Neighborhood-level out-of-hospital cardiac arrest risk and the impact of local CPR interventions

Ventilation Rates and Capnography in Pediatric Out-of-Hospital Cardiac Arrest with Advanced Airways

OBJECTIVES

Ventilation is important in out-of-hospital cardiac arrest resuscitation; however, few studies describe ventilation rates during pediatric out-of-hospital cardiac arrest (pOHCA). Our objective was to characterize ventilations and end-tidal capnography (EtCO2) after advanced airway placement by emergency medical services (EMS) during pOHCA resuscitation.

METHODS

This was a retrospective cohort study that included pediatric (age <18 years) non-traumatic OHCA treated by an urban fire-based EMS system (Columbus Division of Fire, Columbus, Ohio) from April 2019 to December 2020. We identified ventilations delivered during resuscitation by manual review of continuous EtCO2 recorded by cardiac monitors. We also identified ventilations using automated detection algorithms previously validated in adult resuscitation. Mean ventilation rate and EtCO2 were summarized in one-minute (min) epochs from advanced airway insertion through end of resuscitation efforts. We compared return of spontaneous circulation (ROSC) vs non-ROSC ventilation rates using Student's t-tests. Cochran-Armitage test of trend was used to evaluate EtCO2 temporal trends. Associations between ROSC and EtCO2 were tested using a regression model.

RESULTS

We identified 38 pOHCA cases and 30 cases were included for ventilation analysis. Cases were primarily infants (0.7 years, IQR 0.17-2), male (52.6%) and African-American race (63.1%). Most pOHCAs were unwitnessed (65.8%) with non-shockable rhythms (94.8%) and infrequent bystander cardiopulmonary resuscitation (31.2%). Eight patients achieved ROSC (21.2%) and two patients survived (5.3%). Advanced airway attempts included supraglottic airway devices (71.1%), endotracheal intubation (7.8%) or both (7.8%). Ventilation rates ranged from 0-23 per minute. Automated ventilation detection algorithms performed well in pediatric ventilation detection where the mean standard error was 3.7mmHg in EtCO2 values and 1.3 per minute in ventilation rates. Ventilation rates differed between ROSC and non-ROSC groups (9.2 vs 6.9 per min, p < 0.001). Ranges of EtCO2 values included 0-100 mmHg during resuscitation. The EtCO2 trends over time differed between ROSC and non-ROSC groups (59.82 mmHg to 75.9 mmHg vs 20.7 mmHg to 19.0 mmHg, p < 0.01). EtCO2 was significantly associated with ROSC (OR 1.0 95% CI 1.00-1.01, p < 0.001).

CONCLUSIONS

These results offer one of the first perspectives of ventilation in pOHCA. Differences were observed in ventilation rates and EtCO2 trends between ROSC and non-ROSC cases.

Optimisation of the deployment of automated external defibrillators in public places in England

Background

Ambulance services treat over 32,000 patients sustaining an out-of-hospital cardiac arrest annually, receiving over 90,000 calls. The definitive treatment for out-of-hospital cardiac arrest is defibrillation. Prompt treatment with an automated external defibrillator can improve survival significantly. However, their location in the community limits opportunity for their use. There is a requirement to identify the optimal location for an automated external defibrillator to improve out-of-hospital cardiac arrest coverage, to improve the chances of survival.

Methods

This was a secondary analysis of data collected by the Out-of-Hospital Cardiac Arrest Outcomes registry on historical out-of-hospital cardiac arrests, data held on the location of automated external defibrillators registered with ambulance services, and locations of points of interest. Walking distance was calculated between out-of-hospital cardiac arrests, registered automated external defibrillators and points of interest designated as potential sites for an automated external defibrillator. An out-of-hospital cardiac arrest was deemed to be covered if it occurred within 500 m of a registered automated external defibrillator or points of interest. For the optimisation analysis, mathematical models focused on the maximal covering location problem were adapted. A de novo decision-analytic model was developed for the cost-effectiveness analysis and used as a vehicle for assessing the costs and benefits (in terms of quality-adjusted life-years) of deployment strategies. A meeting of stakeholders was held to discuss and review the results of the study.

Results

Historical out-of-hospital cardiac arrests occurred in more deprived areas and automated external defibrillators were placed in more affluent areas. The median out-of-hospital cardiac arrest - automated external defibrillator distance was 638 m and 38.9% of out-of-hospital cardiac arrests occurred within 500 m of an automated external defibrillator. If an automated external defibrillator was placed in all points of interests, the proportion of out-of-hospital cardiac arrests covered varied greatly. The greatest coverage was achieved with cash machines. Coverage loss, assuming an automated external defibrillator was not available outside working hours, varied between points of interest and was greatest for schools. Dividing the country up into 1 km2 grids and placing an automated external defibrillator in the centre increased coverage significantly to 78.8%. The optimisation model showed that if automated external defibrillators were placed in each points-of-interest location out-of-hospital cardiac arrest coverage levels would improve above the current situation significantly, but it would not reach that of optimisation-based placement (based on grids). The coverage efficiency provided by the optimised grid points was unmatched by any points of interest in any region. An economic evaluation determined that all alternative placements were associated with higher quality-adjusted life-years and costs compared to current placement, resulting in incremental cost-effectiveness ratios over £30,000 per additional quality-adjusted life-year. The most appealing strategy was automated external defibrillator placement in halls and community centres, resulting in an additional 0.007 quality-adjusted life-year (non-parametric 95% confidence interval 0.004 to 0.011), an additional expected cost of £223 (non-parametric 95% confidence interval £148 to £330) and an incremental cost-effectiveness ratio of £32,418 per quality-adjusted life-year. The stakeholder meeting agreed that the current distribution of registered publicly accessible automated external defibrillators was suboptimal, and that there was a disparity in their location in respect of deprivation and other health inequalities.

Conclusions

We have developed a data-driven framework to support decisions about public-access automated external defibrillator locations, using optimisation and statistical models. Optimising automated external defibrillator locations can result in substantial improvement in coverage. Comparison between placement based on points of interest and current placement showed that the former improves coverage but is associated with higher costs and incremental cost-effectiveness ratio values over £30,000 per additional quality-adjusted life-year.

Study registration

This study is registered as researchregistry5121.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: NIHR127368) and is published in full in Health and Social Care Delivery Research; Vol. 13, No. 5. See the NIHR Funding and Awards website for further award information.

Factors influencing support for the implementation of community-based out-of-hospital cardiac arrest interventions in high- and low-performing counties

Aim of the study

Survival to hospital discharge from out-of-hospital cardiac arrest (OHCA) after receiving treatment from emergency medical services (EMS) is less than 10% in the United States. Community-focused interventions improve survival rates, but there is limited information on how to gain support for new interventions or program activities within these populations. Using data from the RAndomized Cluster Evaluation of Cardiac ARrest Systems (RACE-CARS) trial, we aimed to identify the factors influencing emergency response agencies' support in implementing an OHCA intervention.

Methods

North Carolina counties were stratified into high-performing or low-performing counties based on the county's cardiac arrest volume, percent of bystander-cardiopulmonary resuscitation (CPR) performed, patient survival to hospital discharge, cerebral performance in patients after cardiac arrest, and perceived engagement in the RACE-CARS project. We randomly selected 4 high-performing and 3 low-performing counties and conducted semi-structured qualitative interviews with emergency response stakeholders in each county.

Results

From 10/2021 to 02/2022, we completed 29 interviews across the 7 counties (EMS (n = 9), telecommunications (n = 7), fire/first responders (n = 7), and hospital representatives (n = 6)). We identified three themes salient to community support for OHCA intervention: (1) initiating support at emergency response agencies; (2) obtaining support from emergency response agency staff (senior leadership and emergency response teams); and (3) and maintaining support. For each theme, we described similarities and differences by high- and low-performing county.

Conclusions

We identified techniques for supporting effective engagement of emergency response agencies in community-based interventions for OHCA improving survival rates. This work may inform future programs and initiatives around implementation of community-based interventions for OHCA.

Facilitating cardiopulmonary resuscitation training in high-risk areas of England: A study protocol

Introduction

Bystanders' interventions improve chances of survival from out-of-hospital cardiac arrest (OHCA) before Emergency Medical Services arrive. Some areas in England are of concern. These high-risk areas have a higher incidence of cardiac arrest combined with lower-than-average bystander CPR rates and are characterised by higher proportions of minority ethnic group residents and deprivation.Collaborating with people from the Black African and Caribbean and South Asian minority communities in deprived areas of England, we aim to develop and evaluate the implementation of theoretically informed intervention(s) to address factors contributing to lower bystander intervention rates.

Methods

The study is a collaborative realist enquiry, informed by the Theoretical Domains Framework and associated Behaviour Change Wheel. It consists of 1) a realist evidence synthesis to produce initial program theories developed from primary workshop data and published evidence. It will include identifying factors contributing to the issue and potential interventions to address them; 2) theoretically informed intervention development, using the initial program theories and behaviour change theory and 3) a realist mixed methods implementation evaluation with embedded feasibility.Public involvement (PPI) as study team and public advisory group members is key to this study.We will conduct realist evidence synthesis, qualitative and statistical analyses appropriate to the various methods used.

Dissemination

We will develop a dissemination plan and materials targeted to members of the public in high-risk areas as well as academic outputs. We will hold an event for participating community groups and stakeholders to share findings and seek advice on next steps.

Study registration

ISRCTN90350842. Registration date 28.03.2023. The study was registered after its start date.

Prevalence and Geographic Features of Patients Eligible for Extracorporeal Cardiopulmonary Resuscitation

OBJECTIVE

This study sought to identify Out of Hospital Cardiac Arrests (OHCA) eligible for Extracorporeal Cardiopulmonary Resuscitation (ECPR), use Geographic Information Systems (GIS) to investigate geographic patterns, and investigate if correlation between ECPR candidacy and Social Determinants of Health (SDoH) exist.

METHODS

This study is of emergency medical service (EMS) runs for OHCA to an urban medical center from January 1, 2016 to December 31, 2020. All runs were filtered to inclusion criteria for ECPR: age 18-65, initial shockable rhythm, and no return of spontaneous circulation within initial defibrillations. Address level data were mapped in a GIS. Cluster detection assessed for granular areas of high concentration. The Center for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI) was overlaid. The SVI ranges from 0-1 with higher values indicating increasing social vulnerability.

RESULTS

There were 670 EMS transports for OHCA during the study period. 12.7% (85/670) met inclusion criteria for ECPR. 90% (77/85) had appropriate addresses for geocoding. Three geographic clusters of events were detected. Two were residential areas and one was concentrated over a public use area of downtown Cleveland. The SVI for these locations was 0.79, indicative of high social vulnerability. Nearly half (32/77, 41.5%) occurred in neighborhoods with the highest level of social vulnerability (SVI ≥0.9).

CONCLUSION

A significant proportion of OHCAs were eligible for ECPR based on prehospital criteria. Utilizing GIS to map and analyze ECPR patients provided insights into the locations of these events and the SDoH that may be driving risk in these places.