Local lay rescuers with AEDs, alerted by text messages, contribute to early defibrillation in a Dutch out-of-hospital cardiac arrest dispatch system

Increasing cost-effectiveness of AEDs using algorithms to optimise location

OBJECTIVES

Volunteer responder systems (VRSs) aim to decrease time to defibrillation by dispatching trained volunteers to automated external defibrillators (AEDs) and out-of-hospital cardiac arrest (OHCA) victims. AEDs are often underutilized due to poor placement. This study provides a cost-effectiveness analysis of adding AEDs at strategic locations to maximize quality-adjusted life years (QALYs).

METHODS

We simulated combined volunteer, police, firefighter, and emergency medical service response scenarios to OHCAs, and applied our methods to a case study of Amsterdam, the Netherlands. We compared the competing strategies of placing additional AEDs, using steps of 40 extra AEDs (0, 40, …, 1480), in addition to the existing 369 AEDs. Incremental cost-effectiveness ratios (ICERs) were calculated for each increase in additional AEDs, from a societal perspective. The effect of AED connection and time to connection on survival to hospital admission and neurological outcome at discharge was estimated using logistic regression, using OHCA data from Amsterdam from 2006 to 2018. Other model inputs were obtained from literature.

RESULTS

Purchasing up to 1120 additional AEDs (ICER €75,669/QALY) was cost-effective at a willingness-to-pay threshold of €80,000/QALY, when positioned strategically. Compared to current practice, adding 1120 AEDs resulted in a gain of 0.111 QALYs (95% CI 0.110-0.112) at an increased cost of €3792 per OHCA (95% CI €3778-€3807). Health benefits per AED diminished as more AEDs were added.

CONCLUSIONS

Our study identified cost-effective strategies to position AEDs at strategic locations in a VRS. The case study findings advocate for a substantial increase in the number of AEDs in Amsterdam.

Community First Responders' role in the current and future rural health and care workforce: a mixed-methods study

Background

Community First Responders are trained volunteers dispatched by ambulance services to potentially life-threatening emergencies such as cardiac arrest in the first vital minutes to provide care until highly skilled ambulance staff arrive. Community First Responder schemes were first introduced to support ambulance services in rural communities, where access to prehospital emergency care is more likely to be delayed. Evidence is lacking on their contribution to rural healthcare provision, how care is provided and how this might be improved.

Objectives

We aimed to describe Community First Responder activities, organisation, costs of provision and outcomes of care together with perceptions and views of patients, public, Community First Responders, ambulance service staff and commissioners of their current and future role including innovations in the rural health and care workforce.

Design

We used a mixed-methods design, using a lens of pragmatism and the 'actor', 'behaviour change' and 'causal pathway' framework to integrate quantitative routine and qualitative (policy, guideline and protocol documents with stakeholder interview) data from 6 of 10 English ambulance services. We identified potential innovations in Community First Responder provision and prioritised these using a modified nominal group technique. Patients and public were involved throughout the study.

Results

In 4.5 million incidents from six English regional ambulance services during 2019, pre COVID-19 pandemic, Community First Responders attended first a higher proportion of calls in rural areas (almost 4% of calls) than in urban areas (around 1.5%). They were significantly more likely to be called out to rural (vs. urban) areas and to attend older (vs. younger), white (vs. minority ethnic) people in more affluent (vs. deprived) areas with cardiorespiratory and neurological (vs. other emergency) conditions for higher-priority emergency or urgent (category 1 and 2 compared with category 3, 4 or 5) calls but did also attend lower-category calls for conditions such as falls. We examined 10 documents from seven ambulance services. Ambulance policies and protocols integrated Community First Responders into ambulance service structures to achieve the safe and effective operation of volunteers. Costs, mainly for training, equipment and support, varied widely but were not always clearly delineated. Community First Responders enabled a faster prehospital response time. There was no clear benefit in out-of-hospital cardiac arrest outcomes. A specific Community First Responder falls response reduced ambulance attendances and was potentially cost saving. We conducted semistructured interviews with 47 different stakeholders engaged in Community First Responder functions. This showed the trajectory of becoming a Community First Responder, the Community First Responder role, governance and practice, and the positive views of Community First Responders from stakeholders despite public lack of understanding of their role. Community First Responders' scope of practice varied between ambulance services and had developed into new areas. Innovations prioritised at the consensus workshop were changes in processes and structures and an expanded scope of practice supported by training, which included counselling, peer support, better communication with the control room, navigation and communication technology, and specific mandatory and standardised training for Community First Responders.

Limitations

Missing data and small numbers of interviews in some stakeholder groups (patients, commissioners) are sources of bias.

Future research

Future research should include a robust evaluation of innovations involving Community First Responders.

Trial registration

This trial is registered as ClinicalTrials.gov, NCT04279262.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: NIHR127920) and is published in full in Health and Social Care Delivery Research; Vol. 12, No. 18. See the NIHR Funding and Awards website for further award information.

Incidence and Survival of Out-of-Hospital Cardiac Arrest in Public Housing Areas in 3 European Capitals

BACKGROUND

Strategies to reach out-of-hospital cardiac arrests (called cardiac arrest) in residential areas and reduce disparities in care and outcomes are warranted. This study investigated incidences of cardiac arrests in public housing areas.

METHODS

This register-based cohort study included cardiac arrest patients from Amsterdam (the Netherlands) from 2016 to 2021, Copenhagen (Denmark) from 2016 to 2021, and Vienna (Austria) from 2018 to 2021. Using Poisson regression adjusted for spatial correlation and city, we compared cardiac arrest incidence rates (number per square kilometer per year and number per 100 000 inhabitants per year) in public housing and other residential areas and examined the proportion of cardiac arrests within public housing and adjacent areas (100-m radius).

RESULTS

Overall, 9152 patients were included of which 3038 (33.2%) cardiac arrests occurred in public housing areas and 2685 (29.3%) in adjacent areas. In Amsterdam, 635/1801 (35.3%) cardiac arrests occurred in public housing areas; in Copenhagen, 1036/3077 (33.7%); and in Vienna, 1367/4274 (32.0%). Public housing areas covered 42.4 (12.6%) of 336.7 km2 and 1 024 470 (24.6%) of 4 164 700 inhabitants. Across the capitals, we observed a lower probability of 30-day survival in public housing versus other residential areas (244/2803 [8.7%] versus 783/5532 [14.2%]). The incidence rates and rate ratio of cardiac arrest in public housing versus other residential areas were incidence rate, 16.5 versus 4.1 n/km2 per year; rate ratio, 3.46 (95% CI, 3.31-3.62) and incidence rate, 56.1 versus 36.8 n/100 000 inhabitants per year; rate ratio, 1.48 (95% CI, 1.42-1.55). The incidence rates and rate ratios in public housing versus other residential areas were consistent across the 3 capitals.

CONCLUSIONS

Across 3 European capitals, one-third of cardiac arrests occurred in public housing areas, with an additional third in adjacent areas. Public housing areas exhibited consistently higher cardiac arrest incidences per square kilometer and 100 000 inhabitants and lower survival than other residential areas. Public housing areas could be a key target to improve cardiac arrest survival in countries with a public housing sector.

Out-of-Hospital Cardiac Arrest in the Eye of the Beholder and Emergency Medical Service

Purpose

Out-of-hospital cardiac arrest (OHCA) remains a global healthcare problem, with low survival and bystander cardiopulmonary resuscitation (CPR) rates. This study aimed to identify event-related factors in OHCA and their impact on return of spontaneous circulation (ROSC) achievement and maintenance until hospital admission.

Patients and Methods

All data were collected from Utstein Resuscitation Registry Template for OHCA from The Institute of Emergency Medicine of Zagreb from January 2012 to August 2022. This cross-sectional research analyzed 2839 Utstein reports, including 2001 male, 836 female, and 8 subjects of unknown gender. The average age was 65.4 ± 16.2 years.

Results

The most frequent place of collapse was private residence, and 27% of collapses were unwitnessed. Dispatcher-provided CPR instructions were provided in 39.7% of cases until the arrival of the emergency service team, which showed a very strong effect on bystander-provided CPR, and were followed in 68.4% of cases, while non-instructed bystander CPR was provided in only 7.9% of cases. Bystander CPR is more likely to be provided in public places than in private residences, often with both compression and ventilation. Bystander CPR was also more likely to be provided to men. Cases with bystander CPR, and compressions with ventilation compared to compression only CPR, showed a significantly greater success in maintaining ROSC later in CPR, both with moderate effects.

Conclusion

Bystander CPR has been shown to have a significant role in achieving and maintaining ROSC until hospital admission. However, our results showed a location-dependent nature of bystanders' willingness to perform CPR as well as sex disparities in patients receiving CPR. With deficient education in basic life support in Croatia, dispatchers need to insist on and instruct bystander CPR performance.

Eligibility of cardiac arrest patients for extracorporeal cardiopulmonary resuscitation and their clinical characteristics: a retrospective two-centre study

BACKGROUND AND IMPORTANCE

Sudden cardiac arrest has a high incidence and often leads to death. A treatment option that might improve the outcomes in refractory cardiac arrest is Extracorporeal Cardiopulmonary Resuscitation (ECPR).

OBJECTIVES

This study investigates the number of in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) patients eligible to ECPR and identifies clinical characteristics that may help to identify which patients benefit the most from ECPR.

DESIGN, SETTINGS AND PARTICIPANTS

A retrospective two-centre study was conducted in Rotterdam, the Netherlands. All IHCA and OHCA patients between 1 January 2017 and 1 January 2020 were screened for eligibility to ECPR. The primary outcome was the percentage of patients eligible to ECPR and patients treated with ECPR. The secondary outcome was the comparison of the clinical characteristics and outcomes of patients eligible to ECPR treated with conventional Cardiopulmonary Resuscitation (CCPR) vs. those of patients treated with ECPR.

MAIN RESULTS

Out of 1246 included patients, 412 were IHCA patients and 834 were OHCA patients. Of the IHCA patients, 41 (10.0%) were eligible to ECPR, of whom 20 (48.8%) patients were actually treated with ECPR. Of the OHCA patients, 83 (9.6%) were eligible to ECPR, of whom 23 (27.7%) were actually treated with ECPR. In the group IHCA patients eligible to ECPR, no statistically significant difference in survival was found between patients treated with CCPR and patients treated with ECPR (hospital survival 19.0% vs. 15.0% respectively, 4.0% survival difference 95% confidence interval -21.3 to 28.7%). In the group OHCA patients eligible to ECPR, no statistically significant difference in-hospital survival was found between patients treated with CCPR and patients treated with ECPR (13.3% vs. 21.7% respectively, 8.4% survival difference 95% confidence interval -30.3 to 10.2%).

CONCLUSION

This retrospective study shows that around 10% of cardiac arrest patients are eligible to ECPR. Less than half of these patients eligible to ECPR were actually treated with ECPR in both IHCA and OHCA.

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.

Automatic measurement of departing times in smartphone alerting systems: A pilot study

AIM

Smartphone alerting systems (SAS) alert volunteers in close vicinity of suspected out-of-hospital cardiac arrest. Some systems use sophisticated algorithms to select those who will probably arrive first. Precise estimation of departing times and travel times may help to further improve algorithms. We developed a global positioning system (GPS) based method for automatic measurements of departing times. The aim of this pilot study was to evaluate feasibility and precision of the method.

METHODS

Region of Lifesavers alerting app (iOS/ Android, version 3.0, FirstAED ApS, Denmark) was used in this study. 27 experiments were performed with 9 students, who were instructed to stay in their flats during the study days. A geofence was set for each alarm in the alerting system with a radius of 10 m (8 cases), 15 m (10 cases), and 20 m (9 cases) around the GPS position at which the alarm was accepted in the app. The system logged responders as being departed when the smartphone position was registered outside the geofence. The students were instructed to manually start a stopwatch at the time of the alert and to stop the stopwatch once they had entered the street in front of their flat.

RESULTS

The median difference between automatically and manually retrieved times were -16 seconds [interquartile range IQR 50 seconds] (geofence 10 m), 30 seconds [IQR 25 seconds] (15 m), and 20 seconds [IQR 13 seconds] (20 m), respectively. The 20 m geofence was associated with the smallest interquartile range.

CONCLUSION

Departing times of volunteer responders in SAS can be retrieved automatically using GPS and a geofence.

Online platform for cardiopulmonary resuscitation and automated external defibrillator training in a rural area: a community clinical trial protocol

INTRODUCTION

Sudden death resulting from cardiorespiratory arrest carries a high mortality rate and frequently occurs out of hospital. Immediate initiation of cardiopulmonary resuscitation (CPR) by witnesses, combined with automated external defibrillator (AED) use, has proven to double survival rates. Recognising the challenges of timely emergency services in rural areas, the implementation of basic CPR training programmes can improve survival outcomes. This study aims to evaluate the effectiveness of online CPR-AED training among residents in a rural area of Tarragona, Spain.

METHODS

Quasi-experimental design, comprising two phases. Phase 1 involves assessing the effectiveness of online CPR-AED training in terms of knowledge acquisition. Phase 2 focuses on evaluating participant proficiency in CPR-AED simulation manoeuvres at 1 and 6 months post training. The main variables include the score difference between pre-training and post-training test (phase 1) and the outcomes of the simulated test (pass/fail; phase 2). Continuous variables will be compared using Student's t-test or Mann-Whitney U test, depending on normality. Pearson's χ2 test will be applied for categorical variables. A multivariate analysis will be conducted to identify independent factors influencing the main variable.

ETHICS AND DISSEMINATION

This study adheres to the tenets outlined in the Declaration of Helsinki and of Good Clinical Practice. It operated within the Smartwatch project, approved by the Clinical Research Ethics Committee of the Primary Care Research Institute IDIAP Jordi Gol i Gurina Foundation, code 23/081-P. Data confidentiality aligns with Spanish and European Commission laws for the protection of personal data. The study's findings will be published in peer-reviewed journals and presented at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT05747495.

Effects of Dispatcher-Assisted Public-Access Defibrillation Programs on the Outcomes of Out-of-Hospital Cardiac Arrest: A Before-and-After Study

BACKGROUND

Public access defibrillation (PAD) programs have been implemented globally over the past decade. Although PAD can substantially increase the survival of cardiac arrest, PAD use remains low. This study aimed to evaluate whether drawing upon the successful experiences of dispatcher-assisted cardiopulmonary resuscitation programs would increase the use of PAD in dispatcher-assisted PAD programs.

METHODS AND RESULTS

This study using a before-and-after design was conducted in Taoyuan City using a local out-of-hospital cardiac arrest registry system and data of dispatcher performance derived from audio recordings. The primary outcomes were the rate of bystander PAD use, sustained return of spontaneous circulation, survival to discharge, and favorable neurological outcomes. The secondary outcomes were the performance of dispatchers in terms of PAD instruction and dispatcher-assisted cardiopulmonary resuscitation administration, the time interval indicators of dispatcher-assisted cardiopulmonary resuscitation. A total of 1159 patients were included and divided into 2 groups: the before-run-in group (502 patients) and the after-run-in group (657 patients). No significant difference was observed between the 2 groups in terms of baseline characteristics. The rate of PAD use in the after-run-in group significantly increased from 5.0% to 8.7% (P=0.015). The rate of favorable neurological outcomes increased from 4.4% to 5.9%, which was not a statistically significant difference. Compared with the before-run-in group, the rate of successful automated external defibrillator acquisition was 13.5% in the after-run-in group (P<0.001).

CONCLUSIONS

Implementing a dispatcher-assisted PAD protocol in a municipality setting significantly increased bystander PAD use without affecting dispatcher performance in out-of-hospital cardiac arrest recognition, cardiopulmonary resuscitation instruction, or dispatcher-assisted cardiopulmonary resuscitation time indicators.

Survival and neurological outcome after bystander versus lay responder defibrillation in out-of-hospital cardiac arrest: A sub-study of the BOX trial

BACKGROUND AND AIM

Bystander defibrillation is associated with increased survival with good neurological outcome after out-of-hospital cardiac arrest (OHCA). Dispatch of lay responders could increase defibrillation rates, however, survival with good neurological outcome in these remain unknown. The aim was to compare long-term survival with good neurological outcome in bystander versus lay responder defibrillated OHCAs.

METHODS

This is a sub-study of the BOX trial, which included OHCA patients from two Danish tertiary cardiac intensive care units from March 2017 to December 2021. The main outcome was defined as 3-month survival with good neurological performance (Cerebral Performance Category of 1or 2, on a scale from 1 (good cerebral performance) to 5 (death or brain death)). For this study EMS witnessed OHCAs were excluded.

RESULTS

Of the 715 patients, a lay responder arrived before EMS in 125 cases (16%). In total, 81 patients were defibrillated by a lay responder (11%), 69 patients by a bystander (10%) and 565 patients by the EMS staff (79%). The 3-month survival with good neurological outcome was 65% and 81% in the lay responder and bystander defibrillated groups, respectively (P = 0.03).

CONCLUSION

In patients with OHCA, 3-month survival with good neurological outcome was higher in bystander defibrillated patients compared with lay responder defibrillated patients.

Trends in community response and long-term outcomes from pediatric cardiac arrest: A retrospective observational study

AIM

This study aimed to investigate trends over time in pre-hospital factors for pediatric out-of-hospital cardiac arrest (pOHCA) and long-term neurological and neuropsychological outcomes. These have not been described before in large populations.

METHODS

Non-traumatic arrest patients, 1 day-17 years old, presented to the Sophia Children's Hospital from January 2002 to December 2020, were eligible for inclusion. Favorable neurological outcome was defined as Pediatric Cerebral Performance Categories (PCPC) 1-2 or no difference with pre-arrest baseline. The trend over time was tested with multivariable logistic and linear regression models with year of event as independent variable.

FINDINGS

Over a nineteen-year study period, the annual rate of long-term favorable neurological outcome, assessed at a median 2.5 years follow-up, increased significantly (OR 1.10, 95%-CI 1.03-1.19), adjusted for confounders. Concurrently, annual automated external defibrillator (AED) use and, among adolescents, initial shockable rhythm increased significantly (OR 1.21, 95% CI 1.10-1.33 and OR 1.15, 95% CI 1.02-1.29, respectively), adjusted for confounders. For generalizability purposes, only the total intelligence quotient (IQ) was considered for trend analysis of all tested domains. Total IQ scores and bystander basic life support (BLS) rate did not change significantly over time.

INTERPRETATION

Long-term favorable neurological outcome, assessed at a median 2.5 years follow-up, improved significantly over the study period. Total IQ scores did not significantly change over time. Furthermore, AED use (OR 1.21, 95%CI 1.10-1.33) and shockable rhythms among adolescents (OR1.15, 95%CI 1.02-1.29) increased over time.

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.

Professional prehospital clinicians' experiences of ethical challenges associated with the collaboration with organised voluntary first responders: a qualitative study

BACKGROUND

Volunteer First Responders are used worldwide. In the Region of Southern Denmark, two types of programs have been established. One of these programs consists of voluntary responders without any requirements of education or training who are summoned to prehospital cardiac arrests. The other type of program is established primarily in the rural areas of the region and consists of volunteers with some mandatory education in first aid. These volunteers are summoned to all urgent cases along with the ambulances. Cooperation between professional healthcare workers and nonprofessionals summoned through official channels may be challenging. This study aimed to explore prehospital clinicians' experiences of ethical challenges in cooperation with volunteer first responders.

METHODS

We conducted 16 semi-structured interviews at four different ambulance stations in the Region of Southern Denmark. Five emergency physicians and 11 emergency medical technicians/paramedics were interviewed. The interviews were transcribed, and the data were analysed using systematic text condensation.

RESULTS

The study's 16 interviews resulted in the identification of some specific categories that challenged the cooperation between the two parties. We identified three main categories: 1. Beneficence, the act of doing good, 2. The risk of harming patients' autonomy 3. Non-maleficence, which is the obligation not to inflict harm on others.

CONCLUSION

This study provides an in-depth insight into the ethical challenges between prehospital clinicians and voluntary first responders from the perspective of the prehospital clinicians. Both programs are considered to have value but only when treating patients with cardiac arrest. Our study highlights potential areas of improvement in the two Danish voluntary programs in their current form.

Prehospital Predictors of Survival in Patients with Out-of-Hospital Cardiac Arrest

Background and Objectives: Despite advances in the treatment of heart diseases, the outcome of patients experiencing sudden cardiac arrest remains poor. The aim of our study was to determine the prehospital variables as predictors of survival outcomes in out-of-hospital cardiac arrest (OHCA) victims. Materials and Methods: This was a retrospective observational cohort study of OHCA cases. EMS protocols created in accordance with the Utstein style reporting for OHCA, first responder intervention reports, medical dispatch center dispatch protocols and hospital medical reports were all reviewed. Multivariate logistic regression was performed with the following variables: age, gender, witnessed status, location, bystander CPR, first rhythm, and etiology. Results: A total of 381 interventions with resuscitation attempts were analyzed. In more than half (55%) of them, bystander CPR was performed. Thirty percent of all patients achieved return of spontaneous circulation (ROSC), 22% of those achieved 30-day survival (7% of all OHCA victims), and 73% of those survived with Cerebral Performance Score 1 or 2. The logistic regression model of adjustment confirms that shockable initial rhythm was a predictor of ROSC [OR: 4.5 (95% CI: 2.5-8.1)] and 30-day survival [OR: 9.3 (95% CI: 2.9-29.2)]. Age was also associated (≤67 years) [OR: 3.9 (95% CI: 1.3-11.9)] with better survival. Conclusions: Elderly patients have a lower survival rate. The occurrence of bystander CPR in cardiac arrest remains alarmingly low. Shockable initial rhythm is associated with a better survival rate and neurological outcome compared with non-shockable rhythm.

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.

Perceived threats and challenges experienced by first responders during their mission for an out-of-hospital cardiac arrest

Aim

No study has systematically captured the perceived threat, discomfort or issues experienced by First Responders (FRs). We aimed to report the FRs' experience during a mission for an out-of-hospital cardiac arrest (OHCA) in a ten-year span.

Methods

We collected all the 40-items questionnaires filled out by the FRs dispatched in Ticino Region (Switzerland) from 01/10/2010 to 31/12/2020. We compared results between FRs alerted by SMS or APP and between professional and citizen FRs.

Results

3391 FRs filled the questionnaire. The OHCA information was considered complete more frequently by FRs alerted by APP (85.6% vs 76.8%, p < 0.001), but a challenge in reaching the location was more frequent (15.5% vs 11.4%, p < 0.001), mainly due to wrong GPS coordinate. The FRs initiated/participated in resuscitation in 64.6% and used an AED in 31.9% of OHCAs, without issue in 97.9%. FRs reported a very high-level of satisfaction (97%) in EMS collaboration, but one-third didn't have the possibility to debrief. Citizen FRs used AED more frequently than professional FRs (34.6% vs 30.7%, p < 0.01), but experienced more often difficulties in performing CPR (2.6% vs 1.2%, p = 0.02) and wore more in need to debrief (19.7% vs 13%, p < 0.01).

Conclusions

We provide a unique picture from the FRs' point of view during a real-life OHCA reporting high-level of satisfaction, great motivation but also the need of systematic debrief. We identified areas of improvements including geolocation accuracy, further training on AED use and support program dedicated to citizen FRs.

The association between the experience of lay responders and response interval to medical emergencies in a rural area: an observational study

AIM

The aim of this retrospective observational study was to determine how response intervals correlated to the experience of the community first responders (CFRs) using data collected from the Danish Island of Langeland via a global positioning system (GPS)-based system.

METHODS

All medical emergency calls involving CFRs in the time period from 21st of April 2012 to 31st of December 2017 were included. Each emergency call activated 3 CFRs. Response intervals were calculated using the time from when the system alerted the CFRs to CFR time of arrival at the emergency site measured by GPS. CFRs response intervals were grouped depending on their level of experience according to ≤ 10, 11-24, 25-49, 50-99, ≥ 100 calls accepted and arrived on-site.

RESULTS

A total of 7273 CFR activations were included. Median response interval for the CFR arriving first on-site (n = 3004) was 4:05 min (IQR 2:42-6:01) and median response interval for the arrival of the CFR with an automated external defibrillator (n = 2594) was 5:46 min (IQR 3:59-8:05). Median response intervals were 5:53 min (3:43-8:29) for ≤ 10 calls (n = 1657), 5:39 min (3:49-8:01) for 11-24 calls (n = 1396), 5:45 min (3:49-8:00) for 25-49 calls (n = 1586), 5:07 min (3:38-7:26) for 50-99 calls (n = 1548) and 4:46 min (3:14-7:32) for ≥ 100 calls (n = 1086) (p < 0.001). There was a significant negative correlation between experience and response intervals (p < 0.001, Spearman's rho = -0.0914).

CONCLUSION

This study found an inverse correlation between CFR experience and response intervals, which could lead to increased survival after a time-critical incident.

Bystander cardiopulmonary resuscitation, automated external defibrillator use, and survival after out-of-hospital cardiac arrest

INTRODUCTION

We aimed to investigate the association between bystander cardiopulmonary resuscitation (CPR) with and without automated external defibrillator (AED) use and neurological outcomes after out-of-hospital cardiac arrest (OHCA) in Korea.

METHODS

This cross-sectional study used a nationwide Korean OHCA registry between 2015 and 2019. Patients were categorised into no bystander CPR and bystander CPR with and without AED use groups. The primary outcome was good neurological recovery at discharge. We also analysed the interaction effects of place of arrest, response time, and whether the OHCA was witnessed.

RESULTS

In total, 93,623 patients were included. Among them, 35,486 (37.9%) were in the no bystander CPR group, 56,187 (60.0%) were in the bystander CPR without AED use group, and 1950 (2.1%) were in the bystander CPR with AED use group. Good neurological recovery was demonstrated in 1286 (3.6%), 3877 (6.9%), and 208 (10.7%) patients in the no CPR, bystander CPR without AED use, and bystander CPR with AED use groups, respectively. Compared to the no bystander CPR group, the adjusted odds ratio (95% confidence intervals) for good neurological recovery was 1.54 (1.45-1.65) and 1.37 (1.15-1.63) in the bystander CPR without and with AED use groups, respectively. The effect of bystander CPR with AED use was more apparent in OHCAs with witnessed arrest and prolonged response time (≥8 min).

CONCLUSION

Bystander CPR was associated with better neurological recovery compared to no bystander CPR; however, the benefits of AED use were not significant. Efforts to disseminate bystander AED availability and ensure proper utilisation are warranted.

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.

Improved ROSC rates in out-of-hospital cardiac arrest patients after introduction of a text message alert system for trained volunteers

OBJECTIVE

To evaluate whether a text message (TM) alert system for trained volunteers contributed to early cardiopulmonary resuscitation, the use of automated external defibrillators (AEDs), return of spontaneous circulation (ROSC) and survival in out-of-hospital cardiac arrest (OHCA) patients in a region with above-average survival rates.

DESIGN

Data on all OHCA patients in 2012 (non-TM group) were compared with those of all OHCA patients in 2018 (TM group). The association of the presence of a TM alert system with ROSC and survival was assessed with multivariate regression analyses.

RESULTS

TM responders reached 42 OHCA patients (15.9%) earlier than the first responders or ambulance. They connected 31 of these 42 OHCA patients (73.8%) to an AED before the ambulance arrived, leading to a higher percentage of AEDs being attached in 2018 compared to the 2012 non-TM group (55% vs 46%, p = 0.03). ROSC was achieved more often in the TM group (61.0% vs 29.4%, p < 0.01). Three-month and 1‑year survival did not differ significantly between the two groups (29.3% vs 24.3%, p = 0.19, and 25.9% vs 23.5%, p = 0.51). Multivariate regression analyses confirmed the positive association of ROSC with the TM alert system (odds ratio 1.49, 95% confidence interval 1.02‑2.19, p = 0.04).

CONCLUSION

A TM alert system seems to improve the chain of survival; because TM responders reached patients early, AEDs were attached more often and more OHCA patients achieved ROSC. However, the introduction of a TM alert system was not associated with improved 3‑month or 1‑year survival in a region with above-average survival rates.

Community Cardiac Arrest as a Challenge for Emergency Medical Services in Poland

The problem of cardiac arrest, particularly out-of-hospital cardiac arrest (OHCA), is the subject of continuous research. The aim of this study was to analyze the use of an automated external defibrillator (AED) during the resuscitation of an adult in public places in Poland between 2015 and 2020. A retrospective analysis of the selected documentation obtained from AED distributors, the medical records obtained from the emergency call center, and the emergency medical teams was conducted. During the analysis period, there were 100 cases of recorded and documented use of AEDs in OHCAs in public places. In 70% of the cases, defibrillation was performed with an AED. This result could be higher, but the study's methodology and limited access to data only allowed for this result. In Poland, there are no legal acts on the registration of automatic external defibrillators and their implementation. Appropriate registries should be introduced nationwide as soon as possible. Due to the inadequacy of the medical records of the emergency medical teams to record the use of automated external defibrillators by a bystander to an incident, changes to these documents should be pursued. Based on such a small cohort, it is not possible to conclude that the return of spontaneous blood circulation is correlated with the use of AEDs and public access to defibrillation PADs.

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.

Are there socioeconomic disparities in geographic accessibility to community first responders to out-of-hospital cardiac arrest in Ireland?

Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide. Without appropriate early resuscitation interventions, the prospect of survival is limited. This means that an effective community response is a critical enabler of increasing the number of people who survive. However, while OHCA incidence is higher in more deprived areas, propensity to volunteer is, in general, associated with higher socioeconomic status. In this context, we consider whether there are socioeconomic disparities in geographic accessibility to volunteer community first responders (CFRs) in Ireland, where CFR groups have developed organically and communities self-select to participate. We use geographic information systems and propensity score matching to generate a set of control areas with which to compare established CFR catchment areas. Differences between CFRs and controls in terms of the distribution of catchment deprivation and social fragmentation scores are assessed using two-sided Kolmogorov-Smirnov tests. Overall we find that while CFR schemes are centred in more deprived and socially fragmented areas, beyond a catchment of 4 min there is no evidence of differences in area-level deprivation or social fragmentation. Our findings show that self-selection as a model of CFR recruitment does not lead to more deprived areas being disadvantaged in terms of access to CFR schemes. This means that community-led health interventions can develop to the benefit of community members across the socioeconomic spectrum and may be relevant for other countries and jurisdictions looking to support similar models within communities.

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Out-of-hospital cardiac arrest (OHCA) is a major cause of unexpected death.

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OHCA is more prevalent in deprived areas and community response is key for survival.

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Irish community first responders (CFRs) self-select to participate in CFR schemes.

•

We consider if there are socioeconomic disparities in geographic access to CFRs.

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Self-selection does not result in deprived areas having worse access to CFR schemes.

How technology can save lives in cardiac arrest

PURPOSE OF REVIEW

Technology is being increasingly implemented in the fields of cardiac arrest and cardiopulmonary resuscitation. In this review, we describe how recent technological advances have been implemented in the chain of survival and their impact on outcomes after cardiac arrest. Breakthrough technologies that are likely to make an impact in the future are also presented.

RECENT FINDINGS

Technology is present in every link of the chain of survival, from prediction, prevention, and rapid recognition of cardiac arrest to early cardiopulmonary resuscitation and defibrillation. Mobile phone systems to notify citizen first responders of nearby out-of-hospital cardiac arrest have been implemented in numerous countries with improvement in bystanders' interventions and outcomes. Drones delivering automated external defibrillators and artificial intelligence to support the dispatcher in recognising cardiac arrest are already being used in real-life out-of-hospital cardiac arrest. Wearables, smart speakers, surveillance cameras, and artificial intelligence technologies are being developed and studied to prevent and recognize out-of-hospital and in-hospital cardiac arrest.

SUMMARY

This review highlights the importance of technology applied to every single step of the chain of survival to improve outcomes in cardiac arrest. Further research is needed to understand the best role of different technologies in the chain of survival and how these may ultimately improve outcomes.

Dispatching citizens as first responders to out-of-hospital cardiac arrests: a systematic review and meta-analysis

Mobile phone technologies to alert citizen first responders to out-of-hospital cardiac arrests (OHCAs) were implemented in numerous countries. This systematic review and meta-analysis aim to investigate whether activating citizen first responders increases bystanders' interventions and improves outcomes. We searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from inception to 24 November 2021, for studies comparing citizen first responders' activation versus standard emergency response in the case of OHCA. The primary outcome was survival at hospital discharge or 30 days. Secondary outcomes were discharge with favourable neurological outcome, bystander-initiated cardiopulmonary resuscitation (CPR), and the use of automated external defibrillators (AEDs) before ambulance arrival. Evidence certainty was evaluated with GRADE. Our search strategy yielded 1215 articles. After screening, we included 10 studies for a total of 23 351 patients. OHCAs for which citizen first responders were activated had higher rates of survival at hospital discharge or 30 days compared with standard emergency response [nine studies; 903/9978 (9.1%) vs. 1104/13 247 (8.3%); odds ratio (OR), 1.45; 95% confidence interval (CI), 1.21-1.74; P < 0.001], return of spontaneous circulation [nine studies; 2575/9169 (28%) vs. 3445/12 607 (27%); OR, 1.40; 95% CI, 1.07-1.81; P = 0.01], bystander-initiated CPR [eight studies; 5876/9074 (65%) vs. 6384/11 970 (53%); OR, 1.75; 95% CI, 1.43-2.15; P < 0.001], and AED use [eight studies; 654/9132 (7.2%) vs. 624/14 848 (4.2%); OR, 1.82; 95% CI, 1.31-2.53; P < 0.001], but similar rates of neurological intact discharge [three studies; 316/2685 (12%) vs. 276/2972 (9.3%); OR, 1.37; 95% CI, 0.81-2.33; P = 0.24]. Alerting citizen first responders to OHCA patients is associated with higher rates of bystander-initiated CPR, use of AED before ambulance arrival, and survival at hospital discharge or 30 days.

Characteristics and motivational factors for joining a lay responder system dispatch to out-of-hospital cardiac arrests

Background

There has been in increase in the use of systems for organizing lay responders for suspected out-of-hospital cardiac arrests (OHCAs) dispatch using smartphone-based technology. The purpose is to increase survival rates; however, such systems are dependent on people’s commitment to becoming a lay responder. Knowledge about the characteristics of such volunteers and their motivational factors is lacking. Therefore, we explored characteristics and quantified the underlying motivational factors for joining a smartphone-based cardiopulmonary resuscitation (CPR) lay responder system.

Methods

In this descriptive cross-sectional study, 800 consecutively recruited lay responders in a smartphone-based mobile positioning first-responder system (SMS-lifesavers) were surveyed. Data on characteristics and motivational factors were collected, the latter through a modified version of the validated survey “Volunteer Motivation Inventory” (VMI). The statements in the VMI, ranked on a Likert scale (1–5), corresponded to(a) intrinsic (an inner belief of doing good for others) or (b) extrinsic (earning some kind of reward from the act) motivational factors.

Results

A total of 461 participants were included in the final analysis. Among respondents, 59% were women, 48% between 25 and 39 years of age, 37% worked within health care, and 66% had undergone post-secondary school. The most common way (44%) to learn about the lay responder system was from a CPR instructor. A majority (77%) had undergone CPR training at their workplace. In terms of motivation, where higher scores reflect greater importance to the participant, intrinsic factors scored highest, represented by the category values (mean 3.97) followed by extrinsic categories reciprocity (mean 3.88) and self-esteem (mean 3.22).

Conclusion

This study indicates that motivation to join a first responder system mainly depends on intrinsic factors, i.e. an inner belief of doing good, but there are also extrinsic factors, such as earning some kind of reward from the act, to consider. Focusing information campaigns on intrinsic factors may be the most important factor for successful recruitment. When implementing a smartphone-based lay responder system, CPR instructors, as a main information source to potential lay responders, as well as the workplace, are crucial for successful recruitment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-022-01009-1.

Optimizing Outcomes After Out-of-Hospital Cardiac Arrest With Innovative Approaches to Public-Access Defibrillation: A Scientific Statement From the International Liaison Committee on Resuscitation

Out-of-hospital cardiac arrest is a global public health issue experienced by ≈3.8 million people annually. Only 8% to 12% survive to hospital discharge. Early defibrillation of shockable rhythms is associated with improved survival, but ensuring timely access to defibrillators has been a significant challenge. To date, the development of public-access defibrillation programs, involving the deployment of automated external defibrillators into the public space, has been the main strategy to address this challenge. Public-access defibrillator programs have been associated with improved outcomes for out-of-hospital cardiac arrest; however, the devices are used in <3% of episodes of out-of-hospital cardiac arrest. This scientific statement was commissioned by the International Liaison Committee on Resuscitation with 3 objectives: (1) identify known barriers to public-access defibrillator use and early defibrillation, (2) discuss established and novel strategies to address those barriers, and (3) identify high-priority knowledge gaps for future research to address. The writing group undertook systematic searches of the literature to inform this statement. Innovative strategies were identified that relate to enhanced public outreach, behavior change approaches, optimization of static public-access defibrillator deployment and housing, evolved automated external defibrillator technology and functionality, improved integration of public-access defibrillation with existing emergency dispatch protocols, and exploration of novel automated external defibrillator delivery vectors. We provide evidence- and consensus-based policy suggestions to enhance public-access defibrillation and guidance for future research in this area.

Optimizing outcomes after out-of-hospital cardiac arrest with innovative approaches to public-access defibrillation: A scientific statement from the International Liaison Committee on Resuscitation

Out-of-hospital cardiac arrest is a global public health issue experienced by ≈3.8 million people annually. Only 8% to 12% survive to hospital discharge. Early defibrillation of shockable rhythms is associated with improved survival, but ensuring timely access to defibrillators has been a significant challenge. To date, the development of public-access defibrillation programs, involving the deployment of automated external defibrillators into the public space, has been the main strategy to address this challenge. Public-access defibrillator programs have been associated with improved outcomes for out-of-hospital cardiac arrest; however, the devices are used in <3% of episodes of out-of-hospital cardiac arrest. This scientific statement was commissioned by the International Liaison Committee on Resuscitation with 3 objectives: (1) identify known barriers to public-access defibrillator use and early defibrillation, (2) discuss established and novel strategies to address those barriers, and (3) identify high-priority knowledge gaps for future research to address. The writing group undertook systematic searches of the literature to inform this statement. Innovative strategies were identified that relate to enhanced public outreach, behavior change approaches, optimization of static public-access defibrillator deployment and housing, evolved automated external defibrillator technology and functionality, improved integration of public-access defibrillation with existing emergency dispatch protocols, and exploration of novel automated external defibrillator delivery vectors. We provide evidence- and consensus-based policy suggestions to enhance public-access defibrillation and guidance for future research in this area.

Cardiopulmonary Resuscitation and Defibrillator Use in Sports

Sudden cardiac arrest (SCA) in young athletes is rare, with an estimated incidence ranging from 0.1 to 2 per 100,000 per athlete year. The creation of SCA registries can help provide accurate data regarding incidence, treatment, and outcomes and help implement primary or secondary prevention strategies that could change the course of these events. Early cardiopulmonary resuscitation (CPR) and defibrillation are the most important determinants of survival and neurological prognosis in individuals who suffer from SCA. Compared with the general population, individuals with clinically silent cardiac disease who practice regular physical exercise are at increased risk of SCA events. While the implementation of national preparticipation screening has been largely debated, with no current consensus, the number of athletes who will be diagnosed with cardiac disease and have an indication for implantable defibrillator cardioverter defibrillator (ICD) is unknown. Many victims of SCA do not have a previous cardiac diagnosis. Therefore, the appropriate use and availability of automated external defibrillators (AEDs) in public spaces is the crucial part of the integrated response to prevent these fatalities both for participating athletes and for spectators. Governments and sports institutions should invest and educate members of the public, security, and healthcare professionals in immediate initiation of CPR and early AED use. Smartphone apps could play an integral part to allow bystanders to alert the emergency services and CPR trained responders and locate and utilize the nearest AED to positively influence the outcomes by strengthening the chain of survival. This review aims to summarize the available evidence on sudden cardiac death prevention among young athletes and to provide some guidance on strategies that can be implemented by governments and on the novel tools that can help save these lives.

Citizen Responder Activation in Out-of-Hospital Cardiac Arrest by Time of Day and Day of Week

Background

We aim to examine diurnal and weekday variations in citizen responder availability and intervention at out‐of‐hospital cardiac arrest (OHCA) resuscitation.

Methods and Results

We included confirmed OHCAs where citizen responders were activated by a smartphone application in the Capital Region of Denmark between September 1, 2017 and August 31, 2018. OHCAs were analyzed by time of day (daytime: 07:00 am–03:59 pm, evening: 4:00–11:59 pm, and nighttime: 12:00–06:59 am) and day of week (Monday–Friday or Saturday–Sunday/public holidays). We included 438 OHCAs where 6836 citizen responders were activated. More citizen responders accepted alarms in the evening (mean 4.8 [95% CI, 4.4–5.3]) compared with daytime (3.7 [95% CI, 3.4–4.4]) and nighttime (1.8 [95% CI, 1.5–2.2]) (P<0.001), and more accepted alarms during weekends (4.3 [95% CI, 3.8–4.9]) compared with weekdays (3.4 [95% CI, 3.2–3.7]) (P<0.001). Proportion of OHCAs where at least 1 citizen responder arrived before Emergency Medical Services were significantly different between day (42.9%), evening (50.3%), and night (26.1%) (P<0.001), and between weekdays (37.2%) and weekends (53.5%) (P=0.002). When responders arrived before Emergency Medical Services, there was no difference of bystander cardiopulmonary resuscitation or defibrillation between daytime, evening, and nighttime (P=0.75 and P=0.22, respectively) or between weekend and weekdays (P=0.29 and P=0.12, respectively).

Conclusions

Citizen responders were more likely to accept OHCA alarms during evening and weekends, with the highest proportion of responders arriving before Emergency Medical Services in the evening. However, there was no significant difference in delivering cardiopulmonary resuscitation or early defibrillation among cases where citizen responders arrived before Emergency Medical Services.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03835403.

Potential of Donation After Unexpected Circulatory Death Programs Defined by Their Demographic Characteristics

Background.

Donation after unexpected circulatory death (uDCD) donors are often suggested to increase the number of donor organs. In 2014, a uDCD protocol was implemented in three transplant centers in the Netherlands which unfortunately did not result in additional transplantations. This study was initiated to identify demographic factors influencing the potential success of uDCD programs.

Methods.

Dutch resuscitation databases covering various demographic regions were analyzed for potential donors. The databases were compared with the uDCD implementation project and successful uDCD programs in Spain, France, and Russia.

Results.

The resuscitation databases showed that 61% of all resuscitated patients were transferred to an emergency department. Age selection reduced this uDCD potential to 46% with only patients aged 18–65 years deemed eligible. Of these patients, 27% died in the emergency department. The urban region of Amsterdam showed the largest potential in absolute numbers (52 patients/y). Comparison with the uDCD implementation project showed large similarities in the percentage of potential donors; however, in absolute numbers, it showed a much smaller potential. Calculation of the potential per million persons and the extrapolation of the potential based on the international experience revealed the largest potential in urban regions.

Conclusions.

Implementation of a uDCD program should not only be based on the number of potential donors calculated from resuscitation databases. They show promising potential uDCD percentages for large rural regions and small urban regions; however, actual numbers per hospital are low, leading to insufficient exposure rates. It is, therefore, recommendable to limit uDCD programs to large urban regions.

Responding to Cardiac Arrest in the Community in the Digital Age

Sudden cardiac arrest (SCA) is a common event, affecting almost 400,000 individuals annually in North America. Initiation of cardiopulmonary resuscitation (CPR) and early defibrillation using an automated external defibrillator (AED) are critical for survival, yet many bystanders are reluctant to intervene. Digital technologies, including mobile devices, social media and crowdsourcing may help play a role to improve survival from SCA. In this article we review the current digital tools and strategies available to increase rates of bystander recognition of SCA, prompt immediate activation of Emergency Medical Services (EMS), initiate high quality CPR and to locate, retrieve and operate AEDs. Smartphones can help to both educate and connect bystanders with EMS dispatchers, through text messaging or video-calling, to encourage the initiation of CPR and retrieval of the closest AED. Wearable devices and household smartspeakers could play a future role in continuous vital signs monitoring in individuals at-risk of lethal arrhythmias and send an alert to either chosen contacts or EMS. Machine learning algorithms and mathematical modeling may aid EMS dispatchers with better recognition of SCA as well as policymakers with where to best place AEDs for optimal accessibility. There are challenges with the use of digital tech, including the need for government regulation and issues with data ownership, accessibility and interoperability. Future research will include smart cities, e-linkages, new technologies and using social media for mass education. Together or in combination, these emerging digital technologies may represent the next leap forward in SCA survival.

Calculating real-world travel routes instead of straight-line distance in the community response to out-of-hospital cardiac arrest

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In out-of-hospital cardiac arrest, straight-line distance estimates substantially underestimated actual travel distance for bystanders retrieving a nearby public-access AED and for volunteer first-responders travelling to the scene.

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Using real-world travel estimates changed the identity of the nearest public-access AED in more than a quarter of out-of-hospital cardiac arrests.

Background

Using straight-line distance to estimate the proximity of public-access Automated External Defibrillators (AEDs) or volunteer first-responders to potential out-of-hospital cardiac arrests (OHCAs) does not reflect real-world travel distance. The difference between estimates may be an important consideration for bystanders and first-responders responding to OHCAs and may potentially impact patient outcome.

Objectives

To explore how calculating real-world travel routes instead of using straight-line distance estimates might impact the community response to OHCA.

Methods

We mapped 4355 OHCA (01/04/2016-31/03/2017) and 2677 AEDs in London (UK), and 1263 OHCA (18/06/2017-17/06/2018) and 4704 AEDs in East Midlands (UK) using ArcGIS mapping software. We determined the distance from OHCAs to the nearest AED using straight-line estimates and real-world travel routes. We mapped locations of potential OHCAs (London: n = 9065, 20/09/2019-22/03/2020; East Midlands: n = 7637, 20/09/2019-17/03/2020) for which volunteer first-responders were alerted by the GoodSAM mobile-phone app, and calculated response distance using straight-line estimates and real-world travel routes. We created Receiver Operating Characteristic (ROC) curves and calculated the Area Under the Curve (AUC) to determine if travel distance predicted whether or not a responder accepted an alert.

Results

Real-world travel routes to the nearest AED were (median) 219 m longer (623 m vs 406 m) than straight-line estimates in London, and 211 m longer (568 m vs 357 m) in East Midlands. The identity of the nearest AED changed on 26% occasions in both areas when calculating real-world travel routes. GoodSAM responders’ real-world travel routes were (median) 222 m longer (601 m vs 379 m) in London, and 291 m longer (814 m vs 523 m) in East Midlands. AUC statistics for both areas demonstrated that neither straight-line nor real-world travel distance predicted whether or not a responder accepted an alert.

Conclusions

Calculating real-world travel routes increases the estimated travel distance and time for those responding to OHCAs. Calculating straight-line distance may overestimate the benefit of the community response to OHCA.

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

Aims

Automated external defibrillators (AEDs) are placed in public, but the majority of out-of-hospital cardiac arrests (OHCA) occur at home.

Methods and results

In residential areas, 785 AEDs were placed and 5735 volunteer responders were recruited. For suspected OHCA, dispatchers activated nearby volunteer responders with text messages, directing two-thirds to an AED first and one-third directly to the patient. We analysed survival (primary outcome) and neurologically favourable survival to discharge, time to first defibrillation shock, and cardiopulmonary resuscitation (CPR) before Emergency Medical Service (EMS) arrival of patients in residences found with ventricular fibrillation (VF), before and after introduction of this text-message alert system. Survival from OHCAs in residences increased from 26% to 39% {adjusted relative risk (RR) 1.5 [95% confidence interval (CI): 1.03–2.0]}. RR for neurologically favourable survival was 1.4 (95% CI: 0.99–2.0). No CPR before ambulance arrival decreased from 22% to 9% (RR: 0.5, 95% CI: 0.3–0.7). Text-message-responders with AED administered shocks to 16% of all patients in VF in residences, while defibrillation by EMS decreased from 73% to 39% in residences (P < 0.001). Defibrillation by first responders in residences increased from 22 to 40% (P < 0.001). Use of public AEDs in residences remained unchanged (6% and 5%) (P = 0.81). Time from emergency call to defibrillation decreased from median 11.7 to 9.3 min; mean difference –2.6 (95% CI: –3.5 to –1.6).

Conclusion

Introducing volunteer responders directed to AEDs, dispatched by text-message was associated with significantly reduced time to first defibrillation, increased bystander CPR and increased overall survival for OHCA patients in residences found with VF.

PulsePoint dispatch associated patient characteristics and prehospital outcomes in a mid-sized metropolitan area

BACKGROUND

Mobile phone-based dispatch of volunteers to out-of-hospital cardiac arrests (OHCA) has been shown to increase the likelihood of early CPR and AED application. In the United States, limited characterization of patients encountered as a result of such systems exists.

AIMS

Examine prehospital case characteristics and outcomes from a multi-year deployment of PulsePoint Respond in Pittsburgh, Pennsylvania.

METHODS

PulsePoint event timing, location, and associated prehospital electronic health records (ePCRs) were obtained for EMS-encountered OHCA cases that did and did not generate PulsePoint alerts within the service area of Pittsburgh EMS from July 2016 to October 2020. ePCRs were reviewed and OHCA case characteristics were extracted according to the Utstein template. PulsePoint-associated OHCA and non-PulsePoint-associated OHCA were compared.

RESULTS

Of 840 total PulsePoint dispatches, 64 (7.6%) were for OHCA associated with a resuscitation attempt. Forty-one (64.1%) were witnessed, 38 (59.4%) received bystander CPR, and 13 (20.0%) of these patients had an AED applied prior to EMS arrival. Twenty-seven (39.7%) had an initial shockable rhythm, and 31 (48.4%) patients achieved ROSC in the field. In the city of Pittsburgh, there were 1229 total OHCA during the study period, with an estimated 29.6% occurring in public. When PulsePoint-associated and publicly occurring non-PulsePoint-associated OHCA were compared, baseline characteristics (age, sex, witnessed status) were similar, but PulsePoint-associated OHCA received more bystander CPR (p = 0.008).

CONCLUSIONS

A minority of PulsePoint dispatches in Pittsburgh were triggered by true OHCA. The majority of OHCA during the study period occurred within private residences where PulsePoint responders are not currently dispatched. PulsePoint dispatches were associated with prognostically favorable OHCA characteristics and increased bystander CPR performance.

Wellbeing, emotional response and stress among lay responders dispatched to suspected out-of-hospital cardiac arrests

BACKGROUND

Systems for smartphone dispatch of lay responders to perform cardio-pulmonary resuscitation (CPR) and bring automated external defibrillators to out-of-hospital cardiac arrests (OHCAs) are advocated by recent international guidelines and emerging worldwide.

OBJECTIVES

This study aimed to investigate the emotional responses, posttraumatic stress reactions and levels of wellbeing among smartphone-alerted lay responders dispatched to suspected OHCAs.

METHODS

Lay responders were stratified by level of exposure: unexposed (Exp-0), tried to reach (Exp-1), and reached the suspected OHCA (Exp-2). Participants rated their emotional responses online, at 90 minutes and at 4-6 weeks after an incident. Level of emotional response was measured in two dimensions of core affect: "alertness" - from deactivation to activation, and "pleasantness" - from unpleasant to pleasant. At 4-6 weeks, WHO wellbeing index and level of posttraumatic stress (PTSD) were also rated.

RESULTS

Altogether, 915 (28%) unexposed and 1471 (64%) exposed responders completed the survey. Alertness was elevated in the exposed groups: Exp-0: 6.7 vs. Exp-1: 7.3 and Exp-2: 7.5, (p < 0.001) and pleasantness was highest in the unexposed group: 6.5, vs. Exp-1: 6.3, and Exp-2: 6.1, (p < 0.001). Mean scores for PTSD at follow-up was below clinical cut-off, Exp-0: 9.9, Exp-1: 8.9 and Exp-2: 8.8 (p = 0.065). Wellbeing index showed no differences, Exp-0: 78.0, Exp-1: 78.5 and Exp-2: 79.9 (p = 0.596).

CONCLUSION

Smartphone dispatched lay responders rated the experience as high-energy and mainly positive. No harm to the lay responders was seen. The exposed groups had low posttraumatic stress scores and high-level general wellbeing at follow-up.

Longer retrieval distances to the automated external defibrillator reduces survival after out-of-hospital cardiac arrest

AIMS

To evaluate and compare survival after out-of-hospital (OHCA), where an automated external defibrillator (AED) was used, in densely, moderately and thinly populated areas. Also, to evaluate the association between AED retrieval distance and survival after OHCA.

METHODS

From 2014 to 2018, AEDs used during OHCA in the region of Southern Denmark were systematically collected. OHCAs were included if the OHCA address was known. OHCAs at nursing homes were excluded. To evaluate population density, a map with 1000 × 1000 meter grid cells was used with each cell color-graded according to the number of inhabitants. Densely, moderately and thinly populated areas were defined as ≥200 inhabitants, 20-199 inhabitants and 0-19 inhabitants per km², respectively. Primary outcome was 30-day survival.

RESULTS

A total of 423 cases of OHCA were included, of which 207 (49%) occurred in densely populated areas, while 78 (18%) and 138 (33%) occurred in moderately and thinly populated areas, respectively. AED retrieval distances were: densely populated 105 m (IQR 5-450), moderately populated 220 m (IQR 5-450) and thinly populated 350 m (IQR 5-1500) (P < 0.001). Thirty-day survival was 40%, 31% and 34%, respectively (P = 0.3). In a multivariable regression analysis, mortality increased with 10% per 100 m an AED was placed further away from the site of OHCA.

CONCLUSION

Survival after OHCA, where an AED was used, did not seem to differ in thinly, moderately and densely populated areas. The length of the AED retrieval distance, however, was correlated with reduced survival after adjusting for other potentially explanatory variables.

The Automated External Defibrillator: Heterogeneity of Legislation, Mapping and Use across Europe. New Insights from the ENSURE Study

INTRODUCTION

The rapid use of an automated external defibrillator (AED) is crucial for increased survival after an out-of-hospital cardiac arrest (OHCA). Many factors could play a role in limiting the chance of an AED use. We aimed to verify the situation regarding AED legislation, the AED mapping system and first responders (FRs) equipped with an AED across European countries.

METHODS

We performed a survey across Europe entitled "European Study about AED Use by Lay Rescuers" (ENSURE), asking the national coordinators of the European Registry of Cardiac Arrest (EuReCa) program to complete it.

RESULTS

Nineteen European countries replied to the survey request for a population covering 128,297,955 inhabitants. The results revealed that every citizen can use an AED in 15 countries whereas a training certificate was required in three countries. In one country, only EMS personnel were allowed to use an AED. An AED mapping system and FRs equipped with an AED were available in only 11 countries. The AED use rate was 12-59% where AED mapping and FR systems were implemented, which was considerably higher than in other countries (0-7.9%), reflecting the difference in OHCA survival.

CONCLUSIONS

Our survey highlighted a heterogeneity in AED legislation, AED mapping systems and AED use in Europe, which was reflected in different AED use and survival.

A binational survey of smartphone activated volunteer responders for out-of-hospital cardiac arrest: Availability, interventions, and post-traumatic stress

BACKGROUND

Responder smartphone apps use global positioning data to enable emergency medical services to alert volunteer responders of nearby potential out-of-hospital cardiac arrests (OHCA).

AIM

To assess volunteer availability, interventions provided and frequency of probable post traumatic stress disorder (PTSD) experienced by responders receiving a smartphone alert.

METHODS

A web-based survey was emailed to alerted responders at week-two post-alert and a PTSD screening survey at week-six, in Victoria, Australia (1/08/2019-8/11/2020), and in New Zealand (18/02/2020-28/10/2020).

RESULTS

We received 1,985 responses to the week-two survey and 1,443 responses to the week-six survey. Of the 1,985 responders, 1,744 (87.9%) had completed cardiopulmonary resuscitation (CPR) training in the last twelve months, and 1,514 (76.3%) had performed CPR at least once. The alert was seen by 1,501 (75.6%) responders, 749 (37.7%) accepted the alert, 538 (27.1%) arrived on scene, and 283 (14.3%) provided care to the patient. In the multivariable analysis, CPR training within twelve months was associated with increased odds of responders accepting alerts (AOR 1.41, 95%CI: 1.02-1.96; p=0.040). Responders who had performed CPR before, were more than twice as likely to provide patient care compared to responders who had not (AOR 2.54, 95%CI: 1.56-4.12; p<0.001). One responder screened positive for probable PTSD.

CONCLUSION

Acceptance rates in Australia and New Zealand were consistent with other smartphone apps. Responder recruitment should be targeted at those with medical backgrounds who have prior CPR experience, as they are more likely to provide care. The very low risk of PTSD is reassuring information when recruiting volunteers.

Analysis of the Way and Correctness of Using Automated External Defibrillators Placed in Public Space in Polish Cities-Continuation of Research

Immediate resuscitation is required for any sudden cardiac arrest. To improve the survival of the patient, a device to be operated by witnesses of the event-automated external defibrillator (AED)-has been produced. The aim of this study is to analyze the way and correctness of use of automated external defibrillators placed in public spaces in Polish cities. The data analyzed (using Excel 2019 and R 3.5.3 software) are 120 cases of use of automated external defibrillators, placed in public spaces in the territory of Poland in 2008-2018. The predominant location of AED use is in public transportation facilities, and the injured party is the traveler. AED use in non-hospital settings is more common in male victims aged 50-60 years. Owners of AEDs inadequately provide information about their use. The documentation that forms the basis of the emergency medical services intervention needs to be refined. There is no mention of resuscitation performed by a witness of an event or of the use of an AED. In addition, Poland lacks the legal basis for maintaining a register of automated external defibrillators. There is a need to develop appropriate documents to determine the process of reporting by the owners of the use of AEDs in out-of-hospital conditions (OHCA).

A review on initiatives for the management of daily medical emergencies prior to the arrival of emergency medical services

Emergency services worldwide face increasing cost pressure that potentially limits their existing resources. In many countries, emergency services also face the issues of staff shortage-creating extra challenges and constraints, especially during crisis times such as the COVID-19 pandemic-as well as long distances to sparsely populated areas resulting in longer response times. To overcome these issues and potentially reduce consequences of daily (medical) emergencies, several countries, such as Sweden, Germany, and the Netherlands, have started initiatives using new types of human resources as well as equipment, which have not been part of the existing emergency systems before. These resources are employed in response to medical emergency cases if they can arrive earlier than emergency medical services (EMS). A good number of studies have investigated the use of these new types of resources in EMS systems, from medical, technical, and logistical perspectives as their study domains. Several review papers in the literature exist that focus on one or several of these new types of resources. However, to the best of our knowledge, no review paper that comprehensively considers all new types of resources in emergency medical response systems exists. We try to fill this gap by presenting a broad literature review of the studies focused on the different new types of resources, which are used prior to the arrival of EMS. Our objective is to present an application-based and methodological overview of these papers, to provide insights to this important field and to bring it to the attention of researchers as well as emergency managers and administrators.

Immediate psychological impact on citizen responders dispatched through a mobile application to out-of-hospital cardiac arrests

Background

Activating citizen responders may increase survival after out-of-hospital cardiac arrest (OHCA) but could induce significant psychological impact on the citizen responders. We examined psychological impact among citizen responders within the first days following resuscitation attempt.

Methods and Results

A mobile phone application to activate citizen responders to perform cardiopulmonary resuscitation (CPR) was implemented in the Capital Region of Denmark. All dispatched citizen responders (September 2017 to May 2019) received a survey 90 minutes after an alarm, including self-rating of perceived psychological impact on a scale of 1–4.

Of 5,395 included citizen responders, most (88.6%) completed the survey within 24 hours.

The majority reported no psychological impact (68.6%), whereas 24.7%, 5.5% and 1.2% reported low, moderate, or severe impact, respectively. Severe impact was more commonly reported in the following groups: No CPR training (3.8% vs 1.2%, p = 0.02), age < 30 years (2.0% vs 0.9%, p < 0.001), female sex (1.8% vs 0.7%, p < 0.001), provided CPR (2.7% vs 1.0%, p < 0.001), and arrived prior to the emergency medical services (EMS) (2.8% vs 0.7%, p < 0.001) compared to no to moderate impact.

Chi square test, Mann-Whitney U test, Fischer’s exact test and a logistic regression model were used to assess differences in psychological impact across groups.

Conclusion

Very few citizen responders reported severe psychological impact. Lack of prior CPR training, younger age, female sex, performing CPR and arrival prior to the EMS were associated with greater psychological impact. Though very few citizen responders reported severe impact, the possibility of professional debriefing should be considered in citizen responder programs.

Towards individualised treatment of out-of-hospital cardiac arrest patients: an update on technical innovations in the prehospital chain of survival

Out-of-hospital cardiac arrest (OHCA) is a major healthcare problem, with approximately 200 weekly cases in the Netherlands. Its critical, time-dependent nature makes it a unique medical situation, of which outcomes strongly rely on infrastructural factors and on-scene care by emergency medical services (EMS). Survival to hospital discharge is poor, although it has substantially improved, to roughly 25% over the last years. Recognised key factors, such as bystander resuscitation and automated external defibrillator use at the scene, have been markedly optimised with the introduction of technological innovations. In an era with ubiquitous smartphone use, the Dutch digital text message alert platform HartslagNu (www.hartslagnu.nl) increasingly contributes to timely care for OHCA victims. Guidelines emphasise the role of cardiac arrest recognition and early high-quality bystander resuscitation, which calls for education and improved registration at HartslagNu. As for EMS care, new technological developments with future potential are the selective use of mechanical chest compression devices and extracorporeal life support. As a future innovation, ‘smart’ defibrillators are under investigation, guiding resuscitative interventions based on ventricular fibrillation waveform characteristics. Taken together, optimisation of available prehospital technologies is crucial to further improve OHCA outcomes, with particular focus on more available trained volunteers in the first phase and additional research on advanced EMS care in the second phase.

Implications for cardiac arrest coverage using straight-line versus route distance to nearest automated external defibrillator

AIM

Quantifying the ratio describing the difference between "true route" and "straight-line" distances from out-of-hospital cardiac arrests (OHCAs) to the closest accessible automated external defibrillator (AED) can help correct likely overestimations in AED coverage. Furthermore, we aimed to examine to what extent the closest AED based on true route distance differed from the closest AED using "straight-line".

METHODS

OHCAs (1994-2016) and AEDs (2016) in Copenhagen, Denmark and in Toronto, Canada (2007-2015 and 2015, respectively) were identified. Three distances were calculated between OHCA and target AED: 1) the straight-line distance ("straight-line") to the closest AED, 2) the corresponding true route distance to the same AED ("true route"), and 3) the closest AED based only on true route distance ("shortest true route"). The ratio between "true route" and "straight-line" distance was calculated and differences in AED coverage (an OHCA ≤ 100 m of an accessible AED) were examined.

RESULTS

The "straight-line" AED coverage of 100 m was 24.2% (n = 2008/8295) in Copenhagen and 6.9% (n = 964/13916) in Toronto. The corresponding "true route" distance reduced coverage to 9.5% (n = 786) and 3.8% (n = 529), respectively. The median ratio between "true route" and "straight-line" distance was 1.6 in Copenhagen and 1.4 in Toronto. In 26.1% (n = 2167) and 22.9% (n = 3181) of all Copenhagen and Toronto OHCAs respectively, the closest AED in "shortest true route" was different than the closest AED initially found by "straight-line".

CONCLUSIONS

Straight-line distance is not an accurate measure of distance and overestimates the actual AED coverage compared to a more realistic true route distance by a factor 1.4-1.6.

Risk of Physical Injury for Dispatched Citizen Responders to Out-of-Hospital Cardiac Arrest

Background

Citizen responder programs are implemented worldwide to dispatch volunteer citizens to participate in out‐of‐hospital cardiac arrest resuscitation. However, the risk of injuries in relation to activation is largely unknown. We aimed to assess the risk of physical injury for dispatched citizen responders.

Methods and Results

Since September 2017, citizen responders have been activated through a smartphone application when located close to a suspected cardiac arrest in the Capital Region of Denmark. A survey was sent to all activated citizen responders, including a specific question about risk of acquiring an injury during activation. We included all surveys from September 1, 2017, to May 15, 2020. From May 15, 2019, to May 15, 2020, we followed up on all survey nonresponders by phone call, e‐mail, or text messages to examine if nonresponders were at higher risk of severe or fatal injuries. In 1665 suspected out‐of‐hospital cardiac arrests, 9574 citizen responders were dispatched and 76.6% (7334) answered the question regarding physical injury. No injury was reported by 99.3% (7281) of the responders. Being at risk of physical injury was reported by 0.3% (24), whereas 0.4% (26) reported an injury (25 minor injuries and 1 severe injury [ankle fracture]). When following up on nonresponders (2472), we reached 99.1% (2449). No one reported acquired injuries, and only 1 reported being at risk of injury.

Conclusions

We found low risk of physical injury reported by volunteer citizen responders dispatched to out‐of‐hospital cardiac arrest. Risk of injury should be considered and monitored as a safety measure in citizen responder programs.