenaline administration on survival and neurological outcomes at one month in children experiencing OHCA with non-shockable rhythm.

METHODS

This study is retrospective cohort study. Here we utilized the Japanese Association for Acute Medicine OHCA registry, focusing on children under 18 years who received adrenaline during non-shockable rhythm cardiac arrest. We performed a risk-set matching analysis with a time-dependent propensity score to address resuscitation time bias. We categorized adrenaline administration as early (within 20 min of emergency medical service personnel contact) or late (after 20 min). We set our primary and secondary outcomes as survival and favorable neurological outcomes at one month after cardiac arrest, respectively.

RESULTS

Of the 701 eligible patients, 300 received adrenaline early. Early versus late adrenaline administration in the risk-set matched cohort of 600 patients did not yield significant differences in survival (risk ratio [RR] 0.98 [95% confidence interval (CI) 0.95-1.01]) or favorable neurological outcome (RR 1.00 [95% CI 0.99-1.00]) at one month. However, in a subgroup analysis of patients with witnessed cardiac arrest, early adrenaline administration appeared to be associated with improved one month survival (RR 0.91 [95% CI 0.85-0.98]).

CONCLUSIONS

Early adrenaline administration in pediatric OHCA was not associated with overall one month survival or neurologic outcome.

Association Between Response Time and Time from Emergency Medical Service Contact with the Patient to Hospital Arrival as well as Survival and Neurological Outcomes in Pediatric Out-of-Hospital Cardiac Arrest

OBJECTIVES

In out-of-hospital cardiac arrest (OHCA), prehospital time is crucial and can be divided into response time, from emergency call to emergency medical service (EMS) contact, and time from EMS contact to hospital arrival. To improve prehospital strategies for pediatric OHCA, it is essential to understand the association between these time intervals and patient outcomes; however, detailed investigations are lacking. The current study aimed to examine the association between response time and time from EMS contact to hospital arrival as well as survival and neurological outcomes in pediatric OHCA.

METHODS

This nationwide retrospective analysis used data from an OHCA registry in Japan between June 2014 and December 2021. Pediatric patients aged <18 years who had OHCA were included in the analysis. The primary outcome was 1-month survival, and the secondary outcome was 1-month favorable neurological outcome. Generalized additive model analyses and logistic regression analyses, adjusted for confounders, were performed to examine the non-linear and linear relationship between response time and patient care time (time from EMS contact with the patient to hospital arrival) and outcomes, respectively.

RESULTS

In the generalized additive model analyses of response time, both survival and neurological outcomes worsened with response time, with outcomes appearing to further decline with a response time of approximately 15 min. On the other hand, there was a linear association between patient care time as well as 1-month survival and favorable neurologic outcomes. In logistic regression analyses, shorter response times were significantly associated with survival (odds ratio [OR]: 0.83, 95% confidence interval [CI]: 0.79-0.91]) and a favorable neurological outcome (OR: 0.75, 95% CI: 0.59-0.93). In contrast, time from EMS contact to hospital arrival was not significantly associated with survival (OR: 0.99, 95% CI: 0.97-1.02) and favorable neurological outcomes (OR: 1.02, 95% CI: 0.97-1.07).

CONCLUSIONS

A response time of <15 min can be associated with better survival and neurological outcomes. However, there is no significant association between time from EMS contact to hospital arrival as well as survival and favorable neurological outcomes.

Association between increasing institutional experience with ECPR and outcomes in patients with out-of-hospital cardiac arrest: A nationwide multicenter observational study in Japan (the JAAM-OHCA registry)

AIM

To determine the association between institutional experience with extracorporeal cardiopulmonary resuscitation (ECPR) and outcomes after out-of-hospital cardiac arrest (OHCA).

METHODS

We analyzed data from the JAAM-OHCA registry, a nationwide multicenter database containing information on patients who experienced OHCA in Japan between June 2014 and December 2020. The study population consisted of patients with OHCA who were in cardiac arrest on hospital arrival and treated with extracorporeal membrane oxygenation (ECMO). Each patient was assigned a sequential number based on the order of initiation of ECPR at each facility. The primary outcome was 30-day survival and the secondary outcome was the interval between hospital admission and initiation of ECMO.

RESULTS

Data for a total of 2,315 patients with OHCA and cardiac arrest on hospital arrival who were treated with ECPR at any of 87 facilities were analyzed. On admission, 1,047 patients had shockable rhythm and 1,268 had non-shockable rhythm. The 30-day survival rate was not significantly associated with the accumulated case volume of ECPR. The interval between hospital arrival and initiation of ECMO decreased significantly with increasing experience of ECPR (p < 0.001, Jonckheere-Terpstra test). In non-shockable cases, 30-day survival tended to improve with increasing experience of ECPR (p = 0.04, Cochran-Armitage trend test).

CONCLUSION

Increasing institutional experience of ECPR did not significantly improve 30-day survival after OHCA but was associated with a shorter interval between hospital arrival and initiation of ECMO. In patients with non-shockable OHCA, increasing experience of ECPR improved 30-day survival. (246/250 words).

Impact of epinephrine on neurological outcomes in out-of-hospital cardiac arrest after automated external defibrillator use in Japan

OHCA (out-of-hospital cardiac arrest) patients have improved neurological outcomes with public-access automated external defibrillator (PAD) use. However, the benefit of epinephrine administration after PAD use remains controversial. The purpose of the study was to investigate the impact of epinephrine administration on neurological outcomes in OHCA patients after PAD use. This study assessed 2,059,417 patients from the All-Japan Utstein Registry between 2005 and 2021. Patients were categorized into two groups: shockable and non-shockable rhythms on emergency medical service (EMS) arrival. Propensity score matching was used to adjust for various confounders and to analyze the impact of epinephrine administration on one-month favorable neurological outcomes. Criteria for bystander PAD was met by 11,629 (0.56%) of the enrolled patients. The mean age was 70 years with 71.9% male. Among them, 38.6% had shockable rhythms and 61.4% had non-shockable rhythms. After the matching, epinephrine administration negatively affected one-month favorable neurological outcome in patients with both shockable (14.7% vs. 41.1%, OR = 0.24, 95% CI = 0.19-0.31) and non-shockable rhythms (3.6% vs. 10.8%, OR = 0.31, 95% CI = 0.23-0.42). These findings suggest that epinephrine administration did not improve neurological outcomes in patients with OHCA after PAD use, providing insights to optimize EMS protocols for OHCA.

Characteristics, outcomes, and prognostic factors in patients with hanging-induced out-of-hospital cardiac arrest: An analysis of a nationwide registry in Japan

AIM

To investigate the characteristics, outcomes, and prognostic factors of patients with hanging-induced out-of-hospital cardiac arrest (OHCA).

METHODS

We analysed data from a population-based Japanese nationwide OHCA registry (2021-2022), comparing patients aged ≥18 years with hanging-induced OHCA to those with other OHCA causes. The primary outcome was 1-month favourable neurological outcomes. Prognostic factors for hanging-induced OHCA were identified using multivariable logistic regression analysis.

RESULTS

Of 263,426 OHCAs, 7,878 (3.0 %) were hanging-induced, with an incidence of 3.1 per 100,000 person-years. Patients with hanging-induced OHCA were younger (median age; 58 vs. 81 years), more frequently males (60.2 % vs. 57.5 %), and less likely to have a witness (1.7 % vs. 42.1 %) and initial shockable rhythm (0.4 % vs. 5.9 %). The chance of 1-month favourable neurological outcomes was significantly lower in patients with hanging-induced OHCA than those with other OHCA causes (0.4 % vs. 2.5 %). Factors associated with favourable neurological outcomes included younger age, witnessed arrest, initial non-asystole cardiac rhythm, and prehospital return of spontaneous circulation (ROSC). Patients with initial non-asystole rhythm and prehospital ROSC had an 11.1 % probability of favourable neurological outcomes, whereas 97.1 % of patients lacking these characteristics had only a 0.1 % probability.

CONCLUSIONS

Prognosis following hanging-induced OHCAs was significantly worse compared to OHCAs of other causes. While some patients with initial non-asystole rhythm and prehospital ROSC may benefit from cardiopulmonary resuscitation, most lack these favourable features and have an exceedingly low chance of achieving favourable neurological outcomes at 1-month post-arrest.

Duration of prehospital and in-hospital cardiopulmonary resuscitation and neurological outcome in paediatric out-of-hospital cardiac arrest

BACKGROUND

Because of their young age and lack of known comorbidities, paediatric patients with out-of-hospital cardiac arrest (OHCA) often undergo prolonged cardiopulmonary resuscitation (CPR). We aimed to determine the association between prehospital and in-hospital CPR duration and neurological outcomes.

METHODS

We conducted a retrospective analysis of data from the Japanese Association for Acute Medicine-OHCA Registry for patients <18 years of age with OHCA between June 2014 and December 2019. All patients received prehospital CPR by emergency medical service (EMS). The aetiologies of arrest included traumatic and atraumatic causes. The primary outcome measure was a 1-month neurological outcome of moderate disability or better (Pediatric Cerebral Performance Category 1-3). We calculated the dynamic probability and cumulative proportion of 1-month moderate disability or better neurological outcomes. Dynamic probability calculates patient outcomes during CPR per min. We performed multivariate logistic regression analysis to explore the association between longer CPR duration (as an ordinal variable) and 1-month poorer neurological outcomes.

RESULTS

Among 1007 eligible children, 252 achieved return of spontaneous circulation and 53 had a 1-month moderate disability or better neurological outcome. The dynamic probability of a 1-month moderate disability or better neurological outcome dropped below 0.01 at 64 min (0.005, 95% CI 0.001 to 0.017). The cumulative proportion of a 1-month moderate disability or better neurological outcome exceeded 0.99 at 68 min (1, 95% CI 1 to 1). With increasing CPR time from CPR initiation by EMS, both crude and adjusted ORs for 1-month neurological outcomes gradually decreased.

CONCLUSION

Using a large Japanese database of paediatric OHCA patients, we found that longer CPR duration was associated with a lower likelihood of a 1-month moderate disability or better neurological outcome. Less than 1% of paediatric patients exhibited 1-month moderate disability or better neurological outcomes when total CPR duration is more than 64 min.

Resuscitation Attempt and Outcomes in Patients With Asystole Out-of-Hospital Cardiac Arrest

Importance

Little is known about the epidemiology of out-of-hospital cardiac arrest (OHCA) in patients with asystole in countries where prehospital resuscitation is not withheld or terminated.

Objective

To investigate the secular trends in the patient outcomes and advanced life support (ALS) procedures and evaluate the association of ALS procedures with favorable outcomes among patients with OHCA and asystole.

Design, Setting, and Participants

This cohort study analyzed data from a nationwide prospective OHCA registry in Japan. OHCA occurred from June 1, 2014, to December 31, 2020. Adults with an initial rhythm of asystole and OHCA were included in the analysis, which was conducted between July 29, 2022, and August 24, 2024.

Exposures

Year of OHCA and prehospital ALS procedures (advanced airway management [AAM] and intravenous epinephrine administration).

Main Outcomes and Measures

Trends in prehospital and in-hospital ALS procedures and patient outcomes were described using the Jonckheere-Terpstra trend test for continuous variables and the Cochran-Armitage trend test for categorical variables. The primary outcome was a favorable neurological outcome at 30 days. The secondary outcomes included a favorable neurological outcome at 90 days and survival at 30 and 90 days. Associations between prehospital procedures and outcomes were analyzed using time-dependent propensity score and risk-set matching.

Results

Of 60 349 patients with OHCA, 35 843 (59.4%) presented with asystole (median age, 77 [IQR, 64-85] years; 20 573 [57.4%] men). Among these, 33 674 patients (93.9%) underwent ALS procedures, with 67 (0.2%) achieving a favorable neurological outcome at 30 days. No significant trends in the outcomes were noted, except for a decline in return of spontaneous circulation (424 of 1848 [22.9%] to 1178 of 5892 [20.0%]; P = .003). Neither AAM (odds ratio [OR], 1.27 [95% CI, 0.76-2.12]; P = .36) nor intravenous epinephrine administration (OR, 0.53 [95% CI, 0.24-1.13]; P = .10) was associated with a favorable neurological outcome at 30 days, although both were associated with survival at 30 days (ORs, 1.45 [95% CI, 1.21-1.74] and 1.81 [95% CI, 1.44-2.27], respectively; P < .001 for both).

Conclusions and Relevance

In this cohort study of patients with OHCA presenting with asystole, the proportion with a favorable neurological outcome at 30 days was substantially low, and no prehospital ALS procedure was associated with a favorable neurological outcome. These findings suggest that discussions regarding implementation of a termination of resuscitation rule for such patients are warranted.

Bystanders' willingness to assist using automated external defibrillators during cardiac arrest

The "bystander effect," in which the presence of others inhibits rescue actions, has not been specifically examined in the context of cardiac arrest; understanding this effect in relation to rescue with automated external defibrillators (AEDs) is important. This study aims to identify the presence of others as a factor inhibiting rescue actions using an AED, from a social psychology perspective. We collected data through a web-based questionnaire involving registered residents in all 47 prefectures of Japan. The participants were presented with hypothetical scenarios of witnessing cardiac arrest events at train stations, under sparse or crowded conditions, and with or without the presence of competent parties (e.g., station staff or security guards). Their willingness to intervene was assessed across three levels of rescue behavior: (1) running and calling for help, (2) retrieving an AED, and (3) using an AED. This study found evidence of the bystander effect, indicating that the presence of competent others reduced behavioral interventions by bystanders during out-of-hospital cardiac arrest (OHCA) events. Moreover, the perceived presence of competent parties at the scene of a cardiac arrest reduced bystanders' willingness to initiate rescue under certain circumstances. While many bystanders were willing to initiate rescue efforts in response to calls for help, they resisted rescues involving an AED. This study observes that a bystander effect occurs among bystanders witnessing OHCA, explores the inhibiting effects of identifying competent parties on the initiation of rescue efforts, and suggests that there are significant invisible barriers to using AEDs in rescuing patients with OHCA.

Incidence, risk factors, and impact of post-return of spontaneous circulation events in patients with out-of-hospital cardiac arrest: A population-based study in Tokyo, Japan

AIM

Patients with the return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA) are unstable and often experience rearrest, after which ROSC may be reattained. This study investigated the incidence and risk factors of post-ROSC events (rearrest and subsequent reattainment of ROSC) and their impact on outcomes in patients with prehospital ROSC following OHCA.

METHODS

Patients with OHCA and prehospital ROSC were identified from the Tokyo Fire Department database between 1 January 2018 and 31 December 2022. The factors associated with post-ROSC events and their impact on 1-month favourable neurological outcome (cerebral performance category scale: 1 or 2) were assessed using multivariable logistic regression analysis.

RESULTS

Overall, 64,000 individuals experienced OHCA, and 6,190 (9.7%) had ROSC. Rearrest was confirmed in 28.4% of patients with ROSC, and was associated with age, time of emergency call, location of cardiac arrest, dispatcher instruction regarding cardiopulmonary resuscitation, first recorded cardiac rhythm, bystander cardiopulmonary resuscitation, defibrillation by a bystander, response time, and prehospital interventions. ROSC reattainment was confirmed in 34.5% of patients with rearrest and associated with the first recorded cardiac rhythm and defibrillation by a bystander. Patients without rearrests had the highest proportion of favourable neurological outcomes, followed by those with solved and unsolved rearrests (38.6% vs. 22.4% and 4.4%, P < 0.001). The difference remained significant after adjustment for confounders.

CONCLUSION

This study revealed population-based incidence and risk factors of post-ROSC events. Rearrest was common, leading to unfavourable neurological outcome; however, its deleterious impact may be mitigated by successful resuscitation efforts.

The ABC (Age, Bystander, and Cardiogram) score for predicting neurological outcomes of cardiac arrests without pre-hospital return of spontaneous circulation: A nationwide population-based study

Aim

We previously proposed the ABC score to predict the neurological outcomes of cardiac arrest without prehospital return of spontaneous circulation (ROSC). Using nationwide population-based data, this study aimed to validate the ABC score through various resuscitation guideline periods.

Methods

We analysed cases with cardiac arrest due to internal causes and failure to achieve prehospital ROSC in the All-Japan Utstein Registry. Patients from the 2007-2009, 2012-2014, and 2017-2019 periods were classified into the 2005, 2010, and 2015 guideline groups, respectively. Neurological outcomes were assessed using cerebral performance categories (CPCs) one month after the cardiac arrest. We defined CPC 1-2 as a favourable outcome. We evaluated the test characteristics of the ABC score, which could range from 0 to 3.

Results

Among the 162,710, 186,228, and 190,794 patients in the 2005, 2010, and 2015 guideline groups, 0.7%, 0.8%, and 0.9% of the patients had CPC 1-2, respectively. The proportions of CPC 1-2 were 2.9%, 3.6%, and 4.6% in patients with ABC scores of 2 and were 9.5%, 13.3%, and 16.8% in patients with ABC scores of 3, respectively. Among patients with ABC scores of 0, 0.2%, 0.1%, and 0.2%, all had CPC 1-2, respectively. The areas under the receiver operating characteristic curves for the ABC score were 0.798, 0.822, and 0.828, respectively.

Conclusions

The ABC score had acceptable discrimination for neurological outcomes in patients without prehospital ROSC in the three guideline periods.

Long-Term Impact of the Kumamoto Earthquake on Out-of-Hospital Cardiac Arrest With Cardiac and Non-Cardiac Origins - An Interrupted Time Series Analysis

BACKGROUND

Possible etiologies of out-of-hospital cardiac arrest (OHCA), including aortic dissection, ruptured aortic aneurysms, and pulmonary embolism, may be classified as non-cardiac causes. We investigated whether cardiac and non-cardiac OHCAs increased following the Kumamoto earthquake and whether the impact on OHCAs extended to regions far from the epicenter.

METHODS AND RESULTS

We prospectively analyzed a nationwide registry of patients who experienced OHCAs between January 2013 and December 2019. Data from cases registered in 7 prefectures, including Kumamoto (Kyushu region; n=82,060), in the All-Japan Utstein Registry were analyzed for OHCAs of cardiac and non-cardiac origin. The numbers of OHCAs before and after the Kumamoto earthquake were compared using an interrupted time series analysis. The incidence of both cardiac (rate ratio [RR] 1.22) and non-cardiac (RR 1.27) OHCAs in Kumamoto Prefecture increased after the earthquake. The difference disappeared when the analysis was limited to patients with non-cardiac OHCAs with a clear cause of cardiac arrest. The number of cardiac and non-cardiac OHCAs did not increase in other prefectures within the Kyushu region.

CONCLUSIONS

The Kumamoto earthquake led to an increase in the incidence of cardiac and non-cardiac OHCAs. However, this was attenuated by increasing distance from the epicenter. Except for cardiac causes, cases complicated by earthquake-related events may include non-cardiac OHCAs due to vascular diseases that might be overlooked.

Left-digit bias in out-hospital cardiac arrest: The JCS-ReSS study

INTRODUCTION

The left-digit bias (LDB), a numerical-related cognitive bias, not only potentially influences decision-making among the general public but also that of medical practitioners. Few studies have investigated its role in out-of-hospital cardiac arrest (OHCA).

METHODS

We retrospectively included all consecutive patients with OHCA witnessed by family members registered in the All-Japan Utstein Registry of the Fire and Disaster Management Agency between January 1, 2005, and December 31, 2020. Target outcomes were the percentage of bystander cardiopulmonary resuscitation (BCPR) performed by family members or paramedics and the percentage of prehospital physician-staffed advanced cardiac life support (ACLS). Using a nonparametric regression discontinuity methodology, we examined whether a significant change occurred in the percentages of BCPR and ACLS at the age thresholds of 60, 70, 80, and 90 years, which would indicate the presence of LDB.

RESULTS

Of the 1,930,273 OHCA cases in the All-Japan Utstein Registry, 384,200 (19.9%) cases witnessed by family members were analyzed. The mean age was 75.8 years (±SD 13.7), with 38.0% (n = 146,137) female. We identified no discontinuities in the percentages of chest compressions, mouth-to-mouth ventilation, or automated external defibrillator (AED) usage by family members for the age thresholds of 60, 70, 80, and 90 years. Moreover, no discontinuities existed in the percentages of chest compressions, advanced airway management, and AED usage by paramedics or prehospital ACLS by physicians for any of the age thresholds.

CONCLUSIONS

In conclusion, our study did not find any evidence that age-related LDB affects medical decision-making in patients with OHCA.

Early versus late advanced airway management for adult patients with out-of-hospital cardiac arrest: A time-dependent propensity score-matched analysis

OBJECTIVE

The objective was to investigate whether early advanced airway management during the entire resuscitation period is associated with favorable neurological outcomes and survival in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

We performed a retrospective cohort study of patients with OHCA aged ≥18 years enrolled in OHCA registry in Japan who received advanced airway management during cardiac arrest between June 2014 and December 2020. To address resuscitation time bias, we performed risk set matching analyses in which patients who did and did not receive advanced airway management were matched at the same time point (min) using the time-dependent propensity score; further, we compared early (≤10 min) and late (>10 min) advanced airway management. The primary and secondary outcome measures were favorable neurological outcomes using Cerebral Performance Category scores and survival at 1 month after cardiac arrest.

RESULTS

Of the 41,101 eligible patients, 21,446 patients received early advanced airway management. Thus, risk set matching was performed with a total of 42,866 patients. In the main analysis, early advanced airway management was significantly associated with favorable neurological outcomes (risk ratio [RR] 0.997, 95% confidence interval [CI] 0.995-0.999) and survival (RR 0.990, 95% CI 0.986-0.994) at 1 month after cardiac arrest. In the sensitivity analysis with early advanced airway management defined as ≤5 min and ≤20 min, the results were comparable.

CONCLUSIONS

Although early advanced airway management was statistically significant for improved neurological outcomes and survival at 1 month after cardiac arrest, the RR was very close to 1, indicating that the timing of advanced airway management has minimal impact on clinical outcomes, and decisions should be made based on the individual needs of the patient.

Neurological prognosis prediction upon arrival at the hospital after out-of-hospital cardiac arrest: R-EDByUS score

AIM

To develop a new scoring model for patients with cardiogenic out-of-hospital cardiac arrest (OHCA) to facilitate neurological prognosis prediction upon hospital arrival by using prehospital resuscitation features alone.

METHODS

Between 2005 and 2019, we enrolled 942,891 adult patients with OHCA of presumed cardiac aetiology from the All-Japan Utstein Registry. Scoring models applied prehospital resuscitation features a priori from the variables the American College of Cardiology algorithm including age, duration to return of spontaneous circulation (ROSC) or hospital arrival, no bystander cardiopulmonary resuscitation (CPR), unwitnessed arrest, and nonshockable rhythm (R-EDByUS score) to predict unfavorable neurological outcomes defined as Cerebral Performance Category 3, 4, or 5 at 1 month. We created nomograms as a "Regression-based model," and created a "Simplified model" in which points were assigned by category for predicting unfavorable neurological outcomes for both the prehospital ROSC cohort (67,064 patients) and the ongoing CPR cohort (875,827 patients). For internal validation, bootstrap optimism-corrected estimates of predictive performance were calculated.

RESULTS

A total of 46,971 (70.0%) and 870,991 (99.4%) patients in the prehospital ROSC and ongoing CPR cohorts, respectively, had unfavorable neurological outcomes. In the prehospital ROSC cohort, the C-statistics of the Regression-based and Simplified models were 0.851 and 0.842, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively. In the ongoing CPR cohort, the C-statistics of the Regression-based and Simplified models were 0.872 and 0.865, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively.

CONCLUSIONS

The R-EDByUS score accurately predicted the neurological prognosis of cardiogenic OHCA upon hospital arrival.

Association between sub-phenotypes identified using latent class analysis and neurological outcomes in patients with out-of-hospital cardiac arrest in Japan

BACKGROUND

In patients who experience out-of-hospital cardiac arrest (OHCA), it is important to assess the association of sub-phenotypes identified by latent class analysis (LCA) using pre-hospital prognostic factors and factors measurable immediately after hospital arrival with neurological outcomes at 30 days, which would aid in making treatment decisions.

METHODS

This study retrospectively analyzed data obtained from the Japanese OHCA registry between June 2014 and December 2019. The registry included a complete set of data on adult patients with OHCA, which was used in the LCA. The association between the sub-phenotypes and 30-day survival with favorable neurological outcomes was investigated. Furthermore, adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by multivariate logistic regression analysis using in-hospital data as covariates.

RESULTS

A total of, 22,261 adult patients who experienced OHCA were classified into three sub-phenotypes. The factor with the highest discriminative power upon patient's arrival was Glasgow Coma Scale followed by partial pressure of oxygen. Thirty-day survival with favorable neurological outcome as the primary outcome was evident in 66.0% participants in Group 1, 5.2% in Group 2, and 0.5% in Group 3. The 30-day survival rates were 80.6%, 11.8%, and 1.3% in groups 1, 2, and 3, respectively. Logistic regression analysis revealed that the ORs (95% CI) for 30-day survival with favorable neurological outcomes were 137.1 (99.4-192.2) for Group 1 and 4.59 (3.46-6.23) for Group 2 in comparison to Group 3. For 30-day survival, the ORs (95%CI) were 161.7 (124.2-212.1) for Group 1 and 5.78 (4.78-7.04) for Group 2, compared to Group 3.

CONCLUSIONS

This study identified three sub-phenotypes based on the prognostic factors available immediately after hospital arrival that could predict neurological outcomes and be useful in determining the treatment strategy of patients experiencing OHCA upon their arrival at the hospital.

Impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest outcomes in Japan

This study investigates the impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest (OHCA) outcomes in Japan, aiming to address a critical research gap. Analyzing data from the All-Japan Utstein registry covering pediatric OHCA cases from 2018 to 2021, the study observed no significant changes in one-month survival, neurological outcomes, or overall performance when comparing the pre-pandemic (2018-2019) and pandemic (2020-2021) periods among 6765 cases. However, a notable reduction in pre-hospital return of spontaneous circulation (ROSC) during the pandemic (15.1-13.1%, p = .020) was identified. Bystander-initiated chest compressions and rescue breaths declined (71.1-65.8%, 22.3-13.0%, respectively; both p < .001), while bystander-initiated automated external defibrillator (AED) use increased (3.7-4.9%, p = .029). Multivariate logistic regression analyses identified factors associated with reduced pre-hospital ROSC during the pandemic. Post-pandemic, there was no noticeable change in the one-month survival rate. The lack of significant change in survival may be attributed to the negative effects of reduced chest compressions and ventilation being offset by the positive impact of widespread AED availability in Japan. These findings underscore the importance of innovative tools and systems for safe bystander cardiopulmonary resuscitation during a pandemic, providing insights to optimize pediatric OHCA care.

External Validation of Updated Prediction Models for Neurological Outcomes at 90 Days in Patients With Out-of-Hospital Cardiac Arrest

BACKGROUND

Few prediction models for individuals with early-stage out-of-hospital cardiac arrest (OHCA) have undergone external validation. This study aimed to externally validate updated prediction models for OHCA outcomes using a large nationwide dataset.

METHODS AND RESULTS

We performed a secondary analysis of the JAAM-OHCA (Comprehensive Registry of In-Hospital Intensive Care for Out-of-Hospital Cardiac Arrest Survival and the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest) registry. Previously developed prediction models for patients with cardiac arrest who achieved the return of spontaneous circulation were updated. External validation was conducted using data from 56 institutions from the JAAM-OHCA registry. The primary outcome was a dichotomized 90-day cerebral performance category score. Two models were updated using the derivation set (n=3337). Model 1 included patient demographics, prehospital information, and the initial rhythm upon hospital admission; Model 2 included information obtained in the hospital immediately after the return of spontaneous circulation. In the validation set (n=4250), Models 1 and 2 exhibited a C-statistic of 0.945 (95% CI, 0.935-0.955) and 0.958 (95% CI, 0.951-0.960), respectively. Both models were well-calibrated to the observed outcomes. The decision curve analysis showed that Model 2 demonstrated higher net benefits at all risk thresholds than Model 1. A web-based calculator was developed to estimate the probability of poor outcomes (https://pcas-prediction.shinyapps.io/90d_lasso/).

CONCLUSIONS

The updated models offer valuable information to medical professionals in the prediction of long-term neurological outcomes for patients with OHCA, potentially playing a vital role in clinical decision-making processes.

Survival After Out-of-Hospital Cardiac Arrest Before and After Legislation for Bystander CPR

Importance

The lack of evidence-based implementation strategies is a major contributor to increasing mortality due to out-of-hospital cardiac arrest (OHCA) in developing countries with limited resources.

Objective

To evaluate whether the implementation of legislation is associated with increased bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use and improved clinical outcomes for patients experiencing OHCA and to provide policy implications for low-income and middle-income settings.

Design, Setting, and Participants

This observational cohort study analyzed a prospective city registry of patients with bystander-witnessed OHCA between January 1, 2010, and December 31, 2022. The Emergency Medical Aid Act was implemented in Shenzhen, China, on October 1, 2018. An interrupted time-series analysis was used to assess changes in outcomes before and after the law. Data analysis was performed from May to October 2023.

Exposure

The Emergency Medical Aid Act stipulated the use of AEDs and CPR training for the public and provided clear legal guidance for OHCA rescuing.

Main Outcomes and Measures

The primary outcomes were rates of bystander-initiated CPR and use of AEDs. Secondary outcomes were rates of prehospital return of spontaneous circulation (ROSC), survival to arrival at the hospital, and survival at discharge.

Results

A total of 13 751 patients with OHCA (median [IQR] age, 59 [43-76] years; 10 011 men [72.83%]) were included, with 7858 OHCAs occurring during the prelegislation period (January 1, 2010, to September 30, 2018) and 5893 OHCAs occurring during the postlegislation period (October 1, 2018, to December 31, 2022). The rates of bystander-initiated CPR (320 patients [4.10%] vs 1103 patients [18.73%]) and AED use (214 patients [4.12%] vs 182 patients [5.29%]) increased significantly after legislation implementation vs rates before the legislation. Rates of prehospital ROSC (72 patients [0.92%] vs 425 patients [7.21%]), survival to arrival at the hospital (68 patients [0.87%] vs 321 patients [5.45%]), and survival at discharge (44 patients [0.56%] vs 165 patients [2.80%]) were significantly increased during the postlegislation period. Interrupted time-series models demonstrated a significant slope change in the rates of all outcomes.

Conclusions and Relevance

These findings suggest that implementation of the Emergency Medical Aid Act in China was associated with increased rates of CPR and public AED use and improved survival of patients with OHCA. The use of a systemwide approach to enact resuscitation initiatives and provide legal support may reduce the burden of OHCA in low-income and middle-income settings.

Association of pre-hospital tracheal intubation with outcomes after out-of-hospital cardiac arrest by drowning comparing to supraglottic airway device: A nationwide propensity score-matched cohort study

AIM OF THE STUDY

This study aimed to compare the survival outcomes of adult patients with out-of-hospital cardiac arrest (OHCA) by drowning who were treated with either endotracheal intubation (ETI) or a supraglottic airway (SGA) device.

METHODS

We compared the outcomes of patients with OHCA by drowning according to airway management using a Japanese nationwide population-based registry (All-Japan Utstein Registry). Adult patients with OHCA treated in 2014-2020 with advanced airway management (ETI or SGA) were included. Patients who received ETI during cardiopulmonary resuscitation were matched with those treated with SGA based on propensity scores in a 1:1 ratio with a 0.2 calliper width. The outcome measures were the return of spontaneous circulation (ROSC), survival at one month, and favourable neurological outcomes defined as a Cerebral Performance Category Scale score of 1 or 2.

RESULTS

Of the 11,703 eligible patients, 4,467 (38.2%) and 7,236 (61.8%) underwent ETI and SGA, respectively. A total of 3,566 patients in each cohort were matched. The ROSC rate was higher in those treated with ETI versus SGA (207/3,566 [5.8%] versus 167/3,566 [4.7%], respectively; adjusted odds ratio, 1.25; 95% confidence interval [CI], 1.02-1.55). There was no intergroup difference in one-month survival or favourable neurological outcome (32/3566 [0.90%] versus 34/3566 [0.95%]; odds ratio, 0.94; 95% CI, 0.58-1.53; and 9/3566 [0.25%] versus 8/3566 [0.22%]; odds ratio, 1.13; 95% CI, 0.43-2.92), respectively.

CONCLUSIONS

In this propensity score-matched study of adult OHCA by drowning, ETI compared to SGA was associated with ROSC but not associated with survival and favourable neurological outcomes at one month.

Development and validation of a prehospital termination of resuscitation (TOR) rule for out - of hospital cardiac arrest (OHCA) cases using general purpose artificial intelligence (AI)

BACKGROUND

Prehospital identification of futile resuscitation efforts (defined as a predicted probability of survival lower than 1%) for out-of-hospital cardiac arrest (OHCA) may reduce unnecessary transport. Reliable prediction variables for OHCA 'termination of resuscitation' (TOR) rules are needed to guide treatment decisions. The Universal TOR rule uses only three variables (Absence of Prehospital ROSC, Event not witnessed by EMS and no shock delivered on the scene) has been externally validated and is used by many EMS systems. Deep learning, an artificial intelligence (AI) platform is an attractive model to guide the development of TOR rule for OHCA. The purpose of this study was to assess the feasibility of developing an AI-TOR rule for neurologically favorable outcomes using general purpose AI and compare its performance to the Universal TOR rule.

METHODS

We identified OHCA cases of presumed cardiac etiology who were 18 years of age or older from 2016 to 2019 in the All-Japan Utstein Registry. We divided the dataset into 2 parts, the first half (2016-2017) was used as a training dataset for rule development and second half (2018-2019) for validation. The AI software (Prediction One®) created the model using the training dataset with internal cross-validation. It also evaluated the prediction accuracy and displayed the ranking of influencing variables. We performed validation using the second half cases and calculated the prediction model AUC. The top four of the 11 variables identified in the model were then selected as prognostic factors to be used in an AI-TOR rule, and sensitivity, specificity, positive predictive value, and negative predictive value were calculated from validation cohort. This was then compared to the performance of the Universal TOR rule using same dataset.

RESULTS

There were 504,561 OHCA cases, 18 years of age or older, 302,799 cases were presumed cardiac origin. Of these, 149,425 cases were used for the training dataset and 153,374 cases for the validation dataset. The model developed by AI using 11 variables had an AUC of 0.969, and its AUC for the validation dataset was 0.965. The top four influencing variables for neurologically favorable outcome were Prehospital ROSC, witnessed by EMS, Age (68 years old and younger) and nonasystole. The AUC calculated using the 4 variables for the AI-TOR rule was 0.953, and its AUC for the validation dataset was 0.952 (95%CI 0.949 -0.954). Of 80,198 patients in the validation cohort that satisfied all four criteria for the AI-TOR rule, 58 (0.07%) had a neurologically favorable one-month survival. The specificity of AI-TOR rule was 0.990, and the PPV was 0.999 for predicting lack of neurologically favorable survival, both the specificity and PPV were higher than that achieved with the universal TOR (0.959, 0.998).

CONCLUSIONS

The accuracy of prediction models using AI software to determine outcomes in OHCA was excellent and the AI-TOR rule's variables from prediction model performed better than the Universal TOR rule. External validation of our findings as well as further research into the utility of using AI platforms for TOR prediction in clinical practice is needed.

Sex Differences in Receipt of Bystander Cardiopulmonary Resuscitation Considering Neighborhood Racial and Ethnic Composition

BACKGROUND

Bystander cardiopulmonary resuscitation (B-CPR) and defibrillation for out-of-hospital cardiac arrest (OHCA) vary by sex, with women being less likely to receive these interventions in public. It is unknown whether sex differences persist when considering neighborhood racial and ethnic composition. We examined the odds of receiving B-CPR stratified by location and neighborhood. We hypothesized that women in predominantly Black neighborhoods will have a lower odds of receiving B-CPR.

METHODS AND RESULTS

We conducted a retrospective study using the Cardiac Arrest Registry to Enhance Survival (CARES). Neighborhoods were classified by census tract. We modeled the odds of receipt of B-CPR (primary outcome), automatic external defibrillation application, and survival to hospital discharge (secondary outcomes) by sex. CARES collected 457 621 arrests (2013-2019); after appropriate exclusion, 309 662 were included. Women who had public OHCA had a 14% lower odds of receiving B-CPR (odds ratio [OR], 0.86 [95% CI, 0.82-0.89]), but effect modification was not seen by neighborhood (P=not significant). In predominantly Black neighborhoods, women who had public OHCA had a 13% lower odds of receiving B-CPR (adjusted OR, 0.87 [95% CI, 0.76-0.98]) and 12% lower odds of receiving automatic external defibrillation application (adjusted OR, 0.88 [95% CI, 0.78-0.99]). In predominantly Hispanic neighborhoods, women who had public OHCA were less likely to receive B-CPR (adjusted OR, 0.83 [95% CI, 0.73-0.96]) and less likely to receive automatic external defibrillation application (adjusted OR, 0.74 [95% CI, 0.64-0.87]).

CONCLUSIONS

Women with public OHCA have a decreased likelihood of receiving B-CPR and automatic external defibrillation application. Findings did not differ significantly according to neighborhood composition. Despite this, our work has implications for considering strategies to reduce disparities around bystander response.

Overview and future prospects of out-of-hospital cardiac arrest registries in Japan

Aim

Out-of-hospital cardiac arrest (OHCA) is a life-threatening emergency with high mortality. The "chain of survival" is critical to improving patient outcomes. To develop and enhance this chain of survival, measuring and monitoring the resuscitation processes and outcomes are essential for quality assurance. In Japan, several OHCA registries have successfully been implemented at both local and national levels. We aimed to review and summarise the conception, strengths, and challenges of OHCA registries in Japan.

Method and results

The following representing registries in Japan were reviewed: the All-Japan Utstein registry, the Utstein Osaka Project/the Osaka-CRITICAL study, the SOS-KANTO study, the JAAM-OHCA study, and the SAVE-J II study. The All-Japan Utstein registry, operated by the Fire and Disaster Management Agency of Japan and one of the largest nationwide population-based registries in the world, collects data concerning all patients with OHCA in Japan, excluding in-hospital data. Other research- and hospital-based registries collect detailed out-of-hospital and in-hospital data. The Osaka-CRITICAL study and the SOS-KANTO study are organized at regional levels, and hospitals in the Osaka prefecture and in the Kanto area participate in these registries. The JAAM-OHCA study is managed by the Japanese Association of Acute Medicine and includes 107 hospitals throughout Japan. The Save-J II study focuses on patients with OHCA treated with extracorporeal cardiopulmonary resuscitation.

Conclusion

Each OHCA registry has its own philosophy, strengths, perspectives, and challenges; however, all have been successful in contributing to the improvement of emergency medical service (EMS) systems through the quality improvement process. These registries are expected to be further utilized to enhance EMS systems and improve outcomes for patients with OHCA, while also contributing to the field of resuscitation science.

Novel and innovative resuscitation systems in Japan

Aim

Out-of-hospital cardiac arrest (OHCA) is a life-threatening emergency that requires rapid and efficient intervention. Recently, several novel approaches have emerged and have been incorporated into resuscitation systems in some local areas of Japan. This review describes innovative resuscitation systems and highlights their strengths.

Main text

First, we discuss the deployment of a physician-staffed ambulance, in which emergency physicians offer advanced resuscitation to patients with OHCA on site. In addition, we describe the experimental practice of extracorporeal membrane oxygenation (ECPR) in a prehospital setting. Second, we describe a physician-staffed helicopter, wherein a medical team provides advanced resuscitation at the scene. We also explain their initiative to provide early ECPR, even in remote areas. Finally, we provide an overview of the "hybrid ER" system which is a "one-fits-all" resuscitation bay equipped with computed tomography and fluoroscopy equipment. This system is expected to help swiftly identify and rule out irreversible causes of cardiac arrest, such as massive subarachnoid hemorrhage, and implement ECPR without delay.

Conclusion

Although these revolutionary approaches may improve the outcomes of patients with OHCA, evidence of their effectiveness remains limited. In addition, it is crucial to ensure cost-effectiveness and sustainability. We will continue to work diligently to assess the effectiveness of these systems and focus on the development of cost-effective and sustainable systems.

Early Versus Late Advanced Airway Management for Pediatric Patients With Out-of-Hospital Cardiac Arrest

STUDY OBJECTIVE

To determine the association between early versus late advanced airway management and improved outcomes in pediatric out-of-hospital cardiac arrest.

METHODS

We performed a retrospective cohort study using data from the out-of-hospital cardiac arrest registry in Japan. We included pediatric patients (<18 years) with out-of-hospital cardiac arrest who had received advanced airway management (tracheal intubation, supraglottic airway, and esophageal obturator). The main exposure was early (≤20 minutes) versus late (>20 minutes) advanced airway management. The primary and secondary outcome measurements were survival and favorable neurologic outcomes at 1 month, respectively. To address resuscitation time bias, we performed risk-set matching analyses using time-dependent propensity scores.

RESULTS

Out of the 864 pediatric patients with both out-of-hospital cardiac arrest and advanced airway management over 67 months (2014 to 2019), we included 667 patients with adequate data (77%). Of these 667 patients, advanced airway management was early for 354 (53%) and late for 313 (47%) patients. In the risk-set matching analysis, the risk of both survival (risk ratio 0.98 for early versus late [95% confidence interval 0.95 to 1.02]) and favorable 1-month neurologic outcomes (risk ratio 0.99 [95% confidence interval 0.97 to 1.00]) was similar between early and late advanced airway management groups. In sensitivity analyses, with time to early advanced airway management defined as ≤10 minutes and ≤30 minutes, both outcomes were again similar.

CONCLUSION

In pediatric out-of-hospital cardiac arrest, the timing of advanced airway management may not affect patient outcomes, but randomized controlled trials are needed to address this question further.

Impact of Updating the Cardiopulmonary Resuscitation Guidelines on Out-of-Hospital Shockable Cardiac Arrest: A Population-Based Cohort Study in Japan

BACKGROUND

International consensus on cardiopulmonary resuscitation (CPR) and emergency cardiovascular care science and treatment recommendations (CoSTR) have reported updates on CPR maneuvers every 5 years since 2000. However, few national population-based studies have investigated the comprehensive effectiveness of those updates for out-of-hospital cardiac arrest due to shockable rhythms. The primary objective of the present study was to determine whether CPR based on CoSTR 2005 or 2010 was associated with improved outcomes in Japan, as compared with CPR based on Guidelines 2000.

METHODS AND RESULTS

From the All-Japan Utstein Registry between 2005 and 2015, we included 73 578 adults who had shockable out-of-hospital cardiac arrest witnessed by bystanders or emergency medical service responders. The study outcomes over an 11-year period were compared between 2005 of the Guidelines 2000 era, from 2006 to 2010 of the CoSTR 2005 era, and from 2011 to 2015 of the CoSTR 2010 era. In the bystander-witnessed group, the adjusted odds ratios for favorable neurological outcomes at 30 days after out-of-hospital cardiac arrest by enrollment year increased year by year (1.19 in 2006, and 3.01 in 2015). Similar results were seen in the emergency medical service responder-witnessed group and several subgroups.

CONCLUSIONS

Compared with CPR maneuvers for shockable out-of-hospital cardiac arrest recommended in the Guidelines 2000, CPR maneuver updates in CoSTR 2005 and 2010 were associated with improved neurologically intact survival year by year in Japan. Increased public awareness and greater dissemination of basic life support may be responsible for the observed improvement in outcomes.

REGISTRATION

URL: https://www.umin.ac.jp/ctr/; Unique identifier: 000009918.

Association Between Advanced Airway Management With Adrenaline Injection and Prognosis in Adult Patients With Asystole Asphyxia Out-of-hospital Cardiac Arrest

BACKGROUND

The neurological prognosis of asphyxia is poor and the effect of advanced airway management (AAM) in the prehospital setting remains unclear. This study aimed to evaluate the association between AAM with adrenaline injection and prognosis in adult patients with asystole asphyxia out-of-hospital cardiac arrest (OHCA).

METHODS

This study assessed all-Japan Utstein cohort registry data between January 1, 2013 and December 31, 2019. We used propensity score matching analyses before logistic regression analysis to evaluate the effect of AAM on favorable neurological outcome.

RESULTS

There were 879,057 OHCA cases, including 70,299 cases of asphyxia OHCAs. We extracted the data of 13,642 cases provided with adrenaline injection by emergency medical service. We divided 7,945 asphyxia OHCA cases in asystole into 5,592 and 2,353 with and without AAM, respectively. After 1:1 propensity score matching, 2,338 asphyxia OHCA cases with AAM were matched with 2,338 cases without AAM. Favorable neurological outcome was not significantly different between the AAM and no AAM groups (adjusted odds ratio [OR] 1.1; 95% confidence interval [CI], 0.5-2.5). However, the return of spontaneous circulation (ROSC) (adjusted OR 1.7; 95% CI, 1.5-1.9) and 1-month survival (adjusted OR 1.5; 95% CI, 1.1-1.9) were improved in the AAM group.

CONCLUSION

AAM with adrenaline injection for patients with asphyxia OHCA in asystole was associated with improved ROSC and 1-month survival rate but showed no differences in neurologically favorable outcome. Further prospective studies may comprehensively evaluate the effect of AAM for patients with asphyxia.

Prediction of the neurological outcomes post-cardiac arrest: A prospective validation of the CAST and rCAST

INTRODUCTION

The neurologic prognosis of out-of-hospital cardiac arrest (OHCA) patients in whom return of spontaneous circulation (ROSC) is achieved remains poor. The aim of this study was to externally and prospectively validate two scoring systems developed by us: the CAST score, a scoring system to predict the neurological prognosis of OHCA patients undergoing targeted temperature management (TTM), and a simplified version of the same score developed for improved ease of use in clinical settings, the revised CAST (rCAST) score.

METHODS

This study was a prospective, multicenter, observational study conducted using the SOS KANTO 2017 registry, an OHCA registry involving hospitals in the Kanto region (including Tokyo) of Japan. The primary outcome was favorable neurological outcome (defined as Cerebral Performance Category score of 1 or 2) at 30 days and the secondary outcomes were favorable neurological outcome at 90 days and survival at 30 and 90 days. The predictive accuracies of the original CAST (oCAST) and rCAST scores were evaluated by using area under the receiver operating characteristic curve (AUC).

RESULTS

Of 9909 OHCA patients, 565 showed ROSC and received TTM. Of these, we analyzed the data of 259 patients in this study. The areas under the receiver operating characteristic curve (AUCs) of the oCAST and rCAST scores for predicting a favorable neurological outcome at 30 days were 0.86 and 0.87, respectively, and those for predicting a favorable neurological outcome at 90 days were 0.87 and 0.88, respectively. The rCAST showed a higher predictive accuracy for the neurological outcome as compared with the NULL-PLEASE score. The patients with a favorable neurological outcome who had been classified into the high severity group based on the rCAST tended to have hypothermia at hospital arrival and to not show any signs of loss of gray-white matter differentiation on brain CT. Neurological function at 90 days was correlated with the rCAST (r = 0.63, p < 0.001).

CONCLUSIONS

rCAST showed high predictive accuracy for the neurological prognosis of OHCA patients managed by TTM, comparable to that of the oCAST score. The scores on the rCAST were strongly correlated with the neurological functions at 90 days, implying that the rCAST is a useful scale for assessing the severity of brain injury after cardiac arrest.

Early modelling of the effects and healthcare costs of the Dutch citizen-rescuer system for out-of-hospital cardiac arrests

OBJECTIVES

1) to analyse the total average healthcare costs of a patient with an out-of-hospital cardiac arrest (OHCA), as well as estimating the operational costs of the citizen-rescuer system (CRS); 2) to conduct an early modelling of the effects and healthcare costs of the Dutch CRS in comparison to no CRS.

METHODS

A health economic modelling study was conducted. Adult patients with OHCA from cardiac causes in the province of Limburg (the Netherlands) were included. The time horizon was from OHCA occurrence up to one year after hospital discharge. First, the total average healthcare costs of OHCA patients were analysed as well as the yearly operating costs of the CRS. Second, an early modelling was conducted to compare from the healthcare perspective the healthcare costs of OHCA patients with the CRS being activated but no responders attended (CRS-NV) versus the CRS being activated with attendance of ≥1 responder(s) (CRS-V).

RESULTS

The total average healthcare costs per patient are €42,533. The yearly operating costs for the CRS are approximately €1.5 million per year in the Netherlands. The early modelling of costs and effects showed that the incremental healthcare costs per patient thus were €4,131 in the CRS-V versus the CRS-NV group (€25,184 in the CRS-V group and €21,053 in the CRS-NV group). Incremental quality-adjusted life years (QALYs) was 5 per 100 patients (16 per 100 patients in the CRS-V group versus 11 per 100 patients in the CRS-NV group). The incremental cost-effectiveness ratio (ICER) was €79,662 per QALY for the CRS-V group.

CONCLUSION

This study shows that patients in the CSR-V group had additional health care costs of €4,131 per patient compared to patients in the CRS-NV group. This increase is caused by patients surviving more often, who then continue to utilise health services, which results in a (logic) increase in healthcare costs. For future research, accurate and up-to-date data on effectiveness and costs of the CRS needs to be collected.

Application of Automated External Defibrillators Among the Public: A Cross-Sectional Study of Knowledge, Attitude, Practice, and Barriers of Use in Saudi Arabia

Background

The likelihood of survival of an out-of-hospital cardiac arrest quadruples with the rapid application of basic life support (BLS). The public's ability to perform cardiopulmonary resuscitation (CPR) and use automated external defibrillators (AEDs) is extremely important. This study aimed to assess the public knowledge, attitudes, and practices (KAP) of utilizing AEDs and to understand barriers to AED application.

Methods

We conducted a cross-sectional study from March 1-30, 2022. An electronic questionnaire was constructed and validated to measure the KAP for public AED utilization and its barriers.

Results

Of the 406 participants, 244 (60.10%) were males. Male respondents had 17% less knowledge and poorer attitude towards using an AED as compared to female respondents. Knowledge and attitudes on using AEDs were low (70.7%) among Saudi nationals compared to those of foreign nationals. Those who were BLS/CPR trained had a 2.5 times greater understanding and willingness to use AEDs in public than those who were not. Barriers to AEDs in CPR/BLS-trained participants were: (1) accidentally hurting the victim (14.3%), (2) duty as a bystander to just call the ambulance and wait for help (12.1%), (3) never taught what to do (n = 41, 18.4%), (4) did not want to be scolded if performed wrong (3.1%), and (5) never witnessed such a situation (51.6%).

Conclusion

There is a strong association between knowledge of and willingness to use AEDs in emergency situations among the public. Misconceptions about AEDs hinder their use. This calls for urgent training programs through accessible technology to reach the public.

The Role of Automated External Defibrillator Use in the Out-of-Hospital Cardiac Arrest Survival Rate and Outcome: A Systematic Review

Out-of-hospital cardiac arrest (OHCA) remains a significant cause of death. The chance of survival significantly increases when immediate defibrillation with an on-site automated external defibrillator (AED) is available. Our aim is to systematically evaluate the impact of public access defibrillators (PAD) on the outcomes of outpatient cardiac arrest. We conducted a systematic review of the data from global studies on the role of bystander and emergency medical service (EMS) interventions, primarily focusing on the usage of AEDs, during OHCA events. The results highlight the critical significance of PADs in improving survival outcomes in OHCA settings. The majority of OHCA incidents occurred in private residences, but public spaces such as schools and airports had better outcomes, likely due to AED accessibility and trained individuals. Placing AEDs in public areas, especially high-risk zones, can boost survival chances. Timely defibrillation, particularly by bystanders, correlated with better survival and neurological conditions. The review emphasizes the importance of widespread cardiopulmonary resuscitation (CPR) and AED training, strategic AED placement, and continuous monitoring of interventions and outcomes to enhance survival rates and neurological recovery after OHCAs. This systematic review showed that bystander interventions, including CPR and AED usage, significantly increased the survival rate. Overall, immediate response and accessibility to AEDs in public areas can significantly improve outcomes in OHCA events.

Machine learning-based analysis of regional differences in out-of-hospital cardiopulmonary arrest outcomes and resuscitation interventions in Japan

Refining out-of-hospital cardiopulmonary arrest (OHCA) resuscitation protocols for local emergency practices is vital. The lack of comprehensive evaluation methods for individualized protocols impedes targeted improvements. Thus, we employed machine learning to assess emergency medical service (EMS) records for examining regional disparities in time reduction strategies. In this retrospective study, we examined Japanese EMS records and neurological outcomes from 2015 to 2020 using nationwide data. We included patients aged ≥ 18 years with cardiogenic OHCA and visualized EMS activity time variations across prefectures. A five-layer neural network generated a neurological outcome predictive model that was trained on 80% of the data and tested on the remaining 20%. We evaluated interventions associated with changes in prognosis by simulating these changes after adjusting for time factors, including EMS contact to hospital arrival and initial defibrillation or drug administration. The study encompassed 460,540 patients, with the model's area under the curve and accuracy being 0.96 and 0.95, respectively. Reducing transport time and defibrillation improved outcomes universally, while combining transport time and drug administration showed varied efficacy. In conclusion, the association of emergency activity time with neurological outcomes varied across Japanese prefectures, suggesting the need to set targets for reducing activity time in localized emergency protocols.

Fifteen-year secular changes in the care and outcomes of patients with out-of-hospital cardiac arrest in Japan: a nationwide, population-based study

AIMS

Countries have implemented initiatives to improve the outcomes of patients with out-of-hospital cardiac arrest (OHCA). However, secular changes in care and outcomes at the national level have not been extensively investigated. This study aimed to determine 15-year secular changes in the outcomes of such patients in Japan.

METHODS AND RESULTS

Using population-based data of patients with OHCA, covering all populations in Japan (2005-19), patients for whom resuscitation was attempted were identified. The primary outcome was a favourable neurological outcome (Cerebral Performance Category 1 or 2: sufficient cerebral function for independent activities of daily life and work in a sheltered environment). Secular changes in outcomes were determined using a mixed-level multivariate logistic regression analysis. Overall, 1 764 440 patients (42.4% women; median age, 78 years) were examined. The incidence, median age, and proportion of patients who received bystander cardiopulmonary resuscitation (CPR) and dispatcher instructions for resuscitation increased significantly during the study period (P  < 0.001). A significant trend was noted toward improved outcomes over time (P for trend < 0.001); favourable neurological outcome proportions 1 month after arrest increased from 1.7-3.0% (odds ratio, 1.03 per 1-incremental year). A remarkable increase was noted in favourable neurological outcomes in younger patients and patients with initial shockable cardiac rhythm, while improvement varied among prefectures.

CONCLUSION

In Japan, collaborative efforts have yielded commendable achievements in the care and outcomes of patients with OHCA over 15 years through to 2019, while the improvement depended on patient characteristics. Further initiatives are needed to improve OHCA outcomes.

Identifying individuals satisfying the termination of resuscitation rule but having potential to achieve favourable neurological outcome following out-of-hospital cardiac arrest

AIM

To develop a simple scoring model that identifies individuals satisfying the termination of resuscitation (TOR) rule but having potential to achieve favourable neurological outcome following out-of-hospital cardiac arrest (OHCA).

METHODS

This study analysed the All-Japan Utstein Registry from 1 January 2010 to 31 December 2019. We identified patients satisfying basic life support (BLS) and advanced life support (ALS) TOR rules and determined factors associated with favourable neurological outcome (cerebral performance category scale of 1 or 2) for each cohort using multivariable logistic regression analysis. Scoring models were derived and validated to identify patient subgroups that might benefit from continued resuscitation efforts.

RESULTS

Among 1,695,005 eligible patients, 1,086,092 (64.1%) and 409,498 (24.2%) satisfied BLS and ALS TOR rules, respectively. One month post-arrest, 2038 (0.2%) and 590 (0.1%) patients in the BLS and ALS cohorts, respectively, achieved favourable neurological outcome. A scoring model derived for the BLS cohort (2 points for age <17 years or ventricular fibrillation/ventricular tachycardia rhythm; 1 point for age <80 years, pulseless electrical activity rhythm, or transport time <25 min) effectively stratified the probability of achieving 1-month favourable neurological outcome, with patients scoring <4 having a probability of <1%, whereas those scoring 4, 5, and 6 having probabilities of 1.1%, 7.1%, and 11.1%, respectively. In the ALS cohort, the probability increased with scores; however, it remained <1%.

CONCLUSION

A simple scoring model comprising age, first documented cardiac rhythm, and transport time effectively stratified the likelihood of achieving favourable neurological outcome in patients satisfying the BLS TOR rule.

Association between bystander intervention and emergency medical services and the return of spontaneous circulation in out-of-hospital cardiac arrests occurring at a train station in the Tokyo metropolitan area: A retrospective cohort study

Aim

The purpose of this study was to stratify patients who achieved return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA) with bystander procedures pre-emergency medical service (EMS) arrival and those who achieved ROSC with procedures post-EMS arrival, compare outcomes at 1-month, and identify factors associated with pre-EMS-arrival-ROSC.

Methods

A retrospective cohort analysis of OHCAs occurring at stations in the Tokyo metropolitan area between 2014 and 2018 was conducted. Subjects were stratified by ROSC phase (categorized as pre- and post-EMS arrival and non-ROSC). Survival at 1-month post-OHCA and the percentage of favourable neurological function in each ROSC phase were analysed. In addition, factors associated with Pre-EMS-arrival-ROSC were identified using multivariable logistic regression analysis. The time of occurrence of OHCA was classified into four-time categories as follows. Rush hour on morning [7:00-9:00], Rush hour on evening [17:00-21:00], Daytime [9:00-17:00], and Night or Early morning [21:00-7:00].

Results

Among the 63,089 OHCA in the dataset, 702 were analysed. At 1-month after OHCA occurrence, Pre-EMS-arrival ROSC had higher survival rates than post-EMS-arrival ROSC (86.8% vs. 54.1%) and CPC1-2 rates (73.6% vs. 38.5%). Pre-EMS-arrival ROSC was associated (adjusted odds ratio [95% confidence interval]) with non-older-adult patients (1.59 [1.05-2.43]), witnessed OHCA (1.82 [1.03-3.31]), evening rush-hour (17:00-21:00; 2.08 [1.05-4.11]), conventional CPR (33.42 [7.82-868.44]), hands-only CPR (17.06 [4.30-436.48]), bystander defibrillation performed once (3.31 [1.59-6.99]).

Conclusions

In an OHCA at a station in Tokyo, ROSC achieved with bystander treatment alone had a better outcome at 1-month compared to ROSC with EMS intervention.

Pre-Arrival Care of the Out-of-Hospital Cardiac Arrest Victim

Lay rescuers play a pivotal role in the recognition and initial management of out-of-hospital cardiac arrest. The provision of timely pre-arrival care by lay responders, including cardiopulmonary resuscitation and the use of automated external defibrillator before emergency medical service arrival, is important link in the chain of survival and has been shown to improve outcomes from cardiac arrest. Although physicians are not directly involved in bystander response to cardiac arrest, they play a key role in emphasizing the importance of bystander interventions.

Impact of Heavy Snowfall on Emergency Transport and Prognosis of Out-of-Hospital Cardiac Arrest Patients: A Nation-Wide Cohort Study

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a significant global cause of mortality, and Emergency Medical Services (EMS) response interval is critical for survival and a neurologically-favorable outcome. Currently, it is unclear whether EMS response interval, neurologically-intact survival, and overall survival differ between snowy and non-snowy periods at heavy snowfall areas.

METHODS

A nation-wide population-based cohort of OHCA patients, registered from 2017 through 2019 in the All-Japan Utstein Registry, was divided into four groups according to areas (heavy snowfall area or other area) and seasons (winter or non-winter): heavy snowfall-winter, heavy snowfall-non-winter, other area-winter, and other area-non-winter. The first coprimary outcome was EMS response interval, and the secondary coprimary outcome was one-month survival and a neurologically-favorable outcome at one month.

RESULTS

A total of 337,781 OHCA patients were divided into four groups: heavy snowfall-winter (N = 15,627), heavy snowfall-non-winter (N = 97,441), other area-winter (N = 32,955), and other area-non-winter (N = 191,758). Longer EMS response intervals (>13 minutes) were most likely in the heavy snowfall-winter group (OR = 1.86; 95% CI, 1.76 to 1.97), and also more likely in heavy snowfall areas in non-winter (OR = 1.44; 95% CI, 1.38 to 1.50). One-month survival in winter was worse not only in the heavy snowfall area (OR = 0.86; 95% CI, 0.78 to 0.94) but also in other areas (OR = 0.91; 95% CI, 0.87 to 0.94). One-month neurologically-favorable outcomes were also comparable between heavy snowfall-winter and other area-non-winter groups.

CONCLUSIONS

This study showed OHCA in heavy snowfall areas in winter resulted in longer EMS response intervals. However, heavy snowfall had little effect on one-month survival or neurologically-favorable outcome at one month.

Manual Chest Compression versus Automated Chest Compression Device during Day-Time and Night-Time Resuscitation Following Out-of-Hospital Cardiac Arrest: A Retrospective Historical Control Study

OBJECTIVE

We assessed the effectiveness of automated chest compression devices depending on the time of admission based on the frequency of iatrogenic chest injuries, the duration of in-hospital resuscitation efforts, and clinical outcomes among out-of-hospital cardiac arrest (OHCA) patients.

METHODS

We conducted a retrospective historical control study of OHCA patients in Japan between 2015-2022. The patients were divided according to time of admission, where day-time was considered 07:00-22:59 and night-time 23:00-06:59. These patients were then divided into two categories based on the in-hospital cardiopulmonary resuscitation (IHCPR) device: manual chest compression (mCC) group and automatic chest compression devices (ACCD) group. We used univariate and multivariate ordered logistic regression models adjusted for pre-hospital confounders to evaluate the impact of ACCD use during IHCPR on outcomes (IHCPR duration, CPR-related chest injuries, and clinical outcomes) in the day-time and night-time groups.

RESULTS

Among 1101 patients with OHCA (day-time, 809; night-time, 292), including 215 patients who underwent ACCD during IHCPR in day-time (26.6%) and 104 patients in night-time group (35.6%), the multivariate model showed a significant association of ACCD use with the outcomes of in-hospital resuscitation and higher rates of return in spontaneous circulation, lower incidence of CPR-related chest injuries, longer in-hospital resuscitation durations, greater survival to Emergency Department and hospital discharge, and greater survival with good neurological outcome to hospital discharge, though only in the night-time group.

CONCLUSIONS

Patients who underwent ACCD during in-hospital resuscitation at night had a significantly longer duration of in-hospital resuscitation, a lower incidence of CPR-related chest injuries, and better outcomes.

Impact of increased reimbursement for ambulance transportation on hospital acceptance in Japan: a difference-in-difference study

OBJECTIVE

Emergency medical services (EMS) often face difficulties in finding accepting hospitals in Japan. The universal medical insurance system in Japan increased the reimbursement for ambulance transportation acceptance at night, and on Sundays and holidays from 1 April 2016. This study investigated the effect of the reimbursement increase on the number of EMS calls, and transportation time from arrival at the scene to arrival at the hospital.

DESIGN

A difference-in-difference study. The treatment group consisted of people who called an ambulance at night while the control group consisted of people who called an ambulance during the daytime.

SETTING

The national ambulance records of the Fire and Disaster Management Agency in Japan from 1 April 2015 to 31 December 2016.

PARTICIPANTS

7 625 463 ambulance dispatches were eligible for inclusion.

PRIMARY AND SECONDARY OUTCOME MEASURES

The changes in EMS calls, transportation time and the number of ambulance transports per 1000 population in one month in a comparison of daytime and night-time transport.

RESULTS

The treatment effect (night-time vs daytime) on the number of EMS calls was -0.013 (95% CI, -0.023 to -0.004), which was significant. The transportation time decreased slightly by 0.080 min (95% CI, -0.157 to -0.004). No impact was observed on the number of ambulance transports per 1000 population per month (0.00; 95% CI, -0.008 to 0.002).

CONCLUSION

An increase in reimbursement for ambulance transportation acceptance was associated with a decrease in the number of EMS calls. Further strategies for decreasing the number of EMS calls are needed to avoid delays in the treatment of emergency patients with critical illness.

A Machine Learning Prediction Model for Non-cardiogenic Out-of-hospital Cardiac Arrest with Initial Non-shockable Rhythm

Objectives

The purpose of this study was to develop and validate a machine learning prediction model for the prognosis of non-cardiogenic out-of-hospital cardiac arrest (OHCA) with an initial non-shockable rhythm.

Design

Data were obtained from a nationwide OHCA registry in Japan. Overall, 222,056 patients with OHCA and an initial non-shockable rhythm were identified from the registry in 2016 and 2017. Patients aged <18 years and OHCA caused by cardiogenic origin, cancer, and external factors were excluded. Finally, 58,854 participants were included.

Methods

Patients were classified into the training dataset (n=29,304, data from 2016) and the test dataset (n=29,550, data from 2017). The training dataset was used to train and develop the machine learning model, and the test dataset was used for internal validation. We selected XGBoost as the machine learning classifier. The primary outcome was the poor prognosis defined as cerebral performance category of 3-5 at 1 month. Eleven prehospital variables were selected as outcome predictors.

Results

In validation, the machine learning model predicted the primary outcome with an accuracy of 90.8% [95% confidence interval (CI): 90.5-91.2], a sensitivity of 91.4% [CI: 90.7-91.4], a specificity of 74.1% [CI: 69.2-78.6], and an area under the receiver operating characteristic value of 0.89 [0.87-0.92]. The important features for model development were the prehospital return of spontaneous circulation, prehospital adrenaline administration, and initial electrical rhythm.

Conclusions

We developed a favorable machine learning model to predict the prognosis of non-cardiogenic OHCA with an initial non-shockable rhythm in the early stage of resuscitation.

Public access defibrillation: challenges and new solutions

PURPOSE OF REVIEW

The purpose of this article is to review the current status of public access defibrillation and the various utility modalities of early defibrillation.

RECENT FINDINGS

Defibrillation with on-site automated external defibrillators (AEDs) has been the conventional approach for public access defibrillation. This strategy is highly effective in cardiac arrests occurring in close proximity to on-site AEDs; however, only a few cardiac arrests will be covered by this strategy. During the last decades, additional strategies for public access defibrillation have developed, including volunteer responder programmes and drone assisted AED-delivery. These programs have increased chances of early defibrillation within a greater radius, which remains an important factor for survival after out-of-hospital cardiac arrest.

SUMMARY

Recent advances in the use of public access defibrillation show great potential for optimizing early defibrillation. With new technological solutions, AEDs can be transported to the cardiac arrest location reaching OHCAs in both public and private locations. Furthermore, new technological innovations could potentially identify and automatically alert the emergency medical services in nonwitnessed OHCA previously left untreated.

PCO2 on arrival as a predictive biomarker in patients with out-of-hospital cardiac arrest

BACKGROUND

Treating patients with out-of-hospital cardiac arrest (OHCA) requires early prediction of outcome, ideally on hospital arrival, as it can inform the clinical decisions involved. This study evaluated whether partial pressure of carbon dioxide (PCO₂) on arrival is associated with outcome at one month OHCA patients.

METHODS

This was a single-center retrospective study of adult OHCA patients treated between January 2016 and December 2020. Outcomes were defined along the Cerebral Performance Category (CPC) scale. Primary outcome was mortality (CPC 5) at one month. Secondary outcomes were death or unfavorable neurological outcome (CPC 3-5) and unfavorable neurological outcome (CPC 3-4) at one month. Multivariable analysis was adjusted for age, sex, witnessed cardiac arrest, bystander cardiopulmonary resuscitation, initial shockable rhythm, and time from call to emergency medical services to hospital arrival.

RESULTS

Out of 977 OHCA patients in the study period, 19 were excluded because they were aged under 18 years, 79 because they underwent extracorporeal cardiopulmonary resuscitation, and 101 due to lack of PCO₂ data. This study included 778 patients total; mortality (CPC 5) at one month was observed in 706 (90.7%), death or unfavorable neurological outcome (CPC 3-5) in 743 (95.5%), and unfavorable neurological outcome (CPC 3-4) in 37 (4.8%). In multivariable analysis, high PCO₂ levels showed significant association with mortality (CPC 5) at one month (odds ratio [OR] [per 5 mmHg], 1.14; 95% confidence interval [CI], 1.08-1.21), death or unfavorable neurological outcome (CPC 3-5) (OR [per 5 mmHg], 1.29; 95% CI, 1.17-1.42), and unfavorable neurological outcome (CPC 3-4) (OR [per 5 mmHg], 1.21; 95% CI, 1.04-1.41).

CONCLUSIONS

High PCO₂ on arrival was significantly associated with mortality and unfavorable neurological outcome in OHCA patients.

Bystander cardiopulmonary resuscitation and cardiac rhythm change over time in patients with out-of-hospital cardiac arrest

BACKGROUND

Whether and how bystander cardiopulmonary resuscitation (CPR) modifies the cardiac rhythm after out-of-hospital cardiac arrest (OHCA) over time remains unclear. We investigated the association between bystander CPR and the likelihood of ventricular fibrillation (VF) or ventricular tachycardia (VT) as the first documented cardiac rhythm.

METHODS

We identified individuals with witnessed OHCA of cardiac origin from a nationwide population-based OHCA registry in Japan between 1 January 2005 and 31 December 2019. The first documented cardiac rhythm was compared between patients who received bystander CPR and those who did not, using a 1:2 propensity score-matched analysis.

RESULTS

Of 309 900 patients with witnessed OHCA of cardiac origin, 71 887 (23.2%) received bystander CPR. Propensity score matching paired 71 882 patients who received bystander CPR with 143 764 who did not. The likelihood of detecting a VF/VT rhythm was significantly higher among patients who received bystander CPR than among those who did not (OR 1.66; 95% CI 1.63 to 1.69; p<0.001). Comparing the two groups at each time point, the difference in the proportions of patients with VF/VT rhythms peaked at 15-20 min but was insignificant at 30 min postcollapse (15 min after collapse; 20.9% vs 13.9%; p<0.001). The likelihood of a pulseless electrical activity rhythm was significantly lower in patients who received bystander CPR during the first 25 min postcollapse (15 min after collapse; 26.2% vs 31.5%; p<0.001). The two groups had no significant difference in the likelihood of asystole (15 min after collapse; 51.0% vs 53.3%; p=0.078).

CONCLUSION

Bystander CPR was associated with a higher VF/VT likelihood and a lower likelihood of pulseless electrical activity at first documented rhythm analysis. Our results support early CPR for OHCA and highlight the need for further research to understand whether and how CPR modifies the cardiac rhythm after arrest.

Association between blood urea nitrogen to creatinine ratio and neurologically favourable outcomes in out-of-hospital cardiac arrest in adults: A multicentre cohort study

BACKGROUND

We aimed to investigate the association between blood urea nitrogen to creatinine ratio (BCR) and survival with favourable neurological outcomes in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

This prospective, multicentre, observational study conducted in Osaka, Japan enrolled consecutive OHCA patients transported to 16 participating institutions from 2012 through 2019. We included adult patients with non-traumatic OHCA who achieved a return of spontaneous circulation and whose blood urea nitrogen and creatinine levels on hospital arrival were available. Based on BCR values, they were divided into: 'low BCR' (BCR <10), 'normal BCR' (10 ≤ BCR < 20), 'high BCR' (20 ≤ BCR < 30), and 'very high BCR' (BCR ≥ 30). We evaluated the association between BCR values and neurologically favourable outcomes, defined as cerebral performance category score of 1 or 2 at one month after OHCA.

RESULTS

Among 4415 eligible patients, the 'normal BCR' group had the highest favourable neurological outcome [19.4 % (461/2372)], followed by 'high BCR' [12.5 % (141/1127)], 'low BCR' [11.2 % (50/445)], and 'very high BCR' groups [6.6 % (31/471)]. In the multivariable analysis, adjusted odds ratios for 'low BCR', 'high BCR', and 'very high BCR' compared with 'normal BCR' for favourable neurological outcomes were 0.58 [95 % confidence interval (CI 0.37-0.91)], 0.70 (95 % CI 0.49-0.99), and 0.40 (95 % CI 0.21-0.76), respectively. Cubic spline analysis indicated that the association between BCR and favourable neurological outcomes was non-linear (p for non-linearity = 0.003). In subgroup analysis, there was an interaction between the aetiology of arrest and BCR in neurological outcome (p for interaction <0.001); favourable neurological outcome of cardiogenic OHCA patients was lower when the BCR was higher or lower, but not in non-cardiogenic OHCA patients.

CONCLUSIONS

Both higher and lower BCR were associated with poor neurological outcomes compared to normal BCR, especially in cardiogenic OHCA patients.

Application of adult prehospital resuscitation rules to pediatric out of hospital cardiac arrest

BACKGROUND

Prehospital termination of resuscitation (TOR) rules can be recommended for adults with out-of-hospital cardiac arrests (OHCAs). This study aimed to investigate whether adult basic life support (BLS) and advanced life support (ALS) TOR rules can predict neurologically unfavorable one-month outcome for pediatric OHCA patients.

METHODS

From a nationwide population-based observational cohort study, we extracted data of consecutive pediatric OHCA patients (0-17 years old) from January 1, 2005, to December 31, 2011. The BLS TOR rule has three criteria, whereas the ALS TOR rule includes two additional criteria. We selected pediatric OHCA patients that met all criteria for each TOR rule and calculated the specificity and positive predictive value (PPV) of each TOR rule for identifying pediatric OHCA patients who did not have neurologically favorable one-month outcome.

RESULTS

Of the 12,740 pediatric OHCA patients eligible for the evaluation of the BLS TOR rule, 10,803 patients met the BLS TOR rule, with a specificity of 0.785 and a PPV of 0.987 for predicting a lack of neurologically favorable one-month survival. Of the 2,091 for the ALS TOR rule, 381 patients met the ALS TOR rule, with a specificity of 0.986 and a PPV of 0.997 for predicting neurologically unfavorable one-month outcome.

CONCLUSIONS

The adult BLS and ALS TOR rules had a high PPV for predicting pediatric OHCA patients without a neurologically favorable survival at one month after onset.

Sex disparities in prehospital advanced cardiac life support in out-of-hospital cardiac arrests in Japan

OBJECTIVE

Sex disparities in out-of-hospital cardiac arrest (OHCA) care processes have been reported. This study aimed to investigate the association between sex and prehospital advanced cardiac life support (ACLS) interventions provided by emergency medical services in Japan.

METHODS

We analyzed data from January 1, 2013, to December 31, 2020, from the All-Japan Utstein Registry of patients with OHCA aged ≥18 years who were resuscitated by bystanders. The primary outcomes were prehospital ACLS interventions, including advanced airway management (AAM) and epinephrine administration. Sex-based disparities in receiving prehospital ACLS interventions were assessed via multivariable logistic regression analyses.

RESULTS

Among 314,460 eligible patients, females with OHCA received fewer prehospital ACLS interventions than males: 83,571/187,834 (44.5%) males vs. 55,086/126,626 (43.5%) females (adjusted odds ratio [AOR] = 0.94, 95% confidence interval [CI] = 0.93-0.96) for AAM and 60,097/187,834 (32.0%) males vs. 35,501/126,626 (28.0%) females (AOR = 0.84, 95% CI = 0.83-0.85) for epinephrine administration. Similar results were also obtained in the subgroup analysis (groups included patients aged 18-74 years and ≥75 years and those with cardiac origin, ventricular fibrillation (VF), non-VF, non-family member witnessed, and family member witnessed).

CONCLUSION

Compared with males, females were less likely to receive prehospital ACLS. Emergency medical service staff must be made aware of this disparity, and off-the-job training on intravenous cannulation or AAM replacement must be conducted. Investigation of the impact of sex disparity on OHCA care processes can facilitate planning of future public health policies to improve survival outcomes.

Clinical characteristics and outcomes after extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest patients with an initial asystole rhythm

AIM

This study aimed to describe the characteristics of cases of out-of-hospital cardiac arrest (OHCA) with an initial asystole rhythm in which extracorporeal cardiopulmonary resuscitation (ECPR) was introduced and discuss the clinical indications for ECPR in such patients.

METHODS

This was a secondary analysis of the SAVE-J II study, a retrospective, multicentre, registry study involving 36 participating institutions in Japan. Patients with an initial asystole rhythm were selected. Favourable neurological outcomes (cerebral performance categories 1-2) constituted the primary outcome.

RESULTS

In total, 202 patients met the inclusion criteria, with favourable neurological outcomes at hospital discharge in 12 patients (5.9%). Causes of cardiac arrest with favourable neurological outcomes were hypothermia (7 cases), acute coronary syndrome (2 cases), arrhythmia (2 cases), and pulmonary embolism (1 case). Among patients with non-hypothermia (temperature ≥32 °C) on hospital arrival with the cardiac rhythm of asystole or pulseless electrical activity (PEA) on arrival, all 107 patients (66 asystole, 41 PEA) who lacked one or more of the requirements (witness; bystander CPR; signs of life or pupil < 5 mm) had unfavourable neurological outcomes. All 5 cases with favourable neurological outcomes, except for 1 case with a short duration of no-flow time that was highly suspected based on the patient's history, met all the requirements on hospital arrival.

CONCLUSIONS

A total of 202 ECPR cases with an initial asystole rhythm, including 12 patients with favourable neurological outcomes, were described. Even if the initial cardiac rhythm is asystole, ECPR could be considered if certain conditions are met.

Intra-arrest partial carbon dioxide level and favorable neurological outcome after out-of-hospital cardiac arrest: a nationwide multicenter observational study in Japan (the JAAM-OHCA registry)

AIMS

Little is known about whether guideline-recommended ventilation during cardiopulmonary resuscitation results in optimal partial carbon dioxide (pCO2) levels or favorable outcomes. This study aimed to evaluate the association between intra-arrest pCO2 level and the outcome after out-of-hospital cardiac arrest (OHCA).

METHODS AND RESULTS

We performed a secondary analysis of a multicenter observational study, including adult patients with OHCA who did not achieve a return of spontaneous circulation (ROSC) upon hospital arrival and whose blood gas analysis was performed before the ROSC between June 2014 and December 2017. The patients were categorized into four quartiles based on their intra-arrest carbon dioxide levels: Quartile 1 (<66.0 mmHg), Quartile 2 (66.1-87.2 mmHg), Quartile 3 (87.3-113.5 mmHg), and Quartile 4 (≥113.6 mmHg). The primary outcome was 1-month survival with favorable neurological outcomes defined as cerebral performance Category 1 or 2. Multivariate logistic regression analysis was used to evaluate the association between pCO2 and favorable neurological outcomes. During the study period, 20 913 patients were eligible for the analysis. The proportion of favorable neurological outcomes was 1.8% (90/5133), 0.7% (35/5232), 0.4% (19/5263), and 0.2% (9/5285) in Quartiles 1-4, respectively. Multivariable logistic regression analysis demonstrated that the probability of favorable neurological outcome decreased with increased intra-arrest carbon dioxide levels (i.e. Q1 vs. Q4, adjusted odds ratio 0.25, 95% confidence interval 0.16-0.55, P for trend <0.001).

CONCLUSION

Lower intra-arrest pCO2 levels were associated with a favorable neurological outcome.

Factors affecting public access defibrillator placement decisions in the United Kingdom: A survey study

Aim

This study aimed to understand current community PAD placement strategies and identify factors which influence PAD placement decision-making in the United Kingdom (UK).

Methods

Individuals, groups and organisations involved in PAD placement in the UK were invited to participate in an online survey collecting demographic information, facilitators and barriers to community PAD placement and information used to decide where a PAD is installed in their experiences. Survey responses were analysed through descriptive statistical analysis and thematic analysis.

Results

There were 106 included responses. Distance from another PAD (66%) and availability of a power source (63%) were most frequently used when respondents are deciding where best to install a PAD and historical occurrence of cardiac arrest (29%) was used the least. Three main themes were identified influencing PAD placement: (i) the relationship between the community and PADs emphasising community engagement to create buy-in; (ii) practical barriers and facilitators to PAD placement including securing consent, powering the cabinet, accessibility, security, funding, and guardianship; and (iii) 'risk assessment' methods to estimate the need for PADs including areas of high footfall, population density and type, areas experiencing health inequalities, areas with delayed ambulance response and current PAD provision.

Conclusion

Decision-makers want to install PADs in locations that maximise impact and benefit to the community, but this can be constrained by numerous social and infrastructural factors. The best location to install a PAD depends on local context; work is required to determine how to overcome barriers to optimal community PAD placement.

Intra-aortic balloon pump use in out-of-hospital cardiac arrest patients who underwent extracorporeal cardiopulmonary resuscitation

AIM

To investigate the effect of intra-aortic balloon pump (IABP) use after extracorporeal membrane oxygenation-assisted cardiopulmonary resuscitation (ECPR) on short-term neurological outcomes and survival in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

We retrospectively analysed data collected between June 2014 and December 2019 from the Japanese OHCA registry. Adult patients (aged ≥18 years) who underwent ECPR were included. We divided the patients into those who received IABP and those who did not receive IABP. The primary outcome was the 30-day favourable neurological outcomes in survived patients. The secondary outcome was the 30-day survival. We performed propensity score matching (PSM) to adjust for confounding factors after multiple imputations of missing data. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated using logistic regression analysis after PSM to adjust for confounding factors after IABP initiation.

RESULTS

Among 2135 adult patients who underwent ECPR, 1173 received IABP. In 842 matched patients, IABP use was associated with survival (aOR, 1.98; 95% CI, 1.39-2.83; p < 0.001). However, IABP use was not significantly associated with the 30-day neurologically favourable outcome in 190 survived patients (aOR, 1.22; 95% CI, 0.79-1.89; p = 0.36).

CONCLUSION

The use of IABP in patients with OHCA who underwent ECPR was associated with 30-day survival. Among survived patients, there was no significant association between IABP use and 30-day neurological outcome. A further well-designed prospective study is needed.