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

Volunteer Responder Recruitment, Voluntary Deployment of Automated External Defibrillators, and Coverage of Out-of-Hospital Cardiac Arrest in Denmark

BACKGROUND

A volunteer responder program to out-of-hospital cardiac arrest (OHCA) was implemented stepwise in Denmark (2017-2020). This study assessed automated external defibrillator (AED) and volunteer responder coverage of historical OHCAs in Denmark.

METHODS

Non-emergency medical services witnessed OHCAs (2016-2020) from the Danish Cardiac Arrest Registry with known location and AEDs from the Danish AED network were included. Volunteer responders with an exact location were identified using the volunteer responder server. A historical OHCA was defined as covered when ≥4 volunteer responders and ≥1 AED were <500 m range. Coverage was examined according to location (public or home), time of day (noon or midnight), and volunteer responder background (lay people or health care professionals).

RESULTS

A total of 22 330 OHCAs and 22 418 AEDs (387 AEDs/100 000 inhabitants) were included. At noon, 34 180 volunteer responders (589 volunteer responders/100 000 inhabitants) were identified as available. During daytime, OHCA coverage was 56% (95% CI, 55.9-57.2, n=12 625) decreasing to 30% (95% CI, 29.8-31.0, n=6793) when including only volunteer responders with a health care background. There was no significant difference in coverage according to time of day or location of arrest. OHCA coverage was 85% (95% CI, 84.2-86.0, n=6153) 4 years after implementation (first area included).

CONCLUSION

Regardless of time of day, more than half of all OHCAs were covered by volunteer responders and AEDs in Denmark. Excluding lay volunteers would almost halve the coverage. Our results indicate successful recruitment of volunteer responders and deployment of AEDs with great potential for improving bystander defibrillation.

Defining the terminology of first responders alerted for out-of-hospital cardiac arrest by medical dispatch centres: An international consensus study on nomenclature

Aim

Emergency medical services target to reduce time to cardiopulmonary resuscitation and defibrillation by alerting additional individuals to out-of-hospital cardiac arrest (OHCA). Multiple terms are used to describe these individuals, potentially causing confusion and hindering comparisons. This international consensus study aimed to establish standardised terminology.

Methods

Forty-six interdisciplinary researchers from four continents participated in a symposium on "Community First Responders" with the objective of standardising relevant terminology. Initially, terms were proposed anonymously for individuals alerted during work hours and those alerted during leisure time. Each term was rated on a 5-point Likert scale. Terms receiving a high level of agreement were included in the final voting process.

Results

Seven terms were suggested for individuals alerted during work hours. In the first voting "first responder", "professional first responder", and "on-duty first responder" achieved high agreement. Ultimately, consensus was reached on the term "on-duty first responder".For individuals alerted during leisure time, ten terms were proposed. Among these, "first responder", "citizen first responder", "community emergency responder", "community first responder", "volunteer first responder", "volunteer responder", and "volunteer community first responder" reached high agreement. In the final vote "community first responder" was selected.The consensus group agreed that the overarching term "first responder" should be used to describe all community-based individuals, who are alerted, regardless of whether they are on duty or off duty.

Conclusion

This consensus study recommends using the terms "on-duty first responder" and "community first responder" to describe individuals additionally alerted by medical dispatch centres to facilitate early intervention in OHCA.

Public participation willingness in out-of-hospital cardiopulmonary resuscitation: A systematic review and meta-analysis

Objective

This systematic review and meta-analysis aimed to identify the main factors influencing the public's willingness to participate in out-of-hospital emergency care.

Methods

Studies were searched in online databases, including PubMed, Embase, Web of Science, and the Cochrane Library. The articles included in this review were published from inception to July 31, 2024. The Iain Crombie assessment tool was used to assess study quality. Meta-analysis was performed using RevMan (version 5.4) software. The review protocol has been registered with PROSPERO (CRD42024570491).

Results

A total of 1,434 research articles were initially identified, among which 18 were incorporated into this study, and all of the included studies were cross-sectional. Meta-analysis results demonstrated that gender (male; OR = 1.37, 95%CI: 1.28-1.47), profession (healthcare provider; OR = 0.17, 95%CI: 0.06-0.47), knowledge and skill level (OR = 1.63, 95%CI: 1.25-2.11), willingness to undergo training (OR = 2.68, 95%CI: 1.89-3.79), interest in first aid (OR = 2.08, 95%CI: 1.60-2.69), previous training (OR = 2.14, 95%CI: 1.49-3.08), and previous first-aid experience (OR = 1.70, 95%CI: 1.37-2.11) were the principal influencing factors of the public's willingness to engage in out-of-hospital cardiopulmonary resuscitation.

Conclusion

Demographic factors, knowledge, belief, and behavior are crucial in influencing public emergency decision-making. Medical personnel could create specialized training programs based on relevant factors to enhance the public's willingness to engage in out-of-hospital CPR.

Mobile applications enhance out-of-hospital cardiac arrest outcomes: a systematic review and meta-analysis

INTRODUCTION

Mobile applications, as innovative tools for promoting bystander cardiopulmonary resuscitation (CPR), have demonstrated potential to improve outcomes for patients experiencing out-of-hospital cardiac arrest (OHCA). This meta-analysis sought to systematically review the technical features of existing mobile applications and evaluate their impact on OHCA patient outcomes under various emergency response strategies. The findings aimed to guide the development and optimization of prehospital public emergency response systems.

METHODS

A systematic search was conducted in databases including China National Knowledge Infrastructure (CNKI), Wanfang Database, Chinese Scientific Journals Database (VIP), SinoMed, PubMed, Embase, Web of Science, and the Cochrane Library, from inception to August 2023. The included studies involved notifying citizens via text messages or smartphone applications to act as first responders or volunteers in OHCA cases. Using a random effects model and subgroup analysis, we synthesized the results to identify sources of heterogeneity and assess outcomes.

RESULTS

Thirteen mobile applications were included, with an average activation rate of 35.3% among patients and a volunteer arrival rate of 53.3%. Compared to traditional emergency medical services, mobile applications significantly improved survival to discharge or 30-day survival rates (RR = 1.34, 95% CI: 1.24-1.44; P < 0.05), return of spontaneous circulation (ROSC) rates upon hospital admission (RR = 1.23, 95% CI: 1.09-1.40; P < 0.05), bystander CPR rates (RR = 1.25, 95% CI: 1.13-1.37; P < 0.05), and bystander defibrillation rates (RR = 1.23, 95% CI: 1.00-1.51; P = 0.05). Subgroup analyses revealed consistent results for bystander CPR rates and survival outcomes, while variations in defibrillation rates and ROSC at admission were observed, indicating potential influences of application design and operational parameters.

CONCLUSIONS

This study highlighted the significant potential of mobile applications in enhancing bystander interventions and improving patient outcomes. Addressing challenges such as improving access to automated external defibrillators and raising public awareness remained essential to maximizing their overall effectiveness. PROSPERO REGISTRATION NUMBER: CRD42023477676.

Advancements in automated external and wearable cardiac defibrillators

PURPOSE OF REVIEW

Survival statistics for out-of-hospital cardiac arrests remain unsatisfactory. Prompt defibrillation of shockable rhythms, such as ventricular fibrillation and pulseless ventricular tachycardia, is crucial for improving survival. Automated external defibrillators (AEDs) and wearable cardiac defibrillators (WCDs) seek to improve the survival rates following out-of-hospital cardiac arrests. We aim to review the indications, utility, advancements, and limitations of AEDs and WCDs, as well as their role in contemporary and future clinical practice.

RECENT FINDINGS

Recent advancements in these technologies, such as smartphone applications and drone delivery of AEDs and less inappropriate shocks and decreased size of WCDs, have increased their ubiquity and efficacy. However, implementation of this technology remains limited due to lack of resources and suboptimal patient adherence.

SUMMARY

Out of hospital cardiac arrests continue to pose a significant public health challenge. Advancements in AEDs and WCDs aim to facilitate prompt defibrillation of shockable rhythms with the goal of improving survival rates. However, they remain underutilized due to limited resources and suboptimal patient adherence. As these technologies continue to evolve to become smaller, lighter and more affordable, their utilization and accessibility are expected to improve.

The impact of smartphone-dispatched CPR-trained volunteers on OHCA outcomes is influenced by patient age

The early initiation of cardiopulmonary resuscitation (CPR) measures by non-professionals before the arrival of Emergency Medical Service (EMS) is known to be crucial for improving outcomes after out-of-hospital cardiac arrest (OHCA). We assessed the impact of deploying CPR-trained volunteers via a smartphone-based alerting system on the outcome of OHCA patients. In a retrospective nonrandomized cohort study, all OHCA cases in the city of Aachen over a six-year period were analysed. We compared patient data, CPR metrics, alerting system data as well as outcome data between the intervention and control groups. From June 2017 to May 2023, 101 out of 852 resuscitations were initiated by volunteers alerted via a smartphone-based alerting system in OHCA events. We found no overall rise in the return of spontaneous circulation (ROSC) rate. An age-dependent subgroup analysis indicated an increased incidence of initially shockable rhythms and an increased ROSC rate for patients younger than 60 years in the intervention group, while implying a lower ROSC rate in patients older than 80 years after mobile responder CPR. Although this study was underpowered to yield statistically significant results, our findings suggest the need for an age-sensitive approach when evaluating the effects of first-responder systems on OHCA cases.

Association between bystander automated external defibrillator use and survival in witnessed out-of-hospital cardiac arrest: A nationwide observational study in South Korea

AIM

Sudden cardiac arrest is a global health issue, with out-of-hospital cardiac arrest (OHCA) posing a major challenge. Bystander cardiopulmonary resuscitation (CPR) and automated external defibrillators (AEDs) improve survival and neurological outcomes. However, their actual usage involves numerous constraints. Therefore, to determine the association between bystander AED use and survival of patients with OHCA, we analyzed South Korea's national OHCA database.

METHODS

This retrospective study included cases from the Korea Disease Control and Prevention Agency's Out-of-Hospital Cardiac Arrest Surveillance database from January 2016 to December 2021. Adult OHCA cases treated with bystander intervention were categorized into two groups, CPR with AEDs and without AEDs. Propensity score matching was employed to control for confounders and analyze bystander AED use's impact on survival to discharge and neurological outcomes.

RESULTS

Of 182,508 OHCA cases, 35,840 met the inclusion criteria, with 234 (0.7%) receiving bystander CPR with AEDs. The survival rate to discharge in the AED and non-AED group was 46.6% and 23.0%, respectively. However, after adjusting for potential confounders, bystander AED use did not significantly affect survival to discharge (adjusted odds ratio [aOR] 1.01, 95% confidence interval [CI] 0.70-1.44) or favorable neurological outcomes (aOR 1.08, 95% CI 0.99-1.18).

CONCLUSION

Survival to discharge or favorable neurological outcomes of patients with OHCA managed using bystander-applied AEDs and those without showed no significant difference. Factors such as AED accessibility and bystander preparedness influence the impact of bystander AED use. Further research should optimize AED deployment and usage strategies to enhance patient survival rate.

Cardiac Arrest and Cardiopulmonary Resuscitation Outcome Reports: 2024 Update of the Utstein Out-of-Hospital Cardiac Arrest Registry Template

The Utstein Out-of-Hospital Cardiac Arrest Resuscitation Registry Template, introduced in 1991 and updated in 2004 and 2015, standardizes data collection to enable research, evaluation, and comparisons of systems of care. The impetus for the current update stemmed from significant advances in the field and insights from registry development and regional comparisons. This 2024 update involved representatives of the International Liaison Committee on Resuscitation and used a modified Delphi process. Every 2015 Utstein data element was reviewed for relevance, priority (core or supplemental), and improvement. New variables were proposed and refined. All changes were voted on for inclusion. The 2015 domains-system, dispatch, patient, process, and outcomes-were retained. Further clarity is provided for the definitions of out-of-hospital cardiac arrest attended resuscitation and attempted resuscitation. Changes reflect advancements in dispatch, early response systems, and resuscitation care, as well as the importance of prehospital outcomes. Time intervals such as emergency medical service response time now emphasize precise reporting of the times used. New flowcharts aid the reporting of system effectiveness for patients with an attempted resuscitation and system efficacy for the Utstein comparator group. Recognizing the varying capacities of emergency systems globally, the writing group provided a minimal dataset for settings with developing emergency medical systems. Supplementary variables are considered useful for research purposes. These revisions aim to elevate data collection and reporting transparency by registries and researchers and to advance international comparisons and collaborations. The overarching objective remains the improvement of outcomes for patients with out-of-hospital cardiac arrest.

Addressing out-of-hospital cardiac arrest with current technology advances: Breaking the deadlock with a mobile network

Out-of-hospital cardiac arrest (OHCA) is a global public health problem, with survival rates remaining low at around 10% or less despite widespread cardiopulmonary resuscitation (CPR) training and availability of automated external defibrillators (AEDs). This is partly due to the challenges of knowing when and where a sudden OHCA occurs and where the nearest AED is located. In response, countries around the world have begun to use network technology-based smartphone applications. These applications are activated by emergency medical service dispatchers and alert preregistered volunteer first responders (VFRs) to nearby OHCAs using Global Positioning System localization. Accumulating evidence, although mostly from observational studies, shows their effectiveness in increasing the rate of bystander CPR, defibrillation, and patient survival. Current guidelines recommend the use of these VFR alerting systems, and the results of ongoing randomized trials are awaited for further dissemination. This article also proposed the concept of a life-saving mobile network (LMN), which uses opportunistic network and wireless sensor network technologies to create a dynamic mesh network of potential victims, rescuers, and defibrillators. The LMN works by detecting a fatal arrhythmia with a wearable sensor device, localizing the victim and the nearest AED with nearby smartphones, and notifying VFRs through peer-to-peer communication. While there are challenges and limitations to implementing the LMN in society, this innovative network technology would reduce the tragedy of sudden cardiac death from OHCA.

Cardiac arrest and cardiopulmonary resuscitation outcome reports: 2024 update of the Utstein Out-of-Hospital Cardiac Arrest Registry template

The Utstein Out-of-Hospital Cardiac Arrest Resuscitation Registry Template, introduced in 1991 and updated in 2004 and 2015, standardizes data collection to enable research, evaluation, and comparisons of systems of care. The impetus for the current update stemmed from significant advances in the field and insights from registry development and regional comparisons. This 2024 update involved representatives of the International Liaison Committee on Resuscitation and used a modified Delphi process. Every 2015 Utstein data element was reviewed for relevance, priority (core or supplemental), and improvement. New variables were proposed and refined. All changes were voted on for inclusion. The 2015 domains-system, dispatch, patient, process, and outcomes-were retained. Further clarity is provided for the definitions of out-of-hospital cardiac arrest attended resuscitation and attempted resuscitation. Changes reflect advancements in dispatch, early response systems, and resuscitation care, as well as the importance of prehospital outcomes. Time intervals such as emergency medical service response time now emphasize precise reporting of the times used. New flowcharts aid the reporting of system effectiveness for patients with an attempted resuscitation and system efficacy for the Utstein comparator group. Recognizing the varying capacities of emergency systems globally, the writing group provided a minimal dataset for settings with developing emergency medical systems. Supplementary variables are considered useful for research purposes. These revisions aim to elevate data collection and reporting transparency by registries and researchers and to advance international comparisons and collaborations. The overarching objective remains the improvement of outcomes for patients with out-of-hospital cardiac arrest.

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.

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.

Volunteer Responder Interventions in Out-of-Hospital Cardiac Arrest in Urban, Suburban, and Rural Areas

BACKGROUND

Patients with out-of-hospital cardiac arrest (OHCA) in rural areas experience longer emergency response times and have lower survival rates compared with patients in urban areas. Volunteer responders might improve care and outcomes for patients with OHCA specifically in rural areas. Therefore, we investigated volunteer responder interventions based on the degree of urbanization.

METHODS AND RESULTS

We included 1310 OHCAs from 3 different regions in Denmark where volunteer responders had arrived at the OHCA location. The location was classified as urban, suburban, or rural according to the Eurostat Degree of Urbanization Tool. A logistic regression model was used to examine associations between the degree of urbanization and volunteer responder arrival before emergency medical services, cardiopulmonary resuscitation, or defibrillation. We found the odds for volunteer responder arrival before emergency medical services more than doubled in rural areas (odds ratio [OR], 2.60 [95% CI, 1.91-3.53]) and suburban areas (OR, 2.05 [95% CI, 1.56-2.69]) compared with urban areas. In OHCA cases where volunteer responders arrived first, odds for bystander cardiopulmonary resuscitation was tripled in rural areas (OR, 3.83 [95% CI, 1.64-8.93]) and doubled in suburban areas (OR, 2.27 [95% CI, 1.17-4.41]) compared with urban areas. Bystander defibrillation was more common in suburban areas (OR, 1.53 [95% CI, 1.02-2.31]), where almost 1 out of 4 patients received bystander defibrillation, compared with urban areas.

CONCLUSIONS

Volunteer responders are significantly more likely to arrive before emergency medical services in rural and suburban areas than in urban areas. Patients with OHCA received more cardiopulmonary resuscitation in rural and suburban areas and more defibrillation in suburban areas than in urban areas.

[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.

Predictive Dispatch of Volunteer First Responders: Algorithm Development and Validation

BACKGROUND

Smartphone-based emergency response apps are increasingly being used to identify and dispatch volunteer first responders (VFRs) to medical emergencies to provide faster first aid, which is associated with better prognoses. Volunteers' availability and willingness to respond are uncertain, leading in recent studies to response rates of 17% to 47%. Dispatch algorithms that select volunteers based on their estimated time of arrival (ETA) without considering the likelihood of response may be suboptimal due to a large percentage of alerts wasted on VFRs with shorter ETA but a low likelihood of response, resulting in delays until a volunteer who will actually respond can be dispatched.

OBJECTIVE

This study aims to improve the decision-making process of human emergency medical services dispatchers and autonomous dispatch algorithms by presenting a novel approach for predicting whether a VFR will respond to or ignore a given alert.

METHODS

We developed and compared 4 analytical models to predict VFRs' response behaviors based on emergency event characteristics, volunteers' demographic data and previous experience, and condition-specific parameters. We tested these 4 models using 4 different algorithms applied on actual demographic and response data from a 12-month study of 112 VFRs who received 993 alerts to respond to 188 opioid overdose emergencies. Model 4 used an additional dynamically updated synthetic dichotomous variable, frequent responder, which reflects the responder's previous behavior.

RESULTS

The highest accuracy (260/329, 79.1%) of prediction that a VFR will ignore an alert was achieved by 2 models that used events data, VFRs' demographic data, and their previous response experience, with slightly better overall accuracy (248/329, 75.4%) for model 4, which used the frequent responder indicator. Another model that used events data and VFRs' previous experience but did not use demographic data provided a high-accuracy prediction (277/329, 84.2%) of ignored alerts but a low-accuracy prediction (153/329, 46.5%) of responded alerts. The accuracy of the model that used events data only was unacceptably low. The J48 decision tree algorithm provided the best accuracy.

CONCLUSIONS

VFR dispatch has evolved in the last decades, thanks to technological advances and a better understanding of VFR management. The dispatch of substitute responders is a common approach in VFR systems. Predicting the response behavior of candidate responders in advance of dispatch can allow any VFR system to choose the best possible response candidates based not only on ETA but also on the probability of actual response. The integration of the probability to respond into the dispatch algorithm constitutes a new generation of individual dispatch, making this one of the first studies to harness the power of predictive analytics for VFR dispatch. Our findings can help VFR network administrators in their continual efforts to improve the response times of their networks and to save lives.