Compression-only CPR or standard CPR in out-of-hospital cardiac arrest

Ventilation during cardiopulmonary resuscitation: A narrative review

Ventilation during cardiopulmonary resuscitation is vital to achieve optimal oxygenation but continues to be a subject of ongoing debate. This narrative review aims to provide an overview of various components and challenges of ventilation during cardiopulmonary resuscitation, highlighting key areas of uncertainty in the current understanding of ventilation management. It addresses the pulmonary pathophysiology during cardiac arrest, the importance of adequate alveolar ventilation, recommendations concerning the maintenance of airway patency, tidal volumes and ventilation rates in both synchronous and asynchronous ventilation. Additionally, it discusses ventilation adjuncts such as the impedance threshold device, the role of positive end-expiratory pressure ventilation, and passive oxygenation. Finally, this review offers directions for future research.

The role of bystander CPR in out-of-hospital cardiac arrest: what the evidence tells us

Out-of-hospital cardiac arrest (OHCA) is a global public health problem. Lay bystanders witness almost half of OHCA, so early recognition is critical to allow immediate initiation of cardiopulmonary resuscitation (CPR) by the bystander. The present investigation aims to analyze the most recent scientific evidence of the effect of bystander CPR on survival after an OHCA. A systematic literature review was carried out at the "Web of Science," "Scopus," and "PubMed" databases, including publications from the last 20 years. After inclusion/exclusion criteria, 37 articles were identified. Results indicate that patients who receive CPR are more likely to survive than those who don't, and CPR is associated with a good quality of life post-OHCA. Emphasis should be placed on practicing chest compressions only when the bystander has not mastered the artificial ventilation technique. Finding an AED is the first step to using it in an OHCA situation. Correct use of an AED by laypeople is associated with nearly double the survival rate after an OHCA when compared to standard CPR. It is important to promote CPR and AED training to non-professionals, such as community residents and youth, as training is associated with higher success rates of effective CPR-AED. A mobile phone positioning system to recruit trained laypeople or text message alerts to send citizen volunteers as well as assistance through a mobile app appear to have significant advantages in practicing effective CPR. The benefits of bystander CPR outweigh the risk of injury to victims, highlighting the need to disseminate training to laypeople.

2024 RECOVER Guidelines: Basic Life Support. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR

OBJECTIVE

To systematically review evidence and devise treatment recommendations for basic life support (BLS) in dogs and cats and to identify critical knowledge gaps.

DESIGN

Standardized, systematic evaluation of literature pertinent to BLS following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by 2 Evidence Evaluators, and findings were reconciled by BLS Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk to benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4 weeks prior to finalization.

SETTING

Transdisciplinary, international collaboration in university, specialty, and emergency practice.

RESULTS

Twenty questions regarding animal position, chest compression point and technique, ventilation strategies, as well as the duration of CPR cycles and chest compression pauses were examined, and 32 treatment recommendations were formulated. Out of these, 25 addressed chest compressions and 7 informed ventilation during CPR. The recommendations were founded predominantly on very low quality of evidence and expert opinion. These new treatment recommendations continue to emphasize the critical importance of high-quality, uninterrupted chest compressions, with a modification suggested for the chest compression technique in wide-chested dogs. When intubation is not possible, bag-mask ventilation using a tight-fitting facemask with oxygen supplementation is recommended rather than mouth-to-nose ventilation.

CONCLUSIONS

These updated RECOVER BLS treatment recommendations emphasize continuous chest compressions, conformation-specific chest compression techniques, and ventilation for all animals. Very low quality of evidence due to absence of clinical data in dogs and cats consistently compromised the certainty of recommendations, emphasizing the need for more veterinary research in this area.

Intentional interruptions during compression only CPR: A scoping review

Introduction

Out of hospital cardiac arrest (OHCA) remains one of the main causes of death among industrialized countries. The initiation of cardiopulmonary resuscitation (CPR) by laypeople before the arrival of emergency medical services improves survival. Mouth-to-mouth ventilation may constitute a hindering factor to start bystander CPR, while during continuous chest compressions (CCC) CPR quality decreases rapidly. The aim of this scoping review is to examine the existing literature on strategies that investigate the inclusion of intentional pauses during compression-only resuscitation (CO-CPR) to improve the performance in the context of single lay rescuer OHCA.

Methods

The protocol of this Scoping review was prospectively registered in Open Science Framework (https://osf.io/rvn8j). A systematic search of PubMed, Scopus, EMBASE, CINAHL was performed.

Results

Six articles were included. All studies were carried out on simulation manikins and involved a total of 1214 subjects. One study had a multicenter design. Three studies were randomized controlled simulation trials, the rest were prospective randomized crossover studies. The tested protocols were heterogeneous and compared CCC to CO-CPR with intentional interruptions of various length. The most common primary outcome was compressions depth. Compression rate, rescuers' perceived exertion and composite outcomes were also evaluated. Compressions depth and perceived exertion improved in most study groups while compression rate and chest compression fraction remained within guidelines indications.

Conclusions

In simulation studies, the inclusion of intentional interruptions during CO-CPR within the specific scenario of single rescuer bystander CPR during OHCA may improve the rate of compressions with correct depth and lower rate of perceived exertion. Further high-quality research and feasibility and safety of protocols incorporating intentional interruptions during CO-CPR may be justified.

Complex Heart-Lung Ventilator Emergencies in the CICU

This review aims to enhance the comprehension and management of cardiopulmonary interactions in critically ill patients with cardiovascular disease undergoing mechanical ventilation. Highlighting the significance of maintaining a delicate balance, this article emphasizes the crucial role of adjusting ventilation parameters based on both invasive and noninvasive monitoring. It provides recommendations for the induction and liberation from mechanical ventilation. Special attention is given to the identification of auto-PEEP (positive end-expiratory pressure) and other situations that may impact hemodynamics and patients' outcomes.

Compression-Only or Standard Cardiopulmonary Resuscitation for Trained Laypersons in Out-of-Hospital Cardiac Arrest: A Nationwide Randomized Trial in Sweden

BACKGROUND

The ongoing TANGO2 (Telephone Assisted CPR. AN evaluation of efficacy amonGst cOmpression only and standard CPR) trial is designed to evaluate whether compression-only cardiopulmonary resuscitation (CPR) by trained laypersons is noninferior to standard CPR in adult out-of-hospital cardiac arrest. This pilot study assesses feasibility, safety, and intermediate clinical outcomes as part of the larger TANGO2 survival trial.

METHODS

Emergency medical dispatch calls of suspected out-of-hospital cardiac arrest were screened for inclusion at 18 dispatch centers in Sweden between January 1, 2017, and March 12, 2020. Inclusion criteria were witnessed event, bystander on the scene with previous CPR training, age above 18 years of age, and no signs of trauma, pregnancy, or intoxication. Cases were randomized 1:1 at the dispatch center to either instructions to perform compression-only CPR (intervention) or instructions to perform standard CPR (control). Feasibility included evaluation of inclusion, randomization, and adherence to protocol. Safety measures were time to emergency medical service dispatch CPR instructions, and to start of CPR, intermediate clinical outcome was defined as 1-day survival.

RESULTS

Of 11 838 calls of suspected out-of-hospital cardiac arrest screened for inclusion, 2168 were randomized and 1250 (57.7%) were out-of-hospital cardiac arrests treated by the emergency medical service. Of these, 640 were assigned to intervention and 610 to control. Crossover from intervention to control occurred in 16.3% and from control to intervention in 18.5%. The median time from emergency call to ambulance dispatch was 1 minute and 36 s (interquartile range, 1.1-2.2) in the intervention group and 1 minute and 30 s (interquartile range, 1.1-2.2) in the control group. Survival to 1 day was 28.6% versus 28.4% (P=0.984) for intervention and control, respectively.

CONCLUSIONS

In this national randomized pilot trial, compression-only CPR versus standard CPR by trained laypersons was feasible. No differences in safety measures or short-term survival were found between the 2 strategies. Efforts to reduce crossover are important and may strengthen the ongoing main trial that will assess differences in long-term survival.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02401633.

Outcomes of out of hospital sudden cardiac arrest in India: A review and proposed reforms

BACKGROUND

Bystander cardiopulmonary resuscitation (CPR) is the cornerstone in managing out-of-hospital cardiac arrest (OHCA). However, India lacks a formal sudden cardiac arrest (SCA) registry and the infrastructure for a robust emergency medical services (EMS) response system. Also, there exists an opportunity to improve widespread health literacy and awareness regarding SCA. Other confounding variables, including religious, societal, and cultural sentiments hindering timely intervention, need to be considered for better SCA outcomes.

OBJECTIVES

We highlight the current trends and practices of managing OHCA in India and lay the groundwork for improving the awareness, education, and infrastructure regarding the management of SCA.

CONCLUSION

Effective management of OHCA in India needs collaborative grassroots reformation. Establishing a large-scale SCA registry and creating official and societal guidelines will be pivotal for transforming OHCA patient outcomes.

Airway Management of the Cardiac Arrest Victim

Appropriate airway management is critical to successful cardiac arrest resuscitation. However, the timing and method of airway management during cardiac arrest have traditionally been guided by expert and consensus opinion informed by observational data. In the last 5 years, recent studies, including several randomized controlled trials (RCTs), have provided additional clarity to help guide airway management. This article will review both current data and guidelines for airway management in cardiac arrest, a stepwise approach to airway management, the utility of various airway adjuncts, and best practices for oxygenation and ventilation in the peri-arrest period.

Cardiopulmonary Resuscitation: The Importance of the Basics

Cardiac arrest is the loss of organized cardiac activity. Unfortunately, survival to hospital discharge is poor, despite recent scientific advances. The goals of cardiopulmonary resuscitation (CPR) are to restore circulation and identify and correct an underlying etiology. High-quality compressions remain the foundation of CPR, optimizing coronary and cerebral perfusion pressure. High-quality compressions must be performed at the appropriate rate and depth. Interruptions in compressions are detrimental to management. Mechanical compression devices are not associated with improved outcomes but can assist in several situations.

The interaction effect of bystander cardiopulmonary resuscitation (CPR) and dispatcher CPR on outcomes after out-of-hospital cardiac arrest

This study aimed to evaluate the effects of bystander cardiopulmonary resuscitation (CPR) and dispatcher-assisted CPR (DA-CPR) on outcomes after out-of-hospital cardiac arrest (OHCA). We conducted a prospective observational study using the Korean Cardiac Arrest Research Consortium registry database and enrolled adults aged > 20 years who sustained OHCA. The study population comprised 13,864 patients from October 1, 2015, to June 30, 2021. All enrolled patients were transported to the emergency room and resuscitated by the emergency medical personnel. Patients with terminal illnesses, pregnancy, "do not resuscitate" cards, and insufficient recorded information were excluded. Good neurologic outcomes were noted in 6.5%, 9.9%, and 9.6% of patients in the "no bystander", "standard bystander", and "compression-only bystander" CPR groups, respectively, and differed significantly (p < 0.001). Survival to discharge differed significantly (p < 0.001) between groups at 10.8%, 13.1%, and 13.2%, respectively. In a multivariable model, the interaction between "compression-only" and DA-CPR showed a positive effect on good neurological outcomes and survival to discharge with an odds ratio of 1.93 (Confidence interval, CI 1.28-2.91, p = 0.002) and 1.74 (CI 1.24-2.44, p = 0.001), respectively. In conclusion, the interaction between compression-only CPR and DA-CPR is significantly associated with good neurological and survival outcomes after OHCA. Education for bystanders and dispatchers should adhere to the current guidelines to improve outcomes among OHCA victims.

Dissemination of Chest Compression-Only Cardiopulmonary Resuscitation by Bystanders for Out-of-Hospital Cardiac Arrest in Students: A Nationwide Investigation in Japan

We aimed to investigate how the types of bystander-initiated cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) among students have changed recently. We also determined the association between two types of bystander-CPRs (i.e., chest compression-only CPR [CCCPR] and conventional CPR with rescue breathing [CCRB]) and survival after OHCA. From a nationwide registry of pediatric OHCAs occurring in school settings in Japan, the data of 253 non-traumatic OHCA patients (elementary, junior high, and high school/technical college students) receiving bystander-CPR between April 2008 and December 2017 were analyzed. Multivariable logistic regression analysis was conducted to assess the impact of different types of bystander-CPR on 30-day survival with favorable neurological outcomes. The proportion of patients receiving CCCPR increased from 25.0% during 2008–2009 to 55.3% during 2016–2017 (p for trend < 0.001). Overall, 53.2% (50/94) of patients receiving CCCPR and 46.5% (74/159) of those receiving CCRB survived for 30 days with favorable neurological outcomes. Multivariable analysis showed no significant difference in outcomes between the two groups (adjusted odds ratio: 1.23, 95% confidence interval: 0.67–2.28). In this setting, CCCPR is a common type of bystander-CPR for OHCA in students, and the effectiveness of CCCPR and CCRB on survival outcomes seems comparable.

Basic life support and systems saving lives

PURPOSE OF REVIEW

To describe recent science in basic life support (BLS) after cardiac arrest and how evolving knowledge in resuscitation is changing current guidelines and practices.

RECENT FINDINGS

The core elements of BLS have remained mostly unchanged since 2005 when Cardiopulmonary Resuscitation recommendations were changed from 2 ventilations to 15 compressions and up to three stacked shocks for shockable rhythms, to 30 compressions to 2 ventilations and single shocks. Since 2010, basic life support has largely focused on the importance of providing high-quality CPR for professional and lay rescuers alike. The most recent resuscitation updates has seen an increased focus on the systems perspective. The 'Systems Saving Lives' concept emphasizes the interconnection between community and Emergency Medical Services (EMS). The main changes in current resuscitation practice are within three important basic life support domains: recognition of cardiac arrest, interaction between rescuers and EMS and improving resuscitation quality.

SUMMARY

This review highlights the importance of strengthening both community and emergency medical services efforts to improve outcomes in cardiac arrest. Strategies that enhance the communication and collaboration between lay rescuers and professional resuscitation systems are important new avenues to pursue in developing systems that save more lives.

The impact of bystander cardiopulmonary resuscitation on patients with out-of-hospital cardiac arrests

Out-of-hospital cardiac arrest (OHCA) is one of the leading causes of death around the world. Bystander cardiopulmonary resuscitation (CPR) is an independent factor to improve OHCA survival. However, the prevalence of bystander CPR remains low worldwide. Community interventions such as mandatory school CPR training or targeting CPR training to family members of high-risk cardiac patients are possible strategies to improve bystander CPR rate. Real-time feedback, hands-on practice with a manikin, and metronome assistance may increase the quality of CPR. Dispatcher-assistance and compression-only CPR for untrained bystanders have shown to increase bystander CPR rate and increase survival to hospital discharge. After return of spontaneous circulation, targeted temperature management should be performed to improve neurological function. This review focuses on the impact of bystander CPR on clinical outcomes and strategies to optimize the prevalence and quality of bystander CPR.

Dispatcher instructions for bystander cardiopulmonary resuscitation and neurologically intact survival after bystander-witnessed out-of-hospital cardiac arrests: a nationwide, population-based observational study

Background

The International Liaison Committee on Resuscitation recommends that dispatchers provide instructions to perform compression-only cardiopulmonary resuscitation (CPR) to callers responding to adults with out-of-hospital cardiac arrest (OHCA). This study aimed to determine the optimal dispatcher-assisted CPR (DA-CPR) instructions for OHCA.

Methods

We analysed the records of 24,947 adult patients (aged ≥ 18 years) who received bystander DA-CPR after bystander-witnessed OHCA. Data were obtained from a prospectively recorded Japanese nationwide Utstein-style database for a 2-year period (2016–2017). Patients were divided into compression-only DA-CPR (n = 22,778) and conventional DA-CPR (with a compression-to-ventilation ratio of 30:2, n = 2169) groups. The primary outcome measure was 1-month neurological intact survival, defined as a cerebral performance category score of 1–2 (CPC 1–2).

Results

The 1-month CPC 1–2 rate was significantly higher in the conventional DA-CPR group than in the compression-only DA-CPR group (before propensity score (PS) matching, 7.5% [162/2169] versus 5.8% [1309/22778], p < 0.01; after PS matching, 7.5% (162/2169) versus 5.7% (123/2169), p < 0.05). Compared with compression-only DA-CPR, conventional DA-CPR was associated with increased odds of 1-month CPC 1–2 (before PS matching, adjusted odds ratio 1.39, 95% confidence interval [CI] 1.14–1.70, p < 0.01; after PS matching, adjusted odds ratio 1.34, 95% CI 1.00–1.79, p < 0.05).

Conclusion

Within the limitations of this retrospective observational study, conventional DA-CPR with a compression-to-ventilation ratio of 30:2 was preferable to compression-only DA-CPR as an optimal DA-CPR instruction for coaching callers to perform bystander CPR for adult patients with bystander-witnessed OHCAs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03825-w.

Compression-Only Versus Rescue-Breathing Cardiopulmonary Resuscitation After Pediatric Out-of-Hospital Cardiac Arrest

BACKGROUND

There are conflicting data regarding the benefit of compression-only bystander cardiopulmonary resuscitation (CO-CPR) compared with CPR with rescue breathing (RB-CPR) after pediatric out-of-hospital cardiac arrest (OHCA).

OBJECTIVES

This study sought to test the hypothesis that RB-CPR is associated with improved neurologically favorable survival compared with CO-CPR following pediatric OHCA, and to characterize age-stratified outcomes with CPR type compared with no bystander CPR (NO-CPR).

METHODS

Analysis of the CARES registry (Cardiac Arrest Registry to Enhance Survival) for nontraumatic pediatric OHCAs (patients aged ≤18 years) from 2013-2019 was performed. Age groups included infants (<1 year), children (1 to 11 years), and adolescents (≥12 years). The primary outcome was neurologically favorable survival at hospital discharge.

RESULTS

Of 13,060 pediatric OHCAs, 46.5% received bystander CPR. CO-CPR was the most common bystander CPR type. In the overall cohort, neurologically favorable survival was associated with RB-CPR (adjusted OR: 2.16; 95% CI: 1.78-2.62) and CO-CPR (adjusted OR: 1.61; 95% CI: 1.34-1.94) compared with NO-CPR. RB-CPR was associated with a higher odds of neurologically favorable survival compared with CO-CPR (adjusted OR: 1.36; 95% CI: 1.10-1.68). In age-stratified analysis, RB-CPR was associated with better neurologically favorable survival versus NO-CPR in all age groups. CO-CPR was associated with better neurologically favorable survival compared with NO-CPR in children and adolescents, but not in infants.

CONCLUSIONS

CO-CPR was the most common type of bystander CPR in pediatric OHCA. RB-CPR was associated with better outcomes compared with CO-CPR. These results support present guidelines for RB-CPR as the preferred CPR modality for pediatric OHCA.

Precision Cardiac Arrest Resuscitation Based on Etiology

Cardiac arrest results from a broad range of etiologies that can be broadly grouped as sudden and asphyxial. Animal studies point to differences in injury pathways invoked in the heart and brain that drive injury and outcome after these different forms of cardiac arrest. Present guidelines largely ignore etiology in their management recommendations. Existing clinical data reveal significant heterogeneity in the utility of presently employed resuscitation and postresuscitation strategies based on etiology. The development of future neuroprotective and cardioprotective therapies should also take etiology into consideration to optimize the chances for successful translation.

Different forms of bystander cardiopulmonary resuscitation in out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA) is a major cause of death in the Western world with an estimated number of 275 000 treated with resuscitation attempts by the Emergency Medical Services (EMS) in Europe each year. Overall survival rates remain low, and most studies indicate that around 1 out 10 will survive to 30 days. Amongst the strongest factors associated with survival in OHCA is first recorded rhythm amendable to defibrillation, early defibrillation and prompt initiation of cardiopulmonary resuscitation (CPR). Overall, CPR started prior to EMS arrival has repeatedly been shown to be associated with survival rates 2-3 times higher compared with no such initiation. The primary goal of CPR is to generate sufficient blood flow to vital organs, mainly the brain and heart, until restoration of spontaneous circulation can be achieved. Barriers to the initiation of CPR by bystanders in OHCA include fear of being incapable, causing harm, and transmission of infectious diseases. Partly due to these barriers, and low rates of CPR, the concept of CPR with compression only was proposed as a simpler form of resuscitation with the aim to be more widely accepted by the public in the 1990s. But how reliable is the evidence supporting this simpler form of CPR, and are the outcomes after CO-CPR comparable to standard CPR?

Computed Tomography Imaging in Simulated Ongoing Cardiopulmonary Resuscitation: No Need to Switch Off the Chest Compression Device during Image Acquisition

Computed tomography (CT) represents the current standard for imaging of patients with acute life-threatening diseases. As some patients present with circulatory arrest, they require cardiopulmonary resuscitation. Automated chest compression devices are used to continue resuscitation during CT examinations, but tend to cause motion artifacts degrading diagnostic evaluation of the chest. The aim was to investigate and evaluate a CT protocol for motion-free imaging of thoracic structures during ongoing mechanical resuscitation. The standard CT trauma protocol and a CT protocol with ECG triggering using a simulated ECG were applied in an experimental setup to examine a compressible thorax phantom during resuscitation with two different compression devices. Twenty-eight phantom examinations were performed, 14 with AutoPulse^® and 14 with corpuls cpr^®. With each device, seven CT examinations were carried out with ECG triggering and seven without. Image quality improved significantly applying the ECG-triggered protocol (p < 0.001), which allowed almost artifact-free chest evaluation. With the investigated protocol, radiation exposure was 5.09% higher (15.51 mSv vs. 14.76 mSv), and average reconstruction time of CT scans increased from 45 to 76 s. Image acquisition using the proposed CT protocol prevents thoracic motion artifacts and facilitates diagnosis of acute life-threatening conditions during continuous automated chest compression.

To ventilate or not to ventilate during bystander CPR - A EuReCa TWO analysis

BACKGROUND

Survival after out-of-hospital cardiac arrest (OHCA) is still low. For every minute without resuscitation the likelihood of survival decreases. One critical step is initiation of immediate, high quality cardiopulmonary resuscitation (CPR). The aim of this subgroup analysis of data collected for the European Registry of Cardiac Arrest Study number 2 (EuReCa TWO) was to investigate the association between OHCA survival and two types of bystander CPR namely: chest compression only CPR (CConly) and CPR with chest compressions and ventilations (FullCPR).

METHOD

In this subgroup analysis of EuReCa TWO, all patients who received bystander CPR were included. Outcomes were return of spontaneous circulation and survival to 30-days or hospital discharge. A multilevel binary logistic regression analysis with survival as the dependent variable was performed.

RESULTS

A total of 5884 patients were included in the analysis, varying between countries from 21 to 1444. Survival was 320 (8%) in the CConly group and 174 (13%) in the FullCPR group. After adjustment for age, sex, location, rhythm, cause, time to scene, witnessed collapse and country, patients who received FullCPR had a significantly higher survival rate when compared to those who received CConly (adjusted odds ration 1.46, 95% confidence interval 1.17-1.83).

CONCLUSION

In this analysis, FullCPR was associated with higher survival compared to CConly. Guidelines should continue to emphasise the importance of compressions and ventilations during resuscitation for patients who suffer OHCA and CPR courses should continue to teach both.

Impact of dispatcher-assisted cardiopulmonary resuscitation on neurologically intact survival in out-of-hospital cardiac arrest: a systematic review

Background

Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) increases neurologically intact survival in out-of-hospital cardiac arrest (OHCA) according to several studies. This systematic review summarizes neurologically intact survival outcomes of DA-CPR in comparison with bystander-initiated CPR and no bystander CPR in OHCA.

Methods

The systematic review was conducted according to the PRISMA guidelines. All studies including adult and/or pediatric OHCAs that compared DA-CPR with bystander-initiated CPR or no bystander CPR were included. Primary outcome was neurologically intact survival at discharge, one-month or longer. Studies were searched for in PubMed (MEDLINE), EMBASE, and the Cochrane Library databases. The risk of bias was evaluated using the Newcastle-Ottawa Scale.

Results

The search string generated 4742 citations of which 33 studies were eligible for inclusion. Due to overlapping study populations, the review included 14 studies. All studies were observational. The study populations were heterogeneous and included adult, pediatric and mixed populations. Some studies reported only witnessed cardiac arrests, arrests of cardiac ethiology, and/or shockable rhythm. The individual studies scored between six and nine on the Newcastle-Ottawa Scale of risk of bias. The median neurologically intact survival at hospital discharge with DA-CPR was 7.0% (interquartile range (IQR): 5.1–10.8%), with bystander-initiated CPR 7.5% (IQR: 6.6–10.2%), and with no bystander CPR 4.4% (IQR: 2.0–9.0%) (four studies). At one-month neurologically intact survival with DA-CPR was 3.1% (IQR: 1.6–3.4%), with bystander-initiated CPR 5.7% (IQR: 5.0–6.0%), and with no bystander CPR 2.5% (IQR: 2.1–2.6%) (three studies).

Conclusion

Both DA-CPR and bystander-initiated CPR increase neurologically intact survival compared with no bystander CPR. However, DA-CPR demonstrates inferior outcomes compared with bystander-initiated CPR. Early CPR is crucial, thus in cases where bystanders have not initiated CPR, DA-CPR provides an opportunity to improve neurologically intact survival following OHCA. Variability in OHCA outcomes across studies and multiple confounding factors were identified.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00875-5.

Cardiac arrest in COVID-19: characteristics and outcomes of in- and out-of-hospital cardiac arrest. A report from the Swedish Registry for Cardiopulmonary Resuscitation

Aim

To study the characteristics and outcome among cardiac arrest cases with COVID-19 and differences between the pre-pandemic and the pandemic period in out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA).

Method and results

We included all patients reported to the Swedish Registry for Cardiopulmonary Resuscitation from 1 January to 20 July 2020. We defined 16 March 2020 as the start of the pandemic. We assessed overall and 30-day mortality using Cox regression and logistic regression, respectively. We studied 1946 cases of OHCA and 1080 cases of IHCA during the entire period. During the pandemic, 88 (10.0%) of OHCAs and 72 (16.1%) of IHCAs had ongoing COVID-19. With regards to OHCA during the pandemic, the odds ratio for 30-day mortality in COVID-19-positive cases, compared with COVID-19-negative cases, was 3.40 [95% confidence interval (CI) 1.31–11.64]; the corresponding hazard ratio was 1.45 (95% CI 1.13–1.85). Adjusted 30-day survival was 4.7% for patients with COVID-19, 9.8% for patients without COVID-19, and 7.6% in the pre-pandemic period. With regards to IHCA during the pandemic, the odds ratio for COVID-19-positive cases, compared with COVID-19-negative cases, was 2.27 (95% CI 1.27–4.24); the corresponding hazard ratio was 1.48 (95% CI 1.09–2.01). Adjusted 30-day survival was 23.1% in COVID-19-positive cases, 39.5% in patients without COVID-19, and 36.4% in the pre-pandemic period.

Conclusion

During the pandemic phase, COVID-19 was involved in at least 10% of all OHCAs and 16% of IHCAs, and, among COVID-19 cases, 30-day mortality was increased 3.4-fold in OHCA and 2.3-fold in IHCA.

European Resuscitation Council Guidelines 2021: Systems saving lives

The European Resuscitation Council (ERC) has produced these Systems Saving Lives guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include chain of survival, measuring performance of resuscitation, social media and smartphones apps for engaging community, European Restart a Heart Day, World Restart a Heart, KIDS SAVE LIVES campaign, lower-resource setting, European Resuscitation Academy and Global Resuscitation Alliance, early warning scores, rapid response systems, and medical emergency team, cardiac arrest centres and role of dispatcher.

Opioid-Associated Out-of-Hospital Cardiac Arrest: Distinctive Clinical Features and Implications for Health Care and Public Responses: A Scientific Statement From the American Heart Association

Opioid overdose is the leading cause of death for Americans 25 to 64 years of age, and opioid use disorder affects >2 million Americans. The epidemiology of opioid-associated out-of-hospital cardiac arrest in the United States is changing rapidly, with exponential increases in death resulting from synthetic opioids and linear increases in heroin deaths more than offsetting modest reductions in deaths from prescription opioids. The pathophysiology of polysubstance toxidromes involving opioids, asphyxial death, and prolonged hypoxemia leading to global ischemia (cardiac arrest) differs from that of sudden cardiac arrest. People who use opioids may also develop bacteremia, central nervous system vasculitis and leukoencephalopathy, torsades de pointes, pulmonary vasculopathy, and pulmonary edema. Emergency management of opioid poisoning requires recognition by the lay public or emergency dispatchers, prompt emergency response, and effective ventilation coupled to compressions in the setting of opioid-associated out-of-hospital cardiac arrest. Effective ventilation is challenging to teach, whereas naloxone, an opioid antagonist, can be administered by emergency medical personnel, trained laypeople, and the general public with dispatcher instruction to prevent cardiac arrest. Opioid education and naloxone distributions programs have been developed to teach people who are likely to encounter a person with opioid poisoning how to administer naloxone, deliver high-quality compressions, and perform rescue breathing. Current American Heart Association recommendations call for laypeople and others who cannot reliably establish the presence of a pulse to initiate cardiopulmonary resuscitation in any individual who is unconscious and not breathing normally; if opioid overdose is suspected, naloxone should also be administered. Secondary prevention, including counseling, opioid overdose education with take-home naloxone, and medication for opioid use disorder, is important to prevent recurrent opioid overdose.

Effect of Machine Learning on Dispatcher Recognition of Out-of-Hospital Cardiac Arrest During Calls to Emergency Medical Services: A Randomized Clinical Trial

IMPORTANCE

Emergency medical dispatchers fail to identify approximately 25% of cases of out-of-hospital cardiac arrest (OHCA), resulting in lost opportunities to save lives by initiating cardiopulmonary resuscitation.

OBJECTIVE

To examine how a machine learning model trained to identify OHCA and alert dispatchers during emergency calls affected OHCA recognition and response.

DESIGN, SETTING, AND PARTICIPANTS

This double-masked, 2-group, randomized clinical trial analyzed all calls to emergency number 112 (equivalent to 911) in Denmark. Calls were processed by a machine learning model using speech recognition software. The machine learning model assessed ongoing calls, and calls in which the model identified OHCA were randomized. The trial was performed at Copenhagen Emergency Medical Services, Denmark, between September 1, 2018, and December 31, 2019.

INTERVENTION

Dispatchers in the intervention group were alerted when the machine learning model identified out-of-hospital cardiac arrest, and those in the control group followed normal protocols without alert.

MAIN OUTCOMES AND MEASURES

The primary end point was the rate of dispatcher recognition of subsequently confirmed OHCA.

RESULTS

A total of 169 049 emergency calls were examined, of which the machine learning model identified 5242 as suspected OHCA. Calls were randomized to control (2661 [50.8%]) or intervention (2581 [49.2%]) groups. Of these, 336 (12.6%) and 318 (12.3%), respectively, had confirmed OHCA. The mean (SD) age among of these 654 patients was 70 (16.1) years, and 419 of 627 patients (67.8%) with known gender were men. Dispatchers in the intervention group recognized 296 confirmed OHCA cases (93.1%) with machine learning assistance compared with 304 confirmed OHCA cases (90.5%) using standard protocols without machine learning assistance (P = .15). Machine learning alerts alone had a significantly higher sensitivity than dispatchers without alerts for confirmed OHCA (85.0% vs 77.5%; P < .001) but lower specificity (97.4% vs 99.6%; P < .001) and positive predictive value (17.8% vs 55.8%; P < .001).

CONCLUSIONS AND RELEVANCE

This randomized clinical trial did not find any significant improvement in dispatchers' ability to recognize cardiac arrest when supported by machine learning even though artificial intelligence did surpass human recognition.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04219306.

Neurological Outcome of Chest Compression-Only Bystander CPR in Asphyxial and Non-Asphyxial Out-Of-Hospital Cardiac Arrest: An Observational Study

Background: According to guidelines and bystander skill, two different methods of cardiopulmonary resuscitation (CPR) are feasible: standard CPR (S-CPR) with mouth-to-mouth ventilations and chest compression-only CPR (CO-CPR) without rescue breathing. CO-CPR appears to be most effective for cardiac causes, but there is a lack of evidence for asphyxial causes of out-of-hospital cardiac arrest (OHCA). Thus, the aim of our study was to compare CO-CPR versus S-CPR in adult OHCA from medical etiologies and assess neurologic outcome in asphyxial and non-asphyxial causes.Methods: Using the French National OHCA Registry (RéAC), we performed a multicenter retrospective study over a five-year period (2013 to 2017). All adult-witnessed OHCA who had benefited from either S-CPR or CO-CPR by bystanders were included. Non-medical causes as well as professional rescuers as witnesses were excluded. The primary end point was 30-day neurological outcome in a weighted population for all medical causes, and then for asphyxial, non-asphyxial and cardiac causes.Results: Of the 8 541 subjects included for all medical causes, 6 742 had a non-asphyxial etiology, including 5 904 of cardiac causes, and 1 799 had an asphyxial OHCA. Among all subjects, 8.6%; 95% CI [8.1-9.3] had a good neurological outcome (i.e. cerebral performance category of 1 or 2). Bystanders who performed S-CPR began more often immediately (89.0%; 95% CI [87.3-90.5] versus 78.2%; 95% CI [77.2-79.2]) and in younger subjects (64.1 years versus 65.7; p < 0.001). In the weighted population, subjects receiving bystander-initiated CO-CPR had an adjusted relative risk (aRR) of 1.04; 95% CI [0.79-1.38] of having a good neurological outcome at 30 days for all medical causes, 1.28; 95% CI [0.92-1.77] for asphyxial etiologies, 1.08; 95% CI [0.80-1.46] for non-asphyxial etiologies and 1.09; 95% CI [0.93-1.28] for cardiac-related OHCA.Conclusions: We observed no significant difference in neurological outcome when lay bystanders of adult OHCA initiated CO-CPR or S-CPR, whether the cause was asphyxial or not.

Current evidence of survival benefit between chest-compression only versus standard cardiopulmonary resuscitation in out-of-hospital cardiac arrest : Updated systematic review and meta-analysis of randomized controlled trials with trial sequential analysis

BACKGROUND

Evidence to support a better cardiopulmonary resuscitation method between standard vs. continuous chest compression (STD-CPR vs. CCC-CPR) is lacking.

MATERIALS AND METHODS

Our systematic review followed PRISMA guidelines. We searched PubMed, ScienceDirect, EBSCOhost, and ProQuest database from 1985 to 26 September 2019 restricted to randomized controlled trial, human study, and English articles. Quality assessment of between-study heterogeneity and a trial sequential analysis (TSA) were conducted. We estimated overall significance with 80% power and adjusted Z values thresholds using O'Brien-Fleming α‑spending function. Required information size with 21% relative risk using the estimation between-group incidences provided from the median rate across trials was determined. Inconclusive TSA result will lead to size estimation of future RCT. Quality of evidence was analyzed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) Handbook and TSA.

RESULTS

Based on three trials in OHCA with dispatcher-guided and bystander-initiated CPR, our meta-analysis favors CCC-CPR for survival to hospital discharge, compared to STD-CPR (RR [Risk Ratio] = 1.21[1.01-1.46], 95% CI, p = 0.68, I² = 0). However, current meta-analyses with 3031 patients appeared to be inconclusive. There is a significant risk of type 1 error and therefore, results are potentially false positive. It is estimated that a minimal of 4331 patients needed to deem a conclusive result and a total of 5894 patients with similar risk profile required to stabilize statistic results in future trials. Quality of evidence is downgraded to moderate due to serious imprecision based on TSA.

CONCLUSION

Based on these analyses, evidence is inadequate to conclude the superiority of one CPR method over the other. Further trials with larger numbers of patients are needed to deem a conclusive and stable meta-analysis.

The understanding and recall of school children in Mumbai in compression only life support cardiopulmonary resuscitation

Background and Aims:

Out of hospital cardiac arrest (OHCA) is a leading cause of mortality worldwide. Increased bystander cardiopulmonary resuscitation (CPR) is observed in regions where school CPR training has been mandatory and led to reduced mortality by OHCA. We would like to explore the feasibility of teaching compression only life support (COLS) CPR to Indian school children through the following objectives determining their understanding of theoretical knowledge after a training session in the Indian Society of Anaesthesiologists' (ISA) COLS protocol and reviewing the information recall three months later.

Methods:

The participants of this quasi-experimental study were 132 school children, aged 12 to 15. The children were all below the age of 18 and consent was obtained vicariously through the principals of the schools and assent from the students in the form of willingness to answer the multiple-choice questionnaires. The study sample comprised of participants who responded to both questionnaires, immediately post-training session and three months later. Their responses were compiled in Excel and analysed using the paired t-test and R programming language.

Results:

None of the children had any previous knowledge on COLS. A one-hour session in COLS proved sufficient to increase the baseline knowledge with a mean post-training score by 82%. On comparing the two scores obtained, a statistically significant attrition rate was observed (P < 0.001).

Conclusion:

The children exhibited good understanding of COLS after a single training session. This makes us believe that more periodic revision, probably by inclusion of COLS in school curricula could be a satisfactory solution towards lowering the attrition in knowledge recall.

Frequency of Medical Reversal Among Published Randomized Controlled Trials Assessing Cardiopulmonary Resuscitation (CPR)

OBJECTIVE

To characterize what proportion of all randomized controlled trials (RCTs) among patients experiencing cardiac arrest find that an established practice is ineffective or harmful, that is, a medical reversal.

METHODS

We reviewed a database of all published RCTs of cardiac arrest patient populations between 1995 and 2014. Articles were classified on the basis of whether they tested a new or existing therapy and whether results were positive or negative. A reversal was defined as a negative RCT of an established practice. Further review and categorization were performed to confirm that reversals were supported by subsequent systematic review, as well as to identify the type of medical practice studied in each reversal. This study was conducted from October 2017 to June 17, 2019.

RESULTS

We reviewed 92 original articles, 76 of which could be conclusively categorized. Of these, 18 (24%) articles examined a new medical practice, whereas 58 (76%) tested an established practice. A total of 18 (24%) studies had positive findings, whereas 58 (76%) reached a negative conclusion. Of the 58 articles testing existing standard of care, 44 (76%) reversed that practice, whereas 14 (24%) reaffirmed it.

CONCLUSION

Reversal of cardiopulmonary resuscitation practices is widespread. This investigation sheds new light on low-value practices and patterns of medical research and suggests that novel resuscitation practices have low pretest probability and should be empirically tested with rigorous trials before implementation.

Outcome of Conventional Bystander Cardiopulmonary Resuscitation in Cardiac Arrest Following Drowning

INTRODUCTION

The concept of compressions only cardiopulmonary resuscitation (CO-CPR) evolved from a perception that lay rescuers may be less likely to perform mouth-to-mouth ventilations during an emergency. This study hopes to describe the efficacy of bystander compressions and ventilations cardiopulmonary resuscitation (CV-CPR) in cardiac arrest following drowning.

HYPOTHESIS/PROBLEM

The aim of this investigation is to test the hypothesis that bystander cardiopulmonary resuscitation (CPR) utilizing compressions and ventilations results in improved survival for cases of cardiac arrest following drowning compared to CPR involving compressions only.

METHODS

The Cardiac Arrest Registry for Enhanced Survival (CARES) was queried for patients who suffered cardiac arrest following drowning from January 1, 2013 through December 31, 2017, and in whom data were available on type of bystander CPR delivered (ie, CV-CPR CO-CPR). The primary outcome of interest was neurologically favorable survival, as defined by cerebral performance category (CPC).

RESULTS

Neurologically favorable survival was statistically significantly associated with CV-CPR in pediatric patients aged five to 15 years (aOR = 2.68; 95% CI, 1.10-6.77; P = .03), as well as all age group survival to hospital discharge (aOR = 1.54; 95% CI, 1.01-2.36; P = .046). There was a trend with CV-CPR toward neurologically favorable survival in all age groups (aOR = 1.35; 95% CI, 0.86-2.10; P = .19) and all age group survival to hospital admission (aOR = 1.29; 95% CI, 0.91-1.84; P = .157).

CONCLUSION

In cases of cardiac arrest following drowning, bystander CV-CPR was statistically significantly associated with neurologically favorable survival in children aged five to 15 years and survival to hospital discharge.

Key components of a community response to out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA) remains a leading cause of death worldwide, with substantial geographical, ethnic and socioeconomic disparities in outcome. Successful resuscitation efforts depend on the 'chain of survival', which includes immediate recognition of cardiac arrest and activation of the emergency response system, early bystander cardiopulmonary resuscitation (CPR) with an emphasis on chest compressions, rapid defibrillation, basic and advanced emergency medical services and integrated post-cardiac arrest care. Well-orchestrated telecommunicator CPR programmes can improve rates of bystander CPR - a critical link in the chain of survival. High-performance CPR by emergency medical service providers includes minimizing interruptions in chest compressions and ensuring adequate depth of compressions. Developing local, regional and statewide systems with dedicated high-performing cardiac resuscitation centres for post-resuscitation care can substantially improve survival after OHCA. Innovative digital tools for recognizing cardiac arrest where and when it occurs, notifying potential citizen rescuers and providing automated external defibrillators at the scene hold the promise of improving survival after OHCA. Improved implementation of the chain of survival can save thousands of lives each year.

The changes in cardiopulmonary resuscitation guidelines: from 2000 to the present

This review aims to determine the changes made in the cardiopulmonary resuscitation (CPR) guidelines from 2000 to the present. The study was mainly undertaken by using International Guidelines from American Heart Association. The main change of CPR was chest compression skill. The guidelines have improved high-quality CPR through the change of chest compression skill. The latest adult CPR guidelines are as follows: (a) push chest quickly (100-120/min), (b) compress appropriately (5-6 cm), (c) relax chest fully (complete chest recoil), (d) avoid interruption of compression, and (e) avoid hyperventilation. The understanding of the latest CPR skills will be helpful in improving survival rate from sudden cardiac death.

The feasibility of a novel method of bystander CPR training: A pilot study

Sudden cardiac arrest is a leading cause of death in the United States, with many occurring out of the hospital. Immediate response by bystanders, through the initiation of cardiopulmonary resuscitation (CPR), leads to increased survival; however, many do not respond due to lack of training and education. This study sought to determine the efficacy of a training model developed to rapidly and effectively train large numbers of individuals on hands-only CPR. Thirty minute training sessions were developed to introduce hands-only CPR to faculty at a university, with questionnaires assessing confidence and knowledge of CPR. Faculty then went on to train their respective students. Ninety-six faculty and staff and 1615 students were trained within 3 weeks, demonstrating this model was effective in rapidly training large numbers of individuals in a short period of time while increasing CPR knowledge and confidence. This method may be effective in other community settings.

Variation in accessibility of the population to an Emergency Medical Communication Centre: a multicentre observational study

Background

Access to an Emergency Medical Communication Centre is essential for the population in emergency situations. Handling inbound calls without delay requires managing activity, process and outcome measures of the Emergency Medical Communication Centre to improve the workforce management and the level of service. France is facing political decisions on the evolution of the organisation of Emergency Medical Communication Centres to improve accessibility for the population. First, we aim to describe the variation in activity between Emergency Medical Communication Centres, and second, to explore the correlation between process measures and outcome measures.

Methods

Using telephone activity data extraction, we conducted an observational multicentre study of six French Emergency Medical Communication Centres from 1 July 2016 to 30 June 2017. We described the activity (number of incoming calls, call rate per 1000 inhabitants), process measure (agent occupation rate), and outcome measure (number of calls answered within 20 s) by hourly range and estimated the correlation between them according to the structural equation methods.

Results

A total of 52,542 h of activity were analysed, during which 2,544,254 calls were received. The annual Emergency Medical Communication Centre call rate was 285.5 [95% CI: 285.2–285.8] per 1000 inhabitants. The average hourly number of calls ranged from 29 to 61 and the call-handled rate from 75 to 98%. There are variations in activity between Emergency Medical Communication Centres. The mean agent occupation rate was correlated with the quality of service at 20 s (coefficient at − 0.54). The number of incoming calls per agent was correlated with the mean occupation rate (coefficient at 0.67). Correlation coefficients varied according to the centres and existed between different process measures.

Conclusions

The activity dynamics of the six Emergency Medical Communication Centres are not identical. This variability, illustrating the particularity of each centre, must be accurately assessed and should be taken into account in managerial considerations. The call taker occupation rate is the leverage in the workforce management to improve the population accessibility.

Bystander-initiated conventional vs compression-only cardiopulmonary resuscitation and outcomes after out-of-hospital cardiac arrest due to drowning

BACKGROUND

Great emphasis has been placed on rescue breathing in out-of-hospital cardiac arrest (OHCA) due to drowning. However, there is no evidence about the effect of rescue breathing on neurologically favorable survival after OHCA due to drowning. The aim of this study is to examine the effect of bystander-initiated conventional (with rescue breathing) versus compression-only (without rescue breathing) cardiopulmonary resuscitation (CPR) in OHCA due to drowning.

METHODS

This nationwide population-based observational study using prospectively collected government-led registry data included patients with OHCA due to drowning who were transported to an emergency hospital in Japan between 2013 and 2016. The primary outcome was one-month neurologically favorable survival.

RESULTS

The full cohort (n = 5121) comprised 2486 (48.5%) male patients, and the mean age was 72.4 years (standard deviation, 21.6). Of these, 968 (18.9%) received conventional CPR, and 4153 (81.1%) received compression-only CPR. 928 patients receiving conventional CPR were propensity-matched with 928 patients receiving compression-only CPR. In the propensity score-matched cohort, one-month neurologically favorable survival was not significantly different between the two groups (7.5% in the conventional CPR group vs. 6.6% in the compression-only CPR group; risk ratio, 1.15; 95% confidence interval, 0.82-1.60; P = 0.4147). This association was consistent across a variety of subgroup analyses.

CONCLUSIONS

Among patients with OHCA due to drowning, there were no differences in one-month neurologically favorable survival between bystander-initiated conventional and compression-only CPR groups, although several important data (e.g., water temperature, submersion duration, or body of water) could not be addressed. Further study is warranted to confirm our findings.

Duration of cardiac arrest requires different ventilation volumes during cardiopulmonary resuscitation in a pig model

There are few studies examining the ventilation strategies recommended by current CPR guidelines. We investigated the influence of different minute volume applying to untreated cardiac arrest with different duration, on resuscitation effects in a pig model. 32 Landrace pigs with 4 or 8 min (16 pigs each) ventricular fibrillation (VF) randomly received two ventilation strategies during CPR. "Guideline" groups received mechanical ventilation with a tidal volume of 7 ml/kg and a frequency of 10/min, while "Baseline" groups received a tidal volume (10 ml/kg) and a frequency used at baseline to maintain an end-tidal PCO₂ (P_ETCO₂) between 35 and 40 mmHg before VF. Mean airway pressures and intrathoracic pressures (P_IT) in the Baseline-4 min group were significantly higher than those in the Guideline-4 min group (all P < 0.05). Similar results were observed in the 8 min pigs, except for no significant difference in minimal P_IT and P_ETCO₂ during 10 min of CPR. Venous pH and venous oxygen saturation were significantly higher in the Baseline-8 min group compared to the Guideline-8 min group (all P < 0.05). Aortic pressure in the Baseline-8 min group was higher than in the Guideline-8 min group. Seven pigs in each subgroup of 4 min VF models achieved the return of spontaneous circulation (ROSC). Higher ROSC was observed in the Baseline-8 min group than in the Guideline-8 min group (87.5% vs. 37.5%, P = 0.039). For 4 min VF but not 8 min VF, a guideline-recommended ventilation strategy had satisfactory results during CPR. A higher minute ventilation resulted in better outcomes for subjects with 8 min of untreated VF through thoracic pump.

Survival in Out-of-Hospital Cardiac Arrest After Standard Cardiopulmonary Resuscitation or Chest Compressions Only Before Arrival of Emergency Medical Services: Nationwide Study During Three Guideline Periods

BACKGROUND

In out-of-hospital cardiac arrest, chest compression-only cardiopulmonary resuscitation (CO-CPR) has emerged as an alternative to standard CPR (S-CPR), using both chest compressions and rescue breaths. Since 2010, CPR guidelines recommend CO-CPR for both untrained bystanders and trained bystanders unwilling to perform rescue breaths. The aim of this study was to describe changes in the rate and type of CPR performed before the arrival of emergency medical services (EMS) during 3 consecutive guideline periods in correlation to 30-day survival.

METHODS

All bystander-witnessed out-of-hospital cardiac arrests reported to the Swedish register for cardiopulmonary resuscitation in 2000 to 2017 were included. Nonwitnessed, EMS-witnessed, and rescue breath-only CPR cases were excluded. Patients were categorized as receivers of no CPR (NO-CPR), S-CPR, or CO-CPR before EMS arrival. Guideline periods 2000 to 2005, 2006 to 2010, and 2011 to 2017 were used for comparisons over time. The primary outcome was 30-day survival.

RESULTS

A total of 30 445 patients were included. The proportions of patients receiving CPR before EMS arrival changed from 40.8% in the first time period to 58.8% in the second period, and to 68.2% in the last period. S-CPR changed from 35.4% to 44.8% to 38.1%, and CO-CPR changed from 5.4% to 14.0% to 30.1%, respectively. Thirty-day survival changed from 3.9% to 6.0% to 7.1% in the NO-CPR group, from 9.4% to 12.5% to 16.2% in the S-CPR group, and from 8.0% to 11.5% to 14.3% in the CO-CPR group. For all time periods combined, the adjusted odds ratio for 30-day survival was 2.6 (95% CI, 2.4-2.9) for S-CPR and 2.0 (95% CI, 1.8-2.3) for CO-CPR, in comparison with NO-CPR. S-CPR was superior to CO-CPR (adjusted odds ratio, 1.2; 95% CI, 1.1-1.4).

CONCLUSIONS

In this nationwide study of out-of-hospital cardiac arrest during 3 periods of different CPR guidelines, there was an almost a 2-fold higher rate of CPR before EMS arrival and a concomitant 6-fold higher rate of CO-CPR over time. Any type of CPR was associated with doubled survival rates in comparison with NO-CPR. These findings support continuous endorsement of CO-CPR as an option in future CPR guidelines because it is associated with higher CPR rates and overall survival in out-of-hospital cardiac arrest.

Association of ventilation with outcomes from out-of-hospital cardiac arrest

AIM OF STUDY

To determine the association between bioimpedence-detected ventilation and out-of-hospital cardiac arrest (OHCA) outcomes.

METHODS

This is a retrospective, observational study of 560 OHCA patients from the Dallas-Fort Worth site enrolled in the Resuscitation Outcomes Consortium Trial of Continuous or Interrupted Chest Compressions During CPR from 4/2012 to 7/2015. We measured bioimpedance ventilation (lung inflation) waveforms in the pause between chest compression segments (Physio-Control LIFEPAK 12 and 15, Redmond, WA) recorded through defibrillation pads. We included cases ≥18 years with presumed cardiac cause of arrest assigned to interrupted 30:2 chest compressions with bag-valve-mask ventilation and ≥2 min of recorded cardiopulmonary resuscitation. We compared outcomes in two a priori pre-specified groups: patients with ventilation waveforms in <50% of pauses (Group 1) versus those with waveforms in ≥50% of pauses (Group 2).

RESULTS

Mean duration of 30:2 CPR was 13 ± 7 min with a total of 7762 pauses in chest compressions. Group 1 (N = 424) had a median 11 pauses and 3 ventilations per patient vs. Group 2 (N = 136) with a median 12 pauses and 8 ventilations per patient, which was associated with improved return of spontaneous circulation (ROSC) at any time (35% vs. 23%, p < 0.005), prehospital ROSC (19.8% vs. 8.7%, p < 0.0009), emergency department ROSC (33% vs. 21%, p < 0.005), and survival to hospital discharge (10.3% vs. 4.0%, p = 0.008).

CONCLUSIONS

This novel study shows that ventilation with lung inflation occurs infrequently during 30:2 CPR. Ventilation in ≥50% of pauses was associated with significantly improved rates of ROSC and survival.

CO2-related vasoconstriction superimposed on ischemic medullary brain autonomic nuclei may contribute to sudden death

INTRODUCTION

In 2015, a multinational randomized controlled phase IV clinical trial of adaptive servoventilation for the management of heart failure with central sleep apnea was halted in progress because more patients in the study group were dying than in the control group. One year later, another large clinical trial reported results on the effectiveness of continuous positive airway pressure (CPAP) in preventing sudden death and other cardiovascular events such as heart attack and stroke in patients with preexisting vascular disease as well as obstructive sleep apnea.

BACKGROUND

Sudden unexpected death has been associated with many types of small and nonmalignant medullary brain lesions, like demyelination plaques - largely asymptomatic until they caused sudden death. Many such medullary lesions, typically without hemorrhage or mass effect, have in themselves been previously considered relatively harmless - in cases where they have been known to be present.

DISCUSSION

Why did not the improved pulmonary ventilation and subsequently improved gas exchange provided during the CPAP and servoventilation clinical trials help to resolve any ischemic lesions that may have been present both in the heart and in the medulla, thereby tending to normalize interactions between the vagal neural structures and the heart? CO₂ is a potent dilator of brain vasculature, thereby increasing blood flow to the brain. When ventilation is increased, even if only to improve it back toward normal from a depressed steady-state level, the alveolar partial pressure of carbon dioxide is decreased, likely resulting in a converse relative vasoconstriction in the brain, thereby reducing blood flow in the brain, especially in watershed areas like the solitary tract nucleus. In normal physiology, this is demonstrated impressively by the ability of hyperventilation to induce loss of consciousness.

CONCLUSIONS

The findings of several clinical trials recently reported, taken together with neuropathology case studies reported elsewhere, suggest that additional research is warranted in regard to the mechanisms by which focal medullary autonomic brain ischemia may be related to sudden death in general medical illnesses - and how it may additionally be influenced by changes in arterial CO₂ levels.

Paediatric traumatic cardiac arrest: the development of an algorithm to guide recognition, management and decisions to terminate resuscitation

INTRODUCTION

Paediatric traumatic cardiac arrest (TCA) is a high acuity, low frequency event. Traditionally, survival from TCA has been reported as low, with some believing resuscitation is futile. Within the adult population, there is growing evidence to suggest that with early and aggressive correction of reversible causes, survival from TCA may be comparable with that seen from medical out-of-hospital cardiac arrests. Key to this survival has been the adoption of a standardised approach to resuscitation. The aim of this study was, by a process of consensus, to develop an algorithm for the management of paediatric TCA for adoption in the UK.

METHODS

A modified consensus development meeting of UK experts involved in the management of paediatric TCA was held. Statements discussed at the meeting were drawn from those that did not reach consensus (positive/negative) from a linked three-round online Delphi study. 19 statements relating to the diagnosis, management and futility of paediatric TCA were initially discussed in small groups before each participant anonymously recorded their agreement with the statement using 'yes', 'no' or 'don't know'. In keeping with our Delphi study, consensus was set a priori at 70%. Statements reaching consensus were included in the proposed algorithm.

RESULTS

41 participants attended the meeting. Of the 19 statements discussed, 13 reached positive consensus and were included in the algorithm. A single statement regarding initial rescue breaths reached negative consensus and was excluded. Consensus was not reached for five statements, including the use of vasopressors and thoracotomy for haemorrhage control in blunt trauma.

CONCLUSION

In attempt to standardise our approach to the management of paediatric TCA and to improve outcomes, we present the first consensus-based algorithm specific to the paediatric population. While this algorithm was developed for adoption in the UK, it may be applicable to similar healthcare systems internationally.

Evolving Strategies in Cardiac Arrest Management

Cardiac arrest is a leading cause of death in the United States, with a hospital discharge rate of approximately 10%. International resuscitation guidelines offer standardized cardiac arrest management approaches, but beyond the guidelines, are promising innovations to improve resuscitative care. Although clinical data do not yet support the routine use of mechanical chest compressions, corticosteroids, thrombolytics, and adjunctive ventilation devices during arrest, these therapies may have an important role in select patients. Extracorporeal membrane oxygenation during cardiopulmonary resuscitation is a promising advancement and may have survival benefit in select patients. The evidence for standard therapies and these innovations is discussed.