Improving survival after out-of-hospital cardiac arrest requires new tools

Wolf Creek XVII part 3: Automated cardiac arrest diagnosis

Introduction

Automated cardiac arrest diagnosis offers the possibility to significantly shorten the interval between onset of out-of-hospital cardiac arrest (OHCA) and notification of EMS, providing the opportunity for earlier resuscitation and possibly increased survival.

Methods

Automated cardiac arrest diagnosis was one of six focus topics for the Wolf Creek XVII Conference held on June 14-17 2023 in Ann Arbor, Michigan, USA. Conference invitees included international thought leaders and scientists in the field of cardiac arrest resuscitation from academia and industry. Participants submitted via online survey knowledge gaps, barriers to translation and research priorities for each focus topic. Expert panels used the survey results and their own perspectives and insights to create and present a preliminary unranked list for each category that was debated, revised and ranked by all attendees to identify the top 5 for each category.

Results

Top knowledge gaps include the accuracy of automated OHCA detection technologies and the feasibility and reliability of automated EMS activation. The main barriers to translation are the risk of false positives potentially overburdening EMS, development and application costs of technology and the challenge of integrating new technology in EMS IT systems. The top research priorities are large-scale evaluation studies to measure real world performance and user research regarding the willingness to adopt these technologies.

Conclusion

Automated cardiac arrest diagnosis has the potential to significantly impact time to resuscitation and survival of OHCA because it could convert unwitnessed events into witnessed events. Validation and feasibility studies are needed. The specificity of the technology must be high not to overburden limited EMS resources. If adequate event classification is achieved, future research could shift toward event prediction, focusing on identifying potential digital biomarkers and signatures of imminent cardiac arrest. Implementation could be challenging due to high costs of development, regulatory considerations and instantiation logistics.

Inverse Association Between Bystander Use of Audiovisual Feedback From an Automated External Defibrillator and Return of Spontaneous Circulation

Background

Treatment with an automated external defibrillator (AED) improves outcome in out‐of‐hospital cardiac arrest (OHCA). Audiovisual feedback from an AED may assist bystanders achieve higher quality cardiopulmonary resuscitation. However, the association between audiovisual feedback and clinical outcomes is not well assessed in real‐life OHCA. The aim of this study was to assess the association between audiovisual feedback from an AED used in bystander resuscitation with rates of return of spontaneous circulation (ROSC) and 30‐day survival in a real‐life cohort of patients with OHCA.

Methods and Results

We included 325 patients treated with bystander AED use before arrival of emergency medical services during 2016 to 2019 from the Capital Region of Denmark. Patients were divided into a “feedback” and a “nonfeedback” group, depending on presence of audiovisual feedback from the AED. Audiovisual feedback was defined as voice prompts with continuous feedback to ongoing resuscitation. Rates of ROSC upon hospital admission and 30‐day survival were assessed, and univariate and multivariable models were applied to decide the association to audiovisual feedback. Multivariable models were adjusted for sex, age, primary heart rhythm, and location of OHCA. A total of 155 (48%) patients had a bystander AED applied with audiovisual feedback and 170 (52%) without audiovisual feedback. A lower rate of ROSC was found in the feedback group compared with the nonfeedback group (33% [n=51] versus 45% [n=76]; P =0.03). No association was observed between AV feedback and 30‐day survival (feedback=27% [n=42] and nonfeedback=31% [n=53]; P =0.49). In the unadjusted logistic regression model, audiovisual feedback was associated with a decreased chance of ROSC (odds ratio, 0.61; 95% CI, 0.38–0.95; P =0.03), which remained significant after adjusted analysis (odds ratio, 0.53; 95% CI, 0.29–0.97; P =0.04), whereas we found no significant association between audiovisual feedback and 30‐day survival in the unadjusted and adjusted analyses.

Conclusions

Audiovisual feedback from an AED used by bystanders was associated with a lower chance of ROSC at hospital admission, but we found no significant difference in 30‐day survival. Focus on early and correct bystander cardiopulmonary resuscitation and AED use remain key for OHCA survival.

Development of a Novel Framework to Propose New Strategies for Automated External Defibrillators Deployment Targeting Residential Out-Of-Hospital Cardiac Arrests: Application to the City of Milan

Public Access Defibrillation (PAD) is the leading strategy in reducing time to first defibrillation in cases of Out-Of-Hospital Cardiac Arrest (OHCA), but PAD programs are underperforming considering their potentiality. Our aim was to develop an analysis and optimization framework, exploiting georeferenced information processed with Geographic Information Systems (GISs), specifically targeting residential OHCAs. The framework, based on an historical database of OHCAs, location of Automated External Defibrillators (AEDs), topographic and demographic information, proposes new strategies for AED deployment focusing on residential OHCAs, where performance assessment was evaluated using AEDs “catchment area” (area that can be reached within 6 min walk along streets). The proposed framework was applied to the city of Milan, Lombardy (Italy), considering the OHCA database of four years (2015–2018), including 8152 OHCA, of which 7179 (88.06%) occurred in residential locations. The proposed strategy for AEDs deployment resulted more effective compared to the existing distribution, with a significant improvement (from 41.77% to 73.33%) in OHCAs’ spatial coverage. Further improvements were simulated with different cost scenarios, resulting in more cost-efficient solutions. Results suggest that PAD programs, either in brand-new territories or in further improvements, could significantly benefit from a comprehensive planning, based on mathematical models for risk mapping and on geographical tools.

Theoretical knowledge and psychomotor skill acquisition of basic life support training programme among secondary school students

BACKGROUND

The aim of the study is to evaluate the theoretical knowledge and psychomotor skill acquisition of basic life support (BLS) by a group of secondary school students in Nigeria pre and post BLS training.

METHODS

This was quasi-experimental study design with 210 participants. They were taught on adult BLS and all the participants practiced BLS on a Resusci-Anne manikin immediately after the training. Data were collected using American Heart Association (AHA) structured questionnaire and psychomotor skills checklist for BLS at baseline, and post BLS training.

RESULTS

The pre-training knowledge score was 1.9±1.4. This increased after the BLS training to 11.4±2.4, and the mean difference between the pre and post BLS training scores was 9.48571. Pre-training psychomotor skill score was 0.00±0.00, this increased to 8.9±1.9 after the training, and the mean difference was 8.90000. The knowledge and psychomotor skill difference between pre and post BLS training was significant (P<0.000).CONCLUSION: Most Nigerian secondary school students were not knowledgeable about BLS. Therefore, there is need for the creation of more awareness among the students.