Survival after Public Access Defibrillation in Stockholm, Sweden – A striking success

Outcome of exercise-related out-of-hospital cardiac arrest is dependent on location: Sports arenas vs outside of arenas

Background

The chance of surviving an out-of-hospital cardiac arrest (OHCA) seems to be increased if the cardiac arrests occurs in relation to exercise. Hypothetically, an exercise-related OHCA at a sports arena would have an even better prognosis, because of an increased likelihood of bystander cardiopulmonary resuscitation (CPR) and higher availability of automated external defibrillators (AEDs). The purpose of the study was to compare survival rates between exercise-related OHCA at sports arenas versus outside of sports arenas.

Methods

Data from all treated exercise-related OHCA outside home reported to the Swedish Register of Cardiopulmonary Resuscitation (SRCR) from 2011 to 2014 in 10 counties of Sweden was analyzed (population 6 million). The registry has in those counties a coverage of almost 100% of all OHCAs.

Results

3714 cases of OHCA outside of home were found. Amongst them, 268(7%) were exercise-related and 164 (61.2%) of those occurred at sports arenas. The 30-day survival rate was higher for exercise-related OHCA at sports arenas compared to outside (55.7% vs 30.0%, p<0.0001). OHCA-victims at sports arenas were younger (mean age±SD 57.6±16.3 years compared to 60.9±17.0 years, p = 0.05), less likely female (4.3% vs 12.2%, p = 0.02) and had a higher frequency of shockable rhythm (73.0% vs 54.3%, p = 0.004). OHCAs at arenas were more often witnessed (83.9% vs 68.9%, p = 0.007), received bystander CPR to a higher extent (90.0% vs 56.8%, p<0.0001) and the AED-use before EMS-arrival was also higher in this group (29.8% vs 11.1%, p = 0.009).

Conclusion

The prognosis is markedly better for exercise-related OHCA occurring at sports arenas compared to outside. Victims of exercise-related OHCA at sports arenas are more likely to receive bystander CPR and to be connected to a public AED. These findings support an increased use of public AEDs and implementation of Medical Action Plans (MAP), to possibly increase survival of exercise-related OHCA even further.

Awareness of basic life support and cardiopulmonary resuscitation among female secondary school students in government schools in Riyadh city, KSA

Background and Objective

Basic life support (BLS) and cardiopulmonary resuscitation (CPR) are urgently required and must be performed when cardiac arrest occurs. These lifesaving procedures must be learned by healthcare professionals. In developed countries, members of the public, academics, and students learn how to carry out these emergency procedures. Knowledge of these simple procedures determines successful outcome. This study was conducted to determine the level of awareness of BLS and CPR among female secondary students at governmental schools in Riyadh city, Saudi Arabia (SA).

Methods

This cross-sectional study was conducted in five governmental secondary schools in Riyadh city, SA, between June 2015 and June 2016. Total of 1224 female students were selected randomly, and data were collected using a self-reported structured questionnaire.

Results

A total of 1170 participants completed the questionnaire. Most of the participants (81.5%) were Saudis. More than 50% of the students (54.8%) did not have information about BLS, and 82.6% felt their knowledge about BLS was insufficient. Only 10.8% of the participants had taken a BLS course, and only 38.5% believe BLS courses should be mandatory.

Conclusion

The level of awareness regarding BLS among female secondary school students in governmental schools in Riyadh was found to be insufficient. The introduction of BLS and CPR courses in the curriculum of governmental secondary schools in Riyadh city is highly recommended.

The prognostic significance of repeated prehospital shocks for out-of-hospital cardiac arrest survival

OBJECTIVES

Patients suffering from an out-of-hospital cardiac arrest (OHCA) associated with an initial shockable rhythm have a better prognosis than their counterparts. The implications of recurrent or refractory malignant arrhythmia in such context remain unclear. The objective of this study is to evaluate the association between the number of prehospital shocks delivered and survival to hospital discharge among patients in OHCA.

METHODS

This cohort study included adult patients with an initial shockable rhythm over a 5-year period from a registry of OHCA in Montreal, Canada. The relationship between the number of prehospital shocks delivered and survival to discharge was described using dynamic probabilities. The association between the number of prehospital shocks delivered and survival to discharge was assessed using multivariable logistic regression.

RESULTS

A total of 1,788 patients (78% male with a mean age of 64 years) were included in this analysis, of whom 536 (30%) received treatments from an advanced care paramedic. A third of the cohort (583 patients, 33%) survived to hospital discharge. The probability of survival was highest with the first shock (33% [95% confidence interval 30%-35%]), but decreased to 8% (95% confidence interval 4%-13%) following nine shocks. A higher number of prehospital shocks was independently associated with lower odds of survival (adjusted odds ratio=0.88 [95% confidence interval 0.85-0.92], p &lt; 0.001).

CONCLUSION

Survival remains possible even after a high number of shocks for patients suffering from an OHCA with an initial shockable rhythm. However, requiring more shocks is independently associated with worse survival.

Association Between Driving Distance From Nearest Fire Station and Survival of Out-of-Hospital Cardiac Arrest

Background

Firefighter first responders dispatched in parallel with emergency medical services (EMS) personnel for out‐of‐hospital cardiac arrests (OHCA) can provide early defibrillation to improve survival. We examined whether survival following first responder defibrillation differed according to driving distance from nearest fire station to OHCA site.

Methods and Results

From the CARES (Cardiac Arrest Registry to Enhance Survival) registry, we identified non‐EMS witnessed OHCAs of presumed cardiac cause from 2010 to 2014 in Durham, Mecklenburg, and Wake counties, North Carolina. We used logistic regression to estimate the association between calculated driving distances (≤1, 1–1.5, 1.5–2, and >2 miles) and survival to hospital discharge following first responder defibrillation compared with defibrillation by EMS personnel. In total, 5020 OHCAs were included in the study. First responders more often applied the first automated external defibrillators at the shortest distances (≤1 mile) versus longest distances (>2 miles) (53.4% versus 46.6%, respectively, P<0.001). When compared with EMS defibrillation, first responder defibrillation within 1 mile and 1 to 1.5 miles of the nearest fire station was associated with increased survival to hospital discharge (odds ratio 2.01 [95% confidence interval 1.46–2.78] and odds ratio 1.61 [95% confidence interval 1.10–2.35], respectively). However, at the longest distances (1.5–2.0 and >2.0 miles), survival following first responder defibrillation did not differ from EMS defibrillation (odds ratio 0.77 [95% confidence interval 0.48–1.21] and odds ratio 0.97 [95% confidence interval 0.67–1.41], respectively).

Conclusions

Shorter driving distance from nearest fire station to OHCA location was associated with improved survival following defibrillation by first responders. These results suggest that the location of first responder units should be considered when organizing prehospital systems of OHCA care.

School Nurses' Perceived Barriers and Perceptual Influences When Implementing AED Programs

School nurses' experienced barriers and benefits with perceptions of self-efficacy are important factors to consider for program implementation in the school setting. Little research has been done in the area of automated external defibrillator (AED) program implementation by the school nurse for the treatment of sudden cardiac arrest. The purpose of this study was to identify benefits of and barriers to AED program implementation in public schools and measure school nurses' self-efficacy related to their role as a change agent in program implementation. Results revealed that school nurses are functioning with a high level of self-efficacy in their ability to influence major health-care decisions in the school setting, and despite barriers, AED program implementation is considered beneficial and a necessary component of emergency care.

Different defibrillation strategies in survivors after out-of-hospital cardiac arrest

BACKGROUND

In the last decade, there has been a rapid increase in the dissemination of automated external defibrillators (AEDs) for prehospital defibrillation of out-of-hospital cardiac arrest patients. The aim of this study was to study the association between different defibrillation strategies on survival rates over time in Copenhagen, Stockholm, Western Sweden and Amsterdam, and the hypothesis was that non-EMS defibrillation increased over time and was associated with increased survival.

METHODS

We performed a retrospective analysis of four prospectively collected cohorts of out-of-hospital cardiac arrest patients between 2008 and 2013. Emergency medical service (EMS)-witnessed arrests were excluded.

RESULTS

A total of 22 453 out-of-hospital cardiac arrest patients with known survival status were identified, of whom 2957 (13%) survived at least 30 days postresuscitation. Of all survivors with a known defibrillation status, 2289 (81%) were defibrillated, 1349 (59%) were defibrillated by EMS, 454 (20%) were defibrillated by a first responder AED and 429 (19%) were defibrillated by an onsite AED and 57 (2%) were unknown. The percentage of survivors defibrillated by first responder AEDs (from 13% in 2008 to 26% in 2013, p<0.001 for trend) and onsite AEDs (from 14% in 2008 to 30% in 2013, p<0.001 for trend) increased. The increased use of these non-EMS AEDs was associated with the increase in survival rate of patients with a shockable initial rhythm.

CONCLUSION

Survivors of out-of-hospital cardiac arrest are increasingly defibrillated by non-EMS AEDs. This increase is primarily due to a large increase in the use of onsite AEDs as well as an increase in first-responder defibrillation over time. Non-EMS defibrillation accounted for at least part of the increase in survival rate of patients with a shockable initial rhythm.

Emerging and Future Technologies in Out-of-Hospital Cardiac Arrest Care

The care for victims of out-of-hospital cardiac arrest is evolving and will be influenced by future and emerging technologies that will play a role in the systems of care for these patients. Recent advances in extracorporeal life support and point-of-care ultrasound imaging, both in-hospital and out-of-hospital, may offer a therapeutic solution in some systems for patients with refractory or recurrent cardiac arrest. Drones capable of delivering automated external defibrillators to the scene of an out-of-hospital cardiac arrest, advances in digital and mobile technologies to notify and leverage bystander response, and wearable life detection technologies may improve survival.

Witnessed out-of-hospital cardiac arrest- effects of emergency dispatch recognition

BACKGROUND

Survival from an out-of-hospital cardiac arrest (OHCA) depends on the sequence of interventions in "the chain of survival". If OHCA is recognized in the emergency medical communication centre (EMCC), the proper emergency medical service (EMS) should be dispatched and cardiopulmonary resuscitation (CPR) instructions should be given to a bystander. The study aimed to examine the impact of OHCA recognition in the EMCC on survival rates and the main elements of the chain of survival.

METHODS

Data from the Helsinki University Hospital's registry of OHCA patients between 1997 and 2013 were studied. Altogether, 2054 EMCC-handled and bystander-witnessed OHCA proven events of cardiac origin were analysed.

RESULTS

In 80.5% of the victims, two EMS units were correctly dispatched and the OHCA was classified as recognized. Achieved return of spontaneous circulation (ROSC) and survival to hospital discharge were 49% and 23%, respectively, if cardiac arrest was recognized by the EMCC and 40% and 16% when it was not (P = 0.003 and 0.002). Dispatchers gave CPR instructions in 60% of the recognized OHCA cases. Bystander-performed CPR increased over time and was given in 58% of the recognized OHCAs and also in 17% of the unrecognized events. EMS delays were shorter if OHCA was recognized as opposed to unrecognized (8 min with an IQR 6.5-10 min vs. 9 min with an IQR 6.5-11 min; P = 0.001).

CONCLUSIONS

Recognition of OHCA by the EMCC was significantly associated with an increased rate of bystander-performed CPR, reduced EMS response time, and increased OHCA patient ROSC and survival rates.

The challenges and possibilities of public access defibrillation

Out-of-hospital cardiac arrest (OHCA) is a major health problem that affects approximately four hundred and thousand patients annually in the United States alone. It is a major challenge for the emergency medical system as decreased survival rates are directly proportional to the time delay from collapse to defibrillation. Historically, defibrillation has only been performed by physicians and in-hospital. With the development of automated external defibrillators (AEDs), rapid defibrillation by nonmedical professionals and subsequently by trained or untrained lay bystanders has become possible. Much hope has been put to the concept of Public Access Defibrillation with a massive dissemination of public available AEDs throughout most Western countries. Accordingly, current guidelines recommend that AEDs should be deployed in places with a high likelihood of OHCA. Despite these efforts, AED use is in most settings anecdotal with little effect on overall OHCA survival. The major reasons for low use of public AEDs are that most OHCAs take place outside high incidence sites of cardiac arrest and that most OHCAs take place in residential settings, currently defined as not suitable for Public Access Defibrillation. However, the use of new technology for identification and recruitment of lay bystanders and nearby AEDs to the scene of the cardiac arrest as well as new methods for strategic AED placement redefines and challenges the current concept and definitions of Public Access Defibrillation. Existing evidence of Public Access Defibrillation and knowledge gaps and future directions to improve outcomes for OHCA are discussed. In addition, a new definition of the different levels of Public Access Defibrillation is offered as well as new strategies for increasing AED use in the society.

Impact of Bystander Automated External Defibrillator Use on Survival and Functional Outcomes in Shockable Observed Public Cardiac Arrests

BACKGROUND

Survival following out-of-hospital cardiac arrest (OHCA) with shockable rhythms can be improved with early defibrillation. Although shockable OHCA accounts for only ≈25% of overall arrests, ≈60% of public OHCAs are shockable, offering the possibility of restoring thousands of individuals to full recovery with early defibrillation by bystanders. We sought to determine the association of bystander automated external defibrillator use with survival and functional outcomes in shockable observed public OHCA.

METHODS

From 2011 to 2015, the Resuscitation Outcomes Consortium prospectively collected detailed information on all cardiac arrests at 9 regional centers. The exposures were shock administration by a bystander-applied automated external defibrillator in comparison with initial defibrillation by emergency medical services. The primary outcome measure was discharge with normal or near-normal (favorable) functional status defined as a modified Rankin Score ≤2. Survival to hospital discharge was the secondary outcome measure.

RESULTS

Among 49 555 OHCAs, 4115 (8.3%) observed public OHCAs were analyzed, of which 2500 (60.8%) were shockable. A bystander shock was applied in 18.8% of the shockable arrests. Patients shocked by a bystander were significantly more likely to survive to discharge (66.5% versus 43.0%) and be discharged with favorable functional outcome (57.1% versus 32.7%) than patients initially shocked by emergency medical services. After adjusting for known predictors of outcome, the odds ratio associated with a bystander shock was 2.62 (95% confidence interval, 2.07-3.31) for survival to hospital discharge and 2.73 (95% confidence interval, 2.17-3.44) for discharge with favorable functional outcome. The benefit of bystander shock increased progressively as emergency medical services response time became longer.

CONCLUSIONS

Bystander automated external defibrillator use before emergency medical services arrival in shockable observed public OHCA was associated with better survival and functional outcomes. Continued emphasis on public automated external defibrillator utilization programs may further improve outcomes of OHCA.

A smartphone application for dispatch of lay responders to out-of-hospital cardiac arrests

BACKGROUND

Dispatch of lay volunteers trained in cardiopulmonary resuscitation (CPR) and equipped with automated external defibrillators (AEDs) may improve survival in cases of out-of-hospital cardiac arrest (OHCA). The aim of this study was to investigate the functionality and performance of a smartphone application for locating and alerting nearby trained laymen/women in cases of OHCA.

METHODS

A system using a smartphone application activated by Emergency Dispatch Centres was used to locate and alert laymen/women to nearby suspected OHCAs. Lay responders were instructed either to perform CPR or collect a nearby AED. An online survey was carried out among the responders.

RESULTS

From February to August 2016, the system was activated in 685 cases of suspected OHCA. Among these, 224 cases were Emergency Medical Services (EMSs)-treated OHCAs (33%). EMS-witnessed cases (n = 11) and cases with missing survey data (n = 15) were excluded. In the remaining 198 OHCAs, lay responders arrived at the scene in 116 cases (58%), and prior to EMSs in 51 cases (26%). An AED was attached in 17 cases (9%) and 4 (2%) were defibrillated. Lay responders performed CPR in 54 cases (27%). Median distance to the OHCA was 560 m (IQR 332-860 m), and 1280 m (IQR 748-1776 m) via AED pick-up. The survey-answering rate was 82%.

CONCLUSION

A smartphone application can be used to alert CPR-trained lay volunteers to OHCAs for CPR. Further improvements are needed to shorten the time to defibrillation before EMS arrival.

Dispatch of Firefighters and Police Officers in Out-of-Hospital Cardiac Arrest: A Nationwide Prospective Cohort Trial Using Propensity Score Analysis

BACKGROUND

Dispatch of basic life support-trained first responders equipped with automated external defibrillators in addition to advanced life support-trained emergency medical services personnel in out-of-hospital cardiac arrest (OHCA) has, in some minor cohort studies, been associated with improved survival. The aim of this study was to evaluate the association between basic life support plus advanced life support response and survival in OHCA at a national level.

METHODS AND RESULTS

This prospective cohort study was conducted from January 1, 2012, to December 31, 2014. People who experienced OHCA in 9 Swedish counties covered by basic life support plus advanced life support response were compared with a propensity-matched contemporary control group of people who experienced OHCA in 12 counties where only emergency medical services was dispatched, providing advanced life support. Primary outcome was survival to 30 days. The analytic sample consisted of 2786 pairs (n=5572) derived from the total cohort of 7308 complete cases. The median time from emergency call to arrival of emergency medical services or first responder was 9 minutes in the intervention group versus 10 minutes in the controls (P<0.001). The proportion of patients admitted alive to the hospital after resuscitation was 31.4% (875/2786) in the intervention group versus 24.9% (694/2786) in the controls (conditional odds ratio, 1.40; 95% confidence interval, 1.24-1.57). Thirty-day survival was 9.5% (266/2786) in the intervention group versus 7.7% (214/2786) in the controls (conditional odds ratio, 1.27; 95% confidence interval, 1.05-1.54).

CONCLUSIONS

In this nationwide interventional trial, using propensity score matching, dispatch of first responders in addition to emergency medical services in OHCA was associated with a moderate, but significant, increase in 30-day survival.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02184468.

Barriers and facilitators to public access defibrillation in out-of-hospital cardiac arrest: a systematic review

Public access defibrillation initiatives make automated external defibrillators available to the public. This facilitates earlier defibrillation of out-of-hospital cardiac arrest victims and could save many lives. It is currently only used for a minority of cases. The aim of this systematic review was to identify barriers and facilitators to public access defibrillation. A comprehensive literature review was undertaken defining formal search terms for a systematic review of the literature in March 2017. Studies were included if they considered reasons affecting the likelihood of public access defibrillation and presented original data. An electronic search strategy was devised searching MEDLINE and EMBASE, supplemented by bibliography and related-article searches. Given the low-quality and observational nature of the majority of articles, a narrative review was performed. Sixty-four articles were identified in the initial literature search. An additional four unique articles were identified from the electronic search strategies. The following themes were identified related to public access defibrillation: knowledge and awareness; willingness to use; acquisition and maintenance; availability and accessibility; training issues; registration and regulation; medicolegal issues; emergency medical services dispatch-assisted use of automated external defibrillators; automated external defibrillator-locator systems; demographic factors; other behavioural factors. In conclusion, several barriers and facilitators to public access defibrillation deployment were identified. However, the evidence is of very low quality and there is not enough information to inform changes in practice. This is an area in urgent need of further high-quality research if public access defibrillation is to be increased and more lives saved. PROSPERO registration number CRD42016035543.

Bystander automated external defibrillator use and clinical outcomes after out-of-hospital cardiac arrest: A systematic review and meta-analysis

AIM

To systematically review studies comparing bystander automated external defibrillator (AED) use to no AED use in regard to clinical outcomes in out-of-hospital cardiac arrest (OHCA), and to provide a descriptive summary of studies on the cost-effectiveness of bystander AED use.

METHODS

We searched Medline, Embase, the Web of Science, and the Cochrane Library for randomized trials and observational studies published before June 1, 2017. Meta-analyses were performed for patients with all rhythms, shockable rhythms, and non-shockable rhythms.

RESULTS

Forty-four observational studies, 3 randomized trials, and 13 cost-effectiveness studies were included. Meta-analysis of 6 observational studies without critical risk of bias showed that bystander AED use was associated with survival to hospital discharge (all rhythms OR: 1.73 [95%CI: 1.36, 2.18], shockable rhythms OR: 1.66 [95%CI: 1.54, 1.79]) and favorable neurological outcome (all rhythms OR: 2.12 [95%CI: 1.36, 3.29], shockable rhythms OR: 2.37 [95%CI: 1.58, 3.57]). There was no association between bystander AED use and neurological outcome for non-shockable rhythms (OR: 0.76 [95%CI: 0.10, 5.87]). The Public-Access Defibrillation trial found higher survival rates when volunteers were equipped with AEDs. The other trials found no survival difference, although their study settings differed. The quality of evidence was low for randomized trials and very low for observational studies. AEDs were cost-effective in settings with high cardiac arrest incidence, with most studies reporting ratios < $100,000 per quality-adjusted life years.

CONCLUSIONS

The evidence supports the association between bystander AED use and improved clinical outcomes, although the quality of evidence was low to very low.

The Effects of Public Access Defibrillation on Survival After Out-of-Hospital Cardiac Arrest: A Systematic Review of Observational Studies

BACKGROUND

Despite recent advances, the average survival after out-of-hospital cardiac arrest (OHCA) remains <10%. Early defibrillation by an automated external defibrillator is the most important intervention for patients with OHCA, showing survival proportions >50%. Accordingly, placement of automated external defibrillators in the community as part of a public access defibrillation program (PAD) is recommended by international guidelines. However, different strategies have been proposed on how exactly to increase and make use of publicly available automated external defibrillators. This systematic review aimed to evaluate the effect of PAD and the different PAD strategies on survival after OHCA.

METHODS

PubMed, Embase, and the Cochrane Library were systematically searched on August 31, 2015 for observational studies reporting survival to hospital discharge in OHCA patients where an automated external defibrillator had been used by nonemergency medical services. PAD was divided into 3 groups according to who applied the defibrillator: nondispatched lay first responders, professional first responders (firefighters/police) dispatched by the Emergency Medical Dispatch Center (EMDC), or lay first responders dispatched by the EMDC.

RESULTS

A total of 41 studies were included; 18 reported PAD by nondispatched lay first responders, 20 reported PAD by EMDC-dispatched professional first responders (firefighters/police), and 3 reported both. We identified no qualified studies reporting survival after PAD by EMDC-dispatched lay first responders. The overall survival to hospital discharge after OHCA treated with PAD showed a median survival of 40.0% (range, 9.1-83.3). Defibrillation by nondispatched lay first responders was associated with the highest survival with a median survival of 53.0% (range, 26.0-72.0), whereas defibrillation by EMDC-dispatched professional first responders (firefighters/police) was associated with a median survival of 28.6% (range, 9.0-76.0). A meta-analysis of the different survival outcomes could not be performed because of the large heterogeneity of the included studies.

CONCLUSIONS

This systematic review showed a median overall survival of 40% for patients with OHCA treated by PAD. Defibrillation by nondispatched lay first responders was found to correlate with the highest impact on survival in comparison with EMDC-dispatched professional first responders. PAD by EMDC-dispatched lay first responders could be a promising strategy, but evidence is lacking.

Time to Delivery of an Automated External Defibrillator Using a Drone for Simulated Out-of-Hospital Cardiac Arrests vs Emergency Medical Services

This study compares the time to delivery of an automated external defibrillator using fully autonomous drones for simulated out-of-hospital cardiac arrests vs emergency medical services real-time responses.

Use of a geographic information system to identify differences in automated external defibrillator installation in urban areas with similar incidence of public out-of-hospital cardiac arrest: a retrospective registry-based study

OBJECTIVES

Early defibrillation in out-of-hospital cardiac arrest (OHCA) is of importance to improve survival. In many countries the number of automated external defibrillators (AEDs) is increasing, but the use is low. Guidelines suggest that AEDs should be installed in densely populated areas and in locations with many visitors. Attempts have been made to identify optimal AED locations based on the incidence of OHCA using geographical information systems (GIS), but often on small datasets and the studies are seldom reproduced. The aim of this paper is to investigate if the distribution of public AEDs follows the incident locations of public OHCAs in urban areas of Stockholm County, Sweden.

METHOD

OHCA data were obtained from the Swedish Register for Cardiopulmonary Resuscitation and AED data were obtained from the Swedish AED Register. Urban areas in Stockholm County were objectively classified according to the pan-European digital mapping tool, Urban Atlas (UA). Furthermore, we reclassified and divided the UA land cover data into three classes (residential, non-residential and other areas). GIS software was used to spatially join and relate public AED and OHCA data and perform computations on relations and distance.

RESULTS

Between 1 January 2012 and 31 December 2014 a total of 804 OHCAs occurred in public locations in Stockholm County and by December 2013 there were 1828 AEDs available. The incidence of public OHCAs was similar in residential (47.3%) and non-residential areas (43.4%). Fewer AEDs were present in residential areas than in non-residential areas (29.4% vs 68.8%). In residential areas the median distance between OHCAs and AEDs was significantly greater than in non-residential areas (288 m vs 188 m, p<0.001).

CONCLUSION

The majority of public OHCAs occurred in areas classified in UA as 'residential areas' with limited AED accessibility. These areas need to be targeted for AED installation and international guidelines need to take geographical location into account when suggesting locations for AED installation.

Recognising out-of-hospital cardiac arrest during emergency calls increases bystander cardiopulmonary resuscitation and survival

BACKGROUND

Initiation of early bystander cardiopulmonary resuscitation (CPR) depends on bystanders' or medical dispatchers' recognition of out-of-hospital cardiac arrest (OHCA). The primary aim of our study was to investigate if OHCA recognition during the emergency call was associated with bystander CPR, return of spontaneous circulation (ROSC), and 30-day survival. Our secondary aim was to identify patient-, setting-, and dispatcher-related predictors of OHCA recognition.

METHODS

We performed an observational study of all OHCA patients' emergency calls in the Capital Region of Denmark from 01/01/2013-31/12/2013. OHCAs were collected from the Danish Cardiac Arrest Registry and the Mobile Critical Care Unit database. Emergency call recordings were identified and evaluated. Multivariable logistic regression analyses were applied to all OHCAs and witnessed OHCAs only to analyse the association between OHCA recognition and bystander CPR, ROSC, and 30-day survival. Univariable logistic regression analyses were applied to identify predictors of OHCA recognition.

RESULTS

We included 779 emergency calls in the analyses. During the emergency calls, 70.1% (n=534) of OHCAs were recognised; OHCA recognition was positively associated with bystander CPR (odds ratio [OR]=7.84, 95% confidence interval [CI]: 5.10-12.05) in all OHCAs; and ROSC (OR=1.86, 95% CI: 1.13-3.06) and 30-day survival (OR=2.80, 95% CI: 1.58-4.96) in witnessed OHCA. Predictors of OHCA recognition were addressing breathing (OR=1.76, 95% CI: 1.17-2.66) and callers located by the patient's side (OR=2.16, 95% CI: 1.46-3.19).

CONCLUSIONS

Recognition of OHCA during emergency calls was positively associated with the provision of bystander CPR, ROSC, and 30-day survival in witnessed OHCA.

Cardiopulmonary Resuscitation Training in Schools Following 8 Years of Mandating Legislation in Denmark: A Nationwide Survey

BACKGROUND

School cardiopulmonary resuscitation (CPR) training has become mandatory in many countries, but whether legislation has translated into implementation of CPR training is largely unknown. We assessed CPR training of students following 8 years of legislative mandates in Denmark.

METHODS AND RESULTS

A nationwide cross-sectional survey of Danish school leadership (n=1240) and ninth-grade homeroom teachers (n=1381) was carried out for school year 2013-2014. Qualitative interviews and the Theory of Planned Behavior were used to construct the survey. Logistic regression models were employed to identify factors associated with completed CPR training. Information from 63.1% of eligible schools was collected: 49.3% (n=611) of leadership and 48.2% (n=665) of teachers responded. According to teachers, 28.4% (95% CI 25.0% to 32.0%) and 10.3% (95% CI 8.1% to 12.8%) of eligible classes had completed CPR and automated external defibrillator training, respectively. Among leadership, 60.2% (95% CI 56.2% to 64.1%) reported CPR training had occurred during the 3 years prior to the survey. Factors associated with completed CPR training included believing other schools were conducting training (odds ratio [OR] 9.68 [95% CI 4.65-20.1]), awareness of mandating legislation (OR 4.19 [95% CI 2.65-6.62]), presence of a school CPR training coordinator (OR 3.01 [95% CI 1.84-4.92]), teacher feeling competent to conduct training (OR 2.78 [95% CI 1.74-4.45]), and having easy access to training material (OR 2.08 [95% CI 1.57-2.76]).

CONCLUSIONS

Despite mandating legislation, school CPR training has not been successfully implemented. Completed CPR training was associated with believing other schools were conducting training, awareness of mandating legislation, presence of a school CPR training coordinator, teachers teacher feeling competent to conduct training, and having easy access to training material. Facilitating these factors may increase rates of school CPR training.

Lay Bystanders' Perspectives on What Facilitates Cardiopulmonary Resuscitation and Use of Automated External Defibrillators in Real Cardiac Arrests

Background

Many patients who suffer an out‐of‐hospital cardiac arrest will fail to receive bystander intervention (cardiopulmonary resuscitation [CPR] or defibrillation) despite widespread CPR training and the dissemination of automated external defibrillators (AEDs). We sought to investigate what factors encourage lay bystanders to initiate CPR and AED use in a cohort of bystanders previously trained in CPR techniques who were present at an out‐of‐hospital cardiac arrest.

Methods and Results

One‐hundred and twenty‐eight semistructured qualitative interviews with CPR‐trained lay bystanders to consecutive out‐of‐hospital cardiac arrest, where an AED was present were conducted (from January 2012 to April 2015, in Denmark). Purposive maximum variation sampling was used to establish the breadth of the bystander perspective. Twenty‐six of the 128 interviews were chosen for further in‐depth analyses, until data saturation. We used cross‐sectional indexing (using software), and inductive in‐depth thematic analyses, to identify those factors that facilitated CPR and AED use. In addition to prior hands‐on CPR training, the following were described as facilitators: prior knowledge that intervention is crucial in improving survival, cannot cause substantial harm, and that the AED will provide guidance through CPR; prior hands‐on training in AED use; during CPR performance, teamwork (ie, support), using the AED voice prompt and a ventilation mask, as well as demonstrating leadership and feeling a moral obligation to act.

Conclusions

Several factors other than previous hands‐on CPR training facilitate lay bystander instigation of CPR and AED use. The recognition and modification of these factors may increase lay bystander CPR rates and patient survival following an out‐of‐hospital cardiac arrest.

Recognition of out-of-hospital cardiac arrest during emergency calls - a systematic review of observational studies

Background

The medical dispatcher plays an essential role as part of the first link in the Chain of Survival, by recognising the out-of-hospital cardiac arrest (OHCA) during the emergency call, dispatching the appropriate first responder or emergency medical services response, performing dispatcher assisted cardiopulmonary resuscitation, and referring to the nearest automated external defibrillator. The objective of this systematic review was to evaluate and compare studies reporting recognition of OHCA patients during emergency calls.

Methods

This systematic review was reported in compliance with the PRISMA guidelines. We systematically searched MEDLINE, Embase and the Cochrane Library on 4 November 2015. Observational studies, reporting the proportion of clinically confirmed OHCAs that was recognised during the emergency call, were included. Two authors independently screened abstracts and full-text articles for inclusion. Data were extracted and the risk of bias within studies was assessed using the QUADAS-2 tool for quality assessment of diagnostic accuracy studies.

Results

A total of 3,180 abstracts were screened for eligibility and 53 publications were assessed in full-text. We identified 16 studies including 6,955 patients that fulfilled the criteria for inclusion in the systematic review. The studies reported recognition of OHCA with a median sensitivity of 73.9% (range: 14.1–96.9%). The selection of study population and the definition of “recognised OHCA” (threshold for positive test) varied greatly between the studies, resulting in high risk of bias. Heterogeneity in the studies precluded meta-analysis.

Conclusion

Among the 16 included studies, we found a median sensitivity for OHCA recognition of 73.9% (range: 14.1–96.9%). However, great heterogeneity between study populations and in the definition of “recognised OHCA”, lead to insufficient comparability of results. Uniform and transparent reporting is required to ensure comparability and development towards best practice.

Unmanned aerial vehicles (drones) in out-of-hospital-cardiac-arrest

Background

The use of an automated external defibrillator (AED) prior to EMS arrival can increase 30-day survival in out-of-hospital cardiac arrest (OHCA) significantly. Drones or unmanned aerial vehicles (UAV) can fly with high velocity and potentially transport devices such as AEDs to the site of OHCAs. The aim of this explorative study was to investigate the feasibility of a drone system in decreasing response time and delivering an AED.

Methods

Data of Global Positioning System (GPS) coordinates from historical OHCA in Stockholm County was used in a model using a Geographic Information System (GIS) to find suitable placements and visualize response times for the use of an AED equipped drone. Two different geographical models, urban and rural, were calculated using a multi-criteria evaluation (MCE) model. Test-flights with an AED were performed on these locations in rural areas.

Results

In total, based on 3,165 retrospective OHCAs in Stockholm County between 2006–2013, twenty locations were identified for the potential placement of a drone.

In a GIS-simulated model of urban OHCA, the drone arrived before EMS in 32 % of cases, and the mean amount of time saved was 1.5 min. In rural OHCA the drone arrived before EMS in 93 % of cases with a mean amount of time saved of 19 min. In these rural locations during (n = 13) test flights, latch-release of the AED from low altitude (3–4 m) or landing the drone on flat ground were the safest ways to deliver an AED to the bystander and were superior to parachute release.

Discussion

The difference in response time for EMS between urban and rural areas is substantial, as is the possible amount of time saved using this UAV-system. However, yet another technical device needs to fit into the chain of survival. We know nothing of how productive or even counterproductive this system might be in clinical reality.

Conclusions

To use drones in rural areas to deliver an AED in OHCA may be safe and feasible. Suitable placement of drone systems can be designed by using GIS models. The use of an AED equipped drone may have the potential to reduce time to defibrillation in OHCA.

Recognition of out-of-hospital cardiac arrest by medical dispatchers in emergency medical dispatch centres in two countries

INTRODUCTION

Survival after out-of-hospital cardiac arrest (OHCA) remains low. Early recognition by emergency medical dispatchers is essential for an effective chain of actions, leading to early cardiopulmonary resuscitation, use of an automated external defibrillator and rapid dispatching of the emergency medical services.

AIM

To analyse and compare the accuracy of OHCA recognition by medical dispatchers in two countries.

METHOD

An observational register-based study collecting data from national cardiac arrest registers in Denmark and Sweden during a six-month period in 2013. Data were analysed in two steps; registry data were merged with electronically registered emergency call data from the emergency medical dispatch centres in the two regions. Cases with missing or non-OHCA dispatch codes were analysed further by auditing emergency call recordings using a uniform data collection template.

RESULTS

The sensitivity for recognition of OHCA was 40.9% (95% CI: 37.1-44.7%) in the Capital Region of Denmark and 78.4% (95% CI: 73.2-83.0%) in the Skåne Region in Sweden (p<0.001). With additional data from the emergency call recordings, the sensitivity was 80.7% (95% CI: 77.7-84.3%) and 86.0% (95% CI: 81.3-89.8%) for the two regions (p=0.06). The majority of the non-recognised OHCA were dispatched with the highest priority.

CONCLUSION

The accuracy of OHCA recognition was high and comparable. We identified large differences in data registration practices despite the use of similar dispatch tools. This raises a discussion of definitions and transparency in general in scientific reporting of OHCA recognition, which is essential if used as quality indicator in emergency medical services.

Availability and use of public access defibrillators in Busan Metropolitan City, South Korea

Out-of-hospital cardiac arrest (OHCA) is considered an important health issue worldwide, and early defibrillation is a key element for a favourable prognosis. In South Korea, public access defibrillation (PAD) programmes were initiated in 2007. However, the impact of PAD programmes on OHCA survival rates remains unclear. This study evaluated the deployment and maintenance status of public automatic external defibrillators (AED), including how frequently they were used, in Busan Metropolitan City, South Korea. Managers of possible AED sites were first contacted by telephone and asked to confirm the possession of an AED. AED suppliers were contacted for AED sales records to identify missing AED sites. AEDs located in ambulances and medical institutions were not included. Investigators visited confirmed AED sites and completed a checklist on AED maintenance and use. In total, 206 AEDs were located, indicative of an AED density of 0.268 AED/km² and a prevalence of 6.07 per 100,000 in Busan Metropolitan City. We found that public AEDs had been used for resuscitation only 15 times, an average rate of use of once every 26.3 years. Our results indicate that AEDs in Busan Metropolitan City are underused according to the guidelines, and several are in low-priority locations. We believe that AED deployment based on cardiac arrest statistics is important to optimise layperson AED training and utilisation.

Public access defibrillation: improving accessibility and outcomes

BACKGROUND

Worldwide, out-of-hospital cardiac arrest (OHCA) remains a serious problem. Public access defibrillation (PAD) has been shown to be effective in improving survival in OHCA with good neurological outcome.

SOURCES OF DATA

Original articles, reviews and national/international guidelines.

AREAS OF AGREEMENT

Limitations to how much we can improve ambulance response times mean that the public have an essential role to play in OHCA survival. Training of laypersons in the use of automated external defibrillators (AEDs) has been shown to improve outcomes. Placement of AEDs should be related to underlying population demographics.

AREAS OF CONTROVERSY

Placements of AEDs face cost constraints. PAD programs also face challenges in the upkeep of AEDs. Concerns about legal liability for lay rescuers to act remain.

GROWING POINTS

Systematic programs should be in place to train the public in PAD. All AEDs should be listed in national registries and available for usage in an emergency.

AREAS TIMELY FOR DEVELOPING RESEARCH

'Smart' technology is being developed to improve accessibility of AEDs.

[Worldwide experience with automated external defibrillators: What have we achieved? What else can we expect?]

INTRODUCTION

In Germany approximately 70,000-100,000 SCD patients die from sudden cardiac death (SCD). SCD is not caused by a single factor but is a multifactorial problem. In 50 % of SCD victims, sudden cardiac death is the first manifestation of heart disease. SCD is caused by ventricular tachyarrhythmias in approximately 90 % of patients, whereas SCD is caused by bradyarrhythmias in 5-10 % of the patients.

METHODS

Risk stratification is not possible in the majority of them prior to the fatal event. Early defibrillation is the method of choice to terminate ventricular fibrillation. Therefore, it is mandatory to install automatic external defibrillators (AED) in places with many people. There is general agreement that early defibrillation with automated external defibrillators (AED) is an effective tool to treat patients with ventricular fibrillation and will improve survival.

CONCLUSION

It seems necessary to teach cardiocompression and AED use, also to children and adolescents. AED therapy "at home" did not improve survival in patients with cardiac arrest and can not be recommended.

Employment and residential characteristics in relation to automated external defibrillator locations

BACKGROUND

Survival from out-of-hospital cardiac arrest (OHCA) is generally poor and varies by geography. Variability in automated external defibrillator (AED) locations may be a contributing factor. To inform optimal placement of AEDs, we investigated AED access in a major US city relative to demographic and employment characteristics.

METHODS AND RESULTS

This was a retrospective analysis of a Philadelphia AED registry (2,559 total AEDs). The 2010 US Census and the Local Employment Dynamics database by ZIP code was used. Automated external defibrillator access was calculated as the weighted areal percentage of each ZIP code covered by a 400-m radius around each AED. Of 47 ZIP codes, only 9% (4) were high-AED-service areas. In 26% (12) of ZIP codes, less than 35% of the area was covered by AED service areas. Higher-AED-access ZIP codes were more likely to have a moderately populated residential area (P = .032), higher median household income (P = .006), and higher paying jobs (P =. 008).

CONCLUSIONS

The locations of AEDs vary across specific ZIP codes; select residential and employment characteristics explain some variation. Further work on evaluating OHCA locations, AED use and availability, and OHCA outcomes could inform AED placement policies. Optimizing the placement of AEDs through this work may help to increase survival.