Alert system-supported lay defibrillation and basic life-support for cardiac arrest at home

Sex Differences in Out-of-Hospital Cardiac Arrest Survival Trends

BACKGROUND

Out-of-hospital cardiac arrest survival rates have improved over time. This study established whether improvements were similar for women and men, and to what extent resuscitation characteristics or in-hospital procedures contributed to sex differences in temporal trends.

METHODS AND RESULTS

This retrospective cohort study included 3386 women and 8564 men from North Holland, the Netherlands, who experienced an out-of-hospital cardiac arrest from a cardiac cause in 2005 to 2017. Yearly rates of 30-day survival and secondary outcomes were calculated. Sex differences in temporal trends were evaluated with age-adjusted Poisson regression analysis, including interaction for sex and out-of-hospital cardiac arrest year. Resuscitation characteristics and in-hospital procedures were added to the model, and a spline at 2013 was considered. During the study period, the average 30-day survival was 24.9% in men and 15.7% in women. The 30-day survival rate increased in men (20% to 27.2%; P<0.001) but not in women (15.0% to 11.6%; P=0.40). The increase in the 30-day survival rate was 3% higher per year in men than in women (rate ratio, 1.03 [95% CI, 1.00-1.05]), with a stronger difference after 2013. Men had a larger increase in survival rate to the hospital arrival than women in 2005 to 2013, and, after 2013, an advantage over women in survival rate after hospital arrival. The sex differences were partly explained by differing trends in shockable initial rhythm (eg, adjusted rate ratio, 1.01 [95% CI, 0.99-1.03] for 30-day survival) and provision of in-hospital procedures.

CONCLUSIONS

Changes in rates of 30-day survival, survival to hospital arrival, and, after 2013, survival from hospital arrival to 30 days were more beneficial in men than women. The differences in trends were partly explained by shockable initial rhythm and in-hospital procedures.

Wolf creek XVII part 4: Amplifying lay-rescuer response

Introduction

Amplifying lay-rescuer response is a key priority to increase survival from out-of-hospital cardiac arrest (OHCA). We describe the current state of lay-rescuer response, how we envision the future, and the gaps, barriers, and research priorities that will amplify response to OHCA.

Methods

'Amplifying Lay-Rescuer Response' was one of six focus topics for the Wolf Creek XVII Conference held on June 14-17, 2023, in Ann Arbor, Michigan, USA. Conference invitees included international thought leaders and scientists in the field of cardiac arrest resuscitation from academia and industry. Participants submitted via online survey knowledge gaps, barriers to translation and research priorities for each focus topic. Expert panels used the survey results and their own perspectives and insights to create and present a preliminary unranked list for each category that was debated, revised and ranked by all attendees to identify the top 5 for each category.

Results

The top five knowledge gaps as ranked by the panel, reflected a recognition of the need to better understand the psycho-social aspects of lay response. The top five barriers to translation reflected issues at the individual, community, societal, structural, and governmental levels. The top five research priorities were focused on understanding the social/psychological and emotional barriers to action, finding the most effective/cost-effective strategies to educate lay persons and implement community life-saving interventions, evaluation of new technological solutions and how to enhance the role of dispatch working with lay-rescuers.

Conclusion

Future research in lay rescuer response should incorporate technology innovations, understand the "humanity" of the situation, leverage implementation science and systems thinking to save lives. This will require the field of resuscitation to engage with scholars outside our traditional ranks and to be open to new ways of thinking about old problems.

Out-of-ospital cardiac arrest & Smartphonespndr trial ( Trial): Methodology and study protocol of a pre-post-design trial of the effect of implementing a smartphone alerting system on survival in out-of-hospital cardiac arrest

Background

Since 2021, international guidelines for cardiopulmonary resuscitation recommend the implementation of so-called "life-saving systems". These systems include smartphone alerting systems (SAS), which enable dispatch centres to alert first responders via smartphone applications, who are in proximity of a suspected out-of-hospital cardiac arrest (OHCA). However, the effect of SAS on survival remains unknown.

Aim

The aim is to assess the rate of survival to hospital discharge in adult patients with OHCA not witnessed by emergency medical services (EMS): before and after SAS implementation.

Design

Multicentre, prospective, observational, intention-to-treat, pre-post design clinical trial.

Population

Adults (aged ≥ 18 years), OHCA not witnessed by EMS, no traumatic cause for cardiac arrest, cardiopulmonary resuscitation initiated or continued by EMS.

Setting

Dispatch-centre-based.

Outcomes

Primary: survival to hospital discharge. Secondary: time to first compression, rate of basic life support measures before EMS arrival, rate of patients with shockable rhythm at EMS arrival, Cerebral Performance Category at hospital discharge, and duration of hospital stay.

Sample size

Assuming an absolute difference in survival rates to hospital discharge of 4% in the two groups (11% before implementation of the SAS versus 15% after) and 80% power, and a type 1 error rate of 0.05, the required sample size is N = 1,109 patients per group (at least N = 2,218 evaluated patients in total).

Conclusions

The HEROES trial will investigate the effects of a SAS on the survival rate after OHCA.

Trial registration

German Clinical Trials Register (DRKS, ID: DRKS00032920).

Access to automated external defibrillators and first responders: Associations with socioeconomic factors and income inequality at small spatial scales

Aim

The 2021 European Resuscitation Council (ERC) guidelines recommend two automated external defibrillators (AEDs)/km2 and at least 10 first responders/km2. We examined 1) access to AEDs and volunteer first responders in line with these guidelines and 2) its associations with socioeconomic factors and income inequality, focusing on small spatial scales.

Method

We considered data on 776 AEDs in February 2022 and 1,173 out-of-hospital cardiac arrests (OHCAs) including 713 OHCA with app-alerted volunteer first responders from February to September 2022 in Berlin. We fit multilevel models to analyse AED area coverage and Poisson models to examine first responder availability across 12 districts and 536 neighbourhoods.

Results

Median AED area coverage according to the 2021 ERC guidelines was 43.1% (interquartile range (IQR) 2.3-87.2) at the neighbourhood level and median number of available first responders per OHCA case was one (IQR 0.0-1.0). AED area coverage showed a positive association with average income tax per capita, with better coverage in the highest compared to the lowest quartile neighbourhoods (coefficient: 0.13, 95% confidence interval (CI): 0.01-0.25). First responder availability was not associated with income tax. AED area coverage and first responder availability were positively associated with income inequality, with better coverage (coefficient: 0.13, 95% CI: 0.04-0.23) and availability (rate ratio: 1.31, 95% CI: 1.03-1.67) in quartiles of highest as compared to lowest inequality.

Conclusion

Access to resuscitation resources is neither equitable nor in accordance with the 2021 ERC guidelines. Ensuring better access necessitates understanding of socioeconomic factors and income inequality at small spatial scales.

Automated cardiac arrest detection using a photoplethysmography wristband: algorithm development and validation in patients with induced circulatory arrest in the DETECT-1 study

BACKGROUND

Unwitnessed out-of-hospital cardiac arrest is associated with low survival chances because of the delayed activation of the emergency medical system in most cases. Automated cardiac arrest detection and alarming using biosensor technology would offer a potential solution to provide early help. We developed and validated an algorithm for automated circulatory arrest detection using wrist-derived photoplethysmography from patients with induced circulatory arrests.

METHODS

In this prospective multicentre study in three university medical centres in the Netherlands, adult patients (aged 18 years or older) in whom short-lasting circulatory arrest was induced as part of routine practice (transcatheter aortic valve implantation, defibrillation testing, or ventricular tachycardia induction) were eligible for inclusion. Exclusion criteria were a known bilateral significant subclavian artery stenosis or medical issues interfering with the wearing of the wristband. After providing informed consent, patients were equipped with a photoplethysmography wristband during the procedure. Invasive arterial blood pressure and electrocardiography were continuously monitored as the reference standard. Development of the photoplethysmography algorithm was based on three consecutive training cohorts. For each cohort, patients were consecutively enrolled. When a total of 50 patients with at least one event of circulatory arrest were enrolled, that cohort was closed. Validation was performed on the fourth set of included patients. The primary outcome was sensitivity for the detection of circulatory arrest.

FINDINGS

Of 306 patients enrolled between March 14, 2022, and April 21, 2023, 291 patients were included in the data analysis. In the development phase (n=205), the first training set yielded a sensitivity for circulatory arrest detection of 100% (95% CI 94-100) and four false positive alarms; the second training set yielded a sensitivity of 100% (94-100), with six false positive alarms; and the third training set yielded a sensitivity of 100% (94-100), with two false positive alarms. In the validation phase (n=86), the sensitivity for circulatory arrest detection was 98% (92-100) and 11 false positive circulatory arrest alarms. The positive predictive value was 90% (95% CI 82-94).

INTERPRETATION

The automated detection of induced circulatory arrests using wrist-derived photoplethysmography is feasible with good sensitivity and low false positives. These promising findings warrant further development of this wearable technology to enable automated cardiac arrest detection and alarming in a home setting.

FUNDING

Dutch Heart Foundation (Hartstichting).

Improving survival after cardiac arrest in Europe: The synergetic effect of rescue chain strategies

Sudden cardiac arrest is a global problem and is considered the third leading cause of death in industrialized countries. Patient survival rates after out-of-hospital cardiac arrest (OHCA) vary significantly between countries and continents. In particular, the 2021 European Resuscitation Council (ERC) Resuscitation Guidelines place a special focus on the chain of survival of patients after OHCA. As a complex, interconnected approach, the focus is on: Raising awareness for cardiac arrest and lay resuscitation, school children's education in resuscitation "KIDS SAVE LIVES", first responder systems - technologies to engage the community, telephone-assisted resuscitation (telephone-CPR; T-CPR) by dispatchers, and cardiac arrest centers (CAC) for further treatment in specialized hospitals. The Systems Saving Lives approach is a comprehensive strategy that emphasizes the interconnectedness of all links in the chain of survival following an OHCA, with a particular focus on the relationship between the community and emergency medical services (EMS). This system-level approach emphasizes the importance of the connection between all those involved in the chain of survival. It has a high potential to improve overall survival after OHCA. Therefore, it is recommended that these strategies be promoted and expanded in all countries.

Reporting standard for describing first responder systems, smartphone alerting systems, and AED networks

Standardized reporting of data is crucial for out-of-hospital cardiac arrest (OHCA) research. While the implementation of first responder systems dispatching volunteers to OHCA is encouraged, there is currently no uniform reporting standard for describing these systems. A steering committee established a literature search to identify experts in smartphone alerting systems. These international experts were invited to a conference held in Hinterzarten, Germany, with 40 researchers from 13 countries in attendance. Prior to the conference, participants submitted proposals for parameters to be included in the reporting standard. The conference comprised five workshops covering different aspects of smartphone alerting systems. Proposed parameters were discussed, clarified, and consensus was achieved using the Nominal Group Technique. Participants voted in a modified Delphi approach on including each category as a core or supplementary element in the reporting standard. Results were presented, and a writing group developed definitions for all categories and items, which were sent to participants for revision and final voting using LimeSurvey web-based software. The resulting reporting standard consists of 68 core items and 21 supplementary items grouped into five topics (first responder system, first responder network, technology/algorithm/strategies, reporting data, and automated external defibrillators (AED)). This proposed reporting standard generated by an expert opinion group fills the gap in describing first responder systems. Its adoption in future research will facilitate comparison of systems and research outcomes, enhancing the transfer of scientific findings to clinical practice.

Early extracorporeal CPR for refractory out-of-hospital cardiac arrest - A pre-planned per-protocol analysis of the INCEPTION-trial

BACKGROUND

Evidence for extracorporeal cardiopulmonary resuscitation (CPR) in refractory out-of-hospital cardiac arrest (OHCA) remains inconclusive. Recently, the INCEPTION-trial, comparing extracorporeal with conventional CPR, found no statistically significant difference in neurologically favorable survival. Since protocol deviations were anticipated, a pre-specified per-protocol analysis was foreseen.

METHODS

The per-protocol analysis of the INCEPTION trial excluded patients not meeting inclusion or exclusion criteria, amongst which time-to-cannulation of >60 minutes, and achieving a return of spontaneous circulation before hospital arrival. Crossovers were excluded as well. The primary outcome (30-day survival in a neurologically favorable condition; cerebral performance category [CPC] 1-2) was primarily analyzed under a frequentist statistical framework. In addition, Bayesian analysis under a minimally informative prior was performed.

RESULTS

Eighty-one patients were included in the per-protocol analysis (extracorporeal CPR n = 33, conventional CPR n = 48). Thirty-day survival with CPC1-2 was 15% in the extracorporeal CPR group versus 9% in the conventional CPR group (adjusted OR 1.9; 95% CI 0.4-9.3; p-value 0.393). Bayesian analysis showed an 84% posterior probability of any ECPR benefit and a 61% posterior probability of a 5% absolute risk reduction for the primary outcome.

CONCLUSION

A pre-planned, pre-specified per-protocol analysis of the INCEPTION-trial, found a higher survival with favorable neurological in patients undergoing ECPR versus CCPR for refractory shockable OHCA. This difference did not reach statistical significance, but results should be interpreted with care, in the light of the small remaining sample size.

[Prehospital resuscitation : Current status, results and strategies for improvement in Germany]

Out-of-hospital cardiac arrest (OHCA) is one of the most frequent causes of death in Europe and is associated with a dismal prognosis. The annual incidence in Germany is approximately 100-120 per 100,000 inhabitants (ca. 80,000-100,000 cases). With the use of cardiopulmonary resuscitation (CPR) about 40% of patients have a return of spontaneous circulation (ROSC); however, after OHCA only 15% of patients survive for 30 days and less than 10% survive with no or only minor neurological deficits. Data from the German Resuscitation Register demonstrate that there was no change in the results over the last 15 years, despite all medical innovations, higher rates of coronary interventions, higher use of mechanical support systems and improvement in intensive care treatment. A high proportion of patients with OHCA have a cardiac or coronary cause. As shown by the data from the German Cardiac Arrest Register (G-CAR) an early coronary angiography is often carried out after CPR in Germany; however, in randomized clinical studies an immediate coronary angiography in patients with non-ST segment elevation in the electrocardiogram (ECG) was not associated with an improvement in the prognosis. In large randomized studies the use of mechanical CPR systems and the implantation of mechanical circulatory support devices after OHCA also did not lead to a reduction in mortality. The most important impact factor for the success of CPR is the time interval between collapse and start of CPR, if possible also by bystander resuscitation. Therefore, the focus of efforts for improving CPR should be on increasing the rate of patients with early CPR. Experiences from Denmark and The Netherlands indicate that this can be successful by education and training of the general population, telephone resuscitation and apps for alerting lay persons.

Automated external defibrillators and the link to first responder systems

PURPOSE OF REVIEW

Automated external defibrillators are a very effective treatment to convert ventricular fibrillation (VF) in out-of-hospital cardiac arrest. The purpose of this paper is to review recent publications related to automated external defibrillators (AEDs).

RECENT FINDINGS

Much of the recent research focus on ways to utilize publicly available AEDs included in different national/regional registers. More and more research present positive associations between engaging volunteers to increase the use of AEDs. There are only a few recent studies focusing on professional first responders such as fire fighters/police with mixed results. The use of unmanned aerial vehicles (drones) lacks clinical data and is therefore difficult to evaluate. On-site use of AED shows high survival rates but suffers from low incidence of out-of-hospital cardiac arrest (OHCA).

SUMMARY

The use of public AEDs in OHCA are still low. Systems focusing on engaging volunteers in the cardiac arrest response have shown to be associated with higher AED usage. Dispatching drones equipped with AEDs is promising, but research lacks clinical data. On-site defibrillation is associated with high survival rates but is not available for most cardiac arrests.

The Lancet Commission to reduce the global burden of sudden cardiac death: a call for multidisciplinary action

Despite major advancements in cardiovascular medicine, sudden cardiac death (SCD) continues to be an enormous medical and societal challenge, claiming millions of lives every year. Efforts to prevent SCD are hampered by imperfect risk prediction and inadequate solutions to specifically address arrhythmogenesis. Although resuscitation strategies have witnessed substantial evolution, there is a need to strengthen the organisation of community interventions and emergency medical systems across varied locations and health-care structures. With all the technological and medical advances of the 21st century, the fact that survival from sudden cardiac arrest (SCA) remains lower than 10% in most parts of the world is unacceptable. Recognising this urgent need, the Lancet Commission on SCD was constituted, bringing together 30 international experts in varied disciplines. Consistent progress in tackling SCD will require a completely revamped approach to SCD prevention, with wide-sweeping policy changes that will empower the development of both governmental and community-based programmes to maximise survival from SCA, and to comprehensively attend to survivors and decedents' families after the event. International collaborative efforts that maximally leverage and connect the expertise of various research organisations will need to be prioritised to properly address identified gaps. The Commission places substantial emphasis on the need to develop a multidisciplinary strategy that encompasses all aspects of SCD prevention and treatment. The Commission provides a critical assessment of the current scientific efforts in the field, and puts forth key recommendations to challenge, activate, and intensify efforts by both the scientific and global community with new directions, research, and innovation to reduce the burden of SCD worldwide.

One-year quality-of-life outcomes of cardiac arrest survivors by initial defibrillation provider

OBJECTIVE

To assess the long-term functional and health-related quality-of-life (HRQoL) outcomes for out-of-hospital cardiac arrest (OHCA) survivors stratified by initial defibrillation provider.

METHODS

This retrospective study included adult non-traumatic OHCA with initial shockable rhythms between 2010 and 2019. Survivors at 12 months after arrest were invited to participate in structured telephone interviews. Outcomes were identified using the Glasgow Outcome Scale-Extended (GOS-E), EuroQol-5 Dimension (EQ-5D), 12-Item Short Form Health Survey and living and work status-related questions.

RESULTS

6050 patients had initial shockable rhythms, 3211 (53.1%) had a pulse on hospital arrival, while 1879 (31.1%) were discharged alive. Bystander defibrillation using the closest automated external defibrillator had the highest survival rate (52.8%), followed by dispatched first responders (36.7%) and paramedics (27.9%). 1802 (29.8%) patients survived to 12-month postarrest; of these 1520 (84.4%) were interviewed. 1088 (71.6%) were initially shocked by paramedics, 271 (17.8%) by first responders and 161 (10.6%) by bystanders. Bystander-shocked survivors reported higher rates of living at home without care (87.5%, 75.2%, 77.0%, p<0.001), upper good recovery (GOS-E=8) (41.7%, 30.4%, 30.6%, p=0.002) and EQ-5D visual analogue scale (VAS) ≥80 (64.9%, 55.9%, 52.9%, p=0.003) compared with first responder and paramedics, respectively. After adjustment, initial bystander defibrillation was associated with higher odds of EQ-5D VAS ≥80 (adjusted OR (AOR) 1.56, 95% CI 1.15-2.10; p=0.004), good functional recovery (GOS-E ≥7) (AOR 1.53, 95% CI 1.12-2.11; p=0.009), living at home without care (AOR 1.77, 95% CI 1.16-2.71; p=0.009) and returning to work (AOR 1.72, 95% CI 1.05-2.81; p=0.031) compared with paramedic defibrillation.

CONCLUSION

Survivors receiving initial bystander defibrillation reported better functional and HRQoL outcomes at 12 months after arrest compared with those initially defibrillated by paramedics.

Characterization of non-cardiac arrest PulsePoint activations in public and private settings

BACKGROUND

Geospatial smartphone application alert systems are used in some communities to crowdsource community response for out-of-hospital cardiac arrest (OHCA). Although the clinical focus of this strategy is OHCA, dispatch identification of OHCA is imperfect so that activation may occur for the non-arrest patient. The frequency and clinical profile of such non-arrest patients has not been well-investigated.

METHODS

We undertook a prospective 3-year cohort investigation of patients for whom a smartphone geospatial application was activated for suspected OHCA in four United States communities (total population ~1 million). The current investigation evaluates those patients with an activation for suspected OHCA who did not experience cardiac arrest. The volunteer response cohort included off-duty, volunteer public safety personnel (verified responders) notified regardless of location (public or private) and laypersons notified to public locations. The study linked the smartphone application information with the EMS records to report the frequency, condition type, and EMS treatment for these non-arrest patients.

RESULTS

Of 1779 calls where volunteers were activated, 756 had suffered OHCA, resulting in 1023 non-arrest patients for study evaluation. The most common EMS assessments were syncope (15.9%, n=163), altered mental status (15.5%, n=159), seizure (14.3%, n=146), overdose (13.0%, n=133), and choking (10.5%, n=107). The assessment distribution was similar for private and public locations. Overall, the most common EMS interventions included placement of an intravenous line (43.1%, n=441), 12-Lead ECG(27.9%, n=285), naloxone treatment (9.8%, n=100), airway or ventilation assistance (8.7%, n=89), and oxygen administration (6.6%, n=68).

CONCLUSIONS

More than half of patients activated for suspected OHCA had conditions other than cardiac arrest. A subset of these conditions may benefit from earlier care that could be provided by both layperson and public safety volunteers if they were appropriately trained and equipped.

Dispatch of Volunteer Responders to Out-of-Hospital Cardiac Arrests

BACKGROUND

Systems for dispatch of volunteer responders to collect automated external defibrillators and/or to provide cardiopulmonary resuscitation (CPR) in cases of nearby out-of-hospital cardiac arrest (OHCA) are widely implemented.

OBJECTIVES

This study aimed to investigate whether the activation of a volunteer responder system to OHCAs was associated with higher rates of bystander CPR, bystander defibrillation, and 30-day survival vs no system activation.

METHODS

This was a retrospective observational analysis within the ESCAPE-NET (European Sudden Cardiac Arrest network: Towards Prevention, Education, New Effective Treatment) collaborative research network. Included were cases of OHCA between 2015 and 2019 from 5 European sites with volunteer responder systems. At all sites, systems were activated by dispatchers at the emergency medical communication center in response to suspected OHCA. Exposed cases (system activation) were compared with nonexposed cases (no system activation). Risk ratios (RRs) were calculated for the outcomes of bystander CPR, bystander defibrillation, and 30-day survival after inverse probability treatment weighting. Missing data were handled using multiple imputation.

RESULTS

In total, 9,553 cases were included. In 4,696 cases, the volunteer responder system was activated, and in 4,857 it was not. The pooled RRs were 1.30 (95% CI: 1.15-1.47) for bystander CPR, 1.89 (95% CI: 1.36-2.63) for bystander defibrillation, and 1.22 (95% CI: 1.07-1.39) for 30-day survival.

CONCLUSIONS

Activation of a volunteer response system in cases of OHCA was associated with a higher chance of bystander CPR, bystander defibrillation, and 30-day survival vs no system activation. A randomized controlled trial is necessary to determine fully the causal effect of volunteer responder systems.

Changes in neurological outcomes of out-of-hospital cardiac arrest during the COVID-19 pandemic in Japan: a population-based nationwide observational study

Background

There is growing interest in the indirect negative effects of coronavirus disease 2019 (COVID-19) on mortality. We aimed to assess its indirect effect on out-of-hospital cardiac arrest (OHCA) outcomes.

Methods

We analysed a prospective nationwide registry of 506,935 patients with OHCA between 2017 and 2020. The primary outcome was favourable neurological outcome (Cerebral Performance Category 1 or 2) at 30 days. The secondary outcomes were public access defibrillation (PAD) and bystander-initiated chest compression. We performed an interrupted time series (ITS) analysis to assess changes in the trends of these outcomes around the declaration of a state of emergency (April 7 - May 25, 2020). We also performed a subgroup analysis stratified by infection spread status.

Findings

We identified 21,868 patients with OHCA witnessed by a bystander who had an initial shockable heart rhythm. ITS analysis showed a drastic decline in PAD use (relative risk [RR], 0.60; 95% confidence interval [CI], 0.49-0.72; p < 0.0001) and a reduction in favourable neurological outcomes (RR, 0.79; 95% CI, 0.68-0.91; p = 0.0032) all over Japan after the state of emergency was declared when compared with the equivalent time period in previous years. The decline in favourable neurological outcomes was more pronounced in areas with COVID-19 spread than in areas without spread (RR, 0.70; 95% CI, 0.58-0.86 vs. RR, 0.87; 95% CI, 0.72-1.03; p for effect modification = 0.019).

Interpretation

COVID-19 is associated with worse neurological outcomes and less PAD use in patients with OHCA.

Funding

None.

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.

Three-year trends in out-of-hospital cardiac arrest across the world: second report from the International Liaison Committee on Resuscitation (ILCOR)

BACKGROUND

The International Liaison Committee on Resuscitation (ILCOR) Research and Registries Working Group previously reported data on systems of care and outcomes of out-of-hospital cardiac arrest (OHCA) in 2015 from 16 national and regional registries. To describe the temporal trends with updated data on OHCA, we report the characteristics of OHCA from 2015 through 2017.

METHODS

We invited national and regional population-based OHCA registries for voluntary participation and included emergency medical services (EMS)-treated OHCA. We collected descriptive summary data of core elements of the latest Utstein style recommendation during 2016 and 2017 at each registry. For registries that participated in the previous 2015 report, we also extracted the 2015 data.

RESULTS

Eleven national registries in North America, Europe, Asia, and Oceania, and 4 regional registries in Europe were included in this report. Across registries, the estimated annual incidence of EMS-treated OHCA was 30.0-97.1 individuals per 100,000 population in 2015, 36.4-97.3 in 2016, and 40.8-100.2 in 2017. The provision of bystander cardiopulmonary resuscitation (CPR) varied from 37.2% to 79.0% in 2015, from 2.9% to 78.4% in 2016, and from 4.1% to 80.3% in 2017. Survival to hospital discharge or 30-day survival for EMS-treated OHCA ranged from 5.2% to 15.7% in 2015, from 6.2% to 15.8% in 2016, and from 4.6% to 16.4% in 2017.

CONCLUSION

We observed an upward temporal trend in provision of bystander CPR in most registries. Although some registries showed favourable temporal trends in survival, less than half of registries in our study demonstrated such a trend.

Association Between Number of Volunteer Responders and Interventions Before Ambulance Arrival for Cardiac Arrest

BACKGROUND

Volunteer responder (VR) programs for activation of laypersons in out-of-hospital cardiac arrest (OHCA) have been deployed worldwide, but the optimal number of VRs to dispatch is unknown.

OBJECTIVES

The purpose of this study was to investigate the association between the number of VRs arriving before Emergency Medical Services (EMS) and the proportion of bystander cardiopulmonary resuscitation (CPR) and defibrillation.

METHODS

We included OHCAs not witnessed by EMS with VR activation from the Capital Region (September 2, 2017, to May 14, 2019) and the Central Region of Denmark (November 5, 2018, to December 31, 2019). We created 4 groups according to the number of VRs arriving before EMS: 0, 1, 2, and 3 or more. Using a logistic regression model adjusted for EMS response time, we examined associations between the number of VRs arriving before EMS and bystander CPR and defibrillation.

RESULTS

We included 906 OHCAs. The adjusted ORs for bystander CPR were 2.40 (95% CI: 1.42-4.05), 3.18 (95% CI: 1.39-7.26), and 2.70 (95% CI: 1.32-5.52) when 1, 2, or 3 or more VRs arrived before EMS (reference), respectively. The adjusted OR for bystander defibrillation increased when 1 (1.97 [95% CI: 1.12-3.52]), 2 (2.88 [95% CI: 1.48-5.58]), or 3 or more (3.85 [95% CI: 2.11-7.01]) VRs arrived before EMS (reference). The adjusted OR of bystander defibrillation increased to 1.95 (95% CI: 1.18-3.22) when ≥3 VRs arrived first compared with 1 VR arriving first (reference).

CONCLUSIONS

We found an association of increased bystander CPR and defibrillation when 1 or more VRs arrived before the EMS with a trend toward increased bystander defibrillation with increasing number of VRs arriving first.

Effect of Smartphone Dispatch of Volunteer Responders on Automated External Defibrillators and Out-of-Hospital Cardiac Arrests: The SAMBA Randomized Clinical Trial

Importance

Smartphone dispatch of volunteer responders to nearby out-of-hospital cardiac arrests (OHCAs) has emerged in several emergency medical services, but no randomized clinical trials have evaluated the effect on bystander use of automated external defibrillators (AEDs).

Objective

To evaluate if bystander AED use could be increased by smartphone-aided dispatch of lay volunteer responders with instructions to collect nearby AEDs compared with instructions to go directly to patients with OHCAs to start cardiopulmonary resuscitation (CPR).

Design, Setting, and Participants

This randomized clinical trial assessed a system for smartphone dispatch of volunteer responders to individuals experiencing OHCAs that was triggered at emergency dispatch centers in response to suspected OHCAs and randomized 1:1. The study was conducted in 2 main Swedish regions: Stockholm and Västra Götaland between December 2018 and January 2020. At study start, there were 3123 AEDs in Stockholm and 3195 in Västra Götaland and 24 493 volunteer responders in Stockholm and 19 117 in Västra Götaland. All OHCAs in which the volunteer responder system was activated by dispatchers were included. Excluded were patients with no OHCAs, those with OHCAs not treated by the emergency medical services, and those with OHCAs witnessed by the emergency medical services.

Interventions

Volunteer responders were alerted through the volunteer responder system smartphone application and received map-aided instructions to retrieve nearest available public AEDs on their way to the OHCAs. The control arm included volunteer responders who were instructed to go directly to the OHCAs to perform CPR.

Main Outcomes and Measures

Overall bystander AED attachment, including those attached by volunteer responders and lay volunteers who did not use the smartphone application.

Results

Volunteer responders were activated for 947 patients with OHCAs. Of those, 461 were randomized to the intervention group (median [IQR] age of patients, 73 [61-81] years; 295 male patients [65.3%]) and 486 were randomized to the control group (median [IQR] age of patients, 73 [63-82] years; 312 male patients [65.3%]). Primary outcome of AED attachment occurred in 61 patients (13.2%) in the intervention arm vs 46 patients (9.5%) in the control arm (difference, 3.8% [95% CI, -0.3% to 7.9%]; P = .08). The majority of AEDs were attached by lay volunteers who were not using the smartphone application (37 in intervention arm, 28 in control). There were no significant differences in secondary outcomes. Among the volunteer responders using the application, crossover was 11% and compliance to instructions was 31%. Volunteer responders attached 38% (41 of 107) of all AEDs and provided 45% (16 of 36) of all defibrillations and 43% (293 of 666) of all CPR.

Conclusions and Relevance

In this study, smartphone dispatch of volunteer responders to OHCAs to retrieve nearby AEDs vs instructions to directly perform CPR did not significantly increase volunteer AED use. High baseline AED attachement rate and crossover may explain why the difference was not significant.

Trial Registration

ClinicalTrials.gov Identifier: NCT02992873.

Smartphone-activated volunteer responders and bystander defibrillation for out-of-hospital cardiac arrest in private homes and public locations

AIMS

To investigate the association between the arrival of smartphone-activated volunteer responders before the Emergency Medical Services (EMS) and bystander defibrillation in out-of-hospital cardiac arrest (OHCA) at home and public locations.

METHODS AND RESULTS

This is a retrospective study (1 September 2017-14 May 2019) from the Stockholm Region of Sweden and the Capital Region of Denmark. We included 1271 OHCAs, of which 1029 (81.0%) occurred in private homes and 242 (19.0%) in public locations. The main outcome was bystander defibrillation. At least one volunteer responder arrived before EMS in 381 (37.0%) of OHCAs at home and 84 (34.7%) in public. More patients received bystander defibrillation when a volunteer responder arrived before EMS at home (15.5 vs. 2.2%, P < 0.001) and in public locations (32.1 vs. 19.6%, P = 0.030). Similar results were found among the 361 patients with an initial shockable heart rhythm (52.7 vs. 11.5%, P < 0.001 at home and 60.0 vs. 37.8%, P = 0.025 in public). The standardized probability of receiving bystander defibrillation increased with longer EMS response times in private homes. The 30-day survival was not significantly higher when volunteer responders arrived before EMS (9.2 vs. 7.7% in private homes, P = 0.41; and 40.5 vs. 35.4% in public locations, P = 0.44).

CONCLUSION

Bystander defibrillation was significantly more common in private homes and public locations when a volunteer responder arrived before the EMS. The standardized probability of bystander defibrillation increased with longer EMS response times in private homes. Our findings support the activation of volunteer responders and suggest that volunteer responders could increase bystander defibrillation, particularly in private homes.

Increased bystander intervention when volunteer responders attend out-of-hospital cardiac arrest

Aim

The primary aim was to investigate the association between alarm acceptance compared to no-acceptance by volunteer responders, bystander intervention, and survival in out-of-hospital cardiac arrest.

Materials and methods

This retrospective observational study included all suspected out-of-hospital cardiac arrests (OHCAs) with activation of volunteer responders in the Capital Region of Denmark (1 November 2018 to 14 May 2019), the Central Denmark Region (1 November 2018 to 31 December 2020), and the Northern Denmark Region (14 February 2020 to 31 December 2020). All OHCAs unwitnessed by Emergency Medical Services (EMS) were analyzed on the basis on alarm acceptance and arrival before EMS. The primary outcomes were bystander cardio-pulmonary resuscitation (CPR), bystander defibrillation and secondary outcome was 30-day survival. A questionnaire sent to all volunteer responders was used with respect to their arrival status.

Results

We identified 1,877 OHCAs with volunteer responder activation eligible for inclusion and 1,725 (91.9%) of these had at least one volunteer responder accepting the alarm (accepted). Of these, 1,355 (79%) reported arrival status whereof 883 (65%) arrived before EMS. When volunteer responders accepted the alarm and arrived before EMS, we found increased proportions and adjusted odds ratio for bystander CPR {94 vs. 83%, 4.31 [95% CI (2.43–7.67)] and bystander defibrillation [13 vs. 9%, 3.16 (1.60–6.25)]} compared to cases where no volunteer responders accepted the alarm.

Conclusion

We observed a fourfold increased odds ratio for bystander CPR and a threefold increased odds ratio for bystander defibrillation when volunteer responders accepted the alarm and arrived before EMS.

Manual chest compression pause duration for ventilations during prehospital advanced life support - An observational study to explore optimal ventilation pause duration for mechanical chest compression devices

AIM

Mechanical chest compression devices in the 30:2 mode generally provide a pause of three seconds to give two insufflations without evidence supporting this pause duration. We aimed to explore the optimal pause duration by measuring the time needed for two insufflations, during advanced life support with manual compressions.

METHODS

Prospectively collected data in the AmsteRdam REsuscitation STudies (ARREST) registry were analysed, including thoracic impedance signal and waveform capnography from manual defibrillators of the Amsterdam ambulance service. Compression pauses were analysed for number of insufflations, time interval from start of the compression pause to the end of the second insufflation, chest compression pause duration and ventilation subintervals.

RESULTS

During 132 out-of-hospital cardiac arrests, 1619 manual chest compression pauses to ventilate were identified. In 1364 (84%) pauses, two insufflations were given. In 28% of these pauses, giving two insufflations took more than three seconds. The second insufflation is completed within 3.8 seconds in 90% and within 5 seconds in 97.5% of these pauses. An increasing likelihood of achieving two insufflations is seen with increasing compression pause duration up to five seconds.

CONCLUSION

The optimal chest compression pause duration for mechanical chest compression devices in the 30:2 mode to provide two insufflations, appears to be five seconds, warranting further studies in the context of mechanical chest compression. A 5-second pause will allow providers to give two insufflations with a very high success rate. In addition, a 5-second pause can also be used for other interventions like rhythm checks and endotracheal intubation.