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

Dispatcher nurses' experiences of handling drones equipped with automated external defibrillators in suspected out-of-hospital cardiac arrest - a qualitative study

BACKGROUND

Reducing the time to treatment by means of cardiopulmonary resuscitation (CPR) and defibrillation is essential to increasing survival after cardiac arrest. A novel method of dispatching drones for delivery of automated external defibrillators (AEDs) to the site of a suspected out-of-hospital cardiac arrest (OHCA) has been shown to be feasible, with the potential to shorten response times compared with the emergency medical services. However, little is known of dispatchers' experiences of using this novel methodology.

METHODS

A qualitative semi-structured interview study with a phenomenological approach was used. Ten registered nurses employed at an emergency medical dispatch centre in Gothenburg, Sweden, were interviewed and the data was analysed by qualitative content analysis. The purpose was to explore dispatcher nurses' experiences of deliveries of AEDs by drones in cases of suspected OHCA.

RESULTS

Three categories were formed. Nurses expressed varying compliance to the telephone-assisted protocol for dispatch of AED-equipped drones. They experienced uncertainty as to how long would be an acceptable interruption from the CPR protocol in order to retrieve a drone-delivered AED. The majority experienced that collegial support was important. Technical support, routines and training need to be improved to further optimise action in cases of drone-delivered AEDs handled by dispatcher nurses.

CONCLUSIONS

Although telephone-assisted routines for drone dispatch in cases of OHCA were available, their use was rare. Registered nurses showed variable degrees of understanding of how to comply with these protocols. Collegial and technical support was considered important, alongside routines and training, which need to be improved to further support bystander use of drone-delivered AEDs. As the possibilities of using drones to deliver AEDs in cases of OHCA are explored more extensively globally, there is a good possibility that this study could be of benefit to other nations implementing similar methods. We present concrete aspects that are important to take into consideration when implementing this kind of methodology at dispatch centres.

Evaluation of functional and electrical features of automatic external defibrillators in extreme altitude and temperature environments

Aims

Human exposure to high-altitude and/or low-temperature areas is increasing and cardiac arrest in these circumstances represents an increasing proportion of all treated cardiac arrests. However, little is known about the performance of automated external defibrillators (AED) in these circumstances. The objective of this study is to assess the functional and electrical features of 6 commercially available AEDs in extreme environments.

Methods

Accuracy of shockable rhythm detection, the time required for self-test, rhythm analysis, and capacitor charging, together with total energy, peak voltage, peak current, and phasic duration of defibrillation waveform measured after placing the AEDs in simulated high-altitude, simulated low-temperature, and natural composite high-altitude and low-temperature environment for 30 min, were compared to those measured in the standard environment.

Results

All of the shockable rhythms were correctly detected and all of the defibrillation shocks were successfully delivered by the AEDs. However, the time required for self-test, rhythm detection, and capacitor charging was shortened by 1.2% (3 AEDs, maximum 12.4%) in the simulated high-altitude environment, was prolonged by 3.6% (4 AEDs, maximum 40.8%) in the simulated low-temperature environment, and was prolonged by 4.1% (5 AEDs, maximum 52.1%) in the natural environment. Additionally, the total delivered energy was decreased by 2.5% (2 AEDs, maximum 6.8%) in the natural environment.

Conclusion

All of the investigated AEDs functioned properly in simulated and natural environments, but a large variation in the functional and electrical feature change was observed. When performing cardiopulmonary resuscitation in extreme environments, the impact of environmental factors may need consideration.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Public Out-of-Hospital Cardiac Arrest in Residential Neighborhoods

BACKGROUND

Although one-half of all public out-of-hospital cardiac arrests (OHCAs) occur outside private homes in residential neighborhoods, their characteristics and outcomes remain unexplored.

OBJECTIVES

The authors assessed interventions before ambulance arrival and survival for public OHCA patients in residential neighborhoods.

METHODS

Public OHCAs from Vienna (2018-2021) and Copenhagen (2016-2020) were designated residential neighborhoods or nonresidential areas. Interventions (cardiopulmonary resuscitation [CPR], automated external defibrillator [AED] attached, and defibrillation) and 30-day survival were compared using a generalized estimation equation model adjusted for age and time of day and presented as ORs.

RESULTS

We included 1,052 and 654 public OHCAs from Vienna and Copenhagen, respectively, and 68% and 55% occurred in residential neighborhoods, respectively. The likelihood of CPR, defibrillation, and survival in residential neighborhoods vs nonresidential areas (reference) were as follows: CPR Vienna, 73% vs 78%, OR: 0.78 (95% CI: 0.57-1.06), CPR Copenhagen, 83% vs 90%, OR: 0.54 (95% CI: 0.34-0.88), and CPR combined, 76% vs 84%, OR: 0.70 (95% CI: 0.53-0.90); AED attached Vienna, 36% vs 44%, OR: 0.69 (95% CI: 0.53-0.90), AED attached Copenhagen, 21% vs 43%, OR: 0.33 (95% CI: 0.24-0.48), and AED attached combined, 31% vs 44%, OR: 0.53 (95% CI: 0.42-0.65); defibrillation Vienna, 14% vs 20%, OR: 0.61 (95% CI: 0.43-0.87), defibrillation Copenhagen, 16% vs 36%, OR: 0.35 (95% CI: 0.24-0.51), and defibrillation combined, 15% vs 27%, OR: 0.46 (95% CI: 0.36-0.61); and 30-day survival rate Vienna, 21% vs 26%, OR: 0.84 (95% CI: 0.58-1.20), 30-day survival rate Copenhagen, 33% vs 44%, OR: 0.65 (95% CI: 0.47-0.90), and 30-day survival rate combined, 25% vs 36%, OR: 0.73 (95% CI: 0.58-0.93).

CONCLUSIONS

Two-thirds of public OHCAs occurred in residential neighborhoods with fewer resuscitative efforts before ambulance arrival and lower survival than in nonresidential areas. Targeted efforts to improve early CPR and defibrillation for public OHCA patients in residential neighborhoods are needed.

Community intervention to improve defibrillation before ambulance arrival in residential neighbourhoods with a high risk of out-of-hospital cardiac arrest: study protocol of a cluster-randomised trial (the CARAMBA trial)

INTRODUCTION

In Denmark, multiple national initiatives have been associated with improved bystander defibrillation and survival following out-of-hospital cardiac arrest (OHCA) in public places. However, OHCAs in residential neighbourhoods continue to have poor outcomes. The Cardiac Arrest in Residential Areas with MoBile volunteer responder Activation trial aims to improve bystander defibrillation and survival following OHCA in residential neighbourhoods with a high risk of OHCA. The intervention consists of: (1) strategically deployed automated external defibrillators accessible at all hours, (2) cardiopulmonary resuscitation (CPR) training of residents and (3) recruitment of residents for a volunteer responder programme.

METHODS AND ANALYSIS

This is a prospective, pair-matched, cluster-randomised, superiority trial with clusters of 26 residential neighbourhoods, testing the effectiveness of the intervention in a real-world setting. The areas are randomised for intervention or control. Intervention and control areas will receive the standard OHCA emergency response, including volunteer responder activation. However, targeted automated external defibrillator deployment, CPR training and volunteer responder recruitment will only be provided in the intervention areas. The primary outcome is bystander defibrillation, and the secondary outcome is 30-day survival. Data on patients who had an OHCA will be collected through the Danish Cardiac Arrest Registry.

ETHICS AND DISSEMINATION

Approval to store OHCA data has been granted from the Legal Office, Capital Region of Denmark (j.nr: 2012-58-0004, VD-2018-28, I-Suite no: 6222, and P-2021-670). In Denmark, formal approval from the ethics committee is only obtainable when the study regards testing medicine or medical equipment on humans or using genome or diagnostic imagine as data source. The Ethics Committee of the Capital Region of Denmark has evaluated the trial and waived formal approval unnecessary (H-19037170). Results will be published in peer-reviewed papers and shared with funders, stakeholders, and housing organisations through summaries and presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04446585).

Spatiotemporal Optimization for the Placement of Automated External Defibrillators Using Mobile Phone Data

With over 350,000 cases occurring each year, out-of-hospital cardiac arrest (OHCA) remains a severe public health concern in the United States. The correct and timely use of automated external defibrillators (AEDs) has been widely acknowledged as an effective measure to improve the survival rate of OHCA. While general guidelines have been provided by the American Heart Association (AHA) for AED deployment, the lack of detailed instructions hindered the adoption of such guidelines under dynamic scenarios with various time and space distributions. Formulating the AED deployment as a location optimization problem under budget and resource constraints, we proposed an overlayed spatio-temporal optimization (OSTO) method, which accounted for the spatiotemporal heterogeneity of potential OHCAs. To highlight the effectiveness of the proposed model, we applied the proposed method to Washington DC using user-generated anonymized mobile device location data. The results demonstrated that optimization-based planning provided an improved AED coverage level. We further evaluated the effectiveness of adding additional AEDs by analyzing the cost-coverage increment curve. In general, our framework provides a systematic approach for municipalities to integrate inclusive planning and budget-limited efficiency into their final decision-making. Given the high practicality and adaptability of the framework, the OSTO is highly amenable to different healthcare facilities' deployment tasks with flexible demand and resource restraints.

Are first responders first? The rally to the suspected out-of-hospital cardiac arrest

BACKGROUND

Time is the crucial factor in the "chain of survival" treatment concept for out-of-hospital cardiac arrest (OHCA). We aimed to measure different response time intervals by comparing emergency medical system (EMS), fire fighters and smartphone aided volunteer responders.

METHODS

In two large Swedish regions, volunteer responders were timed from the alert until they arrived at the scene of the suspected OHCA. The first arriving volunteer responders who tried to fetch an automated external defibrillator (AED-responder) and who ran to perform bystander cardiopulmonary resuscitation (CPR-responder) were compared to both the first arriving EMS and fire fighters. Three-time intervals were measured, from call to dispatch, the unit response time (from dispatch to arrival) and the total response time.

RESULTS

During 22 months, 2631 suspected OHCAs were included. The median time from call to dispatch was in minutes 1.8 (95% CI = 1.7-1.8) for EMS, 2.9 (95% CI = 2.8-3.0) for fire-fighters and 3.0 (95% CI = 2.9-3.1) for volunteer responders. The median unit response time was 8.3 (95% CI = 8.1-8.5) for EMS, 6.8 (95% CI = 6.7-6.9) for fire fighters and 6.0 (95% CI = 5.7-6.2) for AED-responders and 4.6 (95% CI = 4.5-4.8) for CPR-responders. The total response time was 10.4 (95% CI = 10.1-10.6) for EMS, 10.2 (95% CI = 9.9-10.4) for fire fighters, 9.6 (95% CI = 9.1-9.8) for AED-responders and 8.2 (95% CI = 8.0-8.3) for CPR-responders.

CONCLUSION

First arriving volunteer responders had the shortest unit response time when compared to both fire fighters and EMS, however this advantage was reduced by delays introduced at the dispatch center. Earlier automatic dispatch should be considered in further studies.

Medical Drone Managing System for Automated External Defibrillator Delivery Service

One of the common causes of a heart attack is fibrillation, a condition that causes an irregular and often abnormally fast heart rate. There is scientific evidence that the survival rate of sudden cardiac arrest patients who are rescued with cardiopulmonary resuscitation (CPR) and with the use of an automated external defibrillator (AED) is significantly increased. Despite the recommendation that automated external defibrillators should be installed in the workplace, along with a proper management system and training for employees on how to use the device, less than 70% of non-residential areas have an AED installed. The situation is even worse in residential areas, with less than 30% having an AED installed. This research concerns the development of a medical drone managing system that can deliver an AED in case of emergency. An application was developed that can be installed on the mobile phone and/or tablet of the patient or the accompanying person. In the event of a heart attack, the patient or the accompanying person can call a medical drone by sending coordinates to the drone station and a notification to medical staff. The drone station administrator can respond by sending the drone, which automatically lands at the patient’s location. After being tested in a simulation situation, the operational field test yielded satisfactory results. The medical drone can land within 1.5 m of the destination. The designed AED drone can be used not only to deliver AEDs, but also first aid kits and prescribed drugs suitable for medical care. Such a system is especially useful in the current context of the COVID-19 pandemic.

A Review of the Commercially Available ECG Detection and Transmission Systems-The Fuzzy Logic Approach in the Prevention of Sudden Cardiac Arrest

Sudden cardiac death (SCD) constitutes a major clinical and public health problem, whose death burden is comparable to the current worldwide pandemic. This comprehensive review encompasses the following topics: available rescue systems, wearable electrocardiograms (ECG), detection and transmission technology, and a newly developed fuzzy logic algorithm (FA) for heart rhythm classification which is state-of-the art in the field of SCD prevention. Project "PROTECTOR", the Polish Rapid Transtelephonic ECG to Obtain Resuscitation for development of a rapid rescue system for patients at risk of sudden cardiac arrest (SCA), is presented. If a lethal arrhythmia is detected on the basis of FA, the system produces an alarm signal audible for bystanders and transmits the alarm message along with location to the emergency medical center. Phone guided resuscitation can be started immediately because an automated external defibrillator (AED) localization map is available. An automatic, very fast diagnosis is a unique feature of the PROTECTOR prototype. The rapid detection of SCA is based on a processor characterized by 100% sensitivity and 97.8% specificity (as measured in the pilot studies). An integrated circuit which implements FA has already been designed and a diagnosis is made within few seconds, which is extremely important in ischemic brain damage prophylaxis. This circuit could be implemented in smart implants (Sis).

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.

Accessibility of automatic external defibrillators and survival rate of people with out-of-hospital cardiac arrest: A systematic review of real-world studies

OBJECTIVE

To evaluate the relationship between the accessibility of automatic external defibrillators (AEDs) and the survival rate of patients who have out-of-hospital cardiac arrest (OHCA).

METHODS

The systematic review was conducted according to the Cochrane Handbook of Systematic Reviews. We searched the Chinese and English literature databases from 2009 to 2019. Study selection and data collection were conducted by three reviewers. One-month survival rates of OHCA with different AEDs accessibility were estimated using meta-analysis.

RESULTS

Overall 16 studies with 55,537 participants were included. The overall one-month survival rate for OHCA was 27.4%. The one-month survival rate was 35.2% for people receiving AEDs within 5 min, 36.6% between 5 min to 10 min, and 28.4% for longer than 10 min. By distance between the location of the AEDs and the location of the cardiac arrest, the one-month survival rate was 37.1% for those ≤100 m, 22.0% for 100 m-200 m, and 12.8% for >200 m, respectively. The one-month survival rate was 39.3% in schools, sports venues and airports compared with 23.5% in other sites. The number of AEDs allocation was positively correlated, while the time and distance were negatively correlated with the one-month survival rate adjusted for other factors, but they were all non-significant correlations.

CONCLUSION

The improvement of accessibility of AEDs may increase the survival rate of OHCA and the survival rate may be higher in playgrounds, airports, and schools equipped with AEDs. However, the strength of evidence was limited by the considerably heterogeneity of included studies. Verification of these findings in further studies is warranted.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of Autonomous Actions on Bystander-Initiated Cardiopulmonary Resuscitation and Public Access Defibrillation in Tokyo

The frequencies of autonomous bystander-initiated cardiopulmonary resuscitation (CPR) and public access defibrillation have not yet been clarified. We aimed to evaluate the frequency of autonomous actions by citizens not having a duty to act.This retrospective observational study included patients who suffered an out-of-hospital cardiac arrest (OHCA) in Tokyo between January 1, 2013 and December 31, 2017. The Delphi method with a panel of 11 experts classified the locations of OHCA resuscitations into 3 categories as follows; autonomous, non autonomous, and undetermined. The locations determined as autonomous were further divided into 2 groups; home and other locations. Bystander-initiated CPR and application of an automated external defibrillator (AED) pad were evaluated in 43,460 patients with OHCA.Group A (non autonomous), group B (autonomous, not home), and group C (home), consisted of 7,352, 3,193, and 32,915 patients, respectively. Compared with group A, group B and group C had significantly lower rates of bystander-initiated CPR (group A, B, C; 68.3% versus 38.6% versus 23.9%) and AED pad application (groups A, B, C; 26.8% versus 15.1% versus 0.6%). In addition, multivariate analysis demonstrated that an autonomous location of resuscitation was independently associated with the frequencies of bystander-initiated CPR and AED pad application, even after adjusting for age, sex, and witness status.Autonomous actions by citizens were unacceptably infrequent. Therefore, the education and training of citizens is necessary to further enhance autonomous CPR.

How to improve automated external defibrillator placement for out-of-hospital cardiac arrests: A case study

Introduction

In out-of-hospital cardiac arrests (OHCAs), the use of an automatic external defibrillator (AED) by a bystander remains low, as AEDs may be misplaced with respect to the locations of OHCAs. As the distribution of historical OHCAs is potentially predictive of future OHCA locations, the purpose of this study is to assess AED positioning with regard to past locations of OHCAs, in order to improve the efficiency of public access defibrillation programs.

Methods

This is a retrospective observational study from 2014 to 2018. The locations of historical OHCAs and AEDs were loaded into a geodata processing tool. Median distances between AEDs were collected, as well as the number and rates of OHCAs covered (distance of <100 meters from the nearest AED). Areas with high densities of uncovered OHCAs (hotspots) were identified in order to propose the placement of additional AEDs. Areas over-covered by AEDs (overlays) were also identified in order to propose the relocation of overlapping AEDs.

Results

There were 2,971 OHCA, 79.3% of which occurred at home, and 633 AEDs included in the study. The global coverage rate was 7.5%. OHCAs occurring at home had a coverage rate of 4.5%. Forty hotspots were identified, requiring the same number of additional AEDs. The addition of these would increase the coverage from 7.5% to 17.6%. Regarding AED overlays, 17 AEDs were found to be relocatable without reducing the AED coverage of historical OHCAs.

Discussion

This study confirms that geodata tools can assess AED locations and increase the efficiency of their placement. Historical hotspots and AED overlays should be considered, with the aim of efficiently relocating or adding AEDs. At-home OHCAs should become a priority target for future public access defibrillation programs as they represent the majority of OHCAs but have the lowest AED coverage rates.

Effectiveness of a video lesson for the correct use in an emergency of the automated external defibrillator (AED)

BACKGROUND AND AIM OF THE WORK

Every year around 275 thousand people in Europe and 420 thousand in the United States are affected by sudden cardiac arrest. Early electrical defibrillation before the arrival of emergency services can improve survival. Training the population to use the AED is essential. The training method currently in use is the BLSD course, which limits training to a population cohort and may not be enough to meet the requirements of the proposed Law no. 1839/2019. This study aims to verify the effectiveness of an online course that illustrates the practical use of the AED to a population of laypeople.

METHODS

An observational study was conducted to compare a lay population undergoing the view of a video spot and a cohort of people who had participated in BLSD Category A courses. The performances of the two groups were measured immediately after the course and 6 months later.

RESULTS

Overall, the video lesson reported positive results. Six months later the skills were partially retained. The cohort that followed the video lesson showed significant deterioration in the ability to correctly position the pads and in safety.

CONCLUSIONS

Although improved through significant reinforcements, the video spot represents a valid alternative training method for spreading defibrillation with public access and could facilitate the culture of defibrillation as required by the new Italian law proposal.

Which building types give optimal public access defibrillator coverage for out-of-hospital cardiac arrest?

INTRODUCTION

Public access defibrillation is a key component of the early links in the chain of survival. Despite growing numbers of PADs in the community, actual use remains poor, partly because of the difficulties in locating the nearest PAD. We aimed to establish the cover that would be provided if PADs were located in any given building type, which would enable the public to know where the nearest PAD was located.

METHODS

Mapping software was used to classify each and every building type in the South Central Ambulance Service region. The 52 commonest building types were then mapped to all cardiac arrest calls in the same geographical area from Jan 2014 - July 2018. The walking distance from each cardiac arrest to each nearest building type was calculated.

RESULTS

A total of 22,382 cardiac arrests were mapped to a total of 24,155 buildings considered suitable for potential PAD location. Post boxes ranked first in both urban and rural areas, covering 11.7% of cardiac arrests at 100 m and 85.6% of cardiac arrests at 500 m. In urban areas, bus shelters and telephone boxes also provided good coverage (9.7%, 9.5% @ 100 m; 69.2%, 71.9% @ 500 m respectively). In rural areas, good coverage was provided by nursing/care homes and pubs/bars (4.9%, 4.6% @ 100 m; 15.2%, 31.8% @ 500 m respectively).

CONCLUSION

Locating PADs at all post boxes would provide the most effective geographical coverage in both urban and rural areas according to building type. This may be an effective strategy to improve rapid PAD locating.

Prehospital cardiopulmonary resuscitation duration and neurological outcome after adult out-of-hospital cardiac arrest by location of arrest

BACKGROUND

Little is known about the association between prehospital cardiopulmonary resuscitation duration for adults with out-of-hospital cardiac arrest and outcome by the location of arrests. This study aimed to investigate the association between prehospital cardiopulmonary resuscitation duration and one-month survival with favourable neurological outcome.

METHODS

We analysed 276,391 adults aged 18 years and older with out-of-hospital cardiac arrest of medical origin before emergency medical service arrival. Prehospital cardiopulmonary resuscitation duration was defined as the time from emergency medical service-initiated cardiopulmonary resuscitation to prehospital return of spontaneous circulation or to hospital arrival. The primary outcome was one-month survival with favourable neurological outcome (cerebral performance category 1 or 2). The association between prehospital cardiopulmonary resuscitation duration and favourable neurological outcome was assessed using univariable and multivariable logistic regression analyses.

RESULTS

The proportion of favourable neurological outcomes was 2.3% in total, 7.6% in public locations, 1.5% in residential locations and 0.7% in nursing homes (P < 0.001). In univariable and multivariable logistic regression analyses, longer prehospital cardiopulmonary resuscitation duration was associated with poor neurological outcome, regardless of arrest location (P for trend < 0.001). Patients with shockable rhythm in both public and residential locations had better neurological outcome than those in nursing homes at any time point, and residential and public locations had a similar neurological outcome tendency among patients with shockable rhythm.

CONCLUSIONS

Longer prehospital cardiopulmonary resuscitation duration was independently associated with a lower proportion of patients with favourable neurological outcomes. Moreover, the association between prehospital cardiopulmonary resuscitation duration and neurological outcome differed according to the location of arrest and the first documented rhythm.

Out-of-hospital cardiac arrest at place of residence is associated with worse outcomes in patients admitted to intensive care. A post-hoc analysis of the targeted temperature management trial

BACKGROUND

The majority of out-of-hospital cardiac arrests (OHCAs) occur at place of residence, which is associated with worse outcomes in unselected prehospital populations. Our aim was to investigate whether location of arrest was associated with outcome in a selected group of initial survivors admitted to intensive care.

METHODS

This is a post-hoc analysis of the Targeted Temperature Management After Cardiac Arrest (TTM) trial, a multicenter controlled trial, randomizing 950 OHCA patients to an intervention of 33 °C or 36 °C. The location of cardiac arrest was defined as place of residence versus public place or other. The outcome measures were mortality and neurological outcome, as defined by the Cerebral Performance Category Scale, at 180 days.

RESULTS

Approximately half of 938 included patients arrested at place of residence (53%). Location groups did not differ with respect to age (P=0.11) or witnessed arrests (P=0.48) but bystander CPR was less common (P=0.02) at place of residence. OHCA at place of residence was associated with higher 180-day mortality (55% vs. 38%, P<0.001) and worse neurological outcome (61% vs. 43%, P<0.001) compared with a public place or other. After adjusting for known confounders, OHCA at place of residence remained an independent predictor of mortality (P=0.007).

CONCLUSIONS

Half of all initial survivors after OHCA admitted to intensive care had an arrest at place of residence which was independently associated with poor outcomes. Actions to improve outcomes after OHCA at place of residence should be addressed in future trials.