Factors influencing survival after out-of-hospital cardiac arrest

The ABC (Age, Bystander, and Cardiogram) score for predicting neurological outcomes of cardiac arrests without pre-hospital return of spontaneous circulation: A nationwide population-based study

Aim

We previously proposed the ABC score to predict the neurological outcomes of cardiac arrest without prehospital return of spontaneous circulation (ROSC). Using nationwide population-based data, this study aimed to validate the ABC score through various resuscitation guideline periods.

Methods

We analysed cases with cardiac arrest due to internal causes and failure to achieve prehospital ROSC in the All-Japan Utstein Registry. Patients from the 2007-2009, 2012-2014, and 2017-2019 periods were classified into the 2005, 2010, and 2015 guideline groups, respectively. Neurological outcomes were assessed using cerebral performance categories (CPCs) one month after the cardiac arrest. We defined CPC 1-2 as a favourable outcome. We evaluated the test characteristics of the ABC score, which could range from 0 to 3.

Results

Among the 162,710, 186,228, and 190,794 patients in the 2005, 2010, and 2015 guideline groups, 0.7%, 0.8%, and 0.9% of the patients had CPC 1-2, respectively. The proportions of CPC 1-2 were 2.9%, 3.6%, and 4.6% in patients with ABC scores of 2 and were 9.5%, 13.3%, and 16.8% in patients with ABC scores of 3, respectively. Among patients with ABC scores of 0, 0.2%, 0.1%, and 0.2%, all had CPC 1-2, respectively. The areas under the receiver operating characteristic curves for the ABC score were 0.798, 0.822, and 0.828, respectively.

Conclusions

The ABC score had acceptable discrimination for neurological outcomes in patients without prehospital ROSC in the three guideline periods.

Impact of Rapid Response Teams on Pediatric Care: An Interrupted Time Series Analysis of Unplanned PICU Admissions and Cardiac Arrests

Pediatric rapid response teams (RRTs) are expected to significantly lower pediatric mortality in healthcare settings. This study evaluates RRTs' effectiveness in decreasing cardiac arrests and unexpected Pediatric Intensive Care Unit (PICU) admissions. A quasi-experimental study (2014-2017) at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, involved 3261 pediatric inpatients, split into pre-intervention (1604) and post-intervention (1657) groups. Baseline pediatric warning scores and monthly data on admissions, transfers, arrests, and mortality were analyzed pre- and post-intervention. Statistical methods including bootstrapping, segmented regression, and a Zero-Inflation Poisson model were employed to ensure a comprehensive evaluation of the intervention's impact. RRT was activated 471 times, primarily for respiratory distress (29.30%), sepsis (22.30%), clinical anxiety (13.80%), and hematological abnormalities (6.7%). Family concerns triggered 0.1% of activations. Post-RRT implementation, unplanned PICU admissions significantly reduced (RR = 0.552, 95% CI 0.485-0.628, p < 0.0001), and non-ICU cardiac arrests were eliminated (RR = 0). Patient care improvement was notable, with a -9.61 coefficient for PICU admissions (95% CI: -12.65 to -6.57, p < 0.001) and a -1.641 coefficient for non-ICU cardiac arrests (95% CI: -2.22 to -1.06, p < 0.001). Sensitivity analysis showed mixed results for PICU admissions, while zero-inflation Poisson analysis confirmed a reduction in non-ICU arrests. The deployment of pediatric RRTs is associated with fewer unexpected PICU admissions and non-ICU cardiopulmonary arrests, indicating improved PICU management. Further research using robust scientific methods is necessary to conclusively determine RRTs' clinical benefits.

Association Between Delays in Time to Bystander CPR and Survival for Witnessed Cardiac Arrest in the United States

BACKGROUND

Prompt initiation of bystander cardiopulmonary resuscitation (CPR) is critical to survival for out-of-hospital cardiac arrest (OHCA). However, the association between delays in bystander CPR and OHCA survival is poorly understood.

METHODS

In this observational study using a nationally representative US registry, we identified patients who received bystander CPR from a layperson for a witnessed OHCA from 2013 to 2021. Hierarchical logistic regression was used to estimate the association between time to CPR (<1 minute versus 2-3, 4-5, 6-7, 8-9, and ≥10-minute intervals) and survival to hospital discharge and favorable neurological survival (survival to discharge with cerebral performance category of 1 or 2 [ie, without severe neurological disability]).

RESULTS

Of 78 048 patients with a witnessed OHCA treated with bystander CPR, the mean age was 63.5±15.7 years and 25, 197 (32.3%) were women. The median time to bystander CPR was 2 (1-5) minutes, with 10% of patients having a≥10-minute delay before initiation of CPR. Overall, 15 000 (19.2%) patients survived to hospital discharge and 13 159 (16.9%) had favorable neurological survival. There was a graded inverse relationship between time to bystander CPR and survival to hospital discharge (P for trend <0.001). Compared with patients who received CPR within 1 minute, those with a time to CPR of 2 to 3 minutes were 9% less likely to survive to discharge (adjusted odds ratio, 0.91 [95% CI, 0.87-0.95]) and those with a time to CPR 4 to 5 minutes were 27% less likely to survive (adjusted odds ratio, 0.73 [95% CI, 0.68-0.77]). A similar graded inverse relationship was found between time to bystander CPR and favorable neurological survival (P for trend <0.001).

CONCLUSIONS

Among patients with witnessed OHCA, there was a dose-response relationship between delays in bystander initiation of CPR and lower survival rates.

The Minnesota first-responder AED project: Aiming to increase survival in out-of-hospital cardiac arrest

There are 350,000 out-of-hospital cardiac arrest (OHCA) cases annually in the United States of America. Using automated external defibrillators (AEDs) has increased survival in cardiac arrests (CA) with an initial shockable rhythm. Thus, guidelines recommend complete geographical coverage with AEDs. To fill in the gaps in Minnesota, the Center for Resuscitation Medicine at the University of Minnesota raised an $18.8 million grant from the Helmsley Charitable Trust to supply law enforcement first responders with AEDs and, thus, increase survival rates after OHCA by reducing the time to first shock. This report elaborates on the decision-making, fundraising, and logistic strategy required to reach statewide AED coverage.

Methods

The baseline need for AEDs was analyzed using a questionnaire sent out to state law enforcement agencies, state patrols, city and county agencies, and tribal agencies in 2021. Furthermore, OHCA cases of 2021 were reviewed. The combination of this information led to an action plan to equip and train all agencies throughout the state's eight regions with AEDs.

Results

The electronic survey was initially sent out to 358 agencies. The initial response rate was 77% (n = 276). This resulted in a total need of 8300 AEDs to be deployed over three years (2022-2025). As of 2023, over 4769 AEDs have been distributed, covering 237 sites.

Conclusion

By equipping first responders with AED systems, the Center for Resuscitation Medicine aims to shorten the gap in statewide AED coverage, thus increasing the chances of survival after OHCA.

Drowning in Children and Predictive Parameters: A 15-Year Multicenter Retrospective Analysis

BACKGROUND

Drowning is a serious and underestimated public health problem, with the highest morbidity and mortality reported among children. Data regarding pediatric outcomes of drowning are often inadequate, and data collection is poorly standardized among centers. This study aims to provide an overview of a drowning pediatric population in pediatric emergency department, focusing on its main characteristics and management and evaluating prognostic factors.

METHODS

This is a retrospective multicenter study involving eight Italian Pediatric Emergency Departments. Data about patients between 0 to 16 years of age who drowned between 2006 and 2021 were collected and analyzed according to the Utstein-style guidelines for drowning.

RESULTS

One hundred thirty-five patients (60.9% males, median age at the event 5; interquartile range, 3-10) were recruited and only those with known outcome were retained for the analysis (133). Nearly 10% had a preexisting medical conditions with epilepsy being the most common comorbidity. One third were hospitalized in the intensive care unit (ICU) and younger males had a higher rate of ICU admission than female peers. Thirty-five patients (26.3%) were hospitalized in a medical ward while 19 (14.3%) were discharged from the emergency department and 11 (8.3%) were discharged after a brief medical observation less than 24 hours. Six patients died (4.5%). Medium stay in the ED was approximately 40 hours. No difference in terms of ICU admission was found between cardiopulmonary resuscitation performed by bystanders or trained medical personnel ( P = 0.388 vs 0.390).

CONCLUSIONS

This study offers several perspectives on ED victims who drowned. One of the major finding is that no difference in outcomes was seen in patients who received cardiopulmonary resuscitation performed by bystanders or medical services, highlighting the importance of a prompt intervention.

Using the Evidence-Development-Validation-Consensus (EDVC) Approach to Develop and Validate maxSIMdrone: A Training Program for Healthcare Professionals to Provide Cardiac Arrest Care Using Drones

Introduction The challenges of delivering cardiac arrest (CA) courses in rural and remote (R&R) locations worldwide have been further exacerbated by the COVID-19 pandemic. However, it is important to note that this problem has always existed. The implementation of social distancing measures to combat the pandemic has had a significant impact on healthcare and medical education, particularly in relation to the training of students, laypeople (LP), and healthcare professionals (HCPs) in CA care. The combination of pandemic restrictions and pre-existing difficulties faced in R&R locations and large cities has disrupted the provision of comprehensive medical education. The suspension of basic life support and defibrillation (BLSD) courses during the pandemic may have negatively affected pre-hospital care for CA. However, it is essential to acknowledge that challenges in delivering these courses in R&R areas predate the pandemic. Materials and methods A 2021 epidemiological study in the Brazilian Amazon identified CA as the primary cause of death, followed by COVID-19. This highlights the importance of providing BLSD courses and training to emergency medical service (EMS) personnel in R&R locations. Even during a pandemic. Researchers from Ontario Tech University and Memorial University School of Medicine developed a drone with a simulation scenario to train HCPs in automated external defibrillators (AED) operation and guide LP in safe use through BLSD protocols. A literature review showed that different training methods yielded similar outcomes. Based on these findings, the evidence-development-validation-consensus (EDVC) hybrid approach was used to develop and validate an online training program using a learning management system (LMS) as a model. Results Teaching HCPs and LP in R&R locations, such as northern Canada and the Brazilian Amazon, presents challenges due to limited resources and internet access. One potential solution lies in the utilization of remote online LMS that facilitate the administration, documentation, tracking, reporting, automation, and delivery of educational courses and training programs. The literature review indicated that mixed training approaches, including face-to-face, online, and hybrid formats, produced similar outcomes in learning assessment, self-confidence, performance, skills, and knowledge acquisition. These findings support the viability of using LMS as a model to develop and validate a course where drones deliver AEDs and provide training to HCPs and LP in R&R locations. A comprehensive training program should encompass cognitive, affective, and psychomotor learning domains, addressing various skills and knowledge aspects. Conclusion This research study develops and validates LMS teaching methods to support a training program for HCPs and LP in using AEDs delivered by drones. The program combines design-based research and consensus development methods, such as design thinking and think-aloud observations. Drones are used to provide AEDs and develop simulation scenarios for training in R&R locations. The hybrid approach ensures a valid and evidence-based training program. The study presents the EDVC approach used to enhance the maxSIMdrone training program, enabling effective out-of-hospital CA care. The program incorporates participant feedback and improves knowledge and techniques in AED use. It has the potential to improve patient outcomes in resource-limited R&R locations.

Comparing Learning Outcomes in Cardiopulmonary Resuscitation (CPR) and/or Automated External Defibrillator (AED) Training for Laypeople in Face-to-Face, Online, and Mixed Training Methods: An Integrative Literature Review

Cardiovascular diseases and cardiac arrest (CA) are the main causes of death worldwide. This review aims to identify publications on the learning outcomes for the use of an automated external defibrillator (AED) and/or cardiopulmonary resuscitation (CPR) to train laypeople (LP), the method of training used, the year of publication and their recommendations. We employed Miller's assessment pyramid to describe learning outcomes as knowledge, skills, and confidence. The methods of training are face-to-face, online, and mixed. The evidence found in this study will be used to support the development and validation of a simulation-based training program to teach LP to operate AEDs delivered by drones in rural and remote (R&R) locations. This article is an integrative literature review with a quantitative and qualitative research design and is composed of seven steps: research question, inclusion and exclusion criteria, search and selection of studies, the role of a second reviewer of the findings, data analysis, interpretation and discussion of the results, and finally knowledge synthesis. The results of this review demonstrate that there are no significant differences in the learning outcomes of the different training methods. Since these findings suggest good results in all methods, the development of a training program based on face-to-face, online, and mixed, especially for places with few resources such as R&R places, indicates all methods can be used as good practices to develop training programs.

Digit preference and biased conclusions in cardiac arrest studies

BACKGROUND

In cardiac arrest (CA), time is directly predictive of patients' prognosis. The increase in mortality resulting from delayed cardiopulmonary resuscitation has been quantified minute by minute. Times reported in CA management studies could reflect a timestamping bias referred to as "digit preference". This phenomenon leads to a preference for certain numerical values (such as 2, 5, or 10) over others (such as 13). Our objective was to investigate whether or not digit preference phenomenon could be observed in reported times of the day related to CA management, as noted in a national registry.

METHODS

We analyzed data from the French National Electronic Registry of Cardiac Arrests. We analyzed twelve times-of-the-day corresponding to each of the main steps of CA management reported by the emergency physicians who managed the patients in prehospital settings. We postulated that if CA occurred at random times throughout the day, then we could expect to see events related to CA management occurring at a similar rate each minute of each hour of the day, at a fraction of 1/60. We compared the fraction of times reported as multiples of 15 (0, 15, 30, and 45 - on the hour, quarters, half hour) with the expected fraction of 4/60 (i.e. 4 × 1/60).

MAIN RESULTS

A total of 47,211 times-of-the-day in relation to 6131 CA were analyzed. The most overrepresented numbers were: 0, with 3737 occurrences (8% vs 2% expected, p < 0.0001) and 30, with 2807 occurrences (6% vs 2% expected, p < 0.0001). Times-of-the-day as multiples of 15 were overrepresented (22% vs 7% expected, p < 0.0001).

CONCLUSION

Prospectively collected times were considerably influenced by digit preference phenomenon. Studies that are not based on automatic time recordings and that have not evaluated and considered this bias should be interpretated with caution.

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.

Effect of replacing ambulance physicians with paramedics on outcome of resuscitation for prehospital cardiac arrest

INTRODUCTION

Limited evidence suggests that the presence of a prehospital physician improves survival from cardiac arrest. A retrospective study is undertaken to examine this question. In Reykjavik, Iceland, prehospital physicians on ambulances were replaced by emergency medical technicians (EMTs) in 2007. The aim of this study is to compare the outcome of prehospital resuscitation from cardiac arrest during periods of time with and without prehospital physician involvement.

METHODS

All cardiac arrests that underwent prehospital resuscitation by emergency medical systems between 2004 and 2014 were included. The primary outcome was survival to hospital discharge, and the secondary outcome was return of spontaneous circulation (ROSC). Subgroup analyses were performed according to the type of cardiac arrest.

RESULTS

A total of 471 cardiac arrests were included for analysis, 200 treated by prehospital physicians from 2004 to 2007 and 271 treated by EMTs from 2008 to 2014. The overall rate of survival to hospital discharge and ROSC was 23 and 50% during the study period. No significant difference was observed in the rate of survival to hospital discharge [25 vs 22%, difference 3% (95% confidence interval (CI): 11-5%)] or ROSC [53 vs 47%, difference -6% (95% CI: 15-3%)] between these two time periods. In the subgroup of patients with pulseless electrical activity, survival to hospital discharge did not differ between the two periods, but the rate of ROSC was higher in the 'physician period' [50 vs 30%, difference -20% (95% CI: -40 to -1%)].

CONCLUSIONS

The presence of a prehospital physician on the ambulance was not found to result in a significant improvement in survival or ROSC after cardiac arrest compared to care by EMTs. Patients with pulseless electrical activity experienced an increase in ROSC when a physician was present but without improvement in survival to hospital discharge.

Cardiopulmonary resuscitation (CPR) training strategies in the times of COVID-19: a systematic literature review comparing different training methodologies

BACKGROUND

Traditional, instructor led, in-person training of CPR skills has become more challenging due to COVID-19 pandemic. We compared the learning outcomes of standard in-person CPR training (ST) with alternative methods of training such as hybrid or online-only training (AT) on CPR performance, quality, and knowledge among laypersons with no previous CPR training.

METHODS

We searched PubMed and Google Scholar for relevant articles from January 1995 to May 2020. Covidence was used to review articles by two independent researchers. Effective Public Health Practice Project (EPHPP) Quality Assessment Tool was used to assess quality of the manuscripts.

RESULTS

Of the 978 articles screened, twenty met the final inclusion criteria. All included studies had an experimental design and moderate to strong global quality rating. The trainees in ST group performed better on calling 911, time to initiate chest compressions, hand placement and chest compression depth. Trainees in AT group performed better in assessing scene safety, calling for help, response time including initiating first rescue breathing, adequate ventilation volume, compression rates, shorter hands-off time, confidence, willingness to perform CPR, ability to follow CPR algorithm, and equivalent or better knowledge retention than standard teaching methodology.

CONCLUSION

AT methods of CPR training provide an effective alternative to the standard in-person CPR for large scale public training.

PROLOGUE (PROgnostication using LOGistic regression model for Unselected adult cardiac arrest patients in the Early stages): Development and validation of a scoring system for early prognostication in unselected adult cardiac arrest patients

BACKGROUND

Early prognostication after cardiac arrest would be useful. We aimed to develop a scoring model for early prognostication in unselected adult cardiac arrest patients.

METHODS

We retrospectively analysed data of adult non-traumatic cardiac arrest patients treated at a tertiary hospital between 2014 and 2018. The primary outcome was poor outcome at hospital discharge (cerebral performance category, 3-5). Using multivariable logistic regression analysis, independent predictors were identified among known outcome predictors, that were available at intensive care unit admission, in patients admitted in the first 3 years (derivation set, N = 671), and a scoring system was developed with the variables that were retained in the final model. The scoring model was validated in patients admitted in the last 2 years (validation set, N = 311).

RESULTS

The poor outcome rates at hospital discharge were similar between the derivation (66.0%) and validation sets (64.3%). Age <59 years, witnessed collapse, shockable rhythm, adrenaline dose <2 mg, low-flow duration <18 min, reactive pupillary light reflex, Glasgow Coma Scale motor score ≥2, and levels of creatinine <1.21 mg dl^-1, potassium <4.4 mEq l^-1, phosphate <5.8 mg dl^-1, haemoglobin ≥13.2 g dl^-1, and lactate <8 mmol l^-1 were retained in the final multivariable model and used to develop the scoring system. Our model demonstrated excellent discrimination in the validation set (area under the curve of 0.942, 95% confidence interval 0.917-0.968).

CONCLUSIONS

We developed a scoring model for early prognostication in unselected adult cardiac arrest patients. Further validations in various cohorts are needed.

Out-of-hospital cardiac arrest patients with implantable cardioverter-defibrillators: What are their outcomes?

THE AIM OF THE STUDY

To identify the prognostic factors and effects of implantable cardioverter-defibrillators (ICDs) in out-of-hospital cardiac arrest (OHCA) patients with ICDs because the clinical characteristics and outcomes of OHCA patients with ICDs are unknown.

METHODS

The North American Resuscitation Outcomes Consortium (ROC) Cardiac Epistry Version 3 dataset was analyzed. Eligible patients were divided into OHCA patients with and without ICDs. Multivariable regressions were employed to analyze.

RESULTS

Of 51,634 eligible OHCA patients, 581 (1.13%) had implanted ICDs. Among them, 53 (9.1%) patients survived to hospital discharge, and 40 (6.9%) patients had favorable neurological outcome at hospital discharge. Multivariable regression showed ICDs were not associated with OHCA outcomes in the total OHCA patients. In the OHCA patients with ICDs, shockable initial emergency medical services (EMS)-recorded rhythms and the ICD-shock-only defibrillation pattern were independent favorable factors for survival to hospital discharge(OR = 3.3, 95%CI 1.7-6.2, P < 0.001; OR = 2.4, 95%CI 1.1-5.5, P = 0.035, respectively) and neurological outcome at hospital discharge (OR = 6.5, 95%CI 2.9-14.4, P < 0.001; OR = 3.6, 95%CI 1.4-9.1, P = 0.006, respectively). During field resuscitation in OHCA patients with ICDs, at least 34.9% of total patients and 64.6% of patients with initial EMS-recorded VT/VF rhythms needed additional external shocks.

CONCLUSIONS

Shockable initial EMS-recorded rhythms and ICD-shock-only defibrillation pattern were independent factors for the favorable outcomes of OHCA patients with ICDs. ICDs were not associated with the outcomes of OHCA, and additional external shocks were needed in a substantial number of OHCA patients with ICDs during field resuscitation.

Proteomics-Enriched Prediction Model for Poor Neurologic Outcome in Cardiac Arrest Survivors

OBJECTIVES

Neurologic outcome prediction in out-of-hospital cardiac arrest survivors is highly limited due to the lack of consistent predictors of clinically relevant brain damage. The present study aimed to identify novel biomarkers of neurologic recovery to improve early prediction of neurologic outcome.

DESIGN

Prospective, single-center study, SETTING:: University-affiliated tertiary care center.

PATIENTS

We prospectively enrolled 96 out-of-hospital cardiac arrest survivors into our study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Neurologic outcome was assessed by the Cerebral Performance Categories score. To identify plasma biomarkers for poor neurologic outcome (Cerebral Performance Categories score ≥ 3), we performed a three-step proteomics strategy of preselection by shotgun analyses, crosschecking in brain tissue samples, and verification by targeted proteomic analyses using a multistep statistical modeling approach. Sixty-three patients (66%) had a poor neurologic outcome. Out of a total of 299 proteins, we identified α-enolase, 14-3-3 protein ζ/δ, cofilin-1, and heat shock cognate 71 kDa protein as novel biomarkers for poor neurologic outcome. The implementation of these biomarkers into a clinical multimarker model, consisting of previously identified covariates associated to outcome, resulted in a significant improvement of neurologic outcome prediction (C-index, 0.70; explained variation, 11.9%; p for added value, 0.019).

CONCLUSIONS

This study identified four novel biomarkers for the prediction of poor neurologic outcome in out-of-hospital cardiac arrest survivors. The implementation of α-enolase, 14-3-3 protein ζ/δ, cofilin-1, and heat shock cognate 71 kDa protein into a multimarker predictive model along with previously identified risk factors significantly improved neurologic outcome prediction. Each of the proteomically identified biomarkers did not only outperform current risk stratification models but may also reflect important pathophysiologic pathways undergoing during cerebral ischemia.

Association Between Intravenous Fluid Resuscitation and Hospital Mortality in Post Cardiac Arrest Patients: A Retrospective Study

OBJECTIVE

To assess the role for intravenous fluid (IVF) resuscitation in the postarrest state. Primary outcome was survival to hospital discharge and 30-day mortality. Secondary outcomes were associations with amount of vasopressor use and mechanical ventilation days.

DESIGN

Retrospective study design.

SETTING

Single-center tertiary hospital in Philadelphia, Pennsylvania.

PATIENTS

All patients admitted to the intensive care unit between 2018 and 2019.

INTERVENTIONS

Patients were divided into two groups based on amount of IVF received within 24 h <30 mL/kg (restricted) and over 30 mL/kg (liberal).

MEASUREMENTS AND MAIN RESULTS

A total of 264 patients were included in the study, with 200 included in the restrictive (<30 mL/kg) group and 64 included in the liberal (>30 mg/kg) group. There was no difference in 30-day mortality between the two groups with 146 (73%) deaths in the restrictive groups and 44 (69%) deaths in the liberal group (P = 0.53). There was also no significant difference between those who survived to hospital discharge in the liberal and restrictive groups on Kaplan-Meier analysis (Log-rank = 1.476 P = 0.224). However, there was a significant difference between restrictive and liberal groups with the duration of mechanical ventilation (4 ± 6 days vs. 6 ± 9 days; P = 0.03) and in the rates of two or more vasopressor use (38% vs. 59%; P = 0.002). End-stage renal disease (ESRD) (OR = 2.39; P = 0.03) and volume of fluids in mL/kg/24 h (OR = 1.025; P < 0.0001) were independently associated with higher vasopressor need. Volume of fluid in mL/kg/24 h (P = 0.01), ESRD (P = 0.015), and chronic obstructive pulmonary disease (P = 0.04) were significantly associated with duration of mechanical ventilation, even after adjusting for demographic factors, comorbidities, and mortality.

CONCLUSIONS

A liberal strategy of IVF used in resuscitation after cardiac arrest is not associated with higher mortality. However, it predicts higher vasopressor use and duration of mechanical ventilation.

Protocol for a nationwide prospective, observational cohort study of foreign-body airway obstruction in Japan: the MOCHI registry

INTRODUCTION

Foreign body airway obstruction (FBAO) is a major public health issue worldwide. In 2017, there were more than 5000 fatal choking cases in the USA alone, and it was the fourth leading cause of preventable injury-related death in the home and community. In Japan, FBAO is the leading cause of accidental death and with almost 9000 fatalities annually. However, research on FBAO is limited, particularly on the impact of a foreign body (FB) removal manoeuvres by bystanders. The primary objective of this study is to determine the impact of bystander FB removal manoeuvres on 1 month neurological outcome. Our secondary objectives include (1) evaluating the efficacy of a variety of FB removal manoeuvres; (2) identifying risk factors for unsuccessful removal and (3) evaluating the impact of time intervals from incidents of FBAO to FB removal on neurological outcome.

METHODS AND ANALYSIS

We will conduct a nationwide multi-centre prospective cohort study of patients with FBAO who present to approximately 100 emergency departments in both urban and rural areas in Japan. Research personnel at each participating site will collect variables including patient demographics, type of FB and prehospital variables, such as bystander FB removal manoeuvres, medical interventions by prehospital personnel, advanced airway management and diagnostic findings. Our primary outcome is 1 month favourable neurological outcome defined as cerebral performance category 1 or 2. Our secondary outcomes include success of FB removal manoeuvres and complications from the manoeuvres. We hypothesise that bystander FB removal manoeuvres improve patient survival with a favourable neurological outcome.

ETHICS AND DISSEMINATION

This study received research ethics approval from Nippon Medical School Hospital (B-2019-019). Research ethics approval will be obtained from all participating sites before entering patients into the registry. The study was registered at the University Hospital Medical Information Network (UMIN) Clinical Trials Registry.

TRIAL REGISTRATION NUMBER

UMIN 000039907.

Prospective Evaluation of Cardiopulmonary Resuscitation Performed in Dogs and Cats According to the RECOVER Guidelines. Part 1: Prognostic Factors According to Utstein-Style Reporting

Factors associated with positive cardiopulmonary resuscitation (CPR) outcomes defined according to the veterinary Utstein-style CPR reporting guidelines have not been described since implementation of the Reassessment Campaign on Veterinary Resuscitation (RECOVER) CPR clinical guidelines in 2012. The aims of this study were to assess factors associated with positive CPR outcomes at a U.S. veterinary teaching hospital, to re-evaluate these factors since implementation of the RECOVER guidelines compared to reported factors prior to their publication, and to identify potential additional factors since guideline publication. One-hundred and seventy-two dogs and 47 cats that experienced cardiopulmonary arrest (CPA) and had CPR performed were prospectively included in this observational study. Supervising clinicians were asked to complete a data form on CPR events immediately following completion of CPR efforts. Multivariable logistic regression was used to evaluate the effect of twenty hospital, animal, and arrest variables on the three patient outcomes “any return of spontaneous circulation (ROSC),” “sustained ROSC,” and survival to hospital discharge. Cats had significantly higher odds to achieve any ROSC [OR (95%CI) 2.72 (1.12–6.61), p = 0.028] and survive to hospital discharge than dogs [OR (95%CI) 4.87 (1.52–15.58), p = 0.008]. Patients had significantly lower odds of achieving any ROSC if CPA occurred during nighttime hours [OR (95%CI) nighttime = 0.52 (0.27–0.98), p = 0.043], and higher odds if CPA was witnessed [OR (95%CI) 3.45 (1.57–7.55), p = 0.002], if less people were involved in CPR efforts [OR (95%CI) 0.8 (0.66–0.96), p = 0.016], if pulses were palpable during CPR [OR (95%CI) 9.27 (4.16–20.63), p < 0.0005], and if an IV catheter was already in place at the time of CPA [OR (95%CI) 5.07 (2.12–12.07), p = 0.0003]. Odds for survival to hospital discharge were significantly higher if less people were involved in CPR efforts [OR (95%CI) 0.65 (0.46–0.91), p = 0.013] and for patients of the anesthesia service [OR (95%CI) 14.82 (3.91–56.17), p = 0.00007]. Overall, factors associated with improved CPR outcomes have remained similar since incorporation of RECOVER guidelines into daily practice. Witnessed CPA events and high-quality CPR interventions were associated with positive patient outcomes, emphasizing the importance of timely recognition and initiation of CPR efforts. An optimal CPR team size has yet to be determined.

Clinical Survey and Predictors of Outcomes of Pediatric Out-of-Hospital Cardiac Arrest Admitted to the Emergency Department

Pediatric out-of-hospital cardiac arrest (OHCA) is a rare event with severe sequelae. Although the survival to hospital-discharge (STHD) rate has improved from 2–6% to 17.6–40.2%, only 1–4% of OHCA survivors have a good neurological outcome. This study investigated the characteristics of case management before and after admittance to the emergency department (ED) associated with outcomes of pediatric OHCA in an ED. This was a retrospective study of data collected from our ED resuscitation room logbooks dating from 2005 to 2016. All records of children under 18 years old with OHCA were reviewed. Outcomes of interest included sustained return of spontaneous circulation (SROSC), STHD, and neurological outcomes. From the 12-year study period, 152 patients were included. Pediatric OHCA commonly affects males (55.3%, n = 84) and infants younger than 1 year of age (47.4%, n = 72) at home (76.3%, n = 116). Most triggers of pediatric OHCA were respiratory in nature (53.2%, n = 81). Sudden infant death syndrome (SIDS) (29.6%, n = 45), unknown medical causes (25%, n = 38), and trauma (10.5%, n = 16) were the main causes of pediatric OHCA. Sixty-two initial cardiac rhythms at the scene were obtained, most of which were asystole and pulseless electrical activity (PEA) (93.5%, n/all: 58/62). Upon ED arrival, cardiopulmonary resuscitation (CPR) was continued for 32.66 ± 20.71 min in the ED and 34.9% (n = 53) gained SROSC. Among them, 13.8% (n = 21) achieved STHD and 4.6% (n = 7) had a favorable neurological outcome. In multivariate analyses, fewer ED epinephrine doses (p < 0.05), witness of OHCA (p = 0.001), and shorter ED CPR duration (p = 0.007) were factors that increased the rate of SROSC at the ED. A longer emergency medical service (EMS) scene interval (p = 0.047) and shorter ED CPR interval (p = 0.047) improved STHD.

Impact of Bystander Automated External Defibrillator Use on Survival and Functional Outcomes in Shockable Observed Public Cardiac Arrests

BACKGROUND

Survival following out-of-hospital cardiac arrest (OHCA) with shockable rhythms can be improved with early defibrillation. Although shockable OHCA accounts for only ≈25% of overall arrests, ≈60% of public OHCAs are shockable, offering the possibility of restoring thousands of individuals to full recovery with early defibrillation by bystanders. We sought to determine the association of bystander automated external defibrillator use with survival and functional outcomes in shockable observed public OHCA.

METHODS

From 2011 to 2015, the Resuscitation Outcomes Consortium prospectively collected detailed information on all cardiac arrests at 9 regional centers. The exposures were shock administration by a bystander-applied automated external defibrillator in comparison with initial defibrillation by emergency medical services. The primary outcome measure was discharge with normal or near-normal (favorable) functional status defined as a modified Rankin Score ≤2. Survival to hospital discharge was the secondary outcome measure.

RESULTS

Among 49 555 OHCAs, 4115 (8.3%) observed public OHCAs were analyzed, of which 2500 (60.8%) were shockable. A bystander shock was applied in 18.8% of the shockable arrests. Patients shocked by a bystander were significantly more likely to survive to discharge (66.5% versus 43.0%) and be discharged with favorable functional outcome (57.1% versus 32.7%) than patients initially shocked by emergency medical services. After adjusting for known predictors of outcome, the odds ratio associated with a bystander shock was 2.62 (95% confidence interval, 2.07-3.31) for survival to hospital discharge and 2.73 (95% confidence interval, 2.17-3.44) for discharge with favorable functional outcome. The benefit of bystander shock increased progressively as emergency medical services response time became longer.

CONCLUSIONS

Bystander automated external defibrillator use before emergency medical services arrival in shockable observed public OHCA was associated with better survival and functional outcomes. Continued emphasis on public automated external defibrillator utilization programs may further improve outcomes of OHCA.

2015 revised Utstein-style recommended guidelines for uniform reporting of data from drowning-related resuscitation: An ILCOR advisory statement

BACKGROUND

Utstein-style guidelines use an established consensus process, endorsed by the international resuscitation community, to facilitate and structure resuscitation research and publication. The first "Guidelines for Uniform Reporting of Data From Drowning" were published over a decade ago. During the intervening years, resuscitation science has advanced considerably, thus making revision of the guidelines timely. In particular, measurement of cardiopulmonary resuscitation elements and neurological outcomes reporting have advanced substantially. The purpose of this report is to provide updated guidelines for reporting data from studies of resuscitation from drowning.

METHODS

An international group with scientific expertise in the fields of drowning research, resuscitation research, emergency medical services, public health, and development of guidelines met in Potsdam, Germany, to determine the data that should be reported in scientific articles on the subject of resuscitation from drowning. At the Utstein-style meeting, participants discussed data elements in detail, defined the data, determined data priority, and decided how data should be reported, including scoring methods and category details.

RESULTS

The template for reporting data from drowning research was revised extensively, with new emphasis on measurement of quality of resuscitation, neurological outcomes, and deletion of data that have proved to be less relevant or difficult to capture.

CONCLUSIONS

The report describes the consensus process, rationale for selecting data elements to be reported, definitions and priority of data, and scoring methods. These guidelines are intended to improve the clarity of scientific communication and the comparability of scientific investigations.

2015 Revised Utstein-Style Recommended Guidelines for Uniform Reporting of Data From Drowning-Related Resuscitation: An ILCOR Advisory Statement

BACKGROUND

Utstein-style guidelines use an established consensus process, endorsed by the international resuscitation community, to facilitate and structure resuscitation research and publication. The first "Guidelines for Uniform Reporting of Data From Drowning" were published over a decade ago. During the intervening years, resuscitation science has advanced considerably, thus making revision of the guidelines timely. In particular, measurement of cardiopulmonary resuscitation elements and neurological outcomes reporting have advanced substantially. The purpose of this report is to provide updated guidelines for reporting data from studies of resuscitation from drowning.

METHODS

An international group with scientific expertise in the fields of drowning research, resuscitation research, emergency medical services, public health, and development of guidelines met in Potsdam, Germany, to determine the data that should be reported in scientific articles on the subject of resuscitation from drowning. At the Utstein-style meeting, participants discussed data elements in detail, defined the data, determined data priority, and decided how data should be reported, including scoring methods and category details.

RESULTS

The template for reporting data from drowning research was revised extensively, with new emphasis on measurement of quality of resuscitation, neurological outcomes, and deletion of data that have proved to be less relevant or difficult to capture.

CONCLUSIONS

The report describes the consensus process, rationale for selecting data elements to be reported, definitions and priority of data, and scoring methods. These guidelines are intended to improve the clarity of scientific communication and the comparability of scientific investigations.

Increased cardiac arrest survival and bystander intervention in enclosed pedestrian walkway systems

BACKGROUND

Cities worldwide have underground or above-ground enclosed walkway systems for pedestrian travel, representing unique environments for studying out-of-hospital cardiac arrests (OHCAs). The characteristics and outcomes of OHCAs that occur in such systems are unknown.

OBJECTIVE

To determine whether OHCAs occurring in enclosed pedestrian walkway systems have differing demographics, prehospital intervention, and survival outcomes compared to the encompassing city, by examining the PATH walkway system in Toronto.

METHODS

We identified all atraumatic, public-location OHCAs in Toronto from April 2006 to March 2016. Exclusion criteria were obvious death, existing DNR, and EMS-witnessed OHCAs. OHCAs were classified into mutually exclusive location groups: Toronto, Downtown, and PATH-accessible. PATH-accessible OHCAs were those that occurred within the PATH system between the first basement and third floor. We analyzed demographic, prehospital intervention, and survival data using t-tests and chi-squared tests.

RESULTS

We identified 2172 OHCAs: 1752 Toronto, 371 Downtown, and 49 PATH-accessible. Compared to Toronto, a significantly higher proportion of PATH-accessible OHCAs was bystander-witnessed (62.6% vs 83.7%, p=0.003), had bystander CPR (56.6% vs 73.5%, p=0.019), bystander AED use (11.0% vs 42.6%, p<0.001), shockable initial rhythm (45.5% vs 72.9%, p<0.001), and overall survival (18.5% vs 33.3%, p=0.009). Similar significant differences were observed when compared to Downtown.

CONCLUSIONS

This study suggests that OHCAs in enclosed pedestrian walkway systems are uniquely different from other public settings. Bystander resuscitation efforts are significantly more frequent and survival rates are significantly higher. Urban planners in similar infrastructure systems worldwide should consider these findings when determining AED placement and public engagement strategies.

Bystander CPR is associated with improved neurologically favourable survival in cardiac arrest following drowning

BACKGROUND

Cardiac arrest associated with drowning is a major public health concern with limited research available on outcome. This investigation aims to define the population at risk, and identify factors associated with neurologically favourable survival.

METHODS

The Cardiac Arrest Registry for Enhanced Survival (CARES) database was queried for patients who had suffered cardiac arrest following drowning between January 1, 2013 and December 31, 2015. The primary outcomes of interest were for favourable or unfavourable neurological outcome at hospital discharge, as defined by Cerebral Performance Category (CPC).

RESULTS

A total of 919 drowning patients were identified. Neurological outcome data was available in 908 patients. Neurologically favourable survival was significantly associated with bystander CPR (Odds Ratio (OR)=2.94; 95% Confidence Interval (CI) 1.86-4.64; p<0.001), witnessed drowning (OR=2.6; 95% CI 1.69-4.01; p<0.001) and younger age (OR=0.97, 95% CI 0.96-0.98; p<0.001). Public location of drowning (OR=1.17; 95% CI 0.77-1.79; p=0.47), male gender (OR=0.9, 95% CI 0.57-1.43; p=0.66), and shockable rhythm (OR=1.54; 95% CI 0.76-3.12; p=0.23), were not associated with favourable neurological survival. AED application prior to EMS was associated with a decreased likelihood of favourable neurological outcome (OR=0.38; 95% CI 0.28-0.66; p<0.001). In multivariate analysis, bystander CPR (adjusted OR 3.02, 95% CI 1.85-4.92, p<0.001), witnessed drowning (adjusted OR 3.27, 95% CI 2.0-5.36, p<0.001) and younger age (adjusted OR 0.97, 95% CI 0.96-0.98, p<0.001) remained associated with neurologically favourable survival.

CONCLUSIONS

Neurologically favourable survival after drowning remains low but is improved by bystander CPR. Shockable rhythms were uncommon and not associated with improved outcomes.

Assessment of knowledge and skills in using an Automated External Defibrillator (AED) by university students. A quasi-experimental study

AIM

To evaluate layperson (university student) ability to use an automated external defibrillator (AED).

DESIGN

A repeated measures quasi-experimental study with non-probabilistic sampling and a control group was carried out.

SCOPE

Teacher training degree students at the University of Santiago de Compostela (Spain).

PARTICIPANTS

The sample consisted of 129 subjects (69% women and 31% men), between 19-47 years of age (mean 23.2±4.7 years). As inclusion criterion, the subjects were required to have no previous knowledge of AED.

INTERVENTIONS

Times to apply defibrillation with an AED to a mannequin were recorded untrained (T0), after a theoretical and practice explanation lasting less than one minute (T1), and 6 months after the training process (T2).

MAIN VARIABLES OF INTEREST

The primary endpoint was the time taken to deliver a defibrillation discharge. The "improvement effect" variable was defined by the absolute time difference between T1 and T0, while the "degree of forgetfulness effect" variable was defined as the absolute difference between T1 and T2.

RESULTS

The mean times were T0=67.7s; T1=44.2s; T2=45.9s. The time to apply defibrillation was reduced after explanation training (T1<T0) (-23.4s; P<.001). T2 proved shorter than T0 (-21.8s; P<.001) but longer than T1 (1.6s; P=.002). The improvement effect was significant (P<.001), in the same way as the degree of forgetfulness (P=.002).

CONCLUSIONS

Easy handling of AED was demonstrated, since untrained people were able to deliver a discharge. Defibrillation time was reduced after brief training. This time barely increased after 6 months.

Coma Following Cardiac Arrest: A Review of the Clinical Features, Management, and Prognosis

Sudden cardiac death is an important clinical problem that accounts for 750,000 deaths in the United States each year. There are 200,000 cardiac resuscitations each year, of which only 70,000 are successful. Survival depends upon early cardiopulmonary resuscitation and defibrillation. The brain's ability to tolerate no more than a few minutes of circulatory arrest is the major factor limiting the success of cardiopulmonary resusci tation. Cardiac arrest results in a spectrum of clinical disorders depending on the severity of cerebral anoxia. Neurological sequelae in survivors range from transient states of confusion and amnesia to prolonged uncon sciousness in a coma or in the vegetative state. Sequen tial neurological examinations alone or in conjunction with evoked potentials, electroencephalogram, com puted tomography, and positron emission tomography can indicate the degree of central nervous system dam age and the likely outcome. The clinical management of patients in coma following cardiac arrest involves resto ration of cardiopulmonary and metabolic homeostasis. No effective delayed therapy yet exists that can reverse anoxic damage, but several promising therapeutic agents are under laboratory and clinical investigation.

Early cardiopulmonary resuscitation in out-of-hospital cardiac arrest

BACKGROUND

Three million people in Sweden are trained in cardiopulmonary resuscitation (CPR). Whether this training increases the frequency of bystander CPR or the survival rate among persons who have out-of-hospital cardiac arrests has been questioned.

METHODS

We analyzed a total of 30,381 out-of-hospital cardiac arrests witnessed in Sweden from January 1, 1990, through December 31, 2011, to determine whether CPR was performed before the arrival of emergency medical services (EMS) and whether early CPR was correlated with survival.

RESULTS

CPR was performed before the arrival of EMS in 15,512 cases (51.1%) and was not performed before the arrival of EMS in 14,869 cases (48.9%). The 30-day survival rate was 10.5% when CPR was performed before EMS arrival versus 4.0% when CPR was not performed before EMS arrival (P<0.001). When adjustment was made for a propensity score (which included the variables of age, sex, location of cardiac arrest, cause of cardiac arrest, initial cardiac rhythm, EMS response time, time from collapse to call for EMS, and year of event), CPR before the arrival of EMS was associated with an increased 30-day survival rate (odds ratio, 2.15; 95% confidence interval, 1.88 to 2.45). When the time to defibrillation in patients who were found to be in ventricular fibrillation was included in the propensity score, the results were similar. The positive correlation between early CPR and survival rate remained stable over the course of the study period. An association was also observed between the time from collapse to the start of CPR and the 30-day survival rate.

CONCLUSIONS

CPR performed before EMS arrival was associated with a 30-day survival rate after an out-of-hospital cardiac arrest that was more than twice as high as that associated with no CPR before EMS arrival. (Funded by the Laerdal Foundation for Acute Medicine and others.).

Out-of-hospital cardiac arrest -optimal management

Out-of-hospital cardiac arrest (OHCA) has attracted increasing attention over the past years because outcomes have improved impressively lately. The changes for neurological intact outcomes has been poor but several areas have achieved improving survival rates after adjusting their cardiac arrest care. The pre-hospital management is certainly key and decides whether a cardiac arrest patient can be brought back into a spontaneous circulation. However, the whole chain of resuscitation including the in-hospital care have improved also. This review describes aetiologies of OHCA, risk and potential protective factors and recent advances in the pre-hospital and in-hospital management of these patients.

Management of severe hypercapnia post cardiac arrest with extracorporeal carbon dioxide removal

Normocapnia is recommended in intensive care management of patients after out-of-hospital cardiac arrest. While normocapnia is usually achievable, it may be therapeutically challenging, particularly in patients with airflow obstruction. Conventional mechanical ventilation may not be adequate to provide optimal ventilation in such patients. One of the recent advances in critical care management of hypercapnia is the advent of newer, low-flow extracorporeal carbon dioxide clearance devices. These are simpler and less invasive than conventional extracorporeal devices. We report the first case of using a novel, extracorporeal carbon dioxide removal device in Australia on a patient with out-of-hospital cardiac arrest where mechanical ventilation failed to achieve normocapnia.

Effect of Location of Out-of-Hospital Cardiac Arrest on Survival Outcomes

Introduction: This study aims to study how the effect of the location of patient collapses from cardiac arrest, in the residential and non-residential areas within Singapore, relates to certain survival outcomes. Materials and Methods: A retrospective cohort study of data were done from the Cardiac Arrest and Resuscitation Epidemiology (CARE) project. Out-of-hospital cardiac arrest (OHCA) data from October 2001 to October 2004 (CARE) were used. All patients with OHCA as confirmed by the absence of a pulse, unresponsiveness and apnoea were included. All events had occurred in Singapore. Analysis was performed and expressed in terms of the odds ratio (OR) and the corresponding 95% confidence interval (CI). Results: A total of 2375 cases were used for this analysis. Outcomes for OHCA in residential areas were poorer than in non-residential areas—1638 (68.9%) patients collapsed in residential areas, and 14 (0.9%) survived to discharge. This was significantly less than the 2.7% of patients who survived after collapsing in a non-residential area (OR 0.31 [0.16 – 0.62]). Multivariate logistic regression analysis showed that location alone had no independent effect on survival (adjusted OR 1.13 [0.32 – 4.05]); instead, underlying factors such as bystander CPR (OR 3.67 [1.13 – 11.97]) and initial shockable rhythms (OR 6.78 [1.95 – 23.53]) gave rise to better outcomes. Conclusion: Efforts to improve survival from OHCA in residential areas should include increasing CPR by family members, and reducing ambulance response times. Key words: Emergency Medical Services, Non-residential, Prehospital, Residential

Police AED programs: a systematic review and meta-analysis

BACKGROUND

Approximately 359,400 out-of-hospital cardiac arrests occur in the United States every year, and around 60% of them are treated by emergency medical services (EMS) personnel. In order to alleviate the impact of this public health burden, some communities have trained police officers as first responders so that they can provide cardiopulmonary resuscitation and defibrillation to cardiac arrest patients. This paper is a review of the current literature on the impact of police automated external defibrillators (AEDs) programs in these communities.

METHODS AND RESULTS

A literature search of electronic journal databases was conducted to identify articles that evaluated police AED programs and quantified survival rates. The 10 articles that met the inclusion criteria were very heterogeneous in terms of study design, controlling for confounders, outcome definitions, and comparison groups. Two communities found a statistically significant difference in survival and 6 studies reported a statistically significant difference in time to defibrillation after the implementation of these programs. The weighted mean survival rate of the study groups was higher than that of the control groups (p<0.001), as was the weighted mean survival rate of the group first shocked by police compared to those first shocked by EMS (39.4% vs. 28.6%, p<0.001). The pooled relative risk of survival was 1.4 (95% CI: 1.3-1.6).

CONCLUSIONS

Though there are many challenges in initiating these programs, this literature review shows that time to defibrillation decreased and survival from out-of-hospital cardiac arrests increased with the implementation of police AED programs.

Potassium induced cardiac standstill during conventional cardiopulmonary resuscitation in a pig model of prolonged ventricular fibrillation cardiac arrest: a feasibility study

AIM OF THE STUDY

Potassium-based cardioplegia has been the gold standard for cardioprotection during cardiac surgery. We sought to evaluate the feasibility and the effects of potassium-induced cardiac standstill during conventional cardiopulmonary resuscitation (CPR) in a pig model of prolonged ventricular fibrillation (VF).

METHODS

VF was induced in 20 pigs, and circulatory arrest was maintained for 14 min. Animals were then resuscitated by standard CPR. Coincident with the start of CPR, 20 ml of saline (control group) or 0.9 mequiv.kg(-1) of potassium chloride diluted to 20 ml (potassium group) was administered into right atrium.

RESULTS

Administration of potassium resulted in asystole lasting for 1.0 min (0.2) in the potassium group animals. VF reappeared in all but one animal, in which wide QRS complex bradycardia followed. Restoration of spontaneous circulation (ROSC) was attained in two animals (20%) in the control group and in seven animals (70%) in the potassium group (p=0.070). Resuscitated animals in the potassium group required fewer countershocks (3, 4 vs. 2 (1-2)), smaller doses of adrenaline (1.84, 1.84 vs. 0.94 (0.90-1.00)mg), and shorter duration of CPR (8, 10 vs. 4.0 (4.0-4.0)min) than did the control group. Potassium concentrations normalised rapidly after ROSC in both groups, and the potassium concentrations at 5 min (5.5, 6.6 vs. 6.8 (6.5-7.8)mequiv.l(-1)) and 4h (4.9, 5.4 vs. 5.9 (5.1-6.4)mequiv.l(-1)) after ROSC were similar in the both groups.

CONCLUSION

In a pig model of untreated VF cardiac arrest for 14 min, resuscitation with potassium-induced cardiac standstill during conventional CPR was found to be feasible.

Endotracheal versus Intravenous Epinephrine in the Prehospital Treatment of Cardiac Arrest

We performed a retrospective review of the charts of 252 adult, non-traumatic, prehospital cardiac arrest patients treated over a one-year period in order to assess the effectiveness of intravenous (IV) and endotracheal (ET) administration of epinephrine (0.5–1.0 mg) (EPI) in assisting restoration of a spontaneous pulse. Patients initially receiving IV-EPI were more likely to develop a spontaneous pulse earlier than those receiving a similar dose ET (7.3% vs 0.9%; p<0.01. In those patients who received a second dose of EPI, six (2.9%) regained a spontaneous pulse; each had been treated previously with IV-EPI. None who required a third dose of EPI regained a spontaneous pulse. In total, only five (2%) patients survived to discharge. We conclude that, in our system, patients who receive the currently recommended dose of EPI to treat cardiac arrest have a poor prognosis, and that IV-EPI is associated with a higher incidence of return of a spontaneous pulse compared to those treated ET.

Effect of cardiopulmonary resuscitation on restoration of myocardial ATP in prolonged ventricular fibrillation

BACKGROUND

There has been controversy over whether a short period of cardiopulmonary resuscitation (CPR) prior to defibrillation improves survival in patients who experienced a sudden cardiac arrest. However, there have been no reports about whether CPR restores the myocardial energy source during prolonged ventricular fibrillation (VF). The aim of this study is to investigate the effect of CPR in restoring myocardial high energy phosphates during prolonged VF.

METHODS AND RESULTS

Seventy-two adult male Sprague-Dawley rats were used in this study. Baseline adenosine triphosphate (ATP) and adenosine diphosphate (ADP) prior to induction of VF were measured in nine rats, the No-VF group. Sixty-three rats were subjected to 4 min of untreated VF. Animals were then randomized into two groups: No-CPR (n=37) and CPR (n=26). In the No-CPR group, ATPs and ADPs were measured at 4 min (No-CPR4), 6 min (No-CPR6), 8 min (No-CPR8) or 10 min (No-CPR10) after the induction of VF. The CPR group received 2 min (CPR2), 4 min (CPR4) or 6 min (CPR6) of mechanical chest compressions before ATP was measured. Myocardial ATP (nmol/mg protein) was decreased as VF duration was prolonged (No-VF: 5.49±1.71, No-CPR4: 4.27±1.58, No-CPR6: 4.13±1.31, No-CPR8: 3.77±1.42, No-CPR10: 3.52±0.90, p<0.05 between each of No-CPRs vs. No-VF). Two minutes of CPR restored myocardial ATP to the level of No-VF group (5.27±1.67 nmol/mg protein in CPR2, p>0.05 vs. No-VF group). However, myocardial ATP (nmol/mg protein) decreased if the duration of CPR was longer than 2 min (CPR4: 3.77±1.05, CPR6: 3.49±1.08, p<0.05 between CPR4 and CPR6 vs. No-VF).

CONCLUSIONS

CPR for 2 min helps to maintain myocardial ATP after prolonged VF.

Utility of a novel watch-based pulse detection system to detect pulselessness in human subjects

BACKGROUND

The Wriskwatch is a novel, watch-based pulse detection device that detects the loss of a radial pulse via advanced pulse detection technology and immediately contacts emergency medical systems.

OBJECTIVE

The purpose of this first-in-man, prospective, single-blinded, phase 1 study was to evaluate the ability of this device to detect motionlessness and pulselessness in human subjects as a simulation of sudden cardiac death.

METHODS

The study cohort consisted of 34 patients: 24 hospitalized patients and 10 presenting for implantable cardioverter-defibrillator (ICD) testing. We simulated loss of pulse in our hospitalized patients via blood pressure cuff inflation to occlude the brachial arterial pulse at random times in 20 subjects with no inflations in 4 while the patients were instructed to keep perfectly still. Of the 10 patients undergoing ventricular fibrillation (VF) induction during ICD testing, the exact times of VF induction were recorded. A blinded reviewer determined if and when motion and pulse were lost in all patients using only data from the device.

RESULTS

Of the 34 patients, 2 had an unusable signal, 1 had device ejection during ICD testing, and 2 had too much motion artifact and were excluded (5/34 patients, or 14.7% of the total cohort). Of the 29 remaining subjects, 4 had no loss of pulse of which the device correctly identified 3. In the remaining 25 patients, the device correctly identified the time of pulselessness in 23 of 25 (16/17 hospitalized patients and 7/8 ICD patients). Overall, the Wriskwatch was worn for a total of 561.2 minutes. Pulselessness was present for 5.8 minutes. The sensitivity of the watch to detect pulse status (based on 15-second intervals) was 99.9%, and the specificity was 90.3%.

CONCLUSION

The Wriskwatch is a novel device that shows promise as a tool to hasten activation of emergency medical systems and facilitate early defibrillation in patients with cardiac arrest.

The relationship between time to arrival of emergency medical services (EMS) and survival from out-of-hospital ventricular fibrillation cardiac arrest

AIM

We examined the relationship between time from collapse to arrival of emergency medical services (EMS) and survival to hospital discharge for out-of-hospital ventricular fibrillation cardiac arrests in order to determine meaningful interpretations of this association.

METHODS

We calculated survival rates in 1-min intervals from collapse to EMS arrival. Additionally, we used logistic regression to determine the absolute probability of survival per minute of delayed EMS arrival. We created a logistic regression model with spline terms for the time variable to examine the decline in survival in intervals that are hypothesized to be physiologically relevant.

RESULTS

The observed data showed survival declined, on average, by 3% for each minute that EMS was delayed following collapse. Survival rates did not decline appreciably if the time between collapse and arrival of EMS was 4 min or less but they declined by 5.2% per minute between 5 and 10 min. EMS arrival 11-15 min after collapse showed a less steep decline in survival of 1.9% per minute. The spline model that incorporated changes in slope in the time interval variable modeled this relationship more accurately than a model with a continuous term for time (p=0.01).

CONCLUSIONS

The results of our analyses show that survival from out-of-hospital cardiac arrest does not decline at a constant rate following collapse. Models that incorporate changes that reflect the physiological alterations that occur following cardiac arrests are a more accurate way to describe changes in survival rates over time than models that include only a continuous term for time.

Active surface cooling protocol to induce mild therapeutic hypothermia after out-of-hospital cardiac arrest: a retrospective before-and-after comparison in a single hospital

OBJECTIVE

To evaluate whether implementation of a therapeutic hypothermia protocol on arrival in a community hospital improved survival and neurologic outcomes in patients initially found to have ventricular fibrillation, pulseless electrical activity, or asystole, and then successfully resuscitated from out-of-hospital cardiac arrest.

DESIGN

A retrospective study of patients who presented after implementation of a therapeutic hypothermia protocol compared with those who presented before the protocol was implemented.

SETTING

Harborview Medical Center, Seattle, WA.

PATIENTS

A total of 491 consecutive adults with out-of-hospital, nontraumatic cardiac arrest who presented between January 1, 2000 and December 31, 2004.

INTERVENTIONS

An active cooling therapeutic hypothermia protocol, using ice packs, cooling blankets, or cooling pads to achieve a temperature of 32 degrees C to 34 degrees C was initiated on November 18, 2002 for unconscious patients resuscitated from cardiac arrest.

MEASUREMENTS AND MAIN RESULTS

Demographics and outcomes were obtained from medical records and an emergency medical database. The primary outcomes were survival and favorable neurologic outcome at discharge associated with the therapeutic hypothermia protocol. An adjusted analysis was performed, using a multivariate regression. During the therapeutic hypothermia period, 204 patients were brought to the emergency department; of these 204 patients, 132 (65%) ultimately achieved temperatures of <34 degrees C. Of the 72 patients who did not achieve goal temperatures: 40 (20%) died in the emergency department or shortly after being admitted to the hospital, 15 (7%) regained consciousness, four (2%) had contraindications, 13 (6%) had temperature increase or did not have documented use of the therapeutic hypothermia protocol. In the prior period, none of the 287 patients received active cooling. Patients admitted in the therapeutic hypothermia period had a mean esophageal temperature of 34.1 degrees C during the first 12 hrs compared with 35.2 degrees C in the pretherapeutic hypothermia period (p < .01). Survival to hospital discharge improved in the therapeutic hypothermia period in patients with an initial rhythm of ventricular fibrillation (odds ratio, 1.88, 95% confidence interval, 1.03-3.45), however not in patients with nonventricular fibrillation (odds ratio, 1.17, 95% confidence interval, 0.66-2.05). In adjusted analysis, ventricular fibrillation patients during the therapeutic hypothermia period trended toward improved survival (odds ratio, 1.71, 95% confidence interval, 0.85-3.46) and had favorable neurologic outcome (odds ratio, 2.62, 95% confidence interval, 1.1-6.27) compared with the earlier period. This benefit was not observed in patients whose initial rhythm was pulseless electrical activity or asystole.

CONCLUSIONS

The therapeutic hypothermia period was associated with a significant improvement in neurologic outcomes in patients whose initial rhythm was ventricular fibrillation, but not in patients with other rhythms.

Survival increases with CPR by Emergency Medical Services before defibrillation of out-of-hospital ventricular fibrillation or ventricular tachycardia: observations from the Resuscitation Outcomes Consortium

BACKGROUND

Immediate defibrillation is the traditional approach to resuscitation of cardiac arrest due to ventricular fibrillation or tachycardia (VF/VT). Delaying defibrillation to provide chest compressions may improve survival. We examined the effect of the duration of Emergency Medical Services (EMS) cardiopulmonary resuscitation (CPR) prior to first defibrillation on survival in patients with out-of-hospital VF/VT.

MATERIALS AND METHODS

From a prospective multi-center observational registry of EMS-treated out-of-hospital cardiac arrest, we identified 1638 EMS-treated cardiac arrests with first recorded rhythm VF/VT or "shockable" and complete data for analysis. Survival to hospital discharge was determined as a function of EMS CPR duration prior to first shock.

RESULTS

Compared to the reference group of first EMS CPR duration < or =45 s, the odds of survival was greater among patients who received between 46 and 195 s of EMS CPR before first shock (46-75 s odds ratio [OR] 1.15, 95% confidence interval [CI] 0.71-1.87; 76-105 s, OR 1.37, 95% CI 0.80-2.35; 106-135 s, OR 1.53, 95% CI 0.96-2.45; 136-165 s, OR 1.24, 95% CI 0.71-2.15; 166-195 s, OR 1.47, 95% CI 0.85-2.52). The benefit of EMS CPR before defibrillation was reduced when the duration of CPR exceeded 195 s (196-225 s, OR 0.95, 95% CI 0.47-1.81; 226-255 s, OR 0.91, 95% CI 0.46-1.79; 256-285 s, OR 0.46, 95% CI 0.17-1.29; 286-315 s, OR 1.29, 95% CI 0.59-2.85). An optimal EMS CPR duration was not identified and no duration achieved statistical significance.

CONCLUSION

In this observational analysis of VF/VT arrest, between 46 and 195 s of EMS CPR prior to defibrillation was weakly associated with improved survival compared to < or =45 s. Randomized trials are needed to confirm the optimal duration of EMS CPR prior to defibrillation and to assess the impact of first CPR duration on all initial rhythms.

THE IMPACT OF A NEW CPR ASSIST DEVICE ON RATE OF RETURN OF SPONTANEOUS CIRCULATION IN OUT-OF-HOSPITAL CARDIAC ARREST

OBJECTIVE

The San Francisco Fire Department deployed an automated, load-distributing-band chest compression device (AutoPulse, Revivant Corporation) to evaluate its function in a large urban emergency medical services (EMS) service. A retrospective chart review was undertaken to determine whether the AutoPulse had altered short-term patient outcome, specifically, return of spontaneous circulation (ROSC).

METHODS

AutoPulse cardiopulmonary resuscitation (A-CPR) was used by paramedic captains responding to adult cardiac arrests with an average +/-SD response time of 15 +/- 5 minutes. The primary endpoint was patient arrival to an emergency department with measurable spontaneous pulses. The manual CPR comparison group was case-matched for age, gender, initial presenting electrocardiogram rhythm, and the number of doses of Advanced Cardiac Life Support medications as a proxy for treatment time. Matching was performed by an investigator blinded to outcome and treatment group.

RESULTS

Sixty-nine AutoPulse uses were matched to 93 manual-CPR-only cases. A-CPR showed improvement in the primary outcome when compared with manual CPR with any presenting rhythm (A-CPR 39%, manual 29%, p = 0.003). When patients were classified by first presenting rhythm, shockable rhythms showed no difference in outcome (A-CPR 44%, manual 50%, p = 0.340). Outcome was improved with A-CPR in initial presenting asystole and approached significance with pulseless electrical activity (PEA)(asystole: A-CPR 37%, manual 22%, p = 0.008; PEA: A-CPR 38%, manual 23%, p = 0.079).

CONCLUSION

The AutoPulse may improve the overall likelihood of sustained ROSC and may particularly benefit patients with nonshockable rhythms. A prospective randomized trial comparing the AutoPulse with manual CPR in the setting of out-of-hospital sudden cardiac arrest is under way.

Validation of a Predictive Model for Automated External Defibrillator Placement in Rural America

OBJECTIVE

The development of Automated External Defibrillators (AEDs) to treat out-of-hospital cardiac arrest (OOHCA) has greatly expanded the availability of life saving defibrillatory shocks in various settings. However, placement of AEDs in rural areas remains perplexing since OOHCAs are rare and unpredictable. We set out to develop a cost-effective rural AED placement model and to test the validity of the resulting model using OOHCAs attended by EMS.

METHODS

DESIGN

A population-based cross-sectional study. Analytic Plan: An exhaustive literature search was conducted to identify community attributes correlated with successful placement of AEDs in rural regions. Identified attributes were characterized using U.S. Census and CDC heart disease mortality data to estimate the potential risk for AED use and applied this estimate to rural census tracts in all 50 states. Based upon risk, AEDS were assigned to each tract using a first responder model and cost effectiveness was assessed. Using Utah State EMS data, the predicted placement of AEDs in each tract was validated using the actual number of OOHCAs attended by EMS.

RESULTS

A total of 14,586 rural census tracts in 50 U.S. states were evaluated. On average, 2,600 AEDs were situated within each state. AED placement in rural areas proved as cost effective as health screening programs. In Utah, predicted AED placement correlated with the frequency of OOHCAs attended by EMS personnel (rho= 0.55, p < 0.001).

CONCLUSIONS

The resulting model illustrates one potential way to determine the most beneficial location for rural AED placement.

Pronounced platelet hyperfunction in patients with cardiac arrest achieving restoration of spontaneous circulation

OBJECTIVE

Markers of platelet activation are increased in patients undergoing cardiopulmonary resuscitation. Hyperfunctional platelets may contribute to impairment of microcirculatory function and overall poor outcome despite restoration of spontaneous circulation (ROSC). Patients with myocardial infarction have hyperfunctional platelets, which predict the degree of myocardial necrosis. Thus, we hypothesized that platelets may be even more activated in patients whose myocardial infarction leads to cardiac arrest and compared them with patients whose cardiac arrest was due to a noncardiac origin.

DESIGN

Prospective observational study.

SETTING

Emergency department of a tertiary care hospital.

PATIENTS

One hundred four patients with witnessed cardiac arrest who achieved ROSC.

INTERVENTIONS

Blood sampling.

MEASUREMENTS AND MAIN RESULTS

We assessed collagen adenosine diphosphate closure time with the platelet function analyzer-100, and measured plasma levels of von Willebrand factor: ristocetin cofactor activity levels by turbidometry. Independent physicians diagnosed the origin of cardiac arrest. The majority of cardiac arrests were caused by myocardial ischemia. Invariably, collagen adenosine diphosphate closure time values (55 seconds; 95% confidence interval: 52-58 seconds) were much shorter in these patients compared with patients with other causes of cardiac arrest (110 seconds; 95% confidence interval: 84-135 seconds, p < 0.001). von Willebrand factor: ristocetin cofactor activity plasma levels were more than three-fold above normal values in both groups.

CONCLUSIONS

Patients with myocardial ischemia-triggered cardiac arrest had the highest degree of platelet hyperfunction under high shear rates, which was not solely due to increased von Willebrand factor. Future trials are necessary to clarify whether rapid, more aggressive antiplatelet therapy improves outcome after cardiac arrest.

Attitudes toward automated external defibrillator use in Japan

BACKGROUND

The American Heart Association 2005 Guidelines recommend immediate defibrillation for ventricular fibrillation (VF) of short duration, such as witnessed sudden cardiac arrest. However, it is unclear if public-access automated external defibrillators (AEDs) would actually be used in Japan, because there have been few studies about public attitudes regarding AED use. Therefore, we examined Japanese attitudes toward AED use.

METHODS AND RESULTS

Between February and March 2006, 3328 individuals, including high school students, teachers, emergency medical technicians (EMTs), medical nurses, and medical students, were asked about AED knowledge and their willingness to operate an AED. All EMTs, 86% of nurses, and 90% of medical students knew how to use AEDs, while only 15% of high school students and 44% of teachers had such knowledge. All EMTs, 78% of nurses, and 94% of medical students reported they would 'definitely' use the AED, but only 12% of high school students and 35% of teachers gave this reply. The reasons for unwillingness to operate AEDs among both laypeople and health care providers were poor of awareness of what AED is and/or how to use an AED. However, 83% of students and 81% of teachers with AED knowledge reported they would 'definitely' use the AED.

CONCLUSIONS

Many non-medical people in Japan would be unwilling to operate an AED, because they do not know what AED is and/or how to use an AED. However, many would be willing to operate AEDs if they had better understanding of AEDs. Thus, it is necessary to improve public knowledge of AEDs and AED use.