Epidemiology and outcomes from out-of-hospital cardiac arrests in England

Community First Responders' role in the current and future rural health and care workforce: a mixed-methods study

Background

Community First Responders are trained volunteers dispatched by ambulance services to potentially life-threatening emergencies such as cardiac arrest in the first vital minutes to provide care until highly skilled ambulance staff arrive. Community First Responder schemes were first introduced to support ambulance services in rural communities, where access to prehospital emergency care is more likely to be delayed. Evidence is lacking on their contribution to rural healthcare provision, how care is provided and how this might be improved.

Objectives

We aimed to describe Community First Responder activities, organisation, costs of provision and outcomes of care together with perceptions and views of patients, public, Community First Responders, ambulance service staff and commissioners of their current and future role including innovations in the rural health and care workforce.

Design

We used a mixed-methods design, using a lens of pragmatism and the 'actor', 'behaviour change' and 'causal pathway' framework to integrate quantitative routine and qualitative (policy, guideline and protocol documents with stakeholder interview) data from 6 of 10 English ambulance services. We identified potential innovations in Community First Responder provision and prioritised these using a modified nominal group technique. Patients and public were involved throughout the study.

Results

In 4.5 million incidents from six English regional ambulance services during 2019, pre COVID-19 pandemic, Community First Responders attended first a higher proportion of calls in rural areas (almost 4% of calls) than in urban areas (around 1.5%). They were significantly more likely to be called out to rural (vs. urban) areas and to attend older (vs. younger), white (vs. minority ethnic) people in more affluent (vs. deprived) areas with cardiorespiratory and neurological (vs. other emergency) conditions for higher-priority emergency or urgent (category 1 and 2 compared with category 3, 4 or 5) calls but did also attend lower-category calls for conditions such as falls. We examined 10 documents from seven ambulance services. Ambulance policies and protocols integrated Community First Responders into ambulance service structures to achieve the safe and effective operation of volunteers. Costs, mainly for training, equipment and support, varied widely but were not always clearly delineated. Community First Responders enabled a faster prehospital response time. There was no clear benefit in out-of-hospital cardiac arrest outcomes. A specific Community First Responder falls response reduced ambulance attendances and was potentially cost saving. We conducted semistructured interviews with 47 different stakeholders engaged in Community First Responder functions. This showed the trajectory of becoming a Community First Responder, the Community First Responder role, governance and practice, and the positive views of Community First Responders from stakeholders despite public lack of understanding of their role. Community First Responders' scope of practice varied between ambulance services and had developed into new areas. Innovations prioritised at the consensus workshop were changes in processes and structures and an expanded scope of practice supported by training, which included counselling, peer support, better communication with the control room, navigation and communication technology, and specific mandatory and standardised training for Community First Responders.

Limitations

Missing data and small numbers of interviews in some stakeholder groups (patients, commissioners) are sources of bias.

Future research

Future research should include a robust evaluation of innovations involving Community First Responders.

Trial registration

This trial is registered as ClinicalTrials.gov, NCT04279262.

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: NIHR127920) and is published in full in Health and Social Care Delivery Research; Vol. 12, No. 18. See the NIHR Funding and Awards website for further award information.

Prevalence and prognosis of aortic valve diseases in patients hospitalized with heart failure with mildly reduced ejection fraction

AIMS

Data regarding the characterization and outcomes of patients with heart failure (HF) with mildly reduced ejection fraction (HFmrEF) is scarce. This study investigates the characteristics and prognostic impact of native aortic valve diseases (AVD) in patients with HFmrEF.

METHODS AND RESULTS

Consecutive patients hospitalized with HFmrEF (i.e. left ventricular ejection fraction 41-49% and signs and/or symptoms of HF) were retrospectively included at one institution from 2016 to 2022. The prognostic impact of native aortic valve stenosis (AS), aortic valve regurgitation (AR) and mixed AVD (MAVD) was investigated for the primary endpoint of long-term all-cause mortality during a median follow-up of 30 months. Kaplan-Meier, univariable and multivariable Cox proportional analyses were applied. From a total of 2106 patients hospitalized with HFmrEF, the prevalence of AS and AR was 16.5% and 31.2%, respectively (MAVD 7.8%). The presence of moderate/severe AS was associated with a higher risk of long-term all-cause mortality (44.8% vs. 28.7%; p = 0.001) and HF-related rehospitalization (18.6% vs. 12.0%; p = 0.001), even after multivariable adjustment (mortality: hazard ratio [HR] 1.320; 95% confidence interval [CI] 1.035-1.684; p = 0.025; HF-related rehospitalization: HR 1.570; 95% CI 1.101-2.241; p = 0.013). Interestingly, even mild AS was associated with increased risk of long-term all-cause mortality compared to patients without AS (HR 1.477; 95% CI 1.101-1.982; p = 0.009). In contrast, the presence of AR was not associated with long-term outcomes after multivariable adjustment.

CONCLUSIONS

The presence of AS, but not AR, was independently associated with increased risk of all-cause mortality and HF-related rehospitalization in patients with HFmrEF. Even milder stages of AS were associated with impaired prognosis.

The Real Experience of Lay Responders Performing Cardiopulmonary Resuscitation: A Synthesis of Qualitative Evidence

Objectives

To synthesize qualitative evidence on the experience of lay responders performing cardiopulmonary resuscitation (CPR).

Methods

Qualitative evidence synthesis was performed using the Thomas and Harden method. The PubMed, Cochrane Library, Web of Science, OVID Medline, Embase, CINAHL, CNKI, and WanFang databases were systematically searched. The quality of the research was assessed by the Critical Assessment Skills Program Tool (CASP).

Results

A total of 5,610 studies were identified, and 9 studies were included in the analysis. Four analytical themes were generated: emotional ambivalence before CPR, psychological tolerance during CPR, perceived experience after CPR, and enhancing psychological resilience.

Conclusion

Lay responders face complicated psychological experience during CPR, which may be susceptible to psychological effects such as "loss aversion," "bystander effects" and "knowledge curse." In addition to the timely retraining of CPR, lay responders should be instructed to manage psychological distress and improve psychological resilience. More importantly, the psychological sequelae may be long-lasting, requiring ongoing psychological intervention and follow-up based on valuing transdisciplinarity across endeavours.

Identifying organ donors attended by prehospital healthcare professionals - A scoping review

INTRODUCTION

Organ donation is a life-saving intervention that provides hope for patients with end-stage organ failure, improving their longevity and quality of life. However, the demand for organs far exceeds the supply, leading to a significant disparity between patients on transplant waiting lists and the availability of suitable organs. To address this issue, innovative strategies, such as uncontrolled donation after circulatory death (uDCD) programs, have been proposed to expand the donor pool to the prehospital setting.

AIM

This study aimed to systematically map the literature and comprehensively evaluate the involvement of prehospital healthcare professionals in identifying potential organ donors, as well as the barriers and systems impacting this process.

METHODS

A scoping literature review was conducted guided by the PRISMA Extension for Scoping Reviews. Four electronic databases and grey literature were searched for articles examining the participation of prehospital healthcare professionals in the organ or tissue donation process. Relevant data were extracted, organised into narrative and tabular formats, and presented.

RESULTS

A total of 33 articles were included for analysis, predominantly focusing on uDCD programs. The review identified a limited evidence-base regarding the role of prehospital healthcare professionals in organ donation. Four common themes emerged: discrepancies in criteria, decision-making processes, bridging strategies, and ethical considerations.

CONCLUSION

This scoping literature review highlights the significant role of prehospital healthcare professionals in identifying and recruiting organ donors from non-traditional settings. Established uDCD systems show promise in alleviating the burden on transplant waitlists. However, there is a lack of consensus on enrolment criteria, transportation, and ethical considerations for uDCD. Further research is needed to address these gaps, establish evidence-based guidelines, and ensure the efficient and ethical utilisation of potential organ donors from unconventional settings.

Neurological outcome following out of hospital cardiac arrest: Evaluation of performance of existing risk prediction models in a UK cohort

Introduction

Out of hospital cardiac arrest (OHCA) is a common problem. Rates of survival are low and a proportion of survivors are left with an unfavourable neurological outcome. Four models have been developed to predict risk of unfavourable outcome at the time of critical care admission - the Cardiac Arrest Hospital Prognosis (CAHP), MIRACLE2, Out of Hospital Cardiac Arrest (OHCA), and Targeted Temperature Management (TTM) models. This evaluation evaluates the performance of these four models in a United Kingdom population and provides comparison to performance of the Acute Physiology and Chronic Health Evaluation II (APACHE-II) score.

Methods

A retrospective evaluation of the performance of the models was conducted over a 43-month period in 414 adult, non-pregnant patients presenting consecutively following non-traumatic OHCA to the five units in our regional critical care network. Scores were generated for each model for where patients had complete data (CAHP = 347, MIRACLE2 = 375, OHCA = 356, TTM = 385). Cerebral Performance Category (CPC) outcome was calculated for each patient at last documented follow up and an unfavourable outcome defined as CPC ⩾ 3. Performance for discrimination of unfavourable outcome was tested by generating receiver operating characteristic (ROC) curves for each model and comparing the area under the curve (AUC).

Results

Best performance for discrimination of unfavourable outcome was demonstrated by the high risk group of the CAHP score with an AUC of 0.87 [95% CI 0.83-0.91], specificity of 97.1% [95% CI 93.8-100] and positive predictive value (PPV) of 96.3% [95% CI 92.2-100]. The high risk group of the MIRACLE2 model, which is significantly easier to calculate, had an AUC of 0.81 [95% CI 0.76-0.86], specificity of 92.3% [95% CI 87.2-97.4] and PPV of 95.2% [95% CI 91.9-98.4].

Conclusion

The CAHP, MIRACLE2, OHCA and TTM scores all perform comparably in a UK population to the original development and validation cohorts. All four scores outperform APACHE-II in a population of patients resuscitated from OHCA. CAHP and TTM perform best but are more complex to calculate than MIRACLE2, which displays inferior performance.

Health inequalities in cardiopulmonary resuscitation and use of automated electrical defibrillators in out-of-hospital cardiac arrest

Out of hospital cardiac arrest (OHCA) outcomes can be improved by strengthening the chain of survival, namely prompt cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED). However, provision of bystander CPR and AED use remains low due to individual patient factors ranging from lack of education to socioeconomic barriers and due to lack of resources such as limited availability of AEDs in the community. Although the impact of health inequalities on survival from OHCA is documented, it is imperative that we identify and implement strategies to improve public health and outcomes from OHCA overall but with a simultaneous emphasis on making care more equitable. Disparities in CPR delivery and AED use in OHCA exist based on factors including sex, education level, socioeconomic status, race and ethnicity, all of which we discuss in this review. Most importantly, we discuss the barriers to AED use, and strategies on how these may be overcome.

Time Is Life: Golden Ten Minutes on Scene-EuReCa_Serbia 2014-2023

Background and Objectives: This study analyzed the frequency of factors influencing the course and outcomes of out-of-hospital cardiac arrest (OHCA) in Serbia and the prediction of pre-hospital outcomes and survival. Materials and Methods: Data were collected during the period from 1 October 2014, to 31 September 2023, according to the protocol of the EuReCa_One study (clinical trial ID number NCT02236819). Results: Overall 9303 OHCA events were registered with a median age of 71 (IQR 61-81) years and 59.7% of them being males. The annual OHCA incidence was 85.60 ± 20.73/100,000. Within all bystander-witnessed cases, bystander-initiated cardiopulmonary resuscitation in 15.3%. Within the resuscitation-initiated group, return-of-spontaneous circulation (ROSC) on scene (any ROSC) was present in 1037/4053 cases (25.6%) and ROSC on admission to the nearest hospital in 792/4053 cases (19.5%), while 201/4053 patients survived to hospital discharge (5.0%). Predictive potential on pre-hospital outcomes was shown by several factors. Also, of all patients having any ROSC, 89.2% were admitted to the hospital alive. The probability of any ROSC dropped below 50% after 17 min passed after the emergency call and 10 min after the EMS scene arrival. These time intervals were significantly associated with survival to hospital discharge (p < 0.001). Five-minute time intervals between both emergency calls and any ROSC and EMS scene arrival and any ROSC also had a significant predictive potential for survival to hospital discharge (p < 0.001, HR 1.573, 95% CI 1.303-1.899 and p = 0.017, HR 1.184, 95% CI 1.030-1.361, respectively). Conclusions: A 10-min time on scene to any ROSC is a crucial time-related factor for achieving any ROSC, and indirectly admission ROSC and survival to hospital discharge, and represents a golden time interval spent on scene in the management of OHCA patients. A similar effect has a time interval of 17 min from an emergency call. Further investigations should be focused on factors influencing these time intervals, especially time spent on scene.

An Arrhythmia classification approach via deep learning using single-lead ECG without QRS wave detection

Arrhythmia, a frequently encountered and life-threatening cardiac disorder, can manifest as a transient or isolated event. Traditional automatic arrhythmia detection methods have predominantly relied on QRS-wave signal detection. Contemporary research has focused on the utilization of wearable devices for continuous monitoring of heart rates and rhythms through single-lead electrocardiogram (ECG), which holds the potential to promptly detect arrhythmias. However, in this study, we employed a convolutional neural network (CNN) to classify distinct arrhythmias without QRS wave detection step. The ECG data utilized in this study were sourced from the publicly accessible PhysioNet databases. Taking into account the impact of the duration of ECG signal on accuracy, this study trained one-dimensional CNN models with 5-s and 10-s segments, respectively, and compared their results. In the results, the CNN model exhibited the capability to differentiate between Normal Sinus Rhythm (NSR) and various arrhythmias, including Atrial Fibrillation (AFIB), Atrial Flutter (AFL), Wolff-Parkinson-White syndrome (WPW), Ventricular Fibrillation (VF), Ventricular Tachycardia (VT), Ventricular Flutter (VFL), Mobitz II AV Block (MII), and Sinus Bradycardia (SB). Both 10-s and 5-s ECG segments exhibited comparable results, with an average classification accuracy of 97.31%. It reveals the feasibility of utilizing even shorter 5-s recordings for detecting arrhythmias in everyday scenarios. Detecting arrhythmias with a single lead aligns well with the practicality of wearable devices for daily use, and shorter detection times also align with their clinical utility in emergency situations.

The barriers and facilitators to initiation of telephone-assisted bystander cardiopulmonary resuscitation for patients experiencing out-of-hospital cardiac arrest in a private emergency dispatch centre in South Africa

Background

The incidence of cardiovascular diseases, and with it out-of-hospital cardiac arrest (OHCA), is on the increase in low- to middle-income countries (LMICs), like South Africa. Interventions such as mass public cardiopulmonary resuscitation (CPR) training campaigns and public access defibrillators are expensive and out of reach for many LMICs. Telephone-assisted CPR (tCPR) is a cost-effective, scalable alternative. This study explored the barriers and facilitators to tCPR uptake in OHCA in a private South African emergency dispatch centre.

Methods

This qualitative study applied inductive dominant content analysis to emergency call recordings of OHCA cases into a private emergency dispatch centre. Calls were analysed to the latent level to identify barriers and facilitators. Cases were sampled randomly, until data saturation.

Results

Saturation occurred after the analysis of 25 recordings. A further three recordings were analysed to confirm saturation of the facilitators; yielding a final sample size of 28 calls. Overall, t-CPR was offered in 23 (82.1%) cases, but only initiated in 8 (34.8%) of these calls. Five barriers ("Poor Communication"; "Lack of Support"; "Caller Hesitance or Uncertainty;" "Emotionality"; and "Practical Barriers") and three facilitators ("Caller Willingness"; "Support" and "CPR in Progress") were extracted.

Conclusion

Numerous barriers limit the initiation of tCPR in the South African private sector EMS. It is crucial to address these barriers and leverage the facilitators in order to improve tCPR uptake. This study highlights the importance of using specific language techniques and developing tailored tCPR algorithms to overcome these barriers, which is underpinned by standardised training of call-takers.

Route of drug administration in out-of-hospital cardiac arrest: A protocol for a randomised controlled trial (PARAMEDIC-3)

Aims

The PARAMEDIC-3 trial evaluates the clinical and cost-effectiveness of an intraosseous first strategy, compared with an intravenous first strategy, for drug administration in adults who have sustained an out-of-hospital cardiac arrest.

Methods

PARAMEDIC-3 is a pragmatic, allocation concealed, open-label, multi-centre, superiority randomised controlled trial. It will recruit 15,000 patients across English and Welsh ambulance services. Adults who have sustained an out-of-hospital cardiac arrest are individually randomised to an intraosseous access first strategy or intravenous access first strategy in a 1:1 ratio through an opaque, sealed envelope system. The randomised allocation determines the route used for the first two attempts at vascular access. Participants are initially enrolled under a deferred consent model.The primary clinical-effectiveness outcome is survival at 30-days. Secondary outcomes include return of spontaneous circulation, neurological functional outcome, and health-related quality of life. Participants are followed-up to six-months following cardiac arrest. The primary health economic outcome is incremental cost per quality-adjusted life year gained.

Conclusion

The PARAMEDIC-3 trial will provide key information on the clinical and cost-effectiveness of drug route in out-of-hospital cardiac arrest.Trial registration: ISRCTN14223494, registered 16/08/2021, prospectively registered.

Knowledge, attitudes, practices, and self-efficacy of the Chinese public regarding cardiopulmonary resuscitation: an online cross-sectional survey

Objective

To evaluate the current status of Chinese public's knowledge, attitudes, practices (KAP) and self-efficacy regarding cardiopulmonary resuscitation (CPR), and to analyze the factors that influence KAP and self-efficacy.

Methods

An online cross-sectional survey was conducted from February to June 2022 in Mainland China via a self-designed self-filled questionnaire. Potential participants were recruited through WeChat by convenience sampling and snowball sampling methods. Descriptive and quantitative analyses were used for statistical analysis.

Results

The survey included 4,450 participants from 31 provinces, autonomous regions, or municipalities across Mainland China, aged 18 or above. The public's average understanding (clear and very clear) of the knowledge regarding CPR was 67.4% (3,000/4,450), with an average proportion of positive attitudes at 96.8% (4,308/4,450). In practice, the average proportion of good practices was 92.8% (4,130/4,450), while the percentage of good self-efficacy averaged at 58.9% (2,621/4,450), only 42.4% (1,885/4,450) of the participants had confidence in the correct use of automated external defibrillator (AED). Pearson correlation analysis showed a significantly positive correlation among knowledge, attitude, practice, and self-efficacy (p < 0.01). Multiple linear regression analysis revealed that several factors have a significant influence on the public's CPR KAP and self-efficacy, including ever having received CPR training (p < 0.001), hearing about AED (p < 0.001), performing CPR on others (p < 0.001), hearing about CPR (p < 0.001), occupation (p < 0.001), personal health status (p < 0.001), education level (p < 0.001), gender (p < 0.001), and encountering someone in need of CPR (p = 0.021).

Conclusion

The Chinese public demonstrates good knowledge of CPR, positive attitude, and high willingness to perform CPR. However, there is still room for improvement in the mastery of some professional knowledge points related to CPR and AED. It should be noted that knowledge, attitude, practice, and self-efficacy are interrelated and influence each other. Factors such as prior CPR training, hearing about AED, having performed CPR before, hearing about CPR, occupation, personal health status, education level, gender, and having encountered someone in need of CPR have a significant impact on the public's KAP and self-efficacy.

Performance of ECG-Derived Digital Biomarker for Screening Coronary Occlusion in Resuscitated Out-of-Hospital Cardiac Arrest Patients: A Comparative Study between Artificial Intelligence and a Group of Experts

Acute coronary syndrome is a significant part of cardiac etiology contributing to out-of-hospital cardiac arrest (OHCA), and immediate coronary angiography has been proposed to improve survival. This study evaluated the effectiveness of an AI algorithm in diagnosing near-total or total occlusion of coronary arteries in OHCA patients who regained spontaneous circulation. Conducted from 1 July 2019 to 30 June 2022 at a tertiary university hospital emergency department, it involved 82 OHCA patients, with 58 qualifying after exclusions. The AI used was the Quantitative ECG (QCG™) system, which provides a STEMI diagnostic score ranging from 0 to 100. The QCG score's diagnostic performance was compared to assessments by two emergency physicians and three cardiologists. Among the patients, coronary occlusion was identified in 24. The QCG score showed a significant difference between occlusion and non-occlusion groups, with the former scoring higher. The QCG biomarker had an area under the curve (AUC) of 0.770, outperforming the expert group's AUC of 0.676. It demonstrated 70.8% sensitivity and 79.4% specificity. These findings suggest that the AI-based ECG biomarker could predict coronary occlusion in resuscitated OHCA patients, and it was non-inferior to the consensus of the expert group.

Effectiveness of basic life support training course intervention among dental practitioners and students - An experimental study

Aim

To determine the level of knowledge and skill of basic life support (BLS) among undergraduate, postgraduate students, and general practitioners with and without regular attendance of the BLS Healthcare Provider course.

Methodology

The study was carried out at two intervals with two groups. A random sample involving undergraduate students, postgraduate students, and dental professionals was selected for both study groups. Group 1 with 440 participants had not attended BLS for Healthcare Providers Course in the last two years. Group 2 with 410 participants had attended the BLS for Healthcare Providers course regularly once a year. First, participants in Group 1 were evaluated using an MCQ test with 30 questions about their knowledge and skills in BLS. Then, a well-trained BLS instructor team from Dental College & Hospital offered BLS healthcare provider courses to students and dentists. Subsequently, Group 2 participants who had completed a BLS course for healthcare providers last year were also assessed for their knowledge and skills in BLS using another MCQ test.

Results

The marks obtained in the tests were tabulated and analyzed. To determine the association between variables with respect to mean knowledge score, t-test was employed. Multiple group comparison was made using analysis of variance and P < 0.05 was considered statistically significant. The group 1 participants score a mean of 5.7 marks against the Group 2 with a mean score of 27.4 marks out of 30 marks. Knowledge and skill in BLS skills among those in Group 1 without prior BLS training was mainly low. Dental practitioners performed marginally better than students in both groups.

Conclusions

Based on the results, we make the following observations. With the introduction of BLS training into the academic curriculum and routine BLS hands-on workshops, all healthcare providers will be familiar with the BLS skills to effectively manage the life-threatening emergencies.

Cardiac Arrest Bundle of cARE Trial (CABARET) survey of current UK neuroprotective CPR practice

Despite low out of hospital cardiac arrest (OOHCA) survival rates within the UK, animal studies hint at improved cerebral blood flow via a bundled neuroprotective CPR approach. The CABARET study introduces three key devices: the Head Up Position (HUP), Active Compression/Decompression (ACD) CPR, and the Impedance Threshold Device (ITD). A survey involving 27 UK pre-hospital critical care services indicated none are using these interventions widely, either alone or bundled. The CABARET team is now initiating a pilot study to investigate the feasibility of this CPR bundle, aiming to fill the prevailing evidence void in resuscitation research.

Early and late withdrawal of life-sustaining treatment after out-of-hospital cardiac arrest in the United Kingdom: Institutional variation and association with hospital mortality

AIM

Frequency and timing of Withdrawal of Life-Sustaining Treatment (WLST) after Out-of-Hospital Cardiac Arrest (OHCA) vary across Intensive Care Units (ICUs) in the United Kingdom (UK) and may be a marker of lower healthcare quality if instituted too frequently or too early. We aimed to describe WLST practice, quantify its variability across UK ICUs, and assess the effect of institutional deviation from average practice on patients' risk-adjusted hospital mortality.

METHODS

We conducted a retrospective multi-centre cohort study including all adult patients admitted after OHCA to UK ICUs between 2010 and 2017. We identified patient and ICU characteristics associated with early (within 72 h) and late (>72 h) WLST and quantified the between-ICU variation. We used the ICU-level observed-to-expected (O/E) ratios of early and late-WLST frequency as separate metrics of institutional deviation from average practice and calculated their association with patients' hospital mortality.

RESULTS

We included 28,438 patients across 204 ICUs. 10,775 (37.9%) had WLST and 6397 (59.4%) of them had early-WLST. Both WLST types were strongly associated with patient-level demographics and pre-existing conditions but weakly with ICU-level characteristics. After adjustment, we found unexplained between-ICU variation for both early-WLST (Median Odds Ratio 1.59, 95%CrI 1.49-1.71) and late-WLST (MOR 1.39, 95%CrI 1.31-1.50). Importantly, patients' hospital mortality was higher in ICUs with higher O/E ratio of early-WLST (OR 1.29, 95%CI 1.21-1.38, p < 0.001) or late-WLST (OR 1.39, 95%CI 1.31-1.48, p < 0.001).

CONCLUSIONS

Significant variability exists between UK ICUs in WLST frequency and timing. This matters because unexplained higher-than-expected WLST frequency is associated with higher hospital mortality independently of timing, potentially signalling prognostic pessimism and lower healthcare quality.

Wolf Creek XVII Part 5: Mobile AEDs

Introduction

Millions of out-of-hospital cardiac arrests (OHCA) occur globally each year. Survival after OHCA can be improved with the use of automated external defibrillators (AED). The main strategy for facilitating bystander defibrillation has been fixed-location public access defibrillators (PADs). New strategies of mobile AEDs depart from the model of static PADs and have the potential to address known barriers to early defibrillation and improve outcomes.

Methods

Mobile AEDs 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 center around understanding the impact of mobile AEDs on OHCA outcomes in various settings and the impact of novel AED technologies. Top barriers to translation include questionable public comfort/acceptance, financial/regulatory constraints, and a lack of centralized accountability. Top research priorities focus on understanding the impact of the mobile AED strategies and technologies on time to defibrillation and OHCA outcomes.

Conclusion

This work informs research agendas, funding priorities and policy decisions around using mobile AEDs to optimize prehospital response to OHCA.

The use of neurone specific enolase to prognosticate neurological recovery and long term neurological outcomes in OOHCA patients

Introduction

Hypoxic-ischaemic brain injury (HIBI), is a common sequalae following out-of-hospital cardiac arrest (OOHCA), it is reported as the cause of death in 68% of patients who survive to ICU admission, while other patients can be left with permanent neurological disability. Prediction of neurological outcome follows a multimodal approach, including use of the biomarker, neurone specific enolase (NSE). There is however no definitive cut-off value for poor neurological outcome, and little research has analysed NSE and long-term outcomes in survivors. We investigated an NSE threshold for poor short-term neurological outcome and the relationship between NSE and poor neurological outcome in survivors.

Methods

A retrospective study was conducted of all adult OOHCA patients admitted to the Royal County Sussex Hospital ICU between April 2017 and November 2018. NSE levels, Targeted Temperature Management (TTM), cross-sectional imaging, mortality and GCS on ICU discharge were recorded. Assessment of neurological function after a median of 19 months (range 14-32 months) post ICU discharge was undertaken following ICU discharge and related to NSE.

Results

NSE levels were measured in 59 patients; of these 36 (61%) had a poor neurological outcome due to hypoxic ischaemic brain injury. Youden's index and ROC analysis established an NSE cut-off value of 64.5 μg/L, with AUC of 0.901, sensitivity of 77.8% and specificity of 100%. Follow-up of 26 survivors after 19 months did not show a significant relationship between NSE after OOHCA and long-term neurological outcome.

Conclusion

Our results show that NSE >64.5 µg/L has a poor short-term neurological outcome with 100% specificity. Whilst limited by a low sample size, NSE in survivors showed no relationship with neurological outcome post OOHCA in the long term.

Establishment of a prediction model for prehospital return of spontaneous circulation in out-of-hospital patients with cardiac arrest

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide.

AIM

To explore factors influencing prehospital return of spontaneous circulation (P-ROSC) in patients with OHCA and develop a nomogram prediction model.

METHODS

Clinical data of patients with OHCA in Shenzhen, China, from January 2012 to December 2019 were retrospectively analyzed. Least absolute shrinkage and selection operator (LASSO) regression and multivariate logistic regression were applied to select the optimal factors predicting P-ROSC in patients with OHCA. A nomogram prediction model was established based on these influencing factors. Discrimination and calibration were assessed using receiver operating characteristic (ROC) and calibration curves. Decision curve analysis (DCA) was used to evaluate the model's clinical utility.

RESULTS

Among the included 2685 patients with OHCA, the P-ROSC incidence was 5.8%. LASSO and multivariate logistic regression analyses showed that age, bystander cardiopulmonary resuscitation (CPR), initial rhythm, CPR duration, ventilation mode, and pathogenesis were independent factors influencing P-ROSC in these patients. The area under the ROC was 0.963. The calibration plot demonstrated that the predicted P-ROSC model was concordant with the actual P-ROSC. The good clinical usability of the prediction model was confirmed using DCA.

CONCLUSION

The nomogram prediction model could effectively predict the probability of P-ROSC in patients with OHCA.

Trends in use of intraosseous and intravenous access in out-of-hospital cardiac arrest across English ambulance services: A registry-based, cohort study

INTRODUCTION

The optimum route for drug administration in cardiac arrest is unclear. Recent data suggest that use of the intraosseous route may be increasing. This study aimed to explore changes over time in use of the intraosseous and intravenous drug routes in out-of-hospital cardiac arrest in England.

METHODS

We extracted data from the UK Out-of-Hospital Cardiac Arrest Outcomes registry. We included adult out-of-hospital cardiac arrest patients between 2015-2020 who were treated by an English Emergency Medical Service that submitted vascular access route data to the registry. The primary outcome was any use of the intraosseous route during cardiac arrest. We used logistic regression models to describe the association between time (calendar month) and intraosseous use.

RESULTS

We identified 75,343 adults in cardiac arrest treated by seven Emergency Medical Service systems between January 2015 and December 2020. The median age was 72 years, 64% were male and 23% presented in a shockable rhythm. Over the study period, the percentage of patients receiving intraosseous access increased from 22.8% in 2015 to 42.5% in 2020. For each study-month, the odds of receiving any intraosseous access increased by 1.019 (95% confidence interval 1.019 to 1.020, p < 0.001). This observed effect was consistent across sensitivity analyses. We observed a corresponding decrease in use of intravenous access.

CONCLUSION

In England, the use of intraosseous access in out-of-hospital cardiac arrest has progressively increased over time. There is an urgent need for randomised controlled trials to evaluate the clinical effectiveness of the different vascular access routes in cardiac arrest.

Dynamic Course of Clinical State Transitions in Patients Undergoing Advanced Life Support after Out-of-Hospital Cardiac Arrest

OBJECTIVES

Studies of out-of-hospital cardiac arrest generally document the presenting (pulseless electrical activity [PEA], ventricular fibrillation/tachycardia (VF/VT), asystole), and the final states (resuming stable spontaneous circulation [s-ROSC], being declared dead). Only a few studies described the transitions between clinical states during advanced life support (ALS). The aim of this study was to describe and analyze the dynamics of state transitions during ALS.

METHODS

A retrospective analysis of 464 OHCA events was conducted. Any observed state and its corresponding changing time were documented through continuous electrocardiographic and trans-thoracic impedance recording.

RESULTS

When achieved, most s-ROSCs were obtained by 30 min, regardless of the presenting state. After this time point, the persistence of any transient state was associated with a great probability of being declared dead. The most probable change for VF/VT or PEA at any time was the transition to asystole (36.4% and 34.4%, respectively); patients in asystole at any time had a 70% probability of death. Patients achieving s-ROSC mostly came from a VF/VT state.In most cases, the presenting rhythm tended to persist over time during ALS. Asystole was the most stable state; a higher degree of instability was observed when the presenting rhythms were VF/VT or PEA. Transient ROSC episodes occurred mainly as the first transition after the presenting state, especially for initial PEA.

CONCLUSIONS

An understanding of the dynamic course of clinical state transitions during ALS may allow treatment strategies to be tailored in patients affected by OHCA.

Sudden cardiac arrest in athletes and strategies to optimize preparedness

Sudden cardiac arrest (SCA) is the leading cause of death in young athletes. Despite efforts to improve preparedness for cardiac emergencies, the incidence of out-of-hospital cardiac arrests in athletes remains high, and bystander awareness and readiness for SCA support are inadequate. Initiatives such as designing an emergency action plan (EAP) and mandating training in cardiopulmonary resuscitation (CPR) and automated external defibrillator use (AED) for team members and personnel can contribute to improved survival rates in SCA cases. This review provides an overview of SCA in athletes, focusing on identifying populations at the highest risk and evaluating the effectiveness of different screening practices in detecting conditions that may lead to SCA. We summarize current practices and recommendations for improving the response to SCA events, and we highlight the need for ongoing efforts to optimize preparedness through the implementation of EAPs and the training of individuals in CPR and AED use. Additionally, we propose a call to action to increase awareness and training in EAP development, CPR, and AED use for team members and personnel. To improve outcomes of SCA cases in athletes, it is crucial to enhance bystander awareness and preparedness for cardiac emergencies. Implementing EAPs and providing training in CPR and AED use for team members and personnel are essential steps toward improving survival rates in SCA cases.

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.

Knowledge and willingness of schoolteachers in Jordan to perform CPR: a cross-sectional study

OBJECTIVES

This study aimed to assess the cardiopulmonary resuscitation (CPR) knowledge and willingness of schoolteachers in Jordan.

DESIGN

This was a cross-sectional study conducted using an online questionnaire.

SETTING

For inclusion in this study, schoolteachers must be currently teaching at any level in schools across the country. Responses were collected from 1 April 2021 to 30 April 2021.

PARTICIPANTS

All schoolteachers actively working in public or private schools were included in our study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Continuous variables were summarised as means and SD, whereas categorical variables were reported as frequencies and percentages (%). A χ2 test for independence, independent sample t-tests and analysis of variance were used appropriately. A p-value less than 0.05 was used to determine statistical significance.

RESULTS

A total of 385 questionnaires were eligible for analyses. Only 14.5% of the participants received CPR training and overall correct knowledge answers were 18.8% of the total score. Those participants with previous CPR training had higher mean knowledge scores (2.34 vs 1.15, p<0.001). Trained participants were also more likely to provide hands-only CPR to various patient groups than untrained participants (p<0.05). Participants were more willing to provide standard CPR to family members than hands-only CPR (p<0.001), but more willing to provide hands-only CPR to friends (p<0.001), students (75.1% vs 58.2%, p<0.001), neighbour (p<0.001), stranger (p=0.001) and patient from the opposite gender (p<0.001).

CONCLUSIONS

Schoolteachers in Jordan possess limited knowledge of CPR. However, the study participants showed a positive attitude towards performing CPR. The study revealed that they were more inclined to provide hands-only CPR than standard CPR. Policymakers and public health officials can take advantage of these findings to incorporate CPR training programmes for schoolteachers, either as a part of their undergraduate studies or as continuing education programmes with an emphasis on hands-only CPR.

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.

Coronary angiography findings in resuscitated and refractory out-of-hospital cardiac arrest: A systematic review and meta-analysis

INTRODUCTION

Coronary angiography (CAG) frequently reveals coronary artery disease (CAD) after out-of-hospital cardiac arrest (OHCA), but its use is not standardized and often reported in different subpopulations. This systematic review and meta-analysis accurately describes angiographic features in resuscitated and refractory OHCA.

METHODS

PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched up to October 31, 2022. Studies reporting coronary angiography findings after OHCA were considered eligible. The primary outcome was location and rate of coronary lesions. Coronary angiography findings with 95% confidence intervals were pooled with a meta-analysis of proportion.

RESULTS

128 studies (62,845 patients) were included. CAG, performed in 69% (63-75%) of patients, found a significant CAD in 75% (70-79%), a culprit lesion in 63% (59-66%), and a multivessel disease in 46% (41-51%). Compared to patients with return of spontaneous circulation, refractory OHCA was associated with more severe CAD due to a higher rate of left main involvement (17% [12-24%] vs 5.7% [3.1-10%]; p = 0.002) and acute occlusion of left anterior descending artery (27% [17-39%] vs 15% [13-18%]; p = 0.02). Nonshockable patients without ST-elevation were those receiving CAG less frequently, despite significant disease in 54% (31-76%). Left anterior descending artery was the most frequently involved (34% [30-39%]).

CONCLUSIONS

Patients with OHCA have a high prevalence of significant CAD caused by acute and treatable coronary lesions. Refractory OHCA was associated with more severe coronary lesions. CAD was also present in patients with nonshockable rhythm and without ST elevation. However, heterogeneity of studies and selection of patients undergoing CAG limit the certainty of findings.

Characteristics and Treatment Outcomes of Out-of-Hospital Cardiac Arrests Occurring in Public Places: A National Population-Based Observational Study

Sudden cardiac arrest, particularly out-of-hospital cardiac arrest (OHCA), is a global public health concern. However, limited research exists on the epidemiology of OHCAs occurring in public places, trends and impact of bystander intervention, and influence of extraordinary circumstances. This study investigated the epidemiological factors, bystander characteristics, and outcomes of OHCAs that occurred in public places in South Korea from 2016 to 2021 and analyzed the impact of the coronavirus disease 2019 (COVID-19) pandemic. A retrospective analysis was conducted using an Out-of-Hospital Cardiac Arrest Surveillance database, including 33,206 cases of OHCA that occurred in public places. Cases with do-not-resuscitate orders or insufficient data were excluded. A steady increase in bystander-performed cardiopulmonary resuscitation over the years and a constant decrease in bystander automated external defibrillator (AED) use were observed. Survival-to-discharge rates for OHCAs remained relatively steady until a marginal decrease was observed during the pandemic (pandemic, 13.1%; pre-pandemic, 14.4%). Factors affecting survival included the presence of a shockable rhythm, witnessed arrest, cardiac arrest due to disease, use of bystander AED, and period relative to the COVID-19 pandemic. These findings emphasize the critical role of bystanders in outcomes of OHCAs and inform public health strategies on better management of OHCAs in public places.

Cardiac arrest centres: what do they add?

There are wide regional variations in outcome following resuscitated out of hospital cardiac arrest. These geographical differences appear to be due to hospital infrastructure and provider experience rather than baseline characteristics. It is proposed that post-arrest care be delivered in a systematic fashion by concentrating services in Cardiac Arrest Centres, with greater provider experience, 24-hour access to diagnostics, and specialist treatment to minimise the impact of ischaemia-reperfusion injury and treat the causative pathology. These cardiac arrest centres would provide access to targeted critical care, acute cardiac care, radiology services and appropriate neuro-prognostication. However implementation of cardiac arrest networks with specialist receiving hospitals is complex and requires alignment of pre-hospital care services with those delivered in hospital. Furthermore there are no randomised trial data currently supporting pre-hospital delivery to a Cardiac Arrest Centre and definitions are heterogeneous. In this review article, we propose a universal definition of a Cardiac Arrest Centre and review the current observational data evidence and the potential impact of the ARREST trial.

Association between sex and survival after out-of-hospital cardiac arrest: A systematic review and meta-analysis

The current literature on sex differences in 30-day survival following out-of-hospital cardiac arrest (OHCA) is conflicting, with 3 recent systematic reviews reporting opposing results. To address these contradictions, this systematic literature review and meta-analysis aimed to synthesize the literature on sex differences in survival after OHCA by including only population-based studies and through separate meta-analyses of crude and adjusted effect estimates. MEDLINE and Embase databases were systematically searched from inception to March 23, 2022 to identify observational studies reporting sex-specific 30-day survival or survival until hospital discharge after OHCA. Two meta-analyses were conducted. The first included unadjusted effect estimates of the association between sex and survival (comparing males vs females), whereas the second included effect estimates adjusted for possible mediating and/or confounding variables. The PROSPERO registration number was CRD42021237887, and the search identified 6712 articles. After the screening, 164 potentially relevant articles were identified, of which 26 were included. The pooled estimate for crude effect estimates (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.22-1.66) indicated that males have a higher chance of survival after OHCA than females. However, the pooled estimate for adjusted effect estimates shows no difference in survival after OHCA between males and females (OR, 0.93; 95% CI, 0.84-1.03). Both meta-analyses involved high statistical heterogeneity between studies: crude pooled estimate I2 = 95.7%, adjusted pooled estimate I2 = 91.3%. There does not appear to be a difference in survival between males and females when effect estimates are adjusted for possible confounding and/or mediating variables in non-selected populations.

Hypothermia for neuroprotection in adults after cardiac arrest

BACKGROUND

Good neurological outcome after cardiac arrest is difficult to achieve. Interventions during the resuscitation phase and treatment within the first hours after the event are critical for a favourable prognosis. Experimental evidence suggests that therapeutic hypothermia is beneficial, and several clinical studies on this topic have been published. This review was originally published in 2009; updated versions were published in 2012 and 2016.

OBJECTIVES

To evaluate the benefits and harms of therapeutic hypothermia after cardiac arrest in adults compared to standard treatment.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 30 September 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in adults comparing therapeutic hypothermia after cardiac arrest with standard treatment (control). We included studies with adults cooled by any method, applied within six hours of cardiac arrest, to target body temperatures of 32 °C to 34 °C. Good neurological outcome was defined as no or only minor brain damage allowing people to live an independent life.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was 1. neurological recovery. Our secondary outcomes were 2. survival to hospital discharge, 3. quality of life, 4. cost-effectiveness and 5.

ADVERSE EVENTS

We used GRADE to assess certainty.

MAIN RESULTS

We found 12 studies with 3956 participants reporting the effects of therapeutic hypothermia on neurological outcome or survival. There were some concerns about the quality of all the studies, and two studies had high risk of bias overall. When we compared conventional cooling methods versus any type of standard treatment (including a body temperature of 36 °C), we found that participants in the therapeutic hypothermia group were more likely to reach a favourable neurological outcome (risk ratio (RR) 1.41, 95% confidence interval (CI) 1.12 to 1.76; 11 studies, 3914 participants). The certainty of the evidence was low. When we compared therapeutic hypothermia with fever prevention or no cooling, we found that participants in the therapeutic hypothermia group were more likely to reach a favourable neurological outcome (RR 1.60, 95% CI 1.15 to 2.23; 8 studies, 2870 participants). The certainty of the evidence was low. When we compared therapeutic hypothermia methods with temperature management at 36 °C, there was no evidence of a difference between groups (RR 1.78, 95% CI 0.70 to 4.53; 3 studies; 1044 participants). The certainty of the evidence was low. Across all studies, the incidence of pneumonia, hypokalaemia and severe arrhythmia was increased amongst participants receiving therapeutic hypothermia (pneumonia: RR 1.09, 95% CI 1.00 to 1.18; 4 trials, 3634 participants; hypokalaemia: RR 1.38, 95% CI 1.03 to 1.84; 2 trials, 975 participants; severe arrhythmia: RR 1.40, 95% CI 1.19 to 1.64; 3 trials, 2163 participants). The certainty of the evidence was low (pneumonia, severe arrhythmia) to very low (hypokalaemia). There were no differences in other reported adverse events between groups.

AUTHORS' CONCLUSIONS

Current evidence suggests that conventional cooling methods to induce therapeutic hypothermia may improve neurological outcomes after cardiac arrest. We obtained available evidence from studies in which the target temperature was 32 °C to 34 °C.

Characteristics of out-of-hospital cardiac arrest patients in Riyadh province, Saudi Arabia: a cross-sectional study

Introduction

Little work has been done on out-of-hospital cardiac arrest (OHCA) in Saudi Arabia. Our goal is to report the characteristics of OHCA patients and predictors of bystander cardiopulmonary resuscitation (CPR).

Materials and methods

This cross-sectional study utilized data from the Saudi Red Crescent Authority (SRCA), a governmental emergency medical service (EMS). A standardized data collection form based on the "Utstein-style" guidelines was developed. Data were retrieved from the electronic patient care reports that SRCA providers fill out for every case. OHCA cases that were attended by SRCA in Riyadh province between June 1st, 2020 and May 31st, 2021 were included. Multivariate regression analysis was performed to assess independent predictors of bystander CPR.

Results

A total of 1,023 OHCA cases were included. The mean age was 57.2 (±22.6). 95.7% (979/1,023) of cases were adults and 65.2% (667/1,023) were males. Home was the most common location of OHCA [784/1,011 (77.5%)]. The initial recorded rhythm was shockable in 131/742 (17.7%). The EMS mean response time was 15.9 min (±11.1). Bystander CPR was performed in 130/1,023 (12.7%) and was more commonly performed in children as compared to adults [12/44 (27.3%) vs. 118/979 (12.1%), p = 0.003]. Independent predictors of bystander CPR were being a child (OR = 3.26, 95% CI [1.21-8.82], p = 0.02) and having OHCA in a healthcare institution (OR = 6.35, 95% CI [2.15-18.72], p = 0.001).

Conclusion

Our study reported the characteristics of OHCA cases in Saudi Arabia using EMS data. We observed young age at presentation, low rates of bystander CPR, and long response time. These characteristics are distinctly different from other countries and call for urgent attention to OHCA care in Saudi Arabia. Lastly, being a child and having OHCA in a healthcare institution were found to be independent predictors of bystander CPR.

Diagnostic Yield, Safety, and Outcomes of Head-to-Pelvis Sudden Death CT Imaging in Post Arrest Care: The CT FIRST Cohort Study

AIM

Our aim was to test whether a head-to-pelvis CT scan improves diagnostic yield and speed to identify causes for out of hospital circulatory arrest (OHCA).

METHODS

CT FIRST was a prospective observational pre-/post-cohort study of patients successfully resuscitated from OHCA. Inclusion criteria included unknown cause for arrest, age>18 years, stability to undergo CT, and no known cardiomyopathy or obstructive coronary artery disease. A head-to-pelvis sudden death CT (SDCT) scan within 6 hours of hospital arrival was added to the standard of care for patients resuscitated from OHCA (post-cohort) and compared to standard of care (SOC) alone (pre-cohort). The primary outcome was SDCT diagnostic yield. Secondary outcomes included time to identifying OHCA cause and time-critical diagnoses, SDCT safety, and survival to hospital discharge.

RESULTS

Baseline characteristics between the SDCT (N=104) and the SOC (N=143) cohorts were similar. CT scans (either head, chest, and/or abdomen) were ordered in 74 (52%) of SOC patients. Adding SDCT scanning identified 92% of causes for arrest compared to 75% (SOC-cohort; p value <0.001) and reduced the time to diagnosis by 78% (SDCT 3.1 hours, SOC alone 14.1 hours, p <0.0001). Identification of critical diagnoses was similar between cohorts, but SDCT reduced delayed (>6 hours) identification of critical diagnoses by 81% (p<0.001). SDCT safety endpoints were similar including acute kidney injury. Patient survival to discharge was similar between cohorts.

DISCUSSION

SDCT scanning early after OHCA resuscitation safely improved the efficiency and diagnostic yield for causes of arrest compared to the standard of care alone.

CLINICAL TRIALS NUMBER

NCT03111043.

Attitudes and willingness toward out-of-hospital CPR and AED: A questionnaire study among Chinese middle school students

Objectives

This study's purpose was to assess the attitudes and willingness of middle school students to perform cardiopulmonary resuscitation (CPR) and to use automated external defibrillator (AED) in emergencies, and to evaluate the overall effects of first aid training.

Results

Middle school students demonstrated a high willingness to learn CPR (95.87%) and AED (77.90%). However, the rate of CPR (9.87%) and AED (3.51%) training was relatively low. These trainings could improve their confidence while facing emergencies. Their main concerns were "Lack of first aid knowledge", "Lack of confidence in rescue skills" and "Fear of hurting the patient".

Conclusions

Chinese middle school students are willing to learn CPR and AED skills, but relative trainings are insufficient and should be reinforced.

Differences in Outcome of Patients with Cardiogenic Shock Associated with In-Hospital or Out-of-Hospital Cardiac Arrest

Cardiogenic Shock (CS) complicated by in-hospital (IHCA) or out-of-hospital cardiac arrest (OHCA) has a poor outcome. However, studies regarding the prognostic differences between IHCA and OHCA in CS are limited. In this prospective, observational study, consecutive patients with CS were included in a monocentric registry from June 2019 to May 2021. The prognostic impact of IHCA and OHCA on 30-day all-cause mortality was tested within the entire group and in the subgroups of patients with acute myocardial infarction (AMI) and coronary artery disease (CAD). Statistical analyses included univariable t-test, Spearman's correlation, Kaplan-Meier analyses, as well as uni- and multivariable Cox regression analyses. A total of 151 patients with CS and cardiac arrest were included. IHCA on ICU admission was associated with higher 30-day all-cause mortality compared to OHCA in univariable COX regression and Kaplan-Meier analyses. However, this association was solely driven by patients with AMI (77% vs. 63%; log rank p = 0.023), whereas IHCA was not associated with 30-day all-cause mortality in non-AMI patients (65% vs. 66%; log rank p = 0.780). This finding was confirmed in multivariable COX regression, in which IHCA was solely associated with higher 30-day all-cause mortality in patients with AMI (HR = 2.477; 95% CI 1.258-4.879; p = 0.009), whereas no significant association could be seen in the non-AMI group and in the subgroups of patients with and CAD. CS patients with IHCA showed significantly higher all-cause mortality at 30 days compared to patients with OHCA. This finding was primarily driven by a significant increase in all-cause mortality at 30 days in CS patients with AMI and IHCA, whereas no difference could be seen when differentiated by CAD.

Bystander basic life support and survival after out-of-hospital cardiac arrest: A propensity score matching analysis

INTRODUCTION AND OBJECTIVES

In out-of-hospital cardiac arrest, early recognition, calling for emergency medical assistance, and early cardiopulmonary resuscitation are acknowledged to be the three most important components in the chain of survival. However, bystander basic life support (BLS) initiation rates remain low. The objective of the present study was to evaluate the association between bystander BLS and survival after an out-of-hospital cardiac arrest (OHCA).

METHODS

We conducted a retrospective cohort study of all patients with OHCA with a medical etiology treated by a mobile intensive care unit (MICU) in France from July 2011 to September 2021, as recorded in the French National OHCA Registry (RéAC). Cases in which the bystander was an on-duty fire fighter, paramedic, or emergency physician were excluded. We assessed the characteristics of patients who received bystander BLS vs. those who did not. The two classes of patient were then matched 1:1, using a propensity score. Conditional logistic regression was then used to probe the putative association between bystander BLS and survival.

RESULTS

During the study, 52,303 patients were included; BLS was provided by a bystander in 29,412 of these cases (56.2%). The 30-day survival rates were 7.6% in the BLS group and 2.5% in the no-BLS group (p < 0.001). After matching, bystander BLS was associated with a greater 30-day survival rate (odds ratio (OR) [95% confidence interval (CI)] = 1.77 [1.58-1.98]). Bystander BLS was also associated with greater short-term survival (alive on hospital admission; OR [95%CI] = 1.29 [1.23-1.36]).

CONCLUSIONS

The provision of bystander BLS was associated with a 77% greater likelihood of 30-day survival after OHCA. Given than only one in two OHCA bystanders provides BLS, a greater focus on life saving training for laypeople is essential.

Impact of defibrillation with automated external defibrillator by bystander before defibrillation by emergency medical system personnel on neurological outcome of out-of-hospital cardiac arrest with non-cardiac etiology

Aim of the study

Although defibrillation using automated external defibrillator (AED) by bystander prior to emergency medical system (EMS) arrival was associated with favorable outcomes in out-of-hospital cardiac arrest (OHCA) of cardiac cause, whether it improves outcomes of OHCA due to non-cardiac cause is not clear. We aimed to investigate the impact of defibrillation with AED by bystander before defibrillation by EMS personnel on the outcomes of OHCA of presumed non-cardiac cause.

Methods

This was a retrospective cohort study using the All-Japan Utstein registry (reference period: 2013 to 2017). We included adult patients with OHCA of presumed non-cardiac cause, who had initial shockable rhythm, and who received witnessed arrest bystander cardiopulmonary resuscitation (CPR). Exposure variable was defibrillation with AED by bystander in comparison with initial defibrillation by EMS. Logistic regression analyses were conducted to assess the association between bystander AED shock and favorable neurological outcome (Cerebral Performance Category scale 1 or 2) at one month.

Results

Among the 1,053 patients included for analysis, 57 (5.4%) received bystander AED shock. There was no statistically significant difference in the rate of favorable neurological outcome at one month between groups [9 (15.8%) vs 109 (10.9%), p = 0.26]. Logistic regression analysis adjusted for characteristics, intervention, and time course of CPR showed no association between bystander AED shock and favorable neurological outcome [OR (95% CI): 1.63 (0.70-3.77), p = 0.25].

Conclusion

In this study, defibrillation with AED by bystander before defibrillation by EMS personnel was not associated with the favorable outcomes of OHCA of presumed non-cardiac cause.

Factors affecting public access defibrillator placement decisions in the United Kingdom: A survey study

Aim

This study aimed to understand current community PAD placement strategies and identify factors which influence PAD placement decision-making in the United Kingdom (UK).

Methods

Individuals, groups and organisations involved in PAD placement in the UK were invited to participate in an online survey collecting demographic information, facilitators and barriers to community PAD placement and information used to decide where a PAD is installed in their experiences. Survey responses were analysed through descriptive statistical analysis and thematic analysis.

Results

There were 106 included responses. Distance from another PAD (66%) and availability of a power source (63%) were most frequently used when respondents are deciding where best to install a PAD and historical occurrence of cardiac arrest (29%) was used the least. Three main themes were identified influencing PAD placement: (i) the relationship between the community and PADs emphasising community engagement to create buy-in; (ii) practical barriers and facilitators to PAD placement including securing consent, powering the cabinet, accessibility, security, funding, and guardianship; and (iii) 'risk assessment' methods to estimate the need for PADs including areas of high footfall, population density and type, areas experiencing health inequalities, areas with delayed ambulance response and current PAD provision.

Conclusion

Decision-makers want to install PADs in locations that maximise impact and benefit to the community, but this can be constrained by numerous social and infrastructural factors. The best location to install a PAD depends on local context; work is required to determine how to overcome barriers to optimal community PAD placement.

Out-of-Hospital Cardiac Arrest Prospective Epidemiology Monitoring during the First Five Years of EuReCa Program Implementation in Serbia

INTRODUCTION

Poor outcome is still a challenging concern in patients with out-of-hospital cardiac arrest (OHCA) world-wide and there are large differences between European countries regarding not only incidence rates, but survival rates as well. In 2014, Serbian Resuscitation Council initiated regular data collection on epidemiology of OHCA, according to the European Registry of Cardiac Arrest (EuReCa) study protocol.

STUDY OBJECTIVE

The aim of this study is to analyze the results of the first five-year period after initiation of EuReCa study protocol elements implementation in OHCA epidemiological data collection in Serbia.

METHODS

The observed period in this study is about the data on OHCA, collected within the observed area of 16 municipalities covering 1,604,015 citizens, during the period from October 1, 2014 - December 31, 2019. The study included data on all-cause OHCA in both adult and pediatric patients, according to the EuReCa One study protocol, of which all segments were observed.

RESULTS

Within the study period, 5,196 OHCA patients were observed with annual incidence of 83.60/100,000. Of all registered events, 43.9% were witnessed. The most common collapse location was patient's residence (88.7%). Within the group of initiated cardiopulmonary resuscitation (CPR), cardiac etiology was observed in 80.5% of cases and shockable rhythm in 21.7%. Return of spontaneous circulation (ROSC) prior to hospital admission was significantly more frequently achieved and maintained on admission in witnessed cases, cases occurring out of patient's residence, and in cases with shockable initial rhythm (P <.01).

CONCLUSION

The OHCA incidence in Serbia is comparable with the incidence in the majority of European countries, and survival rates are now significantly higher in Utstein events compared to previous results from Serbia. Enrolment of witnessing bystanders in initiating CPR measures remains a concern requiring effort towards understanding of CPR initiation importance and education of general population in administering CPR measures.

The effect of blood pressure on mortality following out-of-hospital cardiac arrest: a retrospective cohort study of the United Kingdom Intensive Care National Audit and Research Centre database

BACKGROUND

Hypotension following out-of-hospital cardiac arrest (OHCA) may cause secondary brain injury and increase mortality rates. Current guidelines recommend avoiding hypotension. However, the optimal blood pressure following OHCA is unknown. We hypothesised that exposure to hypotension and hypertension in the first 24 h in ICU would be associated with mortality following OHCA.

METHODS

We conducted a retrospective analysis of OHCA patients included in the Intensive Care National Audit and Research Centre Case Mix Programme from 1 January 2010 to 31 December 2019. Restricted cubic splines were created following adjustment for important prognostic variables. We report the adjusted odds ratio for associations between lowest and highest mean arterial pressure (MAP) and systolic blood pressure (SBP) in the first 24 h of ICU care and hospital mortality.

RESULTS

A total of 32,349 patients were included in the analysis. Hospital mortality was 56.2%. The median lowest and highest MAP and SBP were similar in survivors and non-survivors. Both hypotension and hypertension were associated with increased mortality. Patients who had a lowest recorded MAP in the range 60-63 mmHg had the lowest associated mortality. Patients who had a highest recorded MAP in the range 95-104 mmHg had the lowest associated mortality. The association between SBP and mortality followed a similar pattern to MAP.

CONCLUSIONS

We found an association between hypotension and hypertension in the first 24 h in ICU and mortality following OHCA. The inability to distinguish between the median blood pressure of survivors and non-survivors indicates the need for research into individualised blood pressure targets for survivors following OHCA.

Mechanical chest compression and extracorporeal life support for out-of-hospital cardiac arrest. A 30-month observational study in the metropolitan area of Milan, Italy

BACKGROUND

Return of spontaneous circulation (ROSC) is achieved in 25% of out-of-hospital cardiac arrest (OHCA) patients. Mechanical chest compression (mechCPR) may maintain better perfusion during transport, allowing hospital treatments like extracorporeal circulation life support (ECLS). We aim to assess the effectiveness of a pre-hospital protocol introduction.

METHODS

Observational, retrospective study assessing all OHCA patients aged 12-75, with no-flow time <20 min in a metropolitan area (Milan, Italy, 2013-2016).

PRIMARY OUTCOMES

ROSC and Cerebral Performance Category score (CPC) ≤2 at hospital discharge. Logistic regressions with multiple comparison adjustments balanced with propensity scores calculated with inverse probability of treatment weighting were performed.

RESULTS

1366 OHCA were analysed; 305 received mechCPR, 1061 manual chest compressions (manCPR), and 108 ECLS. ROSC and CPC ≤2 were associated with low-flow minutes (odds ratio [95% confidence interval] 0.90 [0.88-0.91] and 0.90 [0.87-0.93]), shockable rhythm (2.52 [1.71-3.72] and 10.68 [5.63-20.28]), defibrillations number (1.15 [1.07-1.23] and 1.15 [1.04-1.26]), and mechCPR (1.86 [1.17-2.96] and 2.06 [1.11-3.81]). With resuscitation times >13 min, mechCPR achieved more frequently ROSC compared to manCPR. Among ECLS patients, 70% had time exceeding protocol: 8 (7.5%) had CPC ≤2 (half of them with low-flow times between 45 and 90 min), 2 (1.9%) survived with severe neurological disabilities, and 13 brain-dead (12.0%) became organ donors.

CONCLUSIONS

MechCPR patients achieved ROSC more frequently than manual CPR patients; mechCPR was a crucial factor in an ECLS protocol for refractory OHCA. ECLS offered a chance of survival to patients who would otherwise die.

Effect of a low-cost instruction card for automated external defibrillator operation in lay rescuers: a randomized simulation study

BACKGROUND

To evaluate whether a simplified self-instruction card can help potential rescue providers use automated external defibrillators (AEDs) more accurately and quickly.

METHODS

From June 1, 2018, to November 30, 2019, a prospective longitudinal randomized controlled simulation study was conducted among 165 laypeople (18-65 years old) without prior AED training. A self-instruction card was designed to illuminate key AED operation procedures. Subjects were randomly divided into the card (n=83) and control (n=82) groups with age stratification. They were then individually evaluated in the same simulated scenario to use AED with (card group) or without the self-instruction card (control group) at baseline, post-training, and at the 3-month follow-up.

RESULTS

At baseline, the card group reached a significantly higher proportion of successful defibrillation (31.1% vs. 15.9%, P=0.03), fully baring the chest (88.9% vs. 63.4%, P<0.001), correct electrode placement (32.5% vs. 17.1%, P=0.03), and resuming cardiopulmonary resuscitation (CPR) (72.3% vs. 9.8%, P<0.001). At post-training and follow-up, there were no significant differences in key behaviors, except for resuming CPR. Time to shock and time to resume CPR were shorter in the card group, while time to power-on AED was not different in each phase of tests. In the 55-65 years group, the card group achieved more skill improvements over the control group compared to the other age groups.

CONCLUSION

The self-instruction card could serve as a direction for first-time AED users and as a reminder for trained subjects. This could be a practical, cost-effective way to improve the AED skills of potential rescue providers among different age groups, including seniors.

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.

Impact of COVID-19 on Out-of-Hospital Cardiac Arrest in Korea

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a global public health crisis that has had a significant impact on emergency medical services (EMS). Several studies have reported an increase in the incidence of out-of-hospital cardiac arrest (OHCA) and a decreased survival due to COVID-19, which has been limited to a short period or has been reported in some regions. This study aimed to investigate the effect of COVID-19 on OHCA patients using a nationwide database.

METHODS

We included adult OHCA patients treated by EMS providers from January 19, 2019 to January 20, 2021. The years before and after the first confirmed case in Korea were set as the non-COVID-19 and COVID-19 periods, respectively. The main exposure of interest was the COVID-19 period, and the primary outcome was prehospital return of spontaneous circulation (ROSC). Other OHCA variables were compared before and after the COVID-19 pandemic and analyzed. We performed a multivariable logistic regression analysis to understand the independent effect of the COVID-19 period on prehospital ROSC.

RESULTS

The final analysis included 51,921 eligible patients, including 25,355 (48.8%) during the non-COVID-19 period and 26,566 (51.2%) during the COVID-19 period. Prehospital ROSC deteriorated during the COVID-19 period (10.2% vs. 11.1%, P = 0.001). In the main analysis, the adjusted odds ratios (AORs) for prehospital ROSC showed no significant differences between the COVID-19 and non-COVID-19 periods (AOR [95% confidence interval], 1.02 [0.96-1.09]).

CONCLUSION

This study found that the proportion of prehospital ROSC was lower during the COVID-19 period than during the non-COVID-19 period; however, there was no statistical significance when adjusting for potential confounders. Continuous efforts are needed to restore the broken chain of survival in the prehospital phase and increase the survival rate of OHCA patients.

Augmented-Medication CardioPulmonary Resuscitation Trials in out-of-hospital cardiac arrest: a pilot randomized controlled trial

BACKGROUND

Previously conducted physician-centered trials on the usefulness of vasopressin have yielded negative results; thus, patient-oriented trials have been warranted. We hypothesize that Augmented-Medication CardioPulmonary Resuscitation could be helpful for selected patients with out-of-hospital cardiac arrest (OHCA).

METHODS

This is a double-blind, single-center, randomized, placebo-controlled trial conducted in the emergency department in a tertiary, university-affiliated hospital in Seoul, Korea. A total of 148 adults with non-traumatic OHCA who had initial diastolic blood pressure (DBP) < 20 mm Hg via invasive arterial monitoring during the early cardiac compression period were randomly assigned to two groups. Patients received a dose of 40 IU of vasopressin or placebo with initial epinephrine. The primary endpoint was a sustained return of spontaneous circulation. Secondary endpoints were survival discharge, and neurologic outcomes at discharge.

RESULTS

Of the 180 included patients, 32 were excluded, and 148 were enrolled in the trial. A sustained return of spontaneous circulation was achieved by 27 patients (36.5%) in the vasopressin group and 24 patients (32.4%) in the control group (risk difference, 4.1%; P = .60). Survival discharge and good neurologic outcomes did not differ between groups. The trial group had significantly higher median DBPs during resuscitation than the control group (16.0 vs. 14.5 mm Hg, P < 0.01). There was no difference in end-tidal carbon dioxide, acidosis, and lactate levels at baseline, 10 min, and end-time.

CONCLUSION

Among patients with refractory vasodilatory shock in OHCA, administration of vasopressin, compared with placebo, did not significantly increase the likelihood of return of spontaneous circulation.

Public attitudes towards bystander CPR and their association with social deprivation: Findings from a cross sectional study in North England

Background

Bystander cardiopulmonary resuscitation (BCPR) is undertaken in only 40% of out of hospital cardiac arrests (OHCAs) in the UK. Lower rates of BCPR and public access defibrillator (PAD) use have been correlated with lower socio-economic status (SES). The aim of this study was to examine knowledge and attitudes towards BCPR and PAD's using a study specific questionnaire, and to understand how these potentially interact with individual characteristics and SES.

Methods

Cross-sectional study between July-December 2021 across areas of varying SES in North England.

Results

Six hundred and one individuals completed the survey instrument (mean age = 51.9 years, 52.2 % female). Increased age was associated with being less willing to call 999 (p < 0.001) and follow call handler advice (p < 0.001). Female respondents were less comfortable performing BCPR than male respondents (p = 0.006). Individuals from least deprived areas were less likely to report comfort performing CPR, (p = 0.016) and less likely to know what a PAD is for, (p = 0.025). Higher education level was associated with increased ability to recognise OHCA (p = 0.005) and understanding of what a PAD is for (p < 0.001). Individuals with higher income were more likely to state they would follow advice regarding BCPR (p = 0.017) and report comfort using a PAD (p = 0.029).

Conclusion

Individual characteristics such as age and ethnicity, rather than SES, are indicators of knowledge, willingness, and perceived competency to perform BCPR. Policy makers should avoid using SES alone to target interventions. Future research should examine how cultural identity and social cohesion intersect with these characteristics to influence willingness to perform BCPR.

Drug routes in out-of-hospital cardiac arrest: A summary of current evidence

Recent evidence showing the clinical effectiveness of drug therapy in cardiac arrest has led to renewed interest in the optimal route for drug administration in adult out-of-hospital cardiac arrest. Current resuscitation guidelines support use of the intravenous route for intra-arrest drug delivery, with the intraosseous route reserved for patients in whom intravenous access cannot be established. We sought to evaluate current evidence on drug route for administration of cardiac arrest drugs, with a specific focus on the intravenous and intraosseous route. We identified relevant animal, manikin, and human studies through targeted searches of MEDLINE in June 2022. Across pre-hospital systems, there is wide variation in use of the intraosseous route. Early administration of cardiac arrest drugs is associated with improved patient outcomes. Challenges in obtaining intravenous access mean that the intraosseous access may facilitate earlier drug administration. However, time from administration to the central circulation is unclear with pharmacokinetic data limited mainly to animal studies. Observational studies comparing the effect of intravenous and intraosseous drug administration on patient outcomes are challenging to interpret because of resuscitation time bias and other confounders. To date, no randomised controlled trial has directly compared the effect on patient outcomes of intraosseous compared with intravenous drug administration in cardiac arrest. The International Liaison Committee on Resuscitation has described the urgent need for randomised controlled trials comparing the intravenous and intraosseous route in adult out-of-hospital cardiac arrest. Ongoing clinical trials will directly address this knowledge gap.

British Cardiovascular Intervention Society Consensus Position Statement on Out-of-hospital Cardiac Arrest 2: Post-discharge Rehabilitation

Out-of-hospital cardiac arrest (OHCA) is a major public health issue that poses significant challenges both in immediate management and long-term follow-up. Survivors of OHCA often experience a combination of complex medical, physical and psychological needs that have a significant impact on quality of life. Guidelines suggest a multi-dimensional follow-up to address both physical and non-physical domains for survivors. However, it is likely that there is substantial unwarranted variation in provision of services throughout the UK. Currently, there is no nationally agreed model for the follow-up of OHCA survivors and there is an urgent need for a set of standards and guidelines in order to ensure equal access for all. Accordingly, the British Cardiovascular Interventional Society established a multi-disciplinary working group to develop a position statement that summarises the most up-to-date evidence and provides guidance on essential and desirable services for a dedicated follow-up pathway for survivors of OHCA.

Heroism and paramedic practice: A constructivist metasynthesis of qualitative research

OBJECTIVES

We aimed to identify, appraise, and synthesise the qualitative literature to develop theory on heroism and paramedic practice.

HYPOTHESIS/RESEARCH QUESTION

What does published literature tell us about heroism and paramedic practice?

SETTING

Paramedics and other healthcare workers (HCWs) faced an outpouring of public support for them early in the COVID-19 pandemic which brought into focus the relationship between them and society, where they are portrayed as heroes.

PARTICIPANTS

We conducted a metasynthesis using Evolved Grounded Theory and procedural guidelines of Noblit and Hare to guide analysis. Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols (PRISMA-P) guidelines were also applied.

RESULTS

151 papers were retrieved and eleven included in the final sample. Studies were moderate to very low quality, involving a wide range of methodologies and settings; none specifically explored heroism and paramedic practice. The following interrelated themes were constructed on heroism and paramedic practice: (a) Myth, Folk law, and storytelling in heroism and paramedic practice (b) The epic journey of heroism and paramedic practice (c) Heroes and Zeroes: The fluctuating Societal Value in heroism and paramedic practice (d) Politicisation, and objectification in Heroism and Paramedic practice.

CONCLUSION

Paramedics have long been characterised as heroes, but this may not reflect their everyday experiences. Heroism in paramedic practice can provide scripts for prosocial action, inspiring others, and leading to more social heroic actions. Paramedics may however be ambivalent to such heroism narratives, due to politicisation, and objectification in the media and society. This metasynthesis is only one of many possible constructions of heroism and paramedic practice and is the first point in making sense of and developing theory on heroism and paramedic practice.

STUDY REGISTRATION

PROSPERO: CRD42021234851.