Localization of out-of-hospital cardiac arrest in Göteborg 1994–2002 and implications for public access defibrillation

Cardiac Arrest Management in the Workplace: Improving but Not Enough?

The aim was to describe out-of-hospital cardiac arrest (OHCA) occurring in the workplace of a large emergency network, and compare the evolution of their management in the last 15 years. A retrospective study based on data from the Northern Alps Emergency Network compared characteristics of OHCA between cases in and out the workplace, and between cases occurring from January 2004 to December 2010 and from January 2011 to December 2017. Among the 15,320 OHCA cases included, 320 occurred in the workplace (2.1%). They were more often in younger men, and happened more frequently in an area with access to public defibrillation, had more often a shockable rhythm, had a cardiopulmonary resuscitation started by a bystander more frequently, and had a better outcome. Cardiopulmonary resuscitation started by a bystander was the only chain of survival link that improved for cases occurring after December 2010. Workplace OHCA seems to be managed more effectively than others; however, only a slight survival improvement was observed, suggesting that progress is still needed.

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.

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.

Maximum expected survival rate model for public access defibrillator placement

AIM

Mathematical optimization of automated external defibrillator (AED) placement has demonstrated potential to improve survival of out-of-hospital cardiac arrest (OHCA). Existing models mostly aim to improve accessibility based on coverage radius and do not account for detailed impact of delayed defibrillation on survival. We aimed to predict OHCA survival based on time to defibrillation and developed an AED placement model to directly maximize the expected survival rate.

METHODS

We stratified OHCAs occurring in Singapore (2010-2017) based on time to defibrillation and developed a regression model to predict the Utstein survival rate. We then developed a novel AED placement model, the maximum expected survival rate (MESR) model. We compared the performance of MESR with a maximum coverage model developed for Canada that was shown to be generalizable to other settings (Denmark). The survival gain of MESR was assessed through 10-fold cross-validation for placement of 20 to 1000 new AEDs in Singapore. Statistical analysis was performed using χ² and McNemar's tests.

RESULTS

During the study period, 15,345 OHCAs occurred. The power-law approximation with R² of 91.33% performed best among investigated models. It predicted a survival of 54.9% with defibrillation within the first two minutes after collapse that was reduced by more than 60% without defibrillation within the first 4 minutes. MESR outperformed the maximum coverage model with P-value < 0.05 (<0.0001 in 22 of 30 experiments).

CONCLUSION

We developed a novel AED placement model based on the impact of time to defibrillation on OHCA outcomes. Mathematical optimization can improve OHCA survival.

Impediments to and impact of checklists on performance of emergency interventions in primary care: an in situ simulation-based randomized controlled trial

OBJECTIVE

Medical crises occur rather seldom in the primary care setting, but when they do, initial management impacts on morbidity and mortality. Factors that impede the performance of emergency interventions in primary care have not been studied through in-situ simulation. Checklists reportedly improve crisis management.

DESIGN

This randomized controlled trial evaluated emergency intervention performance during two scenarios (hypoglycemia-coma and anaphylaxis-cardiac arrest) simulated at primary care centers, and whether checklist access improved performance.

SETTING

Twenty-two primary care centers in Southern Sweden participated in the study.

SUBJECTS

A total of 347 personnel performed 100 simulations, 45 with and 55 without checklist access.

MAIN OUTCOME MEASURES

Time and impediments to performance of five emergency interventions in each scenario.

RESULTS

On 28 of the 37 occasions when the adrenalin auto-injector was employed, the administration technique was incorrect. In 9 of 49 scenarios, teams had trouble locating the 30% glucose solution. Median time to supplemental oxygen administration during the first scenario was 186 s compared with 96 s during the second scenario (p < 0.001). Checklist access had no significant impact on time to performance of emergency interventions, aside from shorter time to adequate glucose or glucagon administration (median times 632 s with, 756 s without checklist access; p = 0.03).

CONCLUSION

Unfamiliarity with local emergency equipment impedes the performance of emergency interventions during crises simulated in the primary care setting. Simply providing checklist access does not improve the performance of emergency interventions.KEY POINTSLittle is known about the factors that affect the performance of emergency interventions in the primary care setting.Unfamiliarity with local emergency equipment impedes the performance of emergency interventions during crises simulated in the primary care setting.Simply providing crisis checklist access does not improve the performance of emergency interventions in the primary care setting.

Are there disparities in the location of automated external defibrillators in England?

Background

Early defibrillation is an essential element of the chain of survival for out-of-hospital cardiac arrest (OHCA). Public access defibrillation (PAD) programmes aim to place automated external defibrillators (AED) in areas with high OHCA incidence, but there is sometimes a mismatch between AED density and OHCA incidence.

Objectives

This study aimed to assess whether there were any disparities in the characteristics of areas that have an AED and those that do not in England.

Methods

Details of the location of AEDs registered with English Ambulance Services were obtained from individual services or internet sources. Neighbourhood characteristics of lower layer super output areas (LSOA) were obtained from the Office for National Statistics. Comparisons were made between LSOAs with and without a registered AED.

Results

AEDs were statistically more likely to be in LSOAs with a lower residential but higher workplace population density, with people predominantly from a white ethnic background and working in higher socio-economically classified occupations (p < 0.05). There was a significant correlation between AED coverage and the LSOA Index of Multiple Deprivation (IMD) (r = 0.79, p = 0.007), with only 27.4% in the lowest IMD decile compared to about 45% in highest. AED density varied significantly across the country from 0.82/km² in the north east to 2.97/km² in London.

Conclusions

In England, AEDs were disproportionately placed in more affluent areas, with a lower residential population density. This contrasts with locations where OHCAs have previously occurred. Future PAD programmes should give preference to areas of higher deprivation and be tailored to the local community.

Use of Public Automated External Defibrillators in Out-of-Hospital Cardiac Arrest in Poland

Background and objectives: National medical records indicate that approximately 350,000–700,000 people die each year from sudden cardiac arrest. The guidelines of the European Resuscitation Council (ERC) and the International Liaison Committee on Resuscitation (ILCOR) indicate that in addition to resuscitation, it is important—in the case of so-called defibrillation rhythms—to perform defibrillation as quickly as possible. The aim of this study was to assess the use of public automated external defibrillators in out of hospital cardiac arrest in Poland between 2008 and 2018. Materials and Methods: One hundred and twenty cases of use of an automated external defibrillator placed in a public space between 2008 and 2018 were analyzed. The study material consisted of data on cases of use of an automated external defibrillator in adults (over 18 years of age). Only cases of automated external defibrillators (AED) use in a public place other than a medical facility were analysed, additionally excluding emergency services, i.e., the State Fire Service and the Volunteer Fire Service, which have an AED as part of their emergency equipment. The survey questionnaire was sent electronically to 1165 sites with AEDs and AED manufacturers. A total of 298 relevant feedback responses were received. Results: The analysis yielded data on 120 cases of AED use in a public place. Conclusions: Since 2016, there has been a noticeable increase in the frequency of use of AEDs located in public spaces. This is most likely related to the spread of public access to defibrillation and increased public awareness.

[Current treatment concepts for trauma-related cardiac arrest : Focal points, differences and similarities]

Trauma-related deaths are not only a relevant medical problem but also a socioeconomic one. The care of a polytraumatized patient is one of the less commonly occurring missions in the rescue and emergency medical services. The aim of this article is to compare the similarities and differences between different course concepts and guidelines in the treatment of trauma-related cardiac arrests (TCA) and to filter out the main focus of each concept. Because of the various approaches in the treatment of polytraumatized patients, there are decisive differences between trauma-related cardiac arrests and cardiac arrests from other causes.

Evaluating health facility access using Bayesian spatial models and location analysis methods

BACKGROUND

Floating catchment methods have recently been applied to identify priority regions for Automated External Defibrillator (AED) deployment, to aid in improving Out of Hospital Cardiac Arrest (OHCA) survival. This approach models access as a supply-to-demand ratio for each area, targeting areas with high demand and low supply for AED placement. These methods incorporate spatial covariates on OHCA occurrence, but do not provide precise AED locations, which are critical to the initial intent of such location analysis research. Exact AED locations can be determined using optimisation methods, but they do not incorporate known spatial risk factors for OHCA, such as income and demographics. Combining these two approaches would evaluate AED placement impact, describe drivers of OHCA occurrence, and identify areas that may not be appropriately covered by AED placement strategies. There are two aims in this paper. First, to develop geospatial models of OHCA that account for and display uncertainty. Second, to evaluate the AED placement methods using geospatial models of accessibility. We first identify communities with the greatest gap between demand and supply for allocating AEDs. We then use this information to evaluate models for precise AED location deployment.

METHODS

Case study data set consisted of 2802 OHCA events and 719 AEDs. Spatial OHCA occurrence was described using a geospatial model, with possible spatial correlation accommodated by introducing a conditional autoregressive (CAR) prior on the municipality-level spatial random effect. This model was fit with Integrated Nested Laplacian Approximation (INLA), using covariates for population density, proportion male, proportion over 65 years, financial strength, and the proportion of land used for transport, commercial, buildings, recreation, and urban areas. Optimisation methods for AED locations were applied to find the top 100 AED placement locations. AED access was calculated for current access and 100 AED placements. Priority rankings were then given for each area based on their access score and predicted number of OHCA events.

RESULTS

Of the 2802 OHCA events, 64.28% occurred in rural areas, and 35.72% in urban areas. Additionally, over 70% of individuals were aged over 65. Supply of AEDs was less than demand in most areas. Priority regions for AED placement were identified, and access scores were evaluated for AED placement methodology by ranking the access scores and the predicted OHCA count. AED placement methodology placed AEDs in areas with the highest priority, but placed more AEDs in areas with more predicted OHCA events in each grid cell.

CONCLUSION

The methods in this paper incorporate OHCA spatial risk factors and OHCA coverage to identify spatial regions most in need of resources. These methods can be used to help understand how AED allocation methods affect OHCA accessibility, which is of significant practical value for communities when deciding AED placements.

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.

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.

Automated External Defibrillators and Survival After Nonresidential Out of Hospital Cardiac Arrest in a Small North American City

Most studies demonstrate that the use of automated external defibrillators (AEDs) during out of hospital cardiac arrest is associated with survival, but the majority of these studies were performed in large cities. With this in mind, the aims of our study were to examine AED placement and variables associated with survival after nonresidential out of hospital cardiac arrest (NROHCA) in a small North American city. Cases of NROHCA and locations with AEDs, in Regina, between January 2010 and December 2014 were reviewed. Common locations for NROHCA were identified, the frequency of AED availability was determined, and the relations between survival and AED presence, bystander initiated cardiopulmonary resuscitation (CPR), or shockable rhythms were determined. Only 20% of cases of NROHCA had an AED present on the premise. The presence of an AED (p = 0.94) was not associated with survival to the emergency department, whereas bystander initiated CPR (p <0.01) and shockable rhythm (p <0.01) were associated with survival to the emergency department. The presence of an AED (p = 0.86) and bystander initiated CPR (p = 0.06) were not associated with survival to discharge from the hospital, whereas the presence of a shockable rhythm was (p <0.01). Multivariable logistic regression analysis demonstrated that the presence of a shockable rhythm was independently associated with survival to the emergency department (OR 11.78, p <0.01) and discharge from the hospital (OR 6.08, p <0.01). The optimal locations for AED placement in cities of similar size and density may need to be reexamined, as the findings may have implications for public policies surrounding AED placement.

Cardiopulmonary arrest in primary care clinics: more holes than cheese: a survey of the knowledge and attitudes of primary care physicians regarding resuscitation

BACKGROUND

Patients experiencing pre-arrest symptoms may first refer to their primary care physician. The study's aim was to determine the likelihood that a patient undergoing out-of-hospital cardiac arrest will receive appropriate resuscitation efforts in a primary care clinic in a country with a directive that clinics maintain resuscitation equipment and physicians undergo periodic resuscitation training.

METHODS

An anonymous, 23-question online cross-sectional survey was created and administered to primary care physicians working in community clinics (10/1/2015-5/3/2015). Recruitment was accomplished by posting a link to the survey to all physicians listed as registered Society of Family Medicine members and in other online forums dedicated to residents and board-certified specialists in family medicine in Israel. The primary outcome measure was the proportion of respondents whose responses indicate that they fulfill all conditions for performing resuscitation.

RESULTS

Of approximately 2400 potential respondents, 185 replied to the survey; the study's findings should be viewed as preliminary. Respondents' characteristics were generally similar to those of the study population, but respondents had a higher rate of family medicine specialists. Respondents were mostly female (n = 108, 58%) Israeli graduates who have practiced medicine for > 10 years (72%, n = 134). 55% (n = 101) had undergone basic life support (BLS) training within < 2 years. Although just 5% (n = 10) estimated call-to-Emergency Medical Service (EMS) arrival time to their clinic to be <5 min, only 64% (n = 119) knew the telephone number for summoning EMS. Most confirmed the existence of a resuscitation cart in their clinic (85%, n = 157); 68% confirmed the presence of a defibrillator (n = 126). Most respondents were aware of the location of the defibrillator in their clinic (67%, n = 123), stated its accessibility during working hours (63%, n = 116), and 56% (n = 103) knew how to use it. Only 28% of the questionnaires indicated that all requirements for mounting an effective BLS response had been fulfilled.

CONCLUSIONS

The study suggests that many primary care clinics are under-equipped and their physicians are under-prepared to initiate life-saving services. Steps must be taken to rectify this situation. In addition, to develop more reliable estimates of the phenomena reported in this preliminary study, these issues should be re-examined in the context of a high response rate physician survey.

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.

Cardiopulmonary resuscitation of out-of-hospital traumatic cardiac arrest in Qatar: A nationwide population-based study

BACKGROUND

Traumatic cardiac arrest studies have reported improved survival rates recently, ranging from 1.7-7.5%. This population-based nationwide study aims to describe the epidemiology, interventions and outcomes, and determine predictors of survival from out-of-hospital traumatic cardiac arrest (OHTCA) in Qatar.

METHODS

An observational retrospective population-based study was conducted on OHTCA patients in Qatar, from January 2010 to December 2015. Traumatic cardiac arrest was redefined to include out-of-hospital traumatic cardiac arrest (OHTCA) and in-hospital traumatic cardiac arrest (IHTCA).

RESULTS

A total of 410 OHTCA patients were included in the 6-year study period. The mean annual crude incidence rate of OHTCA was 4.0 per 100,000 population, in Qatar. OHTCA mostly occurred in males with a median age of 33. There was a preponderance of blunt injuries (94.3%) and head injuries (66.3%). Overall, the survival rate was 2.4%. Shockable rhythm, prehospital external hemorrhage control, in-hospital blood transfusion, and surgery were associated with higher odds of survival. Adrenaline (Epinephrine) lowered the odds of survival.

CONCLUSION

The incidence of OHTCA was less than expected, with a low rate of survival. Thoracotomy was not associated with improved survival while Adrenaline administration lowered survival in OHTCA patients with majority blunt injuries. Interventions to enable early prehospital control of hemorrhage, blood transfusion, thoracostomy and surgery improved survival.

Rise and Shock: Optimal Defibrillator Placement in a High-rise Building

OBJECTIVE

Out-of-hospital cardiac arrests (OHCA) in high-rise buildings experience lower survival and longer delays until paramedic arrival. Use of publicly accessible automated external defibrillators (AED) can improve survival, but "vertical" placement has not been studied. We aim to determine whether elevator-based or lobby-based AED placement results in shorter vertical distance travelled ("response distance") to OHCAs in a high-rise building.

METHODS

We developed a model of a single-elevator, n-floor high-rise building. We calculated and compared the average distance from AED to floor of arrest for the two AED locations. We modeled OHCA occurrences using floor-specific Poisson processes, the risk of OHCA on the ground floor (λ₁) and the risk on any above-ground floor (λ). The elevator was modeled with an override function enabling direct travel to the target floor. The elevator location upon override was modeled as a discrete uniform random variable. Calculations used the laws of probability.

RESULTS

Elevator-based AED placement had shorter average response distance if the number of floors (n) in the building exceeded three quarters of the ratio of ground-floor OHCA risk to above-ground floor risk (λ₁/λ) plus one half (n ≥ 3λ₁/4λ + 0.5). Otherwise, a lobby-based AED had shorter average response distance. If OHCA risk on each floor was equal, an elevator-based AED had shorter average response distance.

CONCLUSIONS

Elevator-based AEDs travel less vertical distance to OHCAs in tall buildings or those with uniform vertical risk, while lobby-based AEDs travel less vertical distance in buildings with substantial lobby, underground, and nearby street-level traffic and OHCA risk.

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.

Population movement and sudden cardiac arrest location

BACKGROUND

Although the benefits of automatic external defibrillators are undeniable, their effectiveness could be dramatically improved. One of the key issues is the disparity between the locations of automatic external defibrillators and sudden cardiac arrests (SCAs).

METHODS AND RESULTS

From emergency medical services and other Parisian agencies, data on all SCAs occurring in public places in Paris, France, were prospectively collected between 2000 and 2010 and recorded using 2020 grid areas. For each area, population density, population movements, and landmarks were analyzed. Of the 4176 SCAs, 1255 (30%) occurred in public areas, with a highly clustered distribution of SCAs, especially in areas containing major train stations (12% of SCAs in 0.75% of the Paris area). The association with population density was poor, with a nonsignificant increase in SCAs with population density (P=0.4). Occurrence of public SCAs was, in contrast, highly associated with population movements (P<0.001). In multivariate analysis including other landmarks in each grid cell in the model and demographic characteristics, population movement remained significantly associated with the occurrence of SCA (odds ratio, 1.48; 95% confidence interval, 1.34-1.63; P<0.0001), as well as grid cells containing train stations (odds ratio, 3.80; 95% confidence interval, 2.66-5.36; P<0.0001).

CONCLUSIONS

Using a systematic analysis of determinants of SCA in public places, we demonstrated the extent to which population movements influence SCA distribution. Our findings also suggested that beyond this key risk factor, some areas are dramatically associated with a higher risk of SCA.

Risky locations for out-of-hospital cardiopulmonary arrest in a typical urban city

Background:

The aim of this study is to clarify the circumstances including the locations where critical events resulting in out-of-hospital cardiopulmonary arrest (OHCPA) occur.

Materials and Methods:

Subjects of this population-based observational case series study were the clinical records of patients with nontraumatic and nonneck-hanging OHCPA.

Results:

Of all 1546 cases, 10.3% occurred in a public place (shop, restaurant, workplace, stations, public house, sports venue, and bus), 8.3% on the street, 73.4% in a private location (victim's home, the homes of the victims’ relatives or friends or cheap bedrooms, where poor homeless people live), and 4.1% in residential institutions. In OHCPA occurring in private locations, the frequency of asystole was higher and the outcome was poorer than in other locations. A total of 181 OHCPA cases (11.7%) took place in the lavatory and 166 (10.7%) in the bathroom; of these, only 7 (3.9% of OHCPA in the lavatory) and none in the bath room achieved good outcomes. The frequencies of shockable initial rhythm occurring in the lavatory and in bath room were 3.7% and 1.1% (lower than in other locations, P = 0.011 and 0.002), and cardiac etiology in OHCPA occurring in these locations were 46.7% and 78.4% (the latter higher than in other locations, P < 0.001).

Conclusions:

An unignorable population suffered from OHCPA in private locations, particularly in the lavatory and bathroom; their initial rhythm was usually asystole and their outcomes were poor, despite the high frequency of cardiac etiology in the bathroom. We should try to treat OHCPA victims and to prevent occurrence of OHCPA in these risky spaces by considering their specific conditions.

Defibrillation in rural areas

AIM OF THE STUDY

Automated external defibrillation (AED) and public access defibrillation (PAD) have become cornerstones in the chain of survival in modern cardiopulmonary resuscitation. Most studies of AED and PAD have been performed in urban areas, and evidence is scarce for sparsely populated rural areas. The aim of this review was to review the literature and discuss treatment strategies for out-of-hospital cardiac arrest in rural areas.

METHODS

A Medline search was performed with the keywords automated external defibrillation (617 hits), public access defibrillation (256), and automated external defibrillator public (542). Of these 1415 abstracts and additional articles found by manually searching references, 92 articles were included in this nonsystematic review.

RESULTS

Early defibrillation is crucial for survival with good neurological outcome after cardiac arrest. Rapid defibrillation can be a challenge in sparsely populated and remote areas, where the incidence of cardiac arrest is low and rescuer response times can be long. The few studies performed in rural areas showed that the introduction of AED programs based on a 2-tier emergency medical system, consisting of Basic Life Support and Advanced Life Support teams, resulted in a decrease in collapse-to-defibrillation times and better survival of patients with out-of-hospital cardiac arrest.

CONCLUSIONS

In rural areas, introducing AED programs and a 2-tier emergency medical system may increase survival of out-of-hospital cardiac arrest patients. More studies on AED and PAD in rural areas are required.

Automated External Defibrillators Inaccessible to More Than Half of Nearby Cardiac Arrests in Public Locations During Evening, Nighttime, and Weekends

Background—

Despite wide dissemination, use of automated external defibrillators (AEDs) in community settings is limited. We assessed how AED accessibility affected coverage of cardiac arrests in public locations.

Methods and Results—

We identified cardiac arrests in public locations (1994–2011) in terms of location and time and viewed them in relation to the location and accessibility of all AEDs linked to the emergency dispatch center as of December 31, 2011, in Copenhagen, Denmark. AED coverage of cardiac arrests was defined as cardiac arrests within 100 m (109.4 yd) of an AED and further categorized according to AED accessibility at the time of cardiac arrest. Daytime, evening, and nighttime were defined as 8 am to 3:59 pm , 4 to 11:59 pm , and midnight to 7:59 am , respectively. Of 1864 cardiac arrests in public locations, 61.8% (n=1152) occurred during the evening, nighttime, or weekends. Of 552 registered AEDs, 9.1% (n=50) were accessible at all hours, and 96.4% (n=532) were accessible during the daytime on all weekdays. Regardless of AED accessibility, 28.8% (537 of 1864) of all cardiac arrests were covered by an AED. Limited AED accessibility decreased coverage of cardiac arrests by 4.1% (9 of 217) during the daytime on weekdays and by 53.4% (171 of 320) during the evening, nighttime, and weekends.

Conclusions—

Limited AED accessibility at the time of cardiac arrest decreased AED coverage by 53.4% during the evening, nighttime, and weekends, which is when 61.8% of all cardiac arrests in public locations occurred. Thus, not only strategic placement but also uninterrupted AED accessibility warrant attention if public-access defibrillation is to improve survival after out-of-hospital cardiac arrest.

A Poor Association Between Out-of-Hospital Cardiac Arrest Location and Public Automated External Defibrillator Placement

Introduction

Much attention has been given to the strategic placement of automated external defibrillators (AEDs). The purpose of this study was to examine the correlation of strategically placed AEDs and the actual location of cardiac arrests.

Methods

A retrospective review of data maintained by the Maryland Institute for Emergency Medical Services Systems (MIEMSS), specifically, the Maryland Cardiac Arrest Database and the Maryland AED Registry, was conducted. Location types for AEDs were compared with the locations of out-of-hospital cardiac arrests in Howard County, Maryland. The respective locations were compared using scatter diagrams and r2 statistics.

Results

The r2 statistics for AED location compared with witnessed cardiac arrest and total cardiac arrests were 0.054 and 0.051 respectively, indicating a weak relationship between the two variables in each case. No AEDs were registered in the three most frequently occurring locations for cardiac arrests (private homes, skilled nursing facilities, assisted living facilities) and no cardiac arrests occurred at the locations where AEDs were most commonly placed (community pools, nongovernment public buildings, schools/educational facilities).

Conclusion

A poor association exists between the location of cardiac arrests and the location of AEDs.

LevyMJ, SeamanKG, MillinMG, BissellRA, JenkinsJL. A poor association between out-of-hospital cardiac arrest location and public automated external defibrillator placement. Prehosp Disaster Med. 2013;28(4):1-6.

Identifying Locations for Public Access Defibrillators Using Mathematical Optimization

Background—

Geospatial methods using mathematical optimization to identify clusters of cardiac arrests and prioritize public locations for defibrillator deployment have not been studied. Our objective was to develop such a method and test its performance against a population-guided approach.

Methods and Results—

All public location cardiac arrests in Toronto, Ontario, Canada, from December 16, 2005, to July 15, 2010, and all automated external defibrillator (AED) locations registered with Toronto Emergency Medical Services as of September 2009 were plotted geographically. Current AED coverage was quantified by determining the number of cardiac arrests occurring within 100 m of a registered AED. Clusters of cardiac arrests without a registered AED within 100 m were identified. With the use of mathematical optimization techniques, cardiac arrest coverage improvements were computed and shown to be superior to results from a population-guided deployment method. There were 1310 eligible public location cardiac arrests and 1669 registered AEDs. Of the eligible cardiac arrests, 304 were within 100 m of at least 1 registered AED (23% coverage). The average distance from a cardiac arrest to the closest AED was 281 m. With AEDs deployed in the top 30 locations, an additional 112 historical cardiac arrests would be covered (32% total coverage), and the average distance to the closest AED would be 262 m.

Conclusions—

Geographic clusters of cardiac arrests can be easily identified and prioritized with the use of mathematical modeling. Optimized AED deployment can increase cardiac arrest coverage and decrease the distance to the closest AED. Mathematical modeling can augment public AED deployment programs.

Developing an analytical tool for evaluating EMS system design changes and their impact on cardiac arrest outcomes: combining geographic information systems with register data on survival rates

Background

Out-of-hospital cardiac arrest (OHCA) is a frequent and acute medical condition that requires immediate care. We estimate survival rates from OHCA in the area of Stockholm, through developing an analytical tool for evaluating Emergency Medical Services (EMS) system design changes. The study also is an attempt to validate the proposed model used to generate the outcome measures for the study.

Methods and results

This was done by combining a geographic information systems (GIS) simulation of driving times with register data on survival rates. The emergency resources comprised ambulance alone and ambulance plus fire services. The simulation model predicted a baseline survival rate of 3.9 per cent, and reducing the ambulance response time by one minute increased survival to 4.6 per cent. Adding the fire services as first responders (dual dispatch) increased survival to 6.2 per cent from the baseline level. The model predictions were validated using empirical data.

Conclusion

We have presented an analytical tool that easily can be generalized to other regions or countries. The model can be used to predict outcomes of cardiac arrest prior to investment in EMS design changes that affect the alarm process, e.g. (1) static changes such as trimming the emergency call handling time or (2) dynamic changes such as location of emergency resources or which resources should carry a defibrillator.

Modeling the impact of public access defibrillator range on public location cardiac arrest coverage

BACKGROUND

Public access defibrillation with automated external defibrillators (AEDs) can improve survival from out-of-hospital cardiac arrests (OHCA) occurring in public. Increasing the effective range of AEDs may improve coverage for public location OHCAs.

OBJECTIVE

To quantify the relationship between AED effective range and public location cardiac arrest coverage.

METHODS

This was a retrospective cohort study using the Resuscitation Outcomes Consortium Epistry database. We included all public-location, atraumatic, EMS-attended OHCAs in Toronto, Canada between December 16, 2005 and July 15, 2010. We ran a mathematical model for AED placement that maximizes coverage of historical public OHCAs given pre-specified values of AED effective range and the number of locations to place AEDs. Locations of all non-residential buildings were obtained from the City of Toronto and used as candidate sites for AED placement. Coverage was evaluated for range values from 10 to 300 m and number of AED locations from 10 to 200, both in increments of 10, for a total of 600 unique scenarios. Coverage from placing AEDs in all public buildings was also measured.

RESULTS

There were 1310 public location OHCAs during the study period, with 25,851 non-residential buildings identified as candidate sites for AED placement. Cardiac arrest coverage increased with AED effective range, with improvements in coverage diminishing at higher ranges. For example, for a deployment of 200 AED locations, increasing effective range from 100 m to 200 m covered an additional 15% of cardiac arrests, whereas increasing range further from 200 m to 300 m covered an additional 10%. Placing an AED in each of the 25,851 public buildings resulted in coverage of 50% and 95% under assumed effective ranges of 50 m and 300 m, respectively.

CONCLUSION

Increasing AED effective range can improve cardiac arrest coverage. Mathematical models can help evaluate the potential impact of initiatives which increase AED range.

Location of cardiac arrest in a city center: strategic placement of automated external defibrillators in public locations

BACKGROUND

Public-access defibrillation with automated external defibrillators (AEDs) is being implemented in many countries worldwide with considerable financial implications. The potential benefit and economic consequences of focused or unfocused AED deployment are unknown.

METHODS AND RESULTS

All cardiac arrests in public in Copenhagen, Denmark, from 1994 through 2005 were geographically located, as were 104 public AEDs placed by local initiatives. In accordance with European Resuscitation Council and American Heart Association (AHA) guidelines, areas with a high incidence of cardiac arrests were defined as those with 1 cardiac arrest every 2 or 5 years, respectively. There were 1274 cardiac arrests in public locations. According to the European Resuscitation Council or AHA guidelines, AEDs needed to be deployed in 1.2% and 10.6% of the city area, providing coverage for 19.5% (n=249) and 66.8% (n=851) of all cardiac arrests, respectively. The excessive cost of such AED deployments was estimated to be $33 100 or $41 000 per additional quality-adjusted life year, whereas unguided AED placement covering the entire city had an estimated cost of $108 700 per quality-adjusted life year. Areas with major train stations (1.8 arrests every 5 years per area), large public squares, and pedestrianized areas (0.6 arrests every 5 years per area) were main predictors of frequent cardiac arrests.

CONCLUSIONS

To achieve wide AED coverage, AEDs need to be more widely distributed than recommended by the European Resuscitation Council guidelines but consistent with the American Heart Association guidelines. Strategic placement of AEDs is pivotal for public-access defibrillation, whereas with unguided initiatives, AEDs are likely to be placed inappropriately.

GPs' use of defibrillators and the national radio network in emergency primary healthcare in Norway

OBJECTIVE

To study the geographic size of out-of-hours districts, the availability of defibrillators and use of the national radio network in Norway.

DESIGN

Survey.

SETTING

The emergency primary healthcare system in Norway.

SUBJECTS

A total of 282 host municipalities responsible for 260 out-of-hours districts.

MAIN OUTCOME MEASURES

Size of out-of-hours districts, use of national radio network and access to a defibrillator in emergency situations.

RESULTS

The out-of-hours districts have a wide range of areas, which gives a large variation in driving time for doctors on call. The median longest transport time for doctors in Norway is 45 minutes. In 46% of out-of-hours districts doctors bring their own defibrillator on emergency callouts. Doctors always use the national radio network in 52% of out-of-hours districts. Use of the radio network and access to a defibrillator are significantly greater in out-of-hours districts with a host municipality of fewer then 5000 inhabitants compared with host municipalities of more than 20,000 inhabitants.

CONCLUSION

In half of out-of-hours districts doctors on call always use the national radio network. Doctors in out-of-hours districts with a host municipality of fewer than 5000 inhabitants are in a better state of readiness to attend an emergency, compared with doctors working in larger host municipalities.

[Public access defibrillation. Limited use by trained first responders and laymen]

As ventricular fibrillation is the most frequent initial heart rhythm causing out-of-hospital sudden cardiac arrest, defibrillation is of essential significance. Automated external defibrillators (AEDs) have been available for some years and as a result defibrillation can be carried out by individuals other than physicians and healthcare providers such as trained first responders and untrained lay rescuers. This so-called public access defibrillation nourished hope of progress in the treatment of sudden cardiac arrest. However, several limitations exist, such as low frequency of sudden cardiac arrest in public, rare use of publicly placed AEDs, low cost effectiveness, legal requirements and insufficient public willingness to help. Due to these restrictions of public access defibrillation other measures are more promising than the attempt at general distribution of AEDs. These measures are primary or secondary prophylaxis of sudden cardiac arrest, general knowledge of adequate activation of emergency medical services, implementation of first responder teams equipped with AEDs and particularly a better education in and application of the well-established principles of cardiopulmonary resuscitation.

Cost-effectiveness of automated external defibrillators in public places: con

PURPOSE OF REVIEW

To discuss the clinical effectiveness, public health impact and cost-effectiveness of public access defibrillation.

RECENT FINDINGS

High rates of survival from prehospital ventricular fibrillation have been documented in patients treated by first responders using automated external defibrillators. The recent Public Access Defibrillation trial demonstrated a doubling of cardiac arrest survival in community units where volunteers trained in cardiopulmonary resuscitation were additionally equipped with automated external defibrillators. The cost-effectiveness analysis of the Public Access Defibrillation trial has not yet been published, and previous analyses have lacked full data on cost, outcome, or both. Data from many sources indicate that automated external defibrillator placement at sites with an expected rate of one cardiac arrest per defibrillator per 5 years, as recommended by the American Heart Association, addresses only around 1-2% of prehospital arrests, and will have a minimal impact on population survival.

SUMMARY

While highly targeted provision of automated external defibrillators in areas of greatest risk, such as casinos and airports, may be cost-effective, it will have little impact at a population level. Provision of more widespread public access defibrillation to sites with lower incidence of cardiac arrest is unlikely to be cost-effective, and may represent poorer value for money than alternative healthcare interventions in coronary artery disease.

Monitoring intervention programmes for out-of-hospital cardiac arrest in a mixed urban and rural setting

BACKGROUND

Only a few data are available on the survival rate following out-of-hospital cardiac arrest in different Italian settings. We report an analysis of a 10-year experience in a mixed rural/urban setting, the main variables associated with survival, and the preliminary results of the implementation of an automated external defibrillator (AED) programme operated by lay volunteers on the effectiveness of the existing Emergency Medical Service (EMS).

METHODS

We report data from an observational cohort study on all adults, resuscitated from witnessed cardiac arrest between 1994 and 2004 in the district area of Forlì (Italy). The AED programme was introduced in 2002. Entry variables, time intervals and nodal events were tested according to Utstein recommendations. The predictors of favourable outcomes (Overall Performance Category 1-2) were identified by logistic regression analysis.

RESULTS

The witnessed cardiac arrest rate was 27/100,000 population per year (95% confidence interval, 18-38). The initial rhythm was shockable in 241/479 cases (50.3%). After resuscitation, 55 (11.5%) subjects had a favourable outcome at discharge and 38 (7.9%) at 1 year. Time-to-treatment was longer for EMS than for AED-equipped units (median, 8 min interquartile range, 6-10 (467 cases) versus 6 min interquartile range, 4-8 (13 cases); P<0.013), but the final results of the AED programme were poor, with only 1 subject saved/171,000 inhabitants in 2 years. Positive outcome predictors were male sex, younger age, shockable rhythms, low number of defibrillations, and no history of hypertension, diabetes, myocardial infarction or congestive heart failure.

CONCLUSIONS

Even in a mixed urban/rural setting, survival from out-of-hospital cardiac arrest is dependent on well-known predictors. In our setting, the number of cases saved by an AED programme is limited when accompanied by an efficient traditional EMS. The allocation of resources to an AED programme should be reconsidered in a mixed rural/urban setting.

Home defibrillation: a feasibility study in myocardial infarction survivors at intermediate risk of sudden death

BACKGROUND

Out-of-hospital cardiac arrest occurs at home in 65-80% of cases and is often witnessed. We designed a study to explore the feasibility of a home defibrillation program (a) evaluating the retention of cardiopulmonary resuscitation and automated external defibrillators (AED) use skills (BLSD) (b) assessing the impact on anxiety, depression, and quality of life and (c) recording the critical issues emerging from program implementation.

METHODS

Thirty-three post-myocardial infarction patients and their 56 relatives received BLSD training and an AED. Assessment of BLSD skills, levels of anxiety, and depression and quality of life were scheduled every 3 months for 1 year or until a common stopping date.

RESULTS

Overall BLSD score was 26 +/- 3 at baseline vs. 22 +/- 5 at 3 months (P < .0001), 21 +/- 6 at 6 months (P < .0001), 22 +/- 4 at 9 months (P < .0001) and 23 +/- 5 at 12 months (P = .001). Conversely, the BLSD component AED use" remained stable throughout the study. Quality of life, anxiety, and depression scores remained constant. Compliance to BLSD retraining sessions and AEDs checks decreased over time and was influenced by a concomitant clinical appointment.

CONCLUSIONS

BLSD performance of families of post-myocardial infarction patients decreases over time, even though the ability to operate AEDs appears to be the least affected component. Compliance with retraining sessions and AED checks declines over time and is improved if they are combined with clinical appointments. The implementation of a home defibrillation program does not affect anxiety, depression, or the quality of life.

Cardiac arrest in public locations--an independent predictor for better outcome?

OBJECTIVE

Outcome after cardiac arrest is known to be influenced by immediate access to resuscitation. We aimed to analyse the location of arrest in relation to the prognostic value for outcome.

DESIGN

Retrospective review from prospective databases (ambulance routine documentation database and emergency department database on patients treated for cardiac arrest).

SETTING

Vienna (1.7 million inhabitants) ambulance service and tertiary care facility (university clinics).

PATIENTS

Two independent cohorts: (1) a population-based cohort of patients who were treated for cardiac arrest by the municipal ambulance service outside the hospital. The endpoint in this group was survival to hospital admission with spontaneous circulation. (2) A cohort of patients who were admitted to the emergency department after successful out of hospital resuscitation. The endpoint in this group was survival to 6 months with good neurological status (best Cerebral Performance Category 1 or 2 within 6 months).

MEASUREMENTS

We analysed whether the location of non-traumatic adult out-of-hospital cardiac arrest (public versus private place) was a predictor for good outcome.

RESULTS

PATIENTS who had cardiac arrest in a public location were more likely to arrive in hospital alive (39% versus 31%, crude OR 1.4, 95% CI 1.001-1.975, p=0.049) and were more likely to have a good neurological outcome after 6 months (35% versus 25%, crude OR 1.65, adjusted OR 1.59, 95% CI 1.07-2.36, p=0.023), compared to patients who had cardiac arrest in a non-public location.

CONCLUSION

Cardiac arrest in a public location is independently associated with a better outcome.