Automated External Defibrillators Deployment Research Articles

Overcoming Spatial and Temporal Barriers to Public Access Defibrillators Via Optimization

BackgroundImmediate access to an automated external defibrillator (AED) increases the chance of survival for out-of-hospital cardiac arrest (OHCA). Current deployment usually considers spatial AED access, assuming AEDs are available 24 h a day. ObjectivesThe goal of this study was to develop an optimization model for AED deployment, accounting for spatial and temporal accessibility, to evaluate if OHCA coverage would improve compared with deployment based on spatial accessibility alone. MethodsThis study was a retrospective population-based cohort trial using data from the Toronto Regional RescuNET Epistry cardiac arrest database. We identified all nontraumatic public location OHCAs in Toronto, Ontario, Canada (January 2006 through August 2014) and obtained a list of registered AEDs (March 2015) from Toronto Paramedic Services. Coverage loss due to limited temporal access was quantified by comparing the number of OHCAs that occurred within 100 meters of a registered AED (assumed coverage 24 h per day, 7 days per week) with the number that occurred both within 100 meters of a registered AED and when the AED was available (actual coverage). A spatiotemporal optimization model was then developed that determined AED locations to maximize OHCA actual coverage and overcome the reported coverage loss. The coverage gain between the spatiotemporal model and a spatial-only model was computed by using 10-fold cross-validation. ResultsA total of 2,440 nontraumatic public OHCAs and 737 registered AED locations were identified. A total of 451 OHCAs were covered by registered AEDs under assumed coverage 24 h per day, 7 days per week, and 354 OHCAs under actual coverage, representing a coverage loss of 21.5% (p < 0.001). Using the spatiotemporal model to optimize AED deployment, a 25.3% relative increase in actual coverage was achieved compared with the spatial-only approach (p < 0.001). ConclusionsOne in 5 OHCAs occurred near an inaccessible AED at the time of the OHCA. Potential AED use was significantly improved with a spatiotemporal optimization model guiding deployment.

Eligibility and Disqualification Recommendations for Competitive Athletes With Cardiovascular Abnormalities: Task Force 12: Emergency Action Plans, Resuscitation, Cardiopulmonary Resuscitation, and Automated External Defibrillators: A Scientific Statement From the American Heart Association and American College of Cardiology.

Eligibility and Disqualification Recommendations for Competitive Athletes With Cardiovascular Abnormalities: Task Force 12: Emergency Action Plans, Resuscitation, Cardiopulmonary Resuscitation, and Automated External Defibrillators: A Scientific Statement From the American Heart Association and American College of Cardiology.

Preventing Sudden Cardiac Death: Automated External Defibrillators in Ohio High Schools.

Ohio passed legislation in 2004 for optional public funding of automated external defibrillators (AEDs) in all Ohio high schools. To report occurrences of sudden cardiac arrest in which AEDs were used in Ohio high schools and to evaluate the adherence of Ohio high schools with AEDs to state law and published guidelines on AEDs and emergency action plans (EAPs) in schools. Cross-sectional survey. Web-based survey. A total of 264 of 827 schools that were members of the Ohio High School Athletic Association. We surveyed schools on AED use, AED maintenance, and EAPs. Twenty-five episodes of AED deployment at 22 schools over an 11-year period were reported; 8 (32%) involved students and 17 (68%) involved adults. The reported survival rate was 60% (n = 15). Most events (n = 20, 80%) in both students and adults occurred at or near athletic facilities. The annual use rate of AEDs was 0.7%. Fifty-three percent (n = 140) of schools reported having an EAP in place for episodes of cardiac arrest. Of the schools with EAPs, 57% (n = 80) reported having rehearsed them. Our data supported the placement of AEDs in high schools given the frequency of use for sudden cardiac arrest and the survival rate reported. They also suggested the need for increased awareness of recommendations for EAPs and the need to formulate and practice EAPs. School EAPs should emphasize planning for events in the vicinity of athletic facilities.

Cost-effectiveness of a national public access defibrillation programme

AimProposed Irish legislation aimed at increasing survival from out-of-hospital-cardiac-arrest (OHCA) mandates the provision of automated external defibrillators (AEDs) in a comprehensive range of publicly accessible premises in urban and rural areas. This study estimated the clinical and cost effectiveness of the legislation, compared with alternative programme configurations involving more targeted AED placement. MethodsWe used a cost-utility analysis to estimate the costs and consequences of public access defibrillation (PAD) programmes from a societal perspective, based on AED deployment by building type. Comparator programmes ranged from those that only included building types with the highest incidence of OHCA, to the comprehensive programme outline in the proposed legislation. Data on OHCA incidence and outcomes were obtained from the Irish Out-of-Hospital-Cardiac-Arrest Register (OHCAR). Costs were obtained from the Irish health service, device suppliers and training providers. ResultsThe incremental cost effectiveness ratio (ICER) for the most comprehensive PAD scheme was €928,450/QALY. The ICER for the most scaled-back programme involving AED placement in transport stations, medical practices, entertainment venues, schools (excluding primary) and fitness facilities was €95,640/QALY. A 40% increase in AED utilisation when OHCAs occur in a public area could potentially render this programme cost effective. ConclusionNational PAD programmes involving widespread deployment of static AEDs are unlikely to be cost-effective. To improve cost-effectiveness any prospective programmes should target locations with the highest incidence of OHCA and be supported by efforts to increase AED utilisation, such as improving public awareness, increasing CPR and AED training, and establishing an EMS-linked AED register.

Circulation : Clinical Summaries

<i>Circulation</i> : Clinical Summaries

Cardiac arrests in schools: Assessing use of automated external defibrillators (AED) on school campuses

BackgroundSudden cardiac arrest in schools are infrequent, but emotionally charged events. The purpose of our study was to: (1) describe characteristics and outcomes of school cardiac arrests; and (2) assess the feasibility of conducting school bystander interviews to describe the events surrounding cardiac arrests, assess AED availability and use, and identify barriers to AED use. MethodsWe performed a telephone survey of bystanders to cardiac arrests occurring in K-12 schools in communities participating in the Cardiac Arrest Registry to Enhance Survival (CARES) database and a local cardiac arrest database. The study period was from 8/2005 to 8/2011 and continued in one community through 2011. Utstein style descriptive data and outcomes were collected. A structured telephone interview of a bystander or administrative personnel was conducted for each cardiac arrest event. We collected a descriptive event summary, including provision of bystander CPR, presence of an AED and information regarding AED deployment, training, and use and perceived barriers to AED use. Descriptive data are reported. ResultsDuring the study period there were 30,603 cardiac arrests identified at study communities, of which 47 (0.15%) events were at K-12 schools. Of these, 21 (45.7%) were at high schools, a minority (16, 34.0%) were children (<age 19), most (39, 83.0%) were witnessed arrests, a majority (36, 76.6%) received bystander CPR, and 27 (57.4%) were initially in ventricular fibrillation (VF). Most arrests (28/40, 70%) occurred during the school day (7a–5p). From this population, 15 (31.9%) survived to hospital discharge. A telephone interview was completed for 30 of 47 K-12 events. Nineteen schools had an AED on site. Most schools (84.2%) with AEDs reported that they had a training program, and personnel identified for its use. An AED was applied in 11 of 19 patients, of these 8 were in VF and 4 (all VF) survived to hospital discharge. Bystanders identified multiple reasons for non-use of the AED in the other eight patients. ConclusionsCardiac arrests in schools are rare events, most patients are adults and receive bystander CPR. AED application by laypersons was infrequent but resulted in excellent (4/11) survival. AEDs were not used in a substantial proportion of incidents and further attention must be paid to planning for emergency response on school campuses. We also identified the difficulty in assessing school emergency care and advocate for the development of methods to evaluate the provision of emergency care on school campuses.

Automated external defibrillators and in-hospital cardiac arrest: Patient survival and device performance at an Australian teaching hospital

Abstract Aims To evaluate the effect of automated external defibrillators (AEDs) on patient survival and to describe the performance of AEDs after in-hospital cardiac arrest. Methods Prospectively collected data were analysed for cardiac arrests in the general patient care areas of a teaching hospital during the 3 years before and the 3 years after the deployment of AEDs. The association between availability of an AED and survival to hospital discharge was assessed using multivariate logistic regression. AED performance during automated management of the initial rhythms was assessed using information captured by the AEDs. Results There were 84 cardiac arrests in the AED period and 82 in the pre-AED period. Patient and event characteristics were similar in each period. The initial rhythm was shockable in 16% of cases. Return of spontaneous circulation was higher in the AED period (54% vs. 35%, P = 0.02) but the proportion of hospital survivors in each period was similar (22% vs. 19%, P = 0.56). The adjusted odds ratio for hospital survival when an AED was available was 1.22 (95% CI 0.53–2.84, P = 0.64). An AED was applied in 77/84 (92%) possible cases. Median interruption to chest compressions was 12 s (inter-quartile range 12–13). An automated shock was delivered in 8/13 (62%) possible cases. Conclusions Availability of AEDs was not independently associated with hospital survival. Shockable presenting rhythms were not common and, in keeping with the manufacturer's specifications, the AEDs did not shock all potentially shockable rhythms. The hands-off time associated with automated rhythm management was considerable.

Abstract 182: Risk of Cardiac Arrest by Location Type to Guide Future AED Placement in a Large Urban Center

Introduction: Public access defibrillation (PAD) programs can improve survival from out-of-hospital cardiac arrest (OHCA). We aimed to identify high risk public locations which should be prioritized for automated external defibrillator (AED) placement. Objectives: 1) To determine the average annual incidence of cardiac arrest by location type within the study area, 2) To describe current registered PAD deployment by location type. Methods: An observational cohort study using the Resuscitation Outcomes Consortium Epistry database. We included all public location, non-traumatic, EMS-treated OHCAs from January 1, 2006 to June 30, 2010 in the City of Toronto. The total site counts in each location category were derived from a city planning database and used as the denominator in calculating average annual per site cardiac arrest incidence. AED locations were obtained from an EMS registry. Two investigators independently categorized each OHCA and AED location. Disagreements were resolved by consensus. Results: There were 1297 OHCAs, of which 571 occurred on streets and could not be associated with a specific location type, leaving 726 eligible cases. The average age was 58±17.5 years, 82.7% were male and 13.9% survived to hospital discharge. Of all included patients, 44.9% had bystander CPR attempted and 9.5% had a bystander apply a defibrillator. Table 1 contains data from the top 15 location types ranked on average annual OHCAs per individual site. There were 1616 AED covered locations in the City of Toronto. 57.3% of the registered AED sites were elementary and secondary schools, 16.0% were post secondary schools, 7.8% were offices and 4% were community or recreation centres. Conclusions: We have identified location types with highest risk for cardiac arrest. Most registered AEDs have been placed at Elementary and Secondary Schools which are relatively low risk for OHCA. Our data can guide future AED deployment to increase availability for use in public location OHCA.

Automated external defibrillators and in-hospital cardiac arrest: Patient survival and device performance at an Australian teaching hospital

Aims To evaluate the effect of automated external defibrillators (AEDs) on patient survival and to describe the performance of AEDs after in-hospital cardiac arrest. Methods Prospectively collected data were analysed for cardiac arrests in the general patient care areas of a teaching hospital during the 3 years before and the 3 years after the deployment of AEDs. The association between availability of an AED and survival to hospital discharge was assessed using multivariate logistic regression. AED performance during automated management of the initial rhythms was assessed using information captured by the AEDs. Results There were 84 cardiac arrests in the AED period and 82 in the pre-AED period. Patient and event characteristics were similar in each period. The initial rhythm was shockable in 16% of cases. Return of spontaneous circulation was higher in the AED period (54% vs. 35%, P = 0.02) but the proportion of hospital survivors in each period was similar (22% vs. 19%, P = 0.56). The adjusted odds ratio for hospital survival when an AED was available was 1.22 (95% CI 0.53–2.84, P = 0.64). An AED was applied in 77/84 (92%) possible cases. Median interruption to chest compressions was 12 s (inter-quartile range 12–13). An automated shock was delivered in 8/13 (62%) possible cases. Conclusions Availability of AEDs was not independently associated with hospital survival. Shockable presenting rhythms were not common and, in keeping with the manufacturer's specifications, the AEDs did not shock all potentially shockable rhythms. The hands-off time associated with automated rhythm management was considerable.

Use of automated external defibrillators (AEDs) in managing risk and liability in health/fitness facilities

Health/fitness facilities are considered higher risk sites for sudden cardiac arrest (SCA), however, no legislation or industry standards in Australia mandate the use of automated external defibrillators (AEDs). In this light, the purpose of this study was three-pronged. The main purpose of the study was to outline the health/fitness industry standards in the USA in relation to the use of AEDs. The second purpose was to demonstrate the possible consequences of a failure to meet the industry standards requiring the use of AEDs. The third purpose was to show the possible impact of Good Samaritan type legislation in Australia as supporting the deployment of AEDs in the local industry without fear of legal liability. The conclusions of this paper suggest that standard setting organisations in the fitness industry and the local governments should work in collaboration to increase awareness about the life-saving benefits of AEDs and the immunity protection granted by Good Samaritan laws that can have a positive impact on the wide spread use of AEDs in health/fitness facilities.

Clinical Summaries

Clinical Summaries

Clinical Summaries

Clinical Summaries

Location of Cardiac Arrest in a City Center

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. 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. 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.

Public Access Defibrillators and Fire Extinguishers: Are Comparisons Reasonable?

Sudden cardiac death is a major cause of mortality in the United States of America (Circulation 2008;117:e25-146) with approximately 310000 deaths related to coronary heart disease occurring in emergency departments or in the prehospital environment annually. Several organizations have directed resources toward the treatment of sudden cardiac arrest through a paradigm that has come to be known as the "chain of survival"-prompt activation of emergency response by telephone 911, early bystander cardiopulmonary resuscitation, early defibrillation, and timely advanced cardiac life support (Circulation 1991;83:1832-1847). The ready availability of automated external defibrillators (AEDs) has been advocated as a key component of this chain. Some authors have suggested a "fire extinguisher model" for AED deployment (Circulation 1998;98:2334-2351; Resuscitation 1995;30:151-156; Ann Intern Med 2001;135:990-998). In this model, AEDs are prominently displayed in public places for use by laypersons, much like fire extinguishers. For example, in Chicago's O'Hare Airport, AEDs are placed alongside fire extinguishers in the public concourse (N Engl J Med 2002;347:1242-1247). Advocates of this model suggest that advancing this practice would be a means to widely disbourse life-saving technology that is easy to use. Several experts have questioned this model, suggesting that the cost-effectiveness of distributing AEDs this widely would be prohibitive (BMJ 2002;325:515; Curr Opin Cardiol 2007;22:5-10; BMJ 2003;326:162; Int J Technol Assess Health Care 2007;23:362-367) and may not be more effective than more targeted distribution of AEDs. This literature review will examine the available data on both AEDs and fire extinguishers to determine if these comparisons are reasonable as a means of guiding public policy.

Assessing automated external defibrillators in preventing deaths from sudden cardiac arrest: An economic evaluation

The aim of this study was to evaluate the cost-effectiveness of on-site automated external defibrillators (AEDs) in the initial management of cardiac arrest in Ontario. This was a cost-effectiveness analysis based on published literature and data from the Canadian Institute of Health Information. The participants were fictitious male and female cardiac arrest patients who were initially managed with on-site AEDs, compared with similar patients managed without on-site AEDs. This group included a subgroup of high-risk patients (i.e., heart failure and left ventricular ejection fraction<35 percent). The analysis was conducted in a variety of settings including hospitals and homes in Ontario, Canada. The main outcome evaluated was cost per quality-adjusted life-year (QALY) gained from a payer's perspective. Cost per QALY (all costs reported in Canadian dollars) was $12,768 when AEDs were deployed in hospitals, $511,766 when deployed in office buildings, $2,360,023 when deployed in apartment buildings, $87,569 when deployed in homes of high-risk patients, and $1,529,371 when deployed in homes of people older than 55 years of age. Indiscriminate deployment of AEDs is not a cost-effective means of improving health outcomes of cardiac arrest. Their use should be restricted to emergency response programs, high-risk sites (such as hospitals), and high-risk patients.

Death in correctional facilities: Opportunities for automated external defibrillation

Death due to cardiovascular disease occurs more frequently in prisons than the national average. Due to close surveillance 24 h/day, the ability to reach the patient within 3 min and time consuming access for the EMS crews, it was hypothesised that the deployment of automated external defibrillators (AEDs) might make improvements regarding Call-to-the-First-AED-Prompt (CTP) interval and formed the aim of this study. Our investigation was analysed on an intention to treat basis and conducted in a prospective, open and observational design. As the primary outcome, the CTP-intervals were compared to the arrival intervals of the EMS. As a secondary outcome, an analysis of all deceased inmates was described. The average daily population of inmates in Austrian correctional facilities is 7714. During a period of 13 months, 10 instances in which an AED was activated and electrodes attached to a collapsed inmate, were reported. The CTP-interval (median+/-S.D.) was 2.3+/-1.6 S.D. min. It took the EMS 10.0+/-4.3 S.D. min. to arrive at the patient's side. Four out of 10 cases of cardiac arrest occurred due to myocardial infarction. Of 39 deceased inmates, a post mortem examination was completed in 34 cases. In 13 cases, cardiovascular disease was the cause of death. The main finding was a four-fold reduction of the CTP-interval. This fact indicates the potential improvements which could be achieved with the deployment of AEDs. Our secondary objective revealed that death due to cardiovascular disease was found in a high proportion and could be considered to be a strong incentive to initiate programmes to counter cardiovascular death in prison.

Machine and operator performance analysis of automated external defibrillator utilization.

The availability of an automated external defibrillator (AED) can improve the outcome of patients with out-of-hospital cardiac arrest (OHCA). On June 1, 2000, Taipei City became the first city in Taiwan to equip emergency medical services personnel with AEDs. This study was conducted to assess the performance of the AED machine in detecting ventricular fibrillation (VF) and ventricular tachycardia (VT) in the population, and to assess operator performance in its use. AED use in OHCA patients was assessed over a 1-year period. Electrocardiography and voice records retrieved from AED data cards were analyzed. A shockable rhythm was defined as either VF or VT. AED machine performance was assessed based on the correct identification of these rhythms. Operator performance was evaluated according to American Heart Association guidelines. A total of 978 AED rhythm analyses were obtained for 653 OHCA patients. The sensitivity and specificity for detecting shockable rhythms by the AED machine were 90.0% (95% confidence interval [CI], 85.3% to 93.3%) and 100% (95% CI, 99.5% to 100%), respectively. Sensitivity for coarse VF, fine VF, rapid VT, and slow VT was 97.5%, 74.2%, 63.6% and 60.0%, respectively. An AED was deployed in 18 non-OHCA patients and in 119 patients after they had been moved into the ambulance. Non-compliance with standard procedures occurred during AED use in 162 patients, including interference of movement by cardiopulmonary resuscitation (CPR) in progress in 69, untimely machine turn-off in 49, leads fell off or disconnected in 33, failure of shock delivery after charge in 28, and interference of movement other than CPR in 22. This study found that the AED machine has high specificity and high sensitivity in detecting VF and VT, especially coarse VF. Efforts are needed to improve the timing of AED deployment and emergency medical technician compliance with standard procedures.

Cost-effectiveness of in-home automated external defibrillators for individuals at increased risk of sudden cardiac death.

In-home automated external defibrillators (AEDs) are increasingly recommended as a means for improving survival of cardiac arrests that occur at home. The current study was conducted to explore the relationship between individuals' risk of cardiac arrest and cost-effectiveness of in-home AED deployment. Markov decision model employing a societal perspective. Four hypothetical cohorts of American adults 60 years of age at progressively greater risk for sudden cardiac death (SCD): 1) all adults (annual probability of SCD 0.4%); 2) adults with multiple SCD risk factors (probability 2%); 3) adults with previous myocardial infarction (probability 4%); and 4) adults with ischemic cardiomyopathy unable to receive an implantable defibrillator (probability 6%). Strategy 1: individuals suffering an in-home cardiac arrest were treated with emergency medical services equipped with AEDs (EMS-D). Strategy 2: individuals suffering an in-home cardiac arrest received initial treatment with an in-home AED, followed by EMS. Assuming cardiac arrest survival rates of 15% with EMS-D and 30% with AEDs, the cost per quality-adjusted life-year gained (QALY) of providing in-home AEDs to all adults 60 years of age is 216,000 dollars. Costs of providing in-home AEDs to adults with multiple risk factors (2% probability of SCD), previous myocardial infarction (4% probability), and ischemic cardiomyopathy (6% probability) are 132,000 dollars, 104,000 dollars, and 88,000 dollars, respectively. The cost-effectiveness of in-home AEDs is intimately linked to individuals' risk of SCD. However, providing in-home AEDs to all adults over age 60 appears relatively expensive.

Cost-effectiveness of automated external defibrillator deployment in selected public locations.

The American Heart Association (AHA) recommends an automated external defibrillator (AED) be considered for a specific location if there is at least a 20% annual probability the device will be used. We sought to evaluate the cost-effectiveness of the AHA recommendation and of AED deployment in selected public locations with known cardiac arrest rates. Markov Decision Model employing a societal perspective. Selected public locations in the United States. A simulated cohort of the American public. Strategy 1: individuals experiencing cardiac arrest were treated by emergency medical services equipped with AEDs (EMS-D). Strategy 2: individuals were treated with AEDs deployed as part of a public access defibrillation program. Strategies differed only in the initial availability of an AED and its impact on cardiac arrest survival. Under the base-case assumption that a deployed AED will be used on 1 cardiac arrest every 5 years (20% annual probability of AED use), the cost per quality-adjusted life year (QALY) gained is $30,000 for AED deployment compared with EMS-D care. AED deployment costs less than $50,000 per QALY gained provided that the annual probability of AED use is 12% or greater. Monte Carlo simulation conducted while holding the annual probability of AED use at 20% demonstrated that 87% of the trials had a cost-effectiveness ratio of less than $50,000 per QALY. AED deployment is likely to be cost-effective across a range of public locations. The current AHA guidelines are overly restrictive. Limited expansion of these programs can be justified on clinical and economic grounds.

Saving Time Saves Lives

Consider the following 3 patient stories: Reluctantly, A.B. heaved his bulk out of the air-conditioned car and into the hot, bright afternoon sun. The walk across the steaming macadam parking lot left him breathless, and his hand shook as he buried the cigarette butt into the sand on top of the shining brass receptacle guarding the entrance to the casino. His head pounded with the exertion, and he realized he forgot to take his blood pressure pill. Once he adjusted to the dimly lit interior and breathed the cool air, he caught his breath and cashed in $500 worth of chips. He quickly gravitated to the blackjack table, but in 30 minutes was cleaned out. His chest now ached with a soreness that had been waking him up at night for the last 2 weeks. As A.B. massaged his left breast, he began to feel lightheaded, and then the room went black. When C.D. heard the overhead page announcing that his flight was finally ready for boarding, he gulped down his wine and hurried out of the VIP lounge, lugging the distended briefcase over his shoulder. After showing his passport for what seemed the tenth time, he boarded the DC 10 and headed for the business section. The plane was already 2 hours late, and he was angry that he would miss his connection at Heathrow. But that seemed unimportant now as the fluttering in his chest started again. The doctor had told him it was ventricular tachycardia because of his enlarged heart and suggested a new medication, but he didn’t want to take it. The fluttering increased as the plane took off and continued through dinner. As C.D. settled back with his cognac, he looked down on the Atlantic, making out a few diamonds of light sparkling on the …