Out of hospital cardiac arrest: Past, present, and future

Modeling and simulation of cardiovascular system under cardiac arrest for finding a more effective CPR technique

Cardio-Pulmonary Resuscitation (CPR) saves life. However, all the current CPR methods produce only one third to one quarter of the normal cardiac output and hence post-CPR survival has remained very poor. We report a better CPR technique exhibiting increased cardiac output as compared to existing techniques. Obviously, one cannot perform such studies on humans; therefore, we developed a fluidic model of the cardiovascular system under cardiac arrest. This enabled us to actuate different organs independently, sequentially and/or combinatorially to find the most effective CPR technique. Extensive simulations were performed using Simscape®. Our novel combination (combination-1) shows 10.75% improvement in peak aortic pressure and 8.3% improvement in peak cardiac flow-rate with 120 compressions per minute with respect to the baseline CPR method as per AHA/ERC guidelines. Similar improvements were observed at compression rates of 80 and 100 per minute. In addition to finding a more effective CPR technique, we also present our passive cardiovascular model as an open-source software package where different preconditions and modalities can be set prior to conducting the cardiovascular simulations. Thus, it may also serve as a simulator to explore the cardiovascular system behaviors as well as the effects of different contributing factors.

Real-time hemodynamic responses to epinephrine and their association with ROSC in out-of-hospital cardiac arrest

AIM

This study investigated the association between changes in diastolic blood pressure (DBP), mean arterial pressure (MAP), systolic blood pressure (SBP) following epinephrine administration and return of spontaneous circulation (ROSC) in patients with Out-of-hospital cardiac arrest (OHCA).

METHODS

This retrospective observational study included patients with OHCA treated at a tertiary hospital. Invasive arterial blood pressure monitoring data were recorded during resuscitation in the emergency department. The primary outcome was sustained ROSC, defined as ROSC maintained for at least 20 min. Blood pressure changes were analysed at 15 s intervals. Delta blood pressure was defined as the difference between each blood pressure at 15-0 s before and 165-180 s after epinephrine administration. The association between delta DBP, delta MAP, delta SBP, and sustained ROSC was analysed.

RESULTS

Among 160 patients included in the analysis, patients who achieved sustained ROSC exhibited significantly greater changes in DBP and MAP than those who did not. Median differences in delta DBP and delta MAP between ROSC and no-ROSC groups were 13.7 mmHg (95% confidence interval (CI): 11.3-13.8, p = 0.001) and 14.9 mmHg (95% CI: 12.6-15.7, p = 0.001), respectively. A restricted cubic spline curve showed positive associations of delta DBP and delta MAP with sustained ROSC probability. Multivariable analysis showed adjusted odds ratios of 1.02 (95% CI: 1.00-1.04, p = 0.040) for delta DBP and 1.01 (95% CI: 1.00-1.03, p = 0.010) for delta MAP.

CONCLUSION

Greater delta DBP and delta MAP following epinephrine administration during cardiopulmonary resuscitation were associated with higher likelihood of achieving sustained ROSC in patients with OHCA.

Evaluating the impact of AED training on nurses' emergency response capabilities in China: a cross-sectional survey

BACKGROUND

Automated external defibrillators (AEDs) are critical in emergency cardiac care. However, significant gaps in nurses' knowledge and confidence in using AEDs limit their effectiveness. This study explores the current status of AED training and its impact on nurses' emergency response capabilities across municipal-level and county-level hospitals in China.

METHODS

A cross-sectional survey was conducted from May 20 to August 1, 2024, via telephone and electronic questionnaires in the emergency, intensive care unit (ICU), and general wards of 12 municipal and county-affiliated hospitals. A total of 451 questionnaires were distributed, with 440 valid responses (response rate: 97.6%). Data were analyzed using chi-square tests and multivariate logistic regression in SPSS 24.0 (P < 0.05 considered significant). Key factors influencing AED knowledge and confidence included additional training, hands-on drills, and defibrillation experience.

RESULTS

Only 17.5% of nurses demonstrated sufficient AED knowledge, and 15.9% reported confidence in defibrillation. In municipal-level hospitals, nurses outperformed county hospitals in training access and proficiency. Additional training (OR = 24.50, p < 0.0001) and practical drills (OR = 12.36, p < 0.0001) were strongly associated with improved knowledge and confidence.

CONCLUSIONS

The study highlights the need for enhanced AED training, emphasizing practical drills and scenario-based simulations, particularly in resource-limited county hospitals. Targeted strategies could significantly improve nurses' emergency response capabilities, contributing to better cardiac arrest outcomes.

Survival rates with favorable neurological outcomes after in-hospital and out-of-hospital cardiac arrest: A prospective cohort study

OBJECTIVES

To evaluate the survival rates with favorable neurological outcomes among patients who experienced in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA).

DESIGN

This prospective cohort study assessed 554 adult patients with IHCA or OHCA referred to Hamad General Hospital, Qatar, between February 2015 and November 2021. Neurologic outcomes were measured using the Cerebral Performance Category (CPC) score. Survival rate and neurologic status were re-evaluated at 28 days, hospital discharge, and one year after cardiac arrest (CA).

FINDINGS

For all participants, the hospital discharge and one-year survival rates with a favorable neurological outcome (CPC ≤ 2) were 18.5 % and 19.5 %, respectively. Specifically, among patients with IHCA, the rates were 20.5 % and 19 %, while in patients with OHCA, the rates were 16.4 % and 19.9 %, respectively. Multivariate regression analysis indicated that factors male sex (OR: 2.129, 95 % CI: 1.168-3.881, P = 0.014), initial shockable rhythm (OR: 1.691, 95 % CI: 1.024-2.788, P = 0.041), and the use of ECPR (OR: 1.944, 95 % CI: 1.178-3.209, P = 0.009) were associated with increased likelihood of survival with favorable neurological outcomes at 28 days. Conversely, older age, presence of comorbidities, infection, higher APACHE II score, longer hospital stays, and undergoing tracheostomy were linked to decreased chances of survival with favorable neurological outcomes at different time points.

CONCLUSION

Survival with good neurological outcomes after OHCA was 20.3 %, 16.4 %, and 19.9 % at 28 days, hospital discharge, and one year, respectively. Among patients with IHCA, survival with good neurological outcomes was 20.5 %, 20.5 %, and 19 % at 28 days, hospital discharge, and one year, respectively.

IMPLICATIONS FOR CLINICAL PRACTICE

Care of CA patients in a cardiac arrest center is associated with improved long-term survival with favorable neurological outcomes. Prioritizing early intervention for shockable rhythms and utilizing ECPR where appropriate could enhance patient prognosis.

Understanding cardiac arrest dispatch of physician-paramedic critical care prehospital teams: a survey-based evaluation

BACKGROUND

Appropriate dispatch of critical care teams to out-of-hospital cardiac arrest (OHCA) has been identified as a research priority emergency care in the UK. The study aimed to understand the criteria informing the decision to dispatch a critical care physician-paramedic prehospital team to OHCA in one UK region.

METHODS

An invitation to participate in an anonymised online survey was sent by email to clinicians and non-clinicians working on the critical care (physician-paramedic) dispatch desk for the East of England Ambulance Service NHS Trust between June and July 2023. Demographic data relating to the experience of the dispatchers were collected alongside evaluating the effect of 15 predetermined criteria on OHCA dispatch (based on a pilot survey) on their decision to dispatch a physician-paramedic team. Responses to closed-end questions were calculated as percentages. A compulsory free text question on dispatching the physician-paramedic team was included. Free text data were interpreted by one author and the interpretation reviewed by all authors.

RESULTS

20 respondents (19 critical care paramedics and one non-clinical dispatcher) participated, yielding a 79% response rate for clinical and 17% for non-clinical dispatchers. 'Witnessed cardiac arrest' and return of spontaneous circulation achieved on scene were criteria used by 100% of respondents in informing dispatch of a physician-paramedic team to OHCA. 10 of the 15 preidentified criteria were considered important in their decision-making by at least 75% of respondents. 'Age' was considered as more than just a number, instead incorporating both the nuances of a paediatric cardiac arrest and the importance of physiological reserve and frailty.

CONCLUSION

The only 100% agreement in dispatch criteria was 'witnessed arrest'. Otherwise, variation existed and additional information, like identification of frailty, was gathered to support nuanced decision-making. Wider research across the UK would help identify factors and commonalities in OHCA physician-paramedic dispatch to target improved survival rates.

Cardiac arrest in Australia: a call to action

Sudden cardiac arrest (SCA) represents a major cause of premature mortality globally, with an enormous effect on victims, families, and communities. Cardiac arrest prevention should be considered a health priority in Australia. A multi-faceted strategy will include community awareness, improved fundamental mechanistic understanding, preventive strategies, implementation of best-practice resuscitation strategies, secondary risk assessment of family members, and development of (near) real-time registries to inform areas of need and assess the effectiveness of interventions. Challenges of patient access to specialised care and equity within the Australian and New Zealand healthcare system should also be recognised.

Automated loss of pulse detection on a consumer smartwatch

Out-of-hospital cardiac arrest is a time-sensitive emergency that requires prompt identification and intervention: sudden, unwitnessed cardiac arrest is nearly unsurvivable1-3. A cardinal sign of cardiac arrest is sudden loss of pulse4. Automated biosensor detection of unwitnessed cardiac arrest, and dispatch of medical assistance, may improve survivability given the substantial prognostic role of time3,5, but only if the false-positive burden on public emergency medical systems is minimized5-7. Here we show that a multimodal, machine learning-based algorithm on a smartwatch can reach performance thresholds making it deployable at a societal scale. First, using photoplethysmography, we show that wearable photoplethysmography measurements of peripheral pulselessness (induced through an arterial occlusion model) manifest similarly to pulselessness caused by a common cardiac arrest arrhythmia, ventricular fibrillation. On the basis of the similarity of the photoplethysmography signal (from ventricular fibrillation or arterial occlusion), we developed and validated a loss of pulse detection algorithm using data from peripheral pulselessness and free-living conditions. Following its development, we evaluated the end-to-end algorithm prospectively: there was 1 unintentional emergency call per 21.67 user-years across two prospective studies; the sensitivity was 67.23% (95% confidence interval of 64.32% to 70.05%) in a prospective arterial occlusion cardiac arrest simulation model. These results indicate an opportunity, deployable at scale, for wearable-based detection of sudden loss of pulse while minimizing societal costs of excess false detections7.

Out-of-Hospital Cardiac Arrest Ambulance Delay Zones and AED Placement in a Southern Brazilian City

Out-of-hospital cardiac arrests (OHCAs) have high mortality rates, worsened by limited access to automated external defibrillators (AEDs). This study analyzed OHCA response times, identified areas with prolonged ambulance travel times, and proposed optimal AED locations in a medium-sized city in southern Brazil. Data from 278 non-traumatic OHCA cases (2019-2022) in patients over 18 years old, with ambulance response times under 20 min, were included. Spatial survival analysis assessed the probability of exceeding the recommended 5-min (300 s) ambulance response time. The maximal covering location problem identified 100 strategic AED sites within a 150-s reach for bystanders. AED and ambulance travel times were compared using the Wilcoxon test (p < 0.01). Defibrillation occurred in 89 cases (31.01%), and bystander CPR was performed in 149 cases (51.92%). Despite these efforts, 77% of patients died. The median ambulance response time was 11.63 min, exceeding 5 min in most cases, particularly at peak times like 11 a.m. AED placement in selected locations could cover 76% of OHCA occurrences, with a mean AED travel time of 320 s compared to 709 s for ambulances. Strategic AED placement could enhance early defibrillation and improve survival outcomes.

Revealing the decision-making practices in automated external defibrillator deployment: insights from Shanghai, China

In recent years, the government has promoted the increased deployment of automated external defibrillators (AEDs) in public places with dense crowds, which is of great significance for ensuring that residents enjoy equal health rights. However, it is still unclear what factors decision-makers take into account when formulating deployment plans and whether these factors are related to local characteristics such as population distribution and socioeconomic conditions. Taking Shanghai, China as the research area, we adopted the kernel density estimation and spatial autocorrelation analysis to explore the spatial distribution characteristics of AEDs. We constructed a geographically weighted regression (GWR) model to identify the key factors influencing AED deployment. The results showed that AEDs in Shanghai presented obvious clustering distribution characteristics. The GWR model found that the factors considered by decision-makers in different regions when deploying AEDs followed the guidance of existing policies. It was also found that decision-makers in Shanghai mainly deployed more devices in areas with a high density of the elderly population, dense transportation networks, cultural and educational places, and transportation hubs with large population flows. However, it was observed that the city center might lack sufficient preparation for the elderly group. In order to allocate emergency medical resources more reasonably, it is very important to determine the practices of decision-makers in deploying AEDs. The GWR has shown the potential to evaluate and guide the local implementation of deployment plans.

Language barriers in emergency ambulance calls for cardiac arrest: Cases of missing vital information

In medical emergencies, phoning the ambulance service constitutes a high-stakes interaction. Call-takers rely on callers to provide information about the patient so they can promptly recognise the medical problem and take swift action to remedy it. When a language barrier exists between the call-taker and caller, this can add a further challenge, given that third-party interpreters are rarely engaged, especially for time-critical conditions such as cardiac arrest. Research in cardiac arrest calls has found that language barrier calls experience longer delays to critical points such as recognition of cardiac arrest and commencement of resuscitation. This study aimed to understand, in the absence of interpreters, the interactional challenges that emerged in language barrier emergency calls, as parties worked to communicate the nature of the medical problem. Based on a critical conversation analysis approach, we conducted fine-grained analysis of interactions in audio recordings and transcripts of 33 language barrier calls from an Australian ambulance service in 2019. We found that call takers regularly failed to recognise that the patient had a cardiac arrest. Non-fluent-English callers often provided vital information about the patient, which could have led to cardiac arrest recognition by the call-taker, however such information was missed if it was delivered in an unsolicited or atypical way. Opportunities to recognise cardiac arrest were also missed when call-takers did not probe further after such information was provided or did not provide enough interactional space for callers to complete their turns. We found that the main reason for delays in recognising cardiac arrest was a lack of mutual understanding, which most of the time seemed to remain unbeknownst to participants. The study makes recommendations for emergency medical dispatch centres to cater for language barrier calls, with the goal of fostering a more inclusive prehospital care system and addressing health disparities for non-fluent-English speakers.

Post-Cardiac arrest outcome prediction using machine learning: A systematic review and meta-analysis

BACKGROUND

Early and reliable prognostication in post-cardiac arrest patients remains challenging, with various factors linked to return of spontaneous circulation (ROSC), survival, and neurological results. Machine learning and deep learning models show promise in improving these predictions. This systematic review and meta-analysis evaluates how effective these approaches are in predicting clinical outcomes at different time points using structured data.

METHODS

This study followed PRISMA guidelines, involving a comprehensive search across PubMed, Scopus, and Web of Science databases until March 2024. Studies aimed at predicting ROSC, survival (or mortality), and neurological outcomes after cardiac arrest through the application of machine learning or deep learning techniques with structured data were included. Data extraction followed the guidelines of the CHARMS checklist, and the bias risk was evaluated using PROBAST tool. Models reporting the AUC metric with 95 % confidence intervals were incorporated into the quantitative synthesis and meta-analysis.

RESULTS

After extracting 2,753 initial records, 41 studies met the inclusion criteria, yielding 97 machine learning and 16 deep learning models. The pooled AUC for predicting favorable neurological outcomes (CPC 1 or 2) at hospital discharge was 0.871 (95 % CI: 0.813 - 0.928) for machine learning models and 0.877 (95 % CI: 0.831-0.924) across deep learning algorithms. For survival prediction, this value was found to be 0.837 (95 % CI: 0.757-0.916). Considerable heterogeneity and high risk of bias were observed, mainly attributable to inadequate management of missing data and the absence of calibration plots. Most studies focused on pre-hospital factors, with age, sex, and initial arrest rhythm being the most frequent features.

CONCLUSION

Predictive models utilizing AI-based approaches, including machine and deep learning models exhibit enhanced effectiveness compared to previous regression algorithms, but significant heterogeneity and high risk of bias limit their dependability. Evaluating state-of-the-art deep learning models tailored for tabular data and their clinical generalizability can enhance outcome prediction after cardiac arrest.

BComparison of supraglottic airway device vs. endotracheal intubation for initial airway management in out-of-hospital cardiac arrest: a systematic review and meta-analysis

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) is characterized by the cessation of mechanical cardiac activity and voluntary circulation occurring outside of a hospital setting, making it the leading cause of death worldwide. Recently, the optimal approach to airway management has been a subject of controversy.

METHODS

Follow PRISMA guidelines for systematic evaluation and meta-analysis. The primary outcome was survival assessed by 4 measures: Restoration of spontaneous circulation, survival to hospital or emergency department, evaluation of functional recovery after PCR (measured at both discharge and 3 months after PCR), and neurological function score at discharge.

RESULTS

A total of 6 RCTs (14,205 patients) were included in the systematic review and 4 RCTs (13,053 patients) were included in the meta-analysis. 5 studies (83.3%)of RCTs with ETI controls were notable for their high quality, with low risk of bias judged in all 7 domains of the risk assessment scale. Showed an advantage of SGA (compared to ETI) with potential for ROSC (95% CI [1.02 to 1.18], I2 = 48%, p = 0.01) and survival to hospital or emergency department(95% CI [1.01 to 1.17], I2 = 12%, p = 0.02).

CONCLUSIONS

This systematic review and meta-analysis found a significant association between SGA and the possibility of obtaining ROSC and reaching the hospital or emergency department after CPR in OHCA.

Characteristics of Helicopter Emergency Medical Services (HEMS) Interventions for Burn Patients-A Four-Year Retrospective Analysis

Background: The World Health Organization (WHO) estimates that 180,000 patients die from burns every year, which is considered a serious public health issue. Patients with burns require immediate pre-hospital care and transport to specialized treatment facilities. The aim of this study was to outline the profile of the burn patient from the perspective of the Polish Medical Air Rescue (PMAR), as well as to analyze the medical procedures being implemented. Methods: The study includes 2154 interventions by air emergency medical teams (AEMS) which provided aid for burn patients. The analysis covered the period from 2018 to 2022, including nationwide data made available from the IT systems of the PMAR. Statistical design was used, allowing for correlations of variables, at a significance level of p < 0.05. Results: Patients' ages ranged from 1 month to 96 years (mean 35.05; SD ± 26.88). Adult patients (n = 1409; 65.41%) constituted the vast majority. The number of interventions to children below 1-year-old was noticeable (n = 394; 18.29%). Men were the most likely to suffer burns, up to three times more often than women (n = 1574, 73.07% vs. n = 570, 26.46%. T29-burns to multiple body areas (n = 890)-and T21-burns to the trunk (n = 255)-were most frequently reported as diagnoses according to the ICD-10 classification. A statistically significant association was found between age group and ICD-10 diagnosis (p < 0.001). The vast majority of patients were transported from the scene directly to Burn Treatment Centers (n = 1373; 63.74%). Treatment of pain by helicopter emergency medical services (HEMS) crews appeared to be effective (p < 0.001), and other interventions consisted of administering medications-ketamine (23.72%), rocuronium bromide (15.78%), propofol (14.02%)-and procedures such as sedation (30.87%), as well as intubation (13.42%) and mechanical ventilation (13.23%). Conclusions: The burn patient profile indicates men with a mean age of 35 years. Nevertheless, HEMS crews often carry out missions to infants and newborns. The most common diagnosis was extensive body burns. In 63.74% of the missions, patients were transported to the Burn Treatment Center. The HEMS crews implement effective pharmacological analgesia, and handle rescue medications and procedures to stabilize the patient's condition.

The relationship between race and emergency medical services resuscitation intensity for those in refractory-arrest

Background

Previous studies have reported race-based health disparities in North America. It is unknown if emergency medical service (EMS) treatment of out-of-hospital cardiac arrest (OHCA) varies based on race. We sought to compare markers of resuscitation intensity among different racial groups.

Methods

Using data of adult EMS-treated OHCAs from the Trial of Continuous or Interrupted Chest Compressions During CPR, we analyzed data from participants for whom on-scene return of spontaneous circulation (ROSC) was not achieved. We fit multivariate regression models using a generalized estimating equation, to estimate the association between patient race (White vs. Black vs. "Other") and the following markers for resuscitation intensity: (1) resuscitation attempt duration; (2) intra-arrest transport; (3) number of epinephrine doses; (4) EMS arrival-to-CPR interval, and (5) 9-1-1 to first shock.

Results

From our study cohort of 5370 cases, the median age was 65 years old (IQR: 53-78), 2077 (39 %) were women, 2121 (39 %) were Black, 596 (11 %) were "Other race", 2653 (49 %) were White, and 4715 (88 %) occurred in a private location. With reference to White race, Black race was associated with a longer resuscitation attempt duration and a lower number of epinephrine doses; Black and "Other" race were both associated with a lower odds of intra-arrest transport.

Conclusion

We identified race-based differences in EMS resuscitation intensity for OHCA within a North American cohort, although 40% of race data was missing from this dataset. Future research investigating race-based differences in OHCA management may be warranted.

A Call to Action to Improve Cardiac Arrest Outcomes: A Report From the National Summit for Cardiac Arrest

Sudden cardiac arrest (SCA) represents a major cause of premature mortality globally, with enormous impact and financial cost to victims, families, and communities. SCA prevention should be considered a health priority in Australia. National Cardiac Arrest Summits were held in June 2022 and March 2023, with inclusion from multi-faceted endeavours related to SCA prevention. It was agreed to establish a multidisciplinary Australian Sudden Cardiac Arrest Alliance (AuSCAA) working group charged with developing a national unified strategy, with clear and measurable quality indicators and standardised outcome measures, to amplify the goal of SCA prevention throughout Australia. A multi-faceted prevention strategy will include i) endeavours to progress community awareness, ii) improved fundamental mechanistic understanding, iii) implementation of best-practice resuscitation strategies for all demographics and locations, iv) secondary risk assessment directed to family members, and v) development of (near) real-time registry of cardiac arrest cases to inform areas of need and effectiveness of interventions. Together, we can and should reduce the impact of SCA in Australia.

Outcomes of an extracorporeal cardiopulmonary resuscitation (ECPR) program for in- and out-of-hospital cardiac arrest in a tertiary hospital in Spain

OBJECTIVE

To analyze if the implementation of a multidisciplinary extracorporeal cardiopulmonary resuscitation (ECPR) program in a tertiary hospital in Spain is feasible and could yield survival outcomes similar to international published experiences.

DESIGN

Retrospective observational cohort study.

SETTING

One tertiary referral university hospital in Spain.

PATIENTS

All adult patients receiving ECPR between January 2019 and April 2023.

INTERVENTIONS

Prospective collection of variables and follow-up for up to 180 days.

MAIN VARIABLES OF INTEREST

To assess outcomes, survival with good neurological outcome defined as a Cerebral Performance Categories scale 1-2 at 180 days was used. Secondary variables were collected including demographics and comorbidities, cardiac arrest and cannulation characteristics, ROSC, ECMO-related complications, survival to ECMO decannulation, survival at Intensive Care Unit (ICU) discharge, survival at 180 days, neurological outcome, cause of death and eligibility for organ donation.

RESULTS

Fifty-four patients received ECPR, 29 for OHCA and 25 for IHCA. Initial shockable rhythm was identified in 27 (50%) patients. The most common cause for cardiac arrest was acute coronary syndrome [29 (53.7%)] followed by pulmonary embolism [7 (13%)] and accidental hypothermia [5 (9.3%)]. Sixteen (29.6%) patients were alive at 180 days, 15 with good neurological outcome. Ten deceased patients (30.3%) became organ donors after neuroprognostication.

CONCLUSIONS

The implementation of a multidisciplinary ECPR program in an experienced Extracorporeal Membrane Oxygenation center in Spain is feasible and can lead to good survival outcomes and valid organ donors.

Out-of-hospital cardiac arrest outcomes' determinants: an Italian retrospective cohort study based on Lombardia CARe

This study on the Lombardia Cardiac Arrest Registry (Lombardia CARe,) the most complete nationwide out-of-hospital cardiac arrest (OHCA) registry in Italy, aims at evaluating post-OHCA intra-hospital mortality risk according to patient's characteristics and emergency health service management (EMS), including level of care of first-admission hospital. Out of 12,581 patients included from 2015 to 2022, we considered 1382 OHCA patients admitted alive to hospital and survived more than 24 h. We estimated risk ratios (RRs) of intra-hospital mortality through log-binomial regression models adjusted by patients' and EMS characteristics. The study population consisted mainly of males (66.6%) most aged 60-69 years (24.7%) and 70-79 years (23.7%). Presenting rhythm was non-shockable in 49.9% of patients, EMS intervention time was less than 10 min for 30.3% of patients, and cardiopulmonary resuscitation (CPR) was performed for less than 15 min in 29.9%. Moreover, 61.6% of subjects (n = 852) died during hospital admission. Intra-hospital mortality is associated with non-shockable presenting rhythm (RR 1.27, 95% CI 1.19-1.35) and longer CPR time (RR 1.39, 95% CI 1.28-1.52 for 45 min or more). Patients who accessed to a secondary vs tertiary care hospital were more frequently older, with a non-shockable presenting rhythm and longer EMS intervention time. Non-shockable presenting rhythm accounts for 27% increased risk of intra-hospital death in OHCA patients, independently of first-access hospital level, thus demonstrating that patients' outcomes depend only by intrinsic OHCA characteristics and Health System's resources are utilised as efficiently as possible.

The impact of time to defibrillation on return of spontaneous circulation in out-of-hospital cardiac arrest patients with recurrent shockable rhythms

OBJECTIVE

Optimal timing for subsequent defibrillation attempts for Out-of-hospital cardiac arrest (OHCA) patients with recurrent VF/pVT is uncertain. We investigated the relationship between VF/pVT duration and return of spontaneous circulation (ROSC) in OHCA patients with recurrent shockable rhythms.

METHODS

We analyzed data from the Salt Lake City Fire Department (SLCFD) spanning from 2012 to 2023. The implementation of rhythm-filtering technology since 2011 enabled real-time rhythm interpretation during CPR, with local protocols allowing early defibrillation for recurrent/refractory VF/pVT cases. We included patients experiencing four or five episodes of VF and pVT rhythms and employed generalized estimating equation (GEE) regression analysis to examine the association between VF/pVT durations preceding recurrent defibrillation and return of spontaneous circulation (ROSC).

RESULTS

Analysis of 622 appropriate shocks showed that patients achieving ROSC had significantly shorter median VF/pVT duration than those who did not achieve ROSC (0.83 minutes vs. 1.2 minutes, p = 0.004). Adjusted analysis of those with 4 VF/pVT episodes (N = 142) revealed that longer VF/pVT durations were associated with lower odds of achieving ROSC (odds ratio: 0.81, 95% CI: 0.72-0.93, p = 0.005). Every one-minute delay in intra-arrest defibrillation is predicted to decrease the likelihood of achieving ROSC by 19%.

CONCLUSION

Every one-minute increase in intra-arrest VF/pVT duration was associated with a statistically significant 19% decrease in the chance of achieving ROSC. This highlights the importance of reducing time to shock in managing recurrent VF/pVT. The findings suggest reevaluating the current recommendations of two minutes intervals for rhythm check and shock delivery.

Challenges and best practices of dispatcher-assisted cardiopulmonary resuscitation: A scoping review protocol

Introduction

Improved survival from out-of-hospital cardiac arrest with good neurological outcome was observed in association with dispatcher-assisted cardiopulmonary resuscitation, increasing the number of bystander-initiated resuscitations and minimizing the no-flow time in the first minutes of cardiac arrest.

Objective

The objective of this scoping review is to map and summarise the existing literature on dispatcher-assisted cardiopulmonary resuscitation, focusing on reported experiences, challenges, and best practices, highlighting strategies that could improve the provision of cardiopulmonary resuscitation instructions to bystanders during out-of-hospital cardiac arrest.

Inclusion criteria

Studies related to dispatcher-assisted cardiopulmonary resuscitation, involving human subjects, with an English abstract. The concept of interest is focused on the methods of provision of dispatcher-assisted cardiopulmonary resuscitation analysing specific experiences of implementation, challenges, and best practices, and can be generalized to any country; cultural factors, geographic features, and specific racial or gender-based differences will be analysed and discussed.

Methods

Four databases (PubMed, Embase, Cumulative Index to Nursing & Allied Health Literature, and the Cochrane Library) will be searched for studies published from 2018 to 2023. All study designs, including experimental and observational studies, will be assessed for inclusion. Titles and abstracts of identified citations will be screened for inclusion; subsequently, full texts of potentially relevant sources will be assessed for inclusion by two reviewers. Any disagreements between the reviewers will be resolved through discussion. Relevant grey literature (conference proceedings, government documents, and theses) will be analysed and included. Data will be extracted in a standardized form, following Joanna Briggs Institute recommendations. Results will be synthesized and reported using a narrative approach, categorising findings into themes related to the effectiveness of dispatcher-assisted cardiopulmonary resuscitation, challenges, and best practices.

Effects of a Serious Smartphone Game on Nursing Students' Theoretical Knowledge and Practical Skills in Adult Basic Life Support: Randomized Wait List-Controlled Trial

BACKGROUND

Retention of adult basic life support (BLS) knowledge and skills after professional training declines over time. To combat this, the European Resuscitation Council and the American Heart Association recommend shorter, more frequent BLS sessions. Emphasizing technology-enhanced learning, such as mobile learning, aims to increase out-of-hospital cardiac arrest (OHCA) survival and is becoming more integral in nursing education.

OBJECTIVE

The aim of this study was to investigate whether playing a serious smartphone game called MOBICPR at home can improve and retain nursing students' theoretical knowledge of and practical skills in adult BLS.

METHODS

This study used a randomized wait list-controlled design. Nursing students were randomly assigned in a 1:1 ratio to either a MOBICPR intervention group (MOBICPR-IG) or a wait-list control group (WL-CG), where the latter received the MOBICPR game 2 weeks after the MOBICPR-IG. The aim of the MOBICPR game is to engage participants in using smartphone gestures (eg, tapping) and actions (eg, talking) to perform evidence-based adult BLS on a virtual patient with OHCA. The participants' theoretical knowledge of adult BLS was assessed using a questionnaire, while their practical skills were evaluated on cardiopulmonary resuscitation quality parameters using a manikin and a checklist.

RESULTS

In total, 43 nursing students participated in the study, 22 (51%) in MOBICPR-IG and 21 (49%) in WL-CG. There were differences between the MOBICPR-IG and the WL-CG in theoretical knowledge (P=.04) but not in practical skills (P=.45) after MOBICPR game playing at home. No difference was noted in the retention of participants' theoretical knowledge and practical skills of adult BLS after a 2-week break from playing the MOBICPR game (P=.13). Key observations included challenges in response checks with a face-down manikin and a general neglect of safety protocols when using an automated external defibrillator.

CONCLUSIONS

Playing the MOBICPR game at home has the greatest impact on improving the theoretical knowledge of adult BLS in nursing students but not their practical skills. Our findings underscore the importance of integrating diverse scenarios into adult BLS training.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT05784675); https://clinicaltrials.gov/study/NCT05784675.

Blockchain technology in Cardiovascular Medicine: a glance to the future? Results from a social media survey and future perspectives

The leverage of digital facilities in medicine for disease diagnosis, monitoring, and medical history recording has become increasingly pivotal. However, the advancement of these technologies poses a significant challenge regarding data privacy, given the highly sensitive nature of medical information. In this context, the application of Blockchain technology, a digital system where information is stored in blocks and each block is linked to the one before, has the potential to enhance existing technologies through its exceptional security and transparency. This paradigm is of particular importance in cardiovascular medicine, where the prevalence of chronic conditions leads to the need for secure remote monitoring, secure data storage and secure medical history updating. Indeed, digital support for chronic cardiovascular pathologies is getting more and more crucial. This paper lays its rationale in three primary aims: 1) to scrutinize the existing literature for tangible applications of blockchain technology in the field of cardiology; 2) to report results from a survey aimed at gauging the reception of blockchain technology within the cardiovascular community, conducted on social media; 3) to conceptualize a web application tailored specifically to cardiovascular care based on blockchain technology. We believe that Blockchain technology may contribute to a breakthrough in healthcare digitalization, especially in the field of cardiology; in this context, we hope that the present work may be inspiring for physicians and healthcare stakeholders.

Impact of the COVID-19 pandemic on Canadian emergency medical system management of out-of-hospital cardiac arrest: A retrospective cohort study

AIM

We sought to describe the impact of the COVID-19 pandemic on the care provided by Canadian emergency medical system (EMS) clinicians to patients suffering out of hospital cardiac arrest (OHCA), and whether any observed changes persisted beyond the initial phase of the pandemic.

METHODS

We analysed cases of adult, non-traumatic, OHCA from the Canadian Resuscitation Outcome Consortium (CanROC) registry who were treated between January 27th, 2018, and December 31st, 2021. We used adjusted regression models and interrupted time series analysis to examine the impact of the COVID-19 pandemic (January 27th, 2020 - December 31st, 2021)on the care provided to patients with OHCA by EMS clinicians.

RESULTS

There were 12,947 cases of OHCA recorded in the CanROC registry in the pre-COVID-19 period and 17,488 during the COVID-19 period. We observed a reduction in the cumulative number of defibrillations provided by EMS (aRR 0.91, 95% CI 0.89 - 0.93, p < 0.01), a reduction in the odds of attempts at intubation (aOR 0.33, 95% CI 0.31 - 0.34, p < 0.01), higher rates of supraglottic airway use (aOR 1.23, 95% CI 1.16-1.30, p < 0.01), a reduction in vascular access (aOR for intravenous access 0.84, 95% CI 0.79 - 0.89, p < 0.01; aOR for intraosseous access 0.89, 95% CI 0.82 - 0.96, p < 0.01), a reduction in the odds of epinephrine administration (aOR 0.89, 95% CI 0.85 - 0.94, p < 0.01), and higher odds of resuscitation termination on scene (aOR 1.38, 95% CI 1.31 - 1.46, p < 0.01). Delays to initiation of chest compressions (2 min. vs. 3 min., p < 0.01), intubation (16 min. vs. 19 min., p = 0.01), and epinephrine administration (11 min. vs. 13 min., p < 0.01) were observed, whilst supraglottic airways were inserted earlier (11 min. vs. 10 min., p < 0.01).

CONCLUSION

The COVID-19 pandemic was associated with substantial changes in EMS management of OHCA. EMS leaders should consider these findings to optimise current OHCA management and prepare for future pandemics.

Implementation and use of a supraglottic airway device in the management of out-of-hospital cardiac arrest by firefighter first responders - A prospective feasibility study

Aim

We wanted to assess the implementation and use of a supraglottic airway (SGA) for on-call firefighter first responders in out-of-hospital cardiac arrest.

Methods

We trained 502 firefighter first responders, located at 35 fire stations in the South-East of Norway, in the use of SGA during cardiopulmonary resuscitation in adult out-of-hospital cardiac arrest. Training consisted of 45 minutes of theoretical and practical training in small groups.Primary outcome was successful ventilation with SGA assessed by both firefighter first responders and first paramedic arriving on-scene. Secondary outcomes included time expenditure and complications related to the procedure, evaluation of the training, and descriptive characteristics of the out-of-hospital cardiac arrest cases.

Results

An SGA was used by firefighter first responders in 23 out-of-hospital cardiac arrests, and successful ventilation was achieved in 20 (87%) cases. Air-leak was described in the three unsuccessful cases. The median procedural time was 30 seconds (IQR = 15-40), with no observed procedural complications. Firefighter first responders arrived in median time 9 minutes (IQR = 6-10 min) before the ambulance. They performed chest compressions on all patients and 6 (26%) of the patients received shock with semi-automatic external defibrillator. After training, all participants were able to successfully ventilate a manikin with the SGA. The cost of the SGA equipment for all fire stations was 3955 GBP.

Conclusion

Implementation of an SGA for firefighter first responders in out-of-hospital cardiac arrest management seems feasible, safe and can be introduced with limited amount of training and limited use of resources.

Out-of-hospital cardiac arrest: A data-driven visualization of collaboration, frontier identification, and future trends

One of the main causes of death is out-of-hospital cardiac arrest (OHCA), which has a poor prognosis and poor neurological outcomes. This phenomenon has attracted increasing attention. However, there is still no published bibliometric analysis of OHCA. This bibliometric analysis of publications on OHCA aimed to visualize the current status of research, determine the frontiers of research, and identify future trends. Publications on OHCA were downloaded from the web of science database. The data elements included year, countries/territories, institutions, authors, journals, research areas, citations of publications, etc. Joinpoint regression and exponential models were used to identify and predict the trend of publications, respectively. Knowledge domain maps were applied to conduct contribution and collaboration, cooccurrence, cocitation, and coupled analyses. Timeline and burst detection analysis were used to identify the frontiers in the field. A total of 3 219 publications on OHCA were found from 1998 to 2022 (average annual percentage change = 16.7; 95% CI 14.4, 19.1). It was estimated that 859 articles and reviews would be published in 2025. The following research hotpots were identified: statement, epidemiology, clinical care, factors influencing prognosis and emergency medical services. The research frontier identification revealed that 7 categories were classified, including therapeutic hypothermia, emergency medical services, airway management, myocardial infarction, extracorporeal cardiopulmonary resuscitation, stroke foundation and trial. The burst detection analysis revealed that percutaneous coronary intervention, neurologic outcome, COVID-19 and extracorporeal cardiopulmonary resuscitation are issues that should be given continual attention in the future. This bibliometric analysis may reflect the current status and future frontiers of OHCA research.

Documented Use of Emergency Medical Dispatch Protocols is Associated with Improved Survival in Out of Hospital Cardiac Arrest

OBJECTIVE

There are over 300,000 out-of-hospital cardiac arrests (OHCA) annually in the United States (US) and despite many scientific advances in the field, the survival rate remains low. We seek to determine if return of spontaneous circulation (ROSC) is higher when use of emergency medical dispatch (EMD) protocols is documented for OHCA calls compared to when no EMD protocol use is documented. We also seek identify care-related processes that differ in calls that use EMD protocols.

METHODS

This is a retrospective cohort study of U.S. adults with OHCA prior to emergency medical services (EMS) arrival using 2019 National EMS Information System data. The primary exposure was EMD usage during EMS call. The primary outcome was prehospital ROSC, and secondary outcomes included automated external defibrillator (AED) use before EMS arrival, bystander CPR, and end-of-event EMS survival (survival to the end of the EMS care at transport destination). Multivariable logistic regression adjusted for age, sex, race/ethnicity, primary insurance, rurality, initial rhythm, arrest etiology, and witnessed arrest.

RESULTS

Of the 96,269 OHCA cases included, EMD use was documented in 73%. Overall, 26% of subjects achieved ROSC in EMS care. EMD subjects were more likely to achieve ROSC (27.2% vs. 23.5%, uOR 1.22, 95%CI 1.18 - 1.26) even after adjusting for subject and arrest characteristics (aOR 1.13, 95%CI 1.08 - 1.17). EMD subjects also had higher end-of-event survival (19.1% vs. 16.4%, aOR 1.20, 95%CI 1.15 - 1.25). AED use before EMS arrival was more common in the EMD group (28.3% vs. 26.3% %diff 2.0, 95%CI 1.4 to 2.6), as was CPR before EMS arrival (63.8% vs. 55.1%, difference 8.6%, 95%CI 7.9 to 9.3%).

CONCLUSIONS

In this retrospective analysis, the rate of ROSC was higher in adult OHCA patients when EMD protocol use was reported compared to when it was not reported. The group with documented EMD use also experienced higher rates of bystander AED use, bystander CPR, and end-of-event survival.

Pre-Arrival Care of the Out-of-Hospital Cardiac Arrest Victim

Lay rescuers play a pivotal role in the recognition and initial management of out-of-hospital cardiac arrest. The provision of timely pre-arrival care by lay responders, including cardiopulmonary resuscitation and the use of automated external defibrillator before emergency medical service arrival, is important link in the chain of survival and has been shown to improve outcomes from cardiac arrest. Although physicians are not directly involved in bystander response to cardiac arrest, they play a key role in emphasizing the importance of bystander interventions.

Cardiac arrest in an emergency department in Colombia during 2011-2020: A descriptive study

Background

Cardiac arrest is a public health problem related to high morbidity and mortality. In Colombia, objective data characterize in our population has been not available. The aim of this study has been to determined the epidemiological characteristics of patients with cardiorespiratory arrest treated in an emergency room.

Methods

A retrospective observational cross-sectional cohort study was performed. We included adult patients admitted with a diagnostic of out-of-hospital cardiac arrest (OHCA) or who presented with in-hospital cardiac arrest while in the emergency department (ED).

Results

A total of 415 patients were included 232 were men, and the median age was 67 years. OHCA was presented in 383 patients. In this group, 80.2% required orotracheal intubation, 90.1% received Epinephrine, and and 52.6% received immediate resuscitation. Survival after discharge was 43.1% in patients with non-shockable rhythm registered. Return of spontaneous circulation was achieved in 49.6%. The survival after hospital discharge was 22.2%. Cerebral performance category score <=2 was 20.4%.

Conclusion

In our study, the epidemiological characteristics and outcomes of patients seen in the ED with cardiac arrest are similar to those described in the literature.

Long-Term Mortality in Patients Transferred by Emergency Medical Services: Prospective Cohort Study

OBJECTIVE

This study aimed to determine the long-term mortality (one-year follow-up) associated with patients transferred by Emergency Medical Services (EMS), and to reveal the determinants (causes and risk factors).

METHODS

This was a multicenter, prospective, observational, controlled, ambulance-based study of adult patients transferred by ambulance to emergency departments (EDs) from October 2019 through July 2021 for any cause. A total of six Advanced Life Support (ALS) units, 38 Basic Life Support (BLS) units, and five hospitals from Spain were included. Physiological, biochemical, demographic, and reasons for transfer variables were collected. A longitudinal analysis was performed to determine the factors associated to long-term mortality (any cause).

RESULTS

The final cohort included 1,406 patients. The one-year mortality rate was 21.6% (n = 304). Mortality over the first two days reached 5.2% of all the patients; between Day 2 and Day 30, reached 5.3%; and between Day 31 and Day 365, reached 11.1%. Low Glasgow values, elevated lactate levels, elevated blood urea nitrogen (BUN) levels, low oxygen saturation, high respiratory rate, as well as being old and suffering from circulatory diseases and neurological diseases were risk factors for long-term mortality.

CONCLUSION

The quick identification of patients at risk of long-term worsening could provide an opportunity to customize care through specific follow-up.

Secondary Public Safety Answering Points Delay the Response to out of Hospital Cardiac Arrest

Background: National guidelines recommend that high-performing systems process 9-1-1 calls within 60 s and deliver the first telecommunicator cardiopulmonary resuscitation compression within 90 s. The inability of systems employing secondary public safety answering points (PSAPs) to capture the call arrival timestamp at the primary PSAP is a challenge in out-of-hospital cardiac arrest response time research.Objective: We sought to measure the interval from call receipt at primary PSAPs to call answer at secondary PSAPs in metropolitan areas.Methods: This was a retrospective observational study evaluating 9-1-1 call transfers between PSAPs serving large urban populations. Call transfer records were extracted from the 9-1-1 telephony systems at the primary and secondary PSAPs covering seven metropolitan EMS systems. For each transferred call, we obtained the call arrival timestamp at both the primary and secondary PSAPs. The primary outcome was the interval between these two times. Results were compared to a national standard of 90% of calls forwarded within 30 s of receipt.Results: Data collected at seven metropolitan EMS agencies from January 1, 2021, through June 30, 2021, yielded 299,679 records for evaluation. The median interval required to transfer a 9-1-1 caller from primary to secondary PSAPs was 41 s (IQR 31, 59), and 86 s at the 90th percentile. The 90th percentile performance level at individual agencies ranged from 63 s to 117 s.Conclusions: The primary to secondary PSAP transfer interval lengths observed in this study preclude these EMS agencies from meeting out-of-hospital cardiac arrest performance recommendations at the 90% percentile performance level.

Effect of end-stage kidney disease on the return of spontaneous circulation in Taiwanese adults with out-of-hospital cardiac arrest

Rescuing patients with out-of-hospital cardiac arrest (OHCA), especially those with end-stage kidney disease (ESKD), is challenging. This study hypothesizes that OHCA patients with ESKD undergoing maintenance hemodialysis have (1) higher rates of return of spontaneous circulation (ROSC) during cardio-pulmonary resuscitation (CPR) and (2) lower rates of hyperkalemia and less severe acidosis than those without ESKD. OHCA patients who received CPR between 2011 and 2020 were dichotomized into ESKD and non-ESKD groups. The association of ESKD with "any" and "sustained" ROSC were examined using logistic regression analysis. Furthermore, the effect of ESKD on hospital outcomes for OHCA patients who survived to admission was evaluated using Kaplan-Meier analysis. ESKD patients without "any" ROSC displayed lower potassium and higher pH levels than non-ESKD patients. ESKD was positively associated with "any" ROSC (adjusted-OR: 4.82, 95% CI 2.70-5.16, P < 0.01) and "sustained" ROSC (adjusted-OR: 9.45, 95% CI 3.83-24.13, P < 0.01). Kaplan-Meier analysis demonstrated ESKD patients had a non-inferior hospital survival than non-ESKD patients. OHCA patients with ESKD had lower serum potassium level and less severe acidosis compared to the general population in Taiwan; therefore, should not be treated under the stereotypical assumption that hyperkalemia and acidosis always occur.

Preclinical evaluation of triiodothyronine nanoparticles as a novel therapeutic intervention for resuscitation from cardiac arrest

BACKGROUND

Given emerging evidence of rapid non-genomic cytoprotective effects of triiodothyronine (T3), we evaluated the resuscitative efficacy of two nanoparticle formulations of T3 (T3np) designed to prolong cell membrane receptor-mediated signaling.

METHODS

Swine (n = 40) were randomized to intravenous vehicle (empty np), EPI (0.015 mg/kg), T3np (0.125 mg/kg), or T3np loaded with phosphocreatine (T3np + PCr; 0.125 mg/kg) during CPR following 7-min cardiac arrest (n = 10/group). Hemodynamics and biomarkers of heart (cardiac troponin I; cTnI) and brain (neuron-specific enolase; NSE) injury were assessed for up to 4-hours post-ROSC, at which time the heart and brain were collected for post-mortem analysis.

RESULTS

Compared with vehicle (4/10), the rate of ROSC was higher in swine receiving T3np (10/10; p < 0.01), T3np + PCr (8/10; p = 0.08) or EPI (10/10; p < 0.01) during CPR. Although time to ROSC and survival duration were comparable between groups, EPI was associated with a ∼2-fold higher post-ROSC concentration of cTnI vs T3np and T3np + PCr and the early post-ROSC rise in NSE and neuronal injury were attenuated in T3np-treated vs EPI-treated animals. Analysis of hippocampal ultrastructure revealed deterioration of mitochondrial integrity, reduced active zone length, and increased axonal vacuolization in EPI-treated animals vs controls. However, the frequency of these abnormalities was diminished in animals resuscitated with T3np.

CONCLUSIONS

T3np achieved a ROSC rate and post-ROSC survival that was superior to vehicle and comparable to EPI. The attenuation of selected biomarkers of cardiac and neurologic injury at individual early post-ROSC timepoints in T3np-treated vs EPI-treated animals suggests that T3np administration during CPR may lead to more favorable outcomes in cardiac arrest.

Development of the epidemiology and outcomes of out-of-hospital cardiac arrest using data from the German Resuscitation Register over a 15-year period (EpiCPR study)

BACKGROUND

Sudden cardiac arrest is a relevant problem with a significant number of deaths in Europe.

AIM

Using data from the German Resuscitation Register (GRR), we examined changes in epidemiology and therapeutic interventions over a 15-year period in order to identify key factors contributing to favourable outcome in out-of-hospital cardiac arrest (OHCA) patients.

METHODS

GRR data were analysed in 5-year periods (2006-2010 vs 2011-2015 vs 2016-2020) representing changes in the European Resuscitation Council (ERC) guidelines. Group comparison of OHCA patients was made for epidemiological and resuscitation-associated factors. Endpoints included 30-day survival and hospital discharge with a good neurological outcome (CPC 1,2). Matched-pair analysis compared outcomes, and multivariate binary logistic regression analysis identified variables with effects on survival.

RESULTS

A total of 42,997 GRR patients were studied (2006-2010: n = 3,471, 2011-2015: n = 16,122, 2016-2020: n = 23,404). Proportion of patients over 80 years, use of intraosseous (IO) access and supraglottic airway devices, rate of bystander CPR, and the proportion of telephone CPR increased over the study period. The 30-day survival, and hospital discharge rates with CPC1/2 were unchanged. After adjusting cohorts using matched pairs, a higher CPC1,2 rate was observed (8.8 vs 10.2%, p < 0.03). Logistic regression analysis showed that IO and SAD had an unfavourable impact on outcome.

CONCLUSION

Despite a significant increase in bystander and telephone CPR rates, no improvement in 30-day survival and hospital discharge rate with CPC1,2 was observed. Initial rhythm (VF/VT), cardiac and hypoxic cause of CA, bystander CPR and IV access were identified as factors associated with a favourable neurological outcome.

Development and validation of an interpretable prehospital return of spontaneous circulation (P-ROSC) score for patients with out-of-hospital cardiac arrest using machine learning: A retrospective study

BACKGROUND

Return of spontaneous circulation (ROSC) before arrival at the emergency department is an early indicator of successful resuscitation in out-of-hospital cardiac arrest (OHCA). Several ROSC prediction scores have been developed with European cohorts, with unclear applicability in Asian settings. We aimed to develop an interpretable prehospital ROSC (P-ROSC) score for ROSC prediction based on patients with OHCA in Asia.

METHODS

This retrospective study examined patients who suffered from OHCA between Jan 1, 2009 and Jun 17, 2018 using data recorded in the Pan-Asian Resuscitation Outcomes Study (PAROS) registry. AutoScore, an interpretable machine learning framework, was used to develop P-ROSC. On the same cohort, the P-ROSC was compared with two clinical scores, the RACA and the UB-ROSC. The predictive power was evaluated using the area under the curve (AUC) in the receiver operating characteristic analysis.

FINDINGS

170,678 cases were included, of which 14,104 (8.26%) attained prehospital ROSC. The P-ROSC score identified a new variable, prehospital drug administration, which was not included in the RACA score or the UB-ROSC score. Using only five variables, the P-ROSC score achieved an AUC of 0.806 (95% confidence interval [CI] 0.799-0.814), outperforming both RACA and UB-ROSC with AUCs of 0.773 (95% CI 0.765-0.782) and 0.728 (95% CI 0.718-0.738), respectively.

INTERPRETATION

The P-ROSC score is a practical and easily interpreted tool for predicting the probability of prehospital ROSC.

FUNDING

This research received funding from SingHealth Duke-NUS ACP Programme Funding (15/FY2020/P2/06-A79).