Defibrillators in public places: the introduction of a national scheme for public access defibrillation in England

Automated external defibrillator location and socioeconomic deprivation in Great Britain

OBJECTIVE

The early use of automated external defibrillators (AEDs) improves outcomes in out-of-hospital cardiac arrest (OHCA). We investigated AED access across Great Britain (GB) according to socioeconomic deprivation.

METHODS

Cross-sectional observational study using AED location data from The Circuit: the national defibrillator network led by the British Heart Foundation in partnership with the Association of Ambulance Chief Executives, Resuscitation Council UK and St John Ambulance. We calculated street network distances between all 1 677 466 postcodes in GB and the nearest AED and used a multilevel linear mixed regression model to investigate associations between the distances from each postcode to the nearest AED and Index of Multiple Deprivation, stratified by country and according to 24 hours 7 days a week (24/7) access.

RESULTS

78 425 AED locations were included. Across GB, the median distance from the centre of a postcode to an AED was 726 m (England: 739 m, Scotland: 743 m, Wales: 512 m). For 24/7 access AEDs, the median distances were further (991 m, 994 m, 570 m). In Wales, the average distance to the nearest AED and 24/7 AED was shorter for the most deprived communities. In England, the average distance to the nearest AED was also shorter in the most deprived areas. There was no association between deprivation and average distance to the nearest AED in Scotland. However, the distance to the nearest 24/7 AED was greater with increased deprivation in England and Scotland. On average, a 24/7 AED was in England and Scotland, respectively, 99.2 m and 317.1 m further away in the most deprived than least deprived communities.

CONCLUSION

In England and Scotland, there are differences in distances to the nearest 24/7 accessible AED between the most and least deprived communities. Equitable access to 'out-of-hours' accessible AEDs may improve outcomes for people with OHCA.

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.

Adrenaline to improve survival in out-of-hospital cardiac arrest: the PARAMEDIC2 RCT

BACKGROUND

Adrenaline has been used as a treatment for cardiac arrest for many years, despite uncertainty about its effects on long-term outcomes and concerns that it may cause worse neurological outcomes.

OBJECTIVES

The objectives were to evaluate the effects of adrenaline on survival and neurological outcomes, and to assess the cost-effectiveness of adrenaline use.

DESIGN

This was a pragmatic, randomised, allocation-concealed, placebo-controlled, parallel-group superiority trial and economic evaluation. Costs are expressed in Great British pounds and reported in 2016/17 prices.

SETTING

This trial was set in five NHS ambulance services in England and Wales.

PARTICIPANTS

Adults treated for an out-of-hospital cardiac arrest were included. Patients were ineligible if they were pregnant, if they were aged < 16 years, if the cardiac arrest had been caused by anaphylaxis or life-threatening asthma, or if adrenaline had already been given.

INTERVENTIONS

Participants were randomised to either adrenaline (1 mg) or placebo in a 1 : 1 allocation ratio by the opening of allocation-concealed treatment packs.

MAIN OUTCOME MEASURES

The primary outcome was survival to 30 days. The secondary outcomes were survival to hospital admission, survival to hospital discharge, survival at 3, 6 and 12 months, neurological outcomes and health-related quality of life through to 6 months. The economic evaluation assessed the incremental cost per quality-adjusted life-year gained from the perspective of the NHS and Personal Social Services. Participants, clinical teams and those assessing patient outcomes were masked to the treatment allocation.

RESULTS

From December 2014 to October 2017, 8014 participants were assigned to the adrenaline (n = 4015) or to the placebo (n = 3999) arm. At 30 days, 130 out of 4012 participants (3.2%) in the adrenaline arm and 94 out of 3995 (2.4%) in the placebo arm were alive (adjusted odds ratio for survival 1.47, 95% confidence interval 1.09 to 1.97). For secondary outcomes, survival to hospital admission was higher for those receiving adrenaline than for those receiving placebo (23.6% vs. 8.0%; adjusted odds ratio 3.83, 95% confidence interval 3.30 to 4.43). The rate of favourable neurological outcome at hospital discharge was not significantly different between the arms (2.2% vs. 1.9%; adjusted odds ratio 1.19, 95% confidence interval 0.85 to 1.68). The pattern of improved survival but no significant improvement in neurological outcomes continued through to 6 months. By 12 months, survival in the adrenaline arm was 2.7%, compared with 2.0% in the placebo arm (adjusted odds ratio 1.38, 95% confidence interval 1.00 to 1.92). An adjusted subgroup analysis did not identify significant interactions. The incremental cost-effectiveness ratio for adrenaline was estimated at £1,693,003 per quality-adjusted life-year gained over the first 6 months after the cardiac arrest event and £81,070 per quality-adjusted life-year gained over the lifetime of survivors. Additional economic analyses estimated incremental cost-effectiveness ratios for adrenaline at £982,880 per percentage point increase in overall survival and £377,232 per percentage point increase in neurological outcomes over the first 6 months after the cardiac arrest.

LIMITATIONS

The estimate for survival with a favourable neurological outcome is imprecise because of the small numbers of patients surviving with a good outcome.

CONCLUSIONS

Adrenaline improved long-term survival, but there was no evidence that it significantly improved neurological outcomes. The incremental cost-effectiveness ratio per quality-adjusted life-year exceeds the threshold of £20,000-30,000 per quality-adjusted life-year usually supported by the NHS.

FUTURE WORK

Further research is required to better understand patients' preferences in relation to survival and neurological outcomes after out-of-hospital cardiac arrest and to aid interpretation of the trial findings from a patient and public perspective.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN73485024 and EudraCT 2014-000792-11.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 25. See the NIHR Journals Library website for further project information.

Shocking the system: AEDs in military resuscitation

Automated external defibrillator (AED) devices have been in routine clinical use since the early 1990s to deliver life-saving shocks to appropriate patients in non-clinical environments. As expectations of survival from out-of-hospital cardiac arrest increase, and evidence incontrovertibly points to reduced timelines as the most crucial factor in achieving return of spontaneous circulation, questions regarding the availability and location of AEDs in the UK military need to be readdressed. This article explores the background of AEDs and reviews their history, life-saving potential and defines current and best practice. It goes on to review the evidence surrounding training and looks to identify knowledge gaps that might be addressed effectively by future research. Finally, it makes recommendations regarding training, availability of AEDs on military bases and locations most likely to deliver good outcomes for military personnel in the future.

Characteristics of automated external defibrillator coverage in Philadelphia, PA, based on land use and estimated risk

AIM

Approximately 424,000 out-of-hospital cardiac arrests (OHCA) occur in the US annually. As automated external defibrillators (AED) are an important part of the community response to OHCA, we investigated how well the spatial demand (likelihood of OHCA) was met by the spatial supply (AEDs) in a dense urban environment.

METHODS

Using geographic information system (GIS) software, we applied kernel density and optimized hot spot procedures with two differently-sized radii to model OHCA incidence rates from existing studies, providing an estimate of OHCA likelihood at a given location. We compared these density maps to existing AED coverage in the study area. Descriptive statistics summarized coverage by land use.

RESULTS

With a 420-ft buffer, we found that 56.0% (79.9%, 840-ft buffer) of the land area in the city center was covered by existing AEDs at, though 70.1 (91.5)% of the OHCA risk was covered using kernel density and 79.8% (98.1) was covered using hot spot analysis.

CONCLUSIONS

The difference in coverage by area and risk seems to indicate efficient placement of existing AEDs. Our findings also highlight the possible benefits to expanding the influence of AEDs by lowering search times, and identify opportunities to improve AED coverage in the study area. This article offers one method by which local officials can use spatial data to prioritize attention for AED placement and coverage.

Is knowledge and practice safer in England after the release of national guidance on the resuscitation of patients in mental health and learning disabilities?

This paper reports on the issue of resuscitation in mental health inpatient environments. It reviews the literature on national standards and best practice when emergency situations arise in mental health settings. The discussion on the best practice literature takes place alongside the reporting of a national evaluation of how National Patient Safety Agency improvement guidelines for the provision for life support, and resuscitation for mental health service users was effectively implemented across health-care providers in England. Methods used to establish the effective use of the guidelines include feedback from clinical staff and staff responsible for the implementation of the new national standards for resuscitation. Serious incident data were also compared prior to the release of the national guidelines and after the guideline release dates. This included looking at events around choking and cardiac/respiratory arrest in inpatient areas. There were five deaths post-implementation of the guidelines that were considered to have serious enough error associated with the resuscitation process. This was down from 18 prior to the release of the guidelines. However, our survey showed that despite organisations reporting 100% compliance with the implementation of the guidelines, around half of frontline clinical staff were not aware of them. Although our survey responses show a contradiction between organisational and clinical staff awareness, our analysis suggests a reduction in moderate and severe harm cases and of deaths. There is evidence of a reduction in the worst types of error resulting in death, albeit with small numbers. In 2008, the National Patient Safety Agency issued a Rapid Response Report (RRR) aimed at health-care organisations providing inpatient care for mental health and learning disability patients, requiring organisations to make proper provision for life support and resuscitation for these patients. This paper examines whether effective implementation of the RRR recommendations had occurred across health providers in England. The methods used in this paper are the following: (1) Questionnaires were distributed nationally to clinical staff and implementation leads; (2) A national comparison of the number and severity of pre- and post-RRR release-related incidents involving choking/cardiac/respiratory arrest in Mental Health and Learning Disabilities settings was conducted; (3) Organisational compliance with the patient safety alert for all National Health Service Organisations in England was measured. There were five deaths post-implementation of the RRR that were considered to have serious enough error associated with the resuscitation. This was down from 18 deaths pre the RRR release. Although our survey responses show a contradiction between organisational implementation and clinical staff awareness, our analysis suggests a reduction in moderate and severe harm cases and of deaths. There is evidence of a reduction in the worst types of error resulting in death, albeit with small numbers.

The effect of the AED and AED programs on survival of individuals, groups and populations

OBJECTIVE

The automated external defibrillator (AED) is a tool that contributes to survival with mixed outcomes. This review assesses the effectiveness of the AED, consistencies and variations among studies, and how varying outcomes can be resolved.

METHODS

A worksheet for the International Liaison Committee on Resuscitation (ILCOR) 2010 science review focused on hospital survival in AED programs was the foundation of the articles reviewed. Articles identified in the search covering a broader range of topics were added. All articles were read by at least two authors; consensus discussions resolved differences.

RESULTS

AED use developed sequentially. Use of AEDs by emergency medical technicians (EMTs) compared to manual defibrillators showed equal or superior survival. AED use was extended to trained responders likely to be near victims, such as fire/rescue, police, airline attendants, and casino security guards, with improvement in all venues but not all programs. Broad public access initiatives demonstrated increased survival despite low rates of AED use. Home AED programs have not improved survival; in-hospital trials have had mixed results. Successful programs have placed devices in high-risk sites, maintained the AEDs, recruited a team with a duty to respond, and conducted ongoing assessment of the program.

CONCLUSION

The AED can affect survival among patients with sudden ventricular fibrillation (VF). Components of AED programs that affect outcome include the operator, location, the emergency response system, ongoing maintenance and evaluation. Comparing outcomes is complicated by variations in definitions of populations and variables. The effect of AEDs on individuals can be dramatic, but the effect on populations is limited.

Knowledge and attitudes towards cardiopulmonary resuscitation and defibrillation amongst Asian primary health care physicians

Objective

To assess the knowledge and attitudes of local primary health care physicians in relation to cardiopulmonary resuscitation (CPR) and defibrillation.

Methods

We conducted a survey on general practitioners in Singapore by using a self-administered questionnaire that comprised 29 questions.

Results

The response rate was 80%, with 60 of 75 physicians completing the questionnaire. The average age of the respondents was 52 years. Sixty percent of them reported that they knew how to operate an automated external defibrillator (AED), and 38% had attended AED training. Only 36% were willing to perform mouth-to-mouth ventilation during CPR, and 53% preferred chest compression-only resuscitation (CCR) to standard CPR. We found those aged <50 years were more likely to be trained in basic cardiac life support (BCLS) (P < 0.001) and advanced cardiac life support (P = 0.005) or to have ever attended to a patient with cardiac arrest (P = 0.007). Female physicians tended to agree that all clinics should have AEDs (P = 0.005) and support legislation to make AEDs compulsory in clinics (P < 0.001). We also found that a large proportion of physicians who were trained in BCLS (P = 0.006) were willing to perform mouth-to-mouth ventilation.

Conclusion

Most local primary care physicians realize the importance of defibrillation, and the majority prefer CCR to standard CPR.

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.

Location of Cardiac Arrests in the Public Access Defibrillation Trial

BACKGROUND

The Public Access Defibrillation (PAD) Trial found an overall doubling in the number of out-of-hospital cardiac arrest (CA) survivors when a lay responder team was equipped with an automated external defibrillator (AED), compared with cardiopulmonary resuscitation (CPR) alone.

OBJECTIVES

To describe the types of facilities that participated in the trial and to report the incidence of CA and survival in these different types of facilities.

METHODS

In this post-hoc analysis of PAD Trial data, the physical characteristics of the participating facilities and the numbers of presumed CAs, treatable CAs, and survivors are reported for each category of facilities.

RESULTS

There were 625 presumed CAs at 1,260 participating facilities. Just under half (n = 291) of the presumed CAs were classified as treatable CAs. Treatable CAs occurred at a rate of 2.9 per 1,000 person-years of exposure; rates were highest in fitness centers (5.1) and golf courses (4.8) and lowest in office complexes (0.7) and hotels (0.7). Survival from treatable CA was highest in recreational complexes (0.5), public transportation sites (0.4), and fitness centers (0.4) and lowest in office complexes (0.1) and residential facilities (0.0).

CONCLUSIONS

During the PAD Trial, the exposure-adjusted rate of treatable CA was highest in fitness centers and golf courses, but the incidence per facility was low to moderate. Survival from treatable cardiac arrest was highest in recreational complexes, public transportation facilities, and fitness centers.

A national scheme for public access defibrillation in England and Wales: early results

BACKGROUND

Automated external defibrillators (AEDs) operated by lay persons are used in the UK in a National Defibrillator Programme promoting public access defibrillation (PAD).

METHODS

Two strategies are used: (1) Static AEDs installed permanently in busy public places operated by those working nearby. (2) Mobile AEDs operated by community first responders (CFRs) who travel to the casualty.

RESULTS

One thousand five hundred and thirty resuscitation attempts. With static AEDs, return of spontaneous circulation (ROSC) was achieved in 170/437 (39%) patients, hospital discharge in 113/437 (26%). With mobile AEDs, ROSC was achieved in 110/1093 (10%), hospital discharge in 32 (2.9%) (P<0.001 for both variables). More shocks were administered with static AEDS 347/437 (79%) than mobile AEDs 388/1093 (35.5%) P<0.001. Highly significant advantages existed for witnessed arrests, administration of shocks, bystander CPR before arrival of AED and short delays to start CPR and attach AED. These factors were more common with static AEDs. For CFRs, patients at home did less well than those at other locations for ROSC (P<0.001) and survival (P=.006). Patients at home were older, more arrests were unwitnessed, fewer shocks were given, delays to start CPR and attach electrodes were longer.

CONCLUSIONS

PAD is a highly effective strategy for patients with sudden cardiac arrest due to ventricular fibrillation who arrest in public places where AEDs are installed. Community responders who travel with an AED are less effective, but offer some prospect of resuscitation for many patients who would otherwise receive no treatment. Both strategies merit continuing development.

An observational study describing the geographic-time distribution of cardiac arrests in Singapore: what is the utility of geographic information systems for planning public access defibrillation? (PADS Phase I)

INTRODUCTION

Public access defibrillation (PAD) has shown potential to increase cardiac arrest survival rates.

OBJECTIVES

To describe the geographic epidemiology of prehospital cardiac arrest in Singapore using geographic information systems (GIS) technology and assess the potential for deployment of a PAD program.

METHODS

We conducted an observational prospective study looking at the geographic location of pre-hospital cardiac arrests in Singapore. Included were all patients with out-of-hospital cardiac arrest (OHCA) presented to emergency departments. Patient characteristics, cardiac arrest circumstances, emergency medical service (EMS) response and outcomes were recorded according to the Utstein style. Location of cardiac arrests was spot-mapped using GIS.

RESULTS

From 1 October 2001 to 14 October 2004, 2428 patients were enrolled into the study. Mean age for arrests was 60.6 years with 68.0% male. 67.8% of arrests occurred in residences, with 54.5% bystander witnessed and another 10.5% EMS witnessed. Mean EMS response time was 9.6 min with 21.7% receiving prehospital defibrillation. Cardiac arrest occurrence was highest in the suburban town centers in the Eastern and Southern part of the country. We also identified communities with the highest arrest rates. About twice as many arrests occurred during the day (07:00-18:59 h) compared to night (19:00-06:59 h). The categories with the highest frequencies of occurrence included residential areas, in vehicles, healthcare facilities, along roads, shopping areas and offices/industrial areas.

CONCLUSION

We found a definite geographical distribution pattern of cardiac arrest. This study demonstrates the utility of GIS with a national cardiac arrest database and has implications for implementing a PAD program, targeted CPR training, AED placement and ambulance deployment.

Out-of-hospital cardiac arrests occurring in primary health care facilities in Singapore

OBJECTIVES

To study out-of-hospital cardiac arrests (OHCA) occurring in primary healthcare facilities (HCF) in Singapore and to compare these with arrests occurring in the community.

METHODS

This prospective observational study was part of the Cardiac Arrest and Resuscitation Epidemiology (CARE) project. Included were all patients with OHCA occurring in HCF. Patient characteristics, cardiac arrest circumstances, EMS response and outcomes were recorded according to the Utstein style.

RESULTS

From 1 October 2001 to 14 October 2004, the data from 2428 subjects were received of which 138 patients were OHCA occurring in HCF. This is an incidence of 1.12/100,000 population per year and constituted 6.0% of all OHCA. Arrest occurring in HCF were more likely to be witnessed (p<0.01), or have bystander CPR (p<0.01). The HCF group was also more likely to receive CPR with both compression and ventilation (p<0.01) and have a non-trauma cause of arrest (p=0.03). HCF arrests also had a shorter collapse to call (EMS number) than the non-HCF group (HCF 1.54min versus non-HCF 5.36min, p=0.01). However, no HCF patient received defibrillation prior to EMS arrival. HCF patients were more likely to have return of spontaneous circulation at any time (p=0.05), survival to hospital admission (p<0.01) and survival to discharge (p<0.01) compared to non-HCF patients.

CONCLUSION

This study suggests that primary health care providers do have an important role locally in managing out-of-hospital cardiac arrest. We propose an initiative to encourage early defibrillation by primary health care providers.

Retention of skills in medical students following minimal theoretical instructions on semi and fully automated external defibrillators

AIM OF THE STUDY

There is consent that the use of automated external defibrillators (AED) by laypersons improves survival rates in case of cardiac arrest, but no evident consensus exists on the content and duration of training for this purpose. Acceptance of the implementation of Public Access Defibrillation programmes will depend on practical and target-oriented training concepts. The aim of this prospective randomised interventional study was to evaluate long-term effects of a specific, minimal training programme on using semiautomatic and fully automatic AEDs in simulated cardiac arrest.

MATERIALS AND METHODS

In a mock cardiac arrest scenario 59 medical students with no specific previous medical education were tested during their first semester at medical school. Students who passed any medical emergency training were excluded. The subjects were evaluated before and after attending specified instructions of 15 min duration and after a period of 6 months. Main end points were time to first shock, electrode-positioning and safety throughout the procedure.

RESULTS

Mean time to first shock without prior instructions was 77.7+/-17.05 s. After instruction there was a significant improvement to 56.5+/-9.5 s (p<or=0.01) and after 6 months this time had only slightly elongated (59.9+/-8.9 s; p<or=0.01). Initially, correct electrode placement was observed in 84.4%. No difference was found immediately and 6 months after instructions (93.2% and 98.3%). All individuals performed safely.

CONCLUSION

First year medical students with minimal instruction are able to use semiautomatic as well as fully automatic AED sufficiently fast and safe without prior training. A significant improvement in time to first shock can be detected up to 6 months after receiving non-specific instructions of 15 min duration.

Automated external defibrillators do not recommend false positive shocks under the influence of electromagnetic fields present at public locations

Electromagnetic fields (EMF) reduce the signal quality of electrocardiograms and may lead to the misinterpretation by automated external defibrillators (AED). We designed this investigation as a prospective study, with a randomized sequence of AED applications on healthy volunteers. We chose busy public places where public access defibrillation was possible as test locations. Strong EMF were sought and found at train stations next to accelerating and decelerating trains. The primary outcome variable was the absolute number of shocks advised in the presence of sinus rhythm by five commonly used AED in Austria. For data analysis, the statistician was blinded in regard to the AED models tested. Data analysis was based on a per protocol evaluation. Of 390 tests run, 0 cases of false positive results occurred (95% CI: 0-0.77). AED can be regarded as safe, even with the interference of EMF present at train stations.

Optimal refresher training intervals for AED and CPR skills: A randomised controlled trial

AIM

To determine the optimal refresher training interval for lay volunteer responders in the English National Defibrillator Programme who had previously undertaken a conventional 4-h initial class and a first refresher class at 6 months.

METHODS

Subjects were randomised to receive either two additional refresher classes at intervals of 7 and 12 months or one additional refresher class after 12 months.

RESULTS

Greater skill loss had occurred when the second refresher class was undertaken at 12 compared with 7 months. Skill retention however, was higher in the former group, ultimately resulting in no significant difference in final skill performance. There was no significant difference in performance between subjects attending two versus three refresher classes. On completion of refresher training all subjects were able to deliver countershocks, time to first shock decreased by 17s in both groups, and the proportion of subjects able to perform most skills increased. The execution of several important interventions remained poor, regardless of the total number of classes attended or the interval between them. These included CPR skills, defibrillation pad placement, and pre-shock safety checks. Refresher classes held more frequently and at shorter intervals increased subjects' self-assessed confidence, possibly indicating greater preparedness to use an AED in a real emergency.

CONCLUSIONS

This study shows that the ability to deliver countershocks is maintained whether the second refresher class is held at seven or 12 months after the first. To limit skill deterioration between classes, however, refresher training intervals should not exceed 7 months. The quality of instruction given should be monitored carefully. Learning and teaching strategies require review to improve skill acquisition and maintenance.

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.

A national programme for on-site defibrillation by lay people in selected high risk areas: initial results

OBJECTIVE

To report on the effectiveness of an initiative to reduce deaths from sudden cardiac arrest occurring in busy public places.

SETTING

110 such places identified from ambulance service data as high risk sites.

PATIENTS

172 members of the public who developed cardiac arrest at these sites between April 2000 and March 2004. 20,592 defibrillator months' use is reported, representing one automated external defibrillator (AED) use every 120 months.

INTERVENTION

681 AEDs were installed; staff present at the sites were trained in basic life support and to use AEDs.

MAIN OUTCOME MEASURES

Initial rhythm detected by AED, restoration of spontaneous circulation, survival to hospital discharge.

RESULTS

172 cases of cardiac arrest were treated by trained lay staff working at the site before the arrival of the emergency services during the period. A shockable rhythm was detected in 135 (78%), shocks being administered in 134 an estimated 3-5 minutes after collapse; 38 (28.3%) patients subsequently survived to hospital discharge. Spontaneous circulation was restored in five additional patients who received shocks but died later in hospital. In 37 cases no shock was initially indicated; one patient survived after subsequent treatment by paramedics, cardiopulmonary resuscitation having been given soon after collapse. Overall, irrespective of the initial rhythm, 39 patients (22.7%), were discharged alive from hospital. For witnessed arrests of presumed cardiac cause in ventricular fibrillation (an international Utstein comparator) survival was 37 of 124 (29.8%).

CONCLUSIONS

The use of AEDs by lay people at sites where cardiac arrest commonly occurs is an effective strategy to reduce deaths at these sites.

Resuscitation of out-of-hospital cardiac arrest by Asian primary health-care physicians

AIM

To assess the experience, knowledge and attitudes of local primary health-care doctors towards resuscitation in out-of-hospital cardiac arrest.

METHODS

We conducted a survey of general practitioners (GPs) working in both private and public sectors. The survey consisted of 29 questions and was self-administered.

RESULTS

Response rate was 78.8% with 66 public practice doctors and 23 from private practice. Average ages were 39.8 years (private) and 35.5 years (public) with mean years of practice being 15.1 (private) and 11.4 (public). 47.8% of private and 69.7% of public doctors had been advanced cardiac life-support (ACLS) trained. 13.0% of private and 10.6% of public had witnessed a cardiac arrest in their clinics in the past year. 92.3% of public and 26.1% of private doctors had defibrillators in their clinics (P < 0.01, OR = 34.0, 95% CI = 9.2-125.2). 83.3% (public) versus 52.2% (private) (P < 0.01 OR = 4.6, 95% CI = 1.6-13.0) agreed that all clinics should have defibrillators. 59.1% (public) and 34.8% (private) would support legislation for defibrillators in clinics (P = 0.04, OR = 2.7, 95% CI = 1.01-7.3). Reasons given for not buying defibrillators included 'too expensive' (70.6%) and 'unsure how to use' (5.9%). 66.0% would consider buying a defibrillator if the cost was less than Singapore 3000 dollars (1400 Euro). 69.6% (private) and 63.6% (public) were interested in participating in a GP defibrillation project.

CONCLUSION

Primary care physicians do see themselves as having an important role in resuscitation. We propose a local initiative to equip, educate and encourage defibrillation by GPs in our community.

Circumstances of out of hospital cardiac arrest in patients with ischaemic heart disease

OBJECTIVES

To discover the circumstances of out of hospital cardiac death irrespective of resuscitation attempts.

DESIGN

Prospective community study over the two years 1994 and 1995.

SETTING

The health districts of Brighton, South Glamorgan, and York, UK.

SUBJECTS

1290 victims of sudden death or cardiac arrest caused by coronary heart disease who were under 76 years of age.

INTERVENTIONS

Basic and advanced life support for witnessed cardiac arrests.

MAIN OUTCOME MEASURES

Survival to reach hospital and for 30 days after the arrest.

RESULTS

35 (35%) of 101 patients (mean age 64) whose arrest was witnessed by a doctor or paramedic survived for 30 days compared with 9 of 464 (2%) whose arrest was witnessed by a relative or bystander at home (mean age 66) and 15 of 200 (8%) whose arrest was witnessed in a public place (mean age 61). None of the 525 victims of an unwitnessed arrest survived but the majority of those whose arrest was witnessed had complained of new symptoms before the arrest. Victims who were given basic life support by relatives or bystanders had better survival (14 of 183 (8%)) than those who were not (10 of 481 (2%), p < 0.001). Of the 20% of arrests that occurred in public places, few were in places where public access defibrillators would now be available.

CONCLUSIONS

The burden of out of hospital cardiac arrest is mainly in the home but most victims have premonitory symptoms. Public education to seek help urgently for new or prolonged chest pain seems the most promising method to address the problem.

Minimal instructions improve the performance of laypersons in the use of semiautomatic and automatic external defibrillators

INTRODUCTION

There is evidence that use of automated external defibrillators (AEDs) by laypersons improves rates of survival from cardiac arrest, but there is no consensus on the optimal content and duration of training for this purpose. In this study we examined the use of semiautomatic or automatic AEDs by laypersons who had received no training (intuitive use) and the effects of minimal general theoretical instructions on their performance.

METHODS

In a mock cardiac arrest scenario, 236 first year medical students who had not previously attended any preclinical courses were evaluated in their first study week, before and after receiving prespecified instructions (15 min) once. The primary end-point was the time to first shock for each time point; secondary end-points were correct electrode pad positioning, safety of the procedure and the subjective feelings of the students.

RESULTS

The mean time to shock for both AED types was 81.2 +/- 19.2 s (range 45-178 s). Correct pad placement was observed in 85.6% and adequate safety in 94.1%. The time to shock after instruction decreased significantly to 56.8 +/- 9.9 s (range 35-95 s; P < or = 0.01), with correct electrode placement in 92.8% and adequate safety in 97%. The students were significantly quicker at both evaluations using the semiautomatic device than with the automatic AED (first evaluation: 77.5 +/- 20.5 s versus 85.2 +/- 17 s, P < or = 0.01; second evaluation: 55 +/- 10.3 s versus 59.6 +/- 9.6 s, P < or = 0.01).

CONCLUSION

Untrained laypersons can use semiautomatic and automatic AEDs sufficiently quickly and without instruction. After one use and minimal instructions, improvements in practical performance were significant. All tested laypersons were able to deliver the first shock in under 1 min.

The Department of Health National Defibrillator Programme: analysis of downloads from 250 deployments of public access defibrillators

From April 2000 to November 2002, the Department of Health (England) placed 681 automated external defibrillators (AEDs) in 110 public places for use by volunteer lay first responders. An audit has been undertaken of the first 250 deployments, of which 182 were for confirmed cardiac arrest. Of these, 177 were witnessed whilst 5 occurred in situations that were remote or initially inaccessible to the responders. The response interval between collapse and the initiation of CPR or AED placement was estimated to be 3-5 min in most cases. Ventricular fibrillation or rapid ventricular tachycardia (one case) was the first recorded rhythm in 146 cases (82%). In all, 44 of the 177 witnessed cases are known to have survived to hospital discharge (25%). Complete downloads are available for 173 witnessed cases and of these 140 were shocked: first-shock success, defined as termination of the fibrillatory waveform for 5 s or more, was achieved in 132 of them. When data quality permitted, the downloads were analysed with special reference to the numbers of compressions given and also to interruptions in compression sequences for ventilations, for rhythm analysis by the AED, for clinical checks, and for unexplained operator delays. The average rate of compressions during sequences was 120 min(-1), but because of interruptions, the actual number administered over a full minute from the first CPR prompt was a median of only 38. The speed of response by the lay first responders in relation to AED use was similar to that reported for healthcare professionals.

Public access defibrillation--designing a universal report form and database for a national programme

We describe the design of a universal report form for use by lay-responders using an automated external defibrillator (AED) as part of a national programme for public access defibrillation (PAD). The form was designed initially because the Department of Health in England required detailed audit data about the national programme for public access defibrillation they initiated. At that time (1999) there was very little reported experience of public access defibrillation and none from the UK. The form evolved pragmatically as experience showed the wide range of situations under which lay-persons might use an AED, and also the information likely to be available that could be collected reliably. This report may help others who wish to audit schemes for PAD and facilitate the evolution of an internationally acceptable template for data collection.

Decrease in the occurrence of ventricular fibrillation as the initially observed arrhythmia after out-of-hospital cardiac arrest during 11 years in Sweden

AIM

To describe the change in the occurrence of ventricular fibrillation as initially observed arrhythmia among patients suffering from out-of-hospital cardiac arrest in Sweden.

PATIENTS

All patients included in the Swedish cardiac arrest registry between 1991 until 2001. The registry covers 85% of the population in Sweden.

METHODS

All patients with bystander witnessed out-of-hospital cardiac arrest included in the Swedish Cardiac Arrest Registry between 1991 and 2001 from the same ambulance organisation each year were included in the survey.

RESULTS

Over 11 years, among patients in Sweden with a bystander witnessed out-of-hospital cardiac arrest in whom cardiopulmonary resuscitation (CPR) was attempted (n = 9666), the occurrence of ventricular fibrillation as the initially obseved arrhythmia decreased from 45% in 1991 to 28% in 2001 (P < 0.0001) if the arrest occurred at home, and from 57% to 41% if the arrest occurred outside home (P < 0.0001). This was found despite the fact that the proportion who received bystander CPR increased from 29% in 1991 to 39% in 2001 if the arrest occurred at home (P < 0.0001) and from 54% to 60% if the arrest occurred outside home (NS). There was a significant increase in age among patients with out-of-hospital cardiac arrest at home, no change in the estimated interval between collapse and call but an increase in the interval between call and arrival of the ambulance among patients with out-of-hospital cardiac arrest outside home.

CONCLUSION

During 11 years in Sweden, there was a marked decrease in the proportion of patients found in ventricular fibrillation among patients with a bystander witnessed cardiac arrest regardless whether the arrest occurred at home or outside home. A modest increase in age and interval between call for, and arrival of, the ambulance was associated with these findings.

Skill acquisition and retention in automated external defibrillator (AED) use and CPR by lay responders: a prospective study

This prospective study evaluated the acquisition and retention of skills in cardio-pulmonary resuscitation (CPR) and the use of the automated external defibrillator (AED) by lay volunteers involved in the Department of Health, England National Defibrillator Programme. One hundred and twelve trainees were tested immediately before and after and initial 4-h class; 76 were similarly reassessed at refresher training 6 months later. A standardised test scenario that required assessment of the casualty, CPR and the use of on AED was evaluated using recording manikin data and video recordings. Before training only 44% of subjects delivered a shock. Afterwards, all did so and the average delay to first shock was reduced by 57 s. All trainees placed the defibrillator electrodes in an "acceptable" position after training, but very few did so in the recommended "ideal" position. After refresher training 80% of subjects used the correct sequence for CPR and shock delivery, yet a third failed to perform adequate safety checks before all shocks. The trainees self-assessed AED competence score was 86 (scale 0-100) after the initial class and their confidence that they would act in a real emergency was rated at a similar level. Initial training improved performance of all CPR skills, although all except compression rate had deteriorated after 6 months. The proportion of subjects able to correctly perform most CPR skill was higher following refresher training that after the initial class. Although this course was judged to be effective in teaching delivery of counter-shocks, the need was identified for more emphasis on positioning of electrodes, pre-shock safety checks, airway opening, ventilation volume, checking for signs of a circulation, hand positioning, and depth and rate of chest compressions.

The debate on public place defibrillators: charged but shockingly ill informed

There is growing interest in developing strategies which will enable defibrillation to be administered while waiting for the emergency medical service to arrive.

Use of automated external defibrillator by first responders in out of hospital cardiac arrest: prospective controlled trial

OBJECTIVE

To test the hypothesis that the use of an automated external defibrillator by police and fire fighters results in higher discharge rates for out of hospital cardiac arrest.

DESIGN

Controlled clinical trial with initial random allocation of automated external defibrillators to first responders in four of the eight participating regions; each region switched from control to experimental, and vice versa, every four months.

SETTING

Amsterdam and surroundings, the Netherlands.

PARTICIPANTS

Patients with witnessed out of hospital cardiac arrests, identified by the emergency medical system between January 2000 and January 2002.

MAIN OUTCOMES MEASURES

Survival to hospital discharge; return of spontaneous circulation; admission to hospital.

RESULTS

243 patients (65% in ventricular fibrillation) were included in the experimental area and 226 patients (67% in ventricular fibrillation) in the control area. The median time interval between collapse and first shock was 668 seconds in the experimental area and 769 seconds in the control area (P < 0.001). 44 (18%) patients in the experimental area versus 33 (15%) patients in the control area were discharged (odds ratio 1.3 (95% confidence interval 0.8 to 2.2), P = 0.33), 139 (57%) experimental versus 108 (48%) control patients had return of spontaneous circulation (1.5 (1.0 to 2.2), P = 0.05), and 103 (42%) experimental versus 74 (33%) control patients were admitted (1.5 (1.1 to 1.6), P = 0.02). The median delay from receipt of call to dispatch of the ambulance was 120 seconds, and the delay to dispatch of the first responder was 180 seconds.

CONCLUSIONS

Use of automated external defibrillators by first responders did not significantly increase survival to discharge from hospital, although it did improve return of spontaneous circulation and admission to hospital. Improved dispatch procedures should increase the success of programmes of first responders using external defibrillators.

Reliability of the Cardiff Test of basic life support and automated external defibrillation version 3.1

The introduction of the European Resuscitation Guidelines (2000) for cardiopulmonary resuscitation (CPR) and automated external defibrillation (AED) prompted the development of an up-to-date and reliable method of assessing the quality of performance of CPR in combination with the use of an AED. The Cardiff Test of basic life support (BLS) and AED version 3.1 was developed to meet this need and uses standardised checklists to retrospectively evaluate performance from analyses of video recordings and data drawn from a laptop computer attached to a training manikin. This paper reports the inter- and intra-observer reliability of this test. Data used to assess reliability were obtained from an investigation of CPR and AED skill acquisition in a lay responder AED training programme. Six observers were recruited to evaluate performance in 33 data sets, repeating their evaluation after a minimum interval of 3 weeks. More than 70% of the 42 variables considered in this study had a kappa score of 0.70 or above for inter-observer reliability or were drawn from computer data and therefore not subject to evaluator variability. 85% of the 42 variables had kappa scores for intra-observer reliability of 0.70 or above or were drawn from computer data. The standard deviations for inter- and intra-observer measures of time to first shock were 11.6 and 7.7 s, respectively. The inter- and intra-observer reliability for the majority of the variables in the Cardiff Test of BLS and AED version 3.1 is satisfactory. However, reliability is less acceptable with respect to shaking when checking for responsiveness, initial check/clearing of the airway, checks for signs of circulation, time to first shock and performance of interventions in the correct sequence. Further research is required to determine if modifications to the method of assessing these variables can increase reliability.

Comparison of ease of use of three automated external defibrillators by untrained lay people

The use of automated external defibrillators (AED) by lay people has the potential to markedly increase survival from community cardiac arrest. Wider public use of AEDs requires units that can be operated safely and effectively by people with minimal or no training. This study compares the use of three AEDs by untrained lay people regarding ease-of-use, safety, pad positioning and time to defibrillation. 24 subjects with no prior exposure to the use of AEDs were asked to perform simulated defibrillation on a manikin using three defibrillators: Zoll AEDPlus, Medtronic Physio-Control LifePak CR Plus and Philips/Laerdal HeartStart OnSite Defibrillator. Subjects' performance were videotaped and reviewed for time to defibrillate, pad positioning and safety. Subjects were asked to rate the three units in terms of ease-of-use. Average times to first shock were 74.8 s for the Physio-Control, 83.0 s for the Laerdal and 153.4 s for the Zoll defibrillator. Pad positioning was scored as correct in 23/24 Laerdal trials, 19/24 Physio-Control trials and 14/24 Zoll trials. 23 out of the 24 subjects rated the Zoll most difficult to use. All subjects safely stayed clear of the unit when required. The majority of subjects safely and effectively delivered defibrillating shocks without any prior training and within quite acceptable times. Untrained subjects find the Physio-Control and Laerdal Defibrillator easier to use than the Zoll device. Features of AED design that improved ease of use are discussed.

Opportunities to prevent sudden out-of-hospital death due to coronary heart disease in a community

BACKGROUND

Intervening successfully to reduce the burden of sudden out-of-hospital death due to coronary heart disease (OHCD) requires knowledge of where these deaths occur and whether they are observed by bystanders.

METHODS

To establish the proportion of OHCDs that were witnessed and where they occurred, we reviewed the coroner's notes and medical records of a previously-described sample of OHCD cases among residents of Olmsted County, Minnesota. This cohort (n=113) consisted of a 10% random sample of all Olmsted County residents who died out-of-hospital between 1981 and 1994 and whose deaths were attributed to coronary heart disease.

RESULTS

Excluding deaths in nursing homes (n=27), 71 (83%) of the deaths occurred in private homes and 15 (17%) occurred in public places. The event was not witnessed in 59% of deaths occurring in private homes and in 20% of deaths occurring in public places. The presence or absence of a bystander could not be established for 10% of deaths in private homes and 7% of deaths in public areas.

CONCLUSIONS

A significant proportion of OHCDs occur in private homes and are not witnessed. Prevention of unwitnessed deaths will require programs that result in primary prevention and/or calls to first responders at the time of impending cardiac arrest.

Automated external defibrillation as part BLS: implications for education and practice

The latest Adult Basic Life Support (BLS) guidelines support the inclusion of the use of the automated external defibrillator (AED), as part of basic life support (BLS). Emphasis on the provision of early defibrillation as part of BLS acknowledges the importance of this manoeuvre in the successful termination of ventricular fibrillation. The ramifications of such changes for both first responders and organisations implementing the guidelines should not be underestimated. Issues relating to resourcing, content and duration of training and retraining, auditing and evaluation require further exploration. To consider these issues now seems particularly pertinent, given the recent launch of the UK Government's paper on public health, 'Saving Lives-Our Healthier Nation' which seeks to deploy AEDs in busy public places for use by trained members of the lay public. Additionally, defibrillation has been identified as one of the key competencies that all trained nurses and other health care providers should be able to undertake. This paper will consider the background to the current guideline changes, analyse the wider implications of translating the recommendations into practice, and offer possible solutions to address the issues raised. Whilst the analysis is particularly pertinent to the United Kingdom, many of the issues raised have international importance.