Percutaneous left ventricular assist devices in refractory cardiac arrest: The role of chest compressions.

Background: Recent studies describe an emerging role for percutaneous left ventricular assist devices such as Impella CP® as rescue therapy for refractory cardiac arrest. We hypothesized that the addition of mechanical chest compressions to percutaneous left ventricular assist device assisted CPR would improve hemodynamics by compressing the right ventricle and augmenting pulmonary blood flow and left ventricular filling. We performed a pilot study to test this hypothesis using a swine model of prolonged cardiac arrest. Methods: Eight Yorkshire swine were anesthetized, intubated, and instrumented for hemodynamic monitoring. They were subjected to untreated ventricular fibrillation for 5.75 (SD 2.90) minutes followed by mechanical chest compressions for a mean of 20.0 (SD 5.0) minutes before initiation of percutaneous left ventricular assist device. After percutaneous left ventricular assist device initiation, mechanical chest compressions was stopped (n = 4) or continued (n = 4). Defibrillation was attempted 4, 8 and 12 minutes after initiating percutaneous left ventricular assist device circulatory support. Results: The percutaneous left ventricular assist device + mechanical chest compressions group had significantly higher percutaneous left ventricular assist device flow prior to return of spontaneous heartbeat at four- and twelve-minutes after percutaneous left ventricular assist device initiation, and significantly higher end tidal CO2 at 4-minutes after percutaneous left ventricular assist device initiation, when compared with the percutaneous left ventricular assist device alone group. Carotid artery flow was not significantly different between the two groups. Conclusion: The addition of mechanical chest compressions to percutaneous left ventricular assist device support during cardiac arrest may generate higher percutaneous left ventricular assist device and carotid artery flow prior to return of spontaneous heartbeat compared to percutaneous left ventricular assist device alone. Further studies are needed to determine if this approach improves other hemodynamic parameters or outcomes after prolonged cardiac arrest.

Wolf Creek XVII Part 7: Mechanical circulatory support.

Introduction: Failure to restore spontaneous circulation remains a major cause of death for cardiac arrest (CA) patients. Mechanical circulatory support, specifically extracorporeal cardiopulmonary resuscitation (ECPR), has emerged as a feasible and efficacious rescue strategy for selected refractory CA patients. Methods: Mechanical Circulatory Support was one of six focus topics for the Wolf Creek XVII Conference held on June 14-17, 2023 in Ann Arbor, Michigan, USA. Conference invitees included international thought leaders and scientists in the field of CA resuscitation from academia and industry. Participants submitted via online survey knowledge gaps, barriers to translation and research priorities for each focus topic. Expert panels used the survey results and their own perspectives and insights to create and present a preliminary unranked list for each category that was debated, revised and ranked by all attendees to identify the top 5 for each category. Results: Top 5 knowledge gaps included optimal patient selection, pre-ECPR treatments, logistical and programmatic characteristics of ECPR programs, generalizability and effectiveness of ECPR, and prevention of reperfusion injury. Top 5 barriers to translation included cost/resource limitations, technical challenges, collaboration across multiple disciplines, limited patient population, and early identification of eligible patients. Top 5 research priorities focused on comparing the outcomes of prehospital/rapid transport strategies vs in-hospital ECPR initiation, implementation of high-performing ECPR system vs standard care, rapid patient identification tools vs standard clinical judgment, post-cardiac arrest bundled care vs no bundled care, and standardized ECPR clinical protocol vs routine care. Conclusion: This overview can serve as an innovative guide to transform the care and outcome of patients with refractory CA.

Effect of percutaneous ventricular assisted device on post-cardiac arrest myocardial dysfunction in swine model with prolonged cardiac arrest.

BACKGROUND: It remains unclear if percutaneous left ventricular assist device (pLVAD) reduces post-cardiac arrest myocardial dysfunction. METHODS: This is a prespecified analysis of a subset of swine that achieved return of spontaneous circulation (ROSC) in a study comparing pLVAD, transient aortic occlusion (AO), or both during cardiopulmonary resuscitation (CPR). Devices were initiated after 24 minutes of ventricular fibrillation cardiac arrest (8 min no-flow and 16 min mechanical CPR). AO was discontinued post-ROSC, and pLVAD support or standard care were continued. Beginning 60 minutes post-ROSC, pLVAD support was weaned to < 1.0 L/min and subsequently removed at 240 minutes. The primary outcome was cardiac index (CI), stroke volume index (SVI), and left ventricular ejection fraction (LVEF) at 240 minutes post-ROSC. Data are shown as mean (standard error). RESULTS: Seventeen swine achieved ROSC without complication and were included in this analysis (pLVAD group, n = 11 and standard care group, n = 6). For the primary outcomes, the pLVAD group had significantly higher CI of 4.2(0.3) vs. 3.1(0.4) L/min/m2 (p = 0.043) and LVEF 60(3) vs. 49(4) % (p = 0.029) at 240 minutes after ROSC when compared with the standard care group, while SVI was not statistically significantly different (32[3] vs. 23[4] mL/min/m2, p = 0.054). During the first 60 minutes post-ROSC, the pLVAD group had significantly higher coronary perfusion pressure, lower LV stroke work index, and total pulmonary resistance index. CONCLUSION: These results suggest that early pLVAD support after ROSC is associated with better recovery myocardial function compared to standard care after prolonged cardiac arrest.

Coagulofibrinolytic effects of recombinant soluble thrombomodulin in prolonged porcine cardiac arrest.

Aim: To evaluate coagulofibrinolytic abnormalities and the effects of ART-123 (recombinant human thrombomodulin alpha) in a porcine model of cardiac arrest and prolonged cardiopulmonary resuscitation (CA/CPR). Methods: Fifteen pigs (n = 5 per group) underwent 8 minutes of no-flow CA followed by 50 minutes of mechanical CPR, while 2 pigs underwent sham arrest. CA/CPR animals were randomized to receive saline or 1 mg/kg ART-123 pre-arrest (5 minutes prior to ventricular fibrillation) or post-arrest (2 minutes after initiation of CPR). Arterial and venous blood samples were drawn at multiple time points for blood gas analysis and measurement of plasma and whole blood markers of coagulation and fibrinolysis. Results: In saline-treated CA/CPR, but not sham animals, robust and persistent activation of coagulation and fibrinolysis was observed throughout resuscitation. After 50 minutes of CPR, plasma tests and thromboelastography indicated a mix of hypercoagulability and consumptive coagulopathy. ART-123 had a robust anticoagulant effect, reducing both thrombin-antithrombin (TAT) complexes and d-dimer (p < 0.05 for each). The duration of anticoagulant effect varied depending on the timing of ART-123 administration. Similarly, ART-123 when given prior to cardiac arrest was found to have pro-fibrinolytic effects, increasing free tissue plasminogen activator (tPA, p = 0.02) and decreasing free plasminogen activator inhibitor-1 (PAI-1, p = 0.04). Conclusion: A porcine model of prolonged CA/CPR reproduces many of the coagulofibrinolytic abnormalities observed in human cardiac arrest patients. ART-123 demonstrates a combination of anticoagulant and profibrinolytic effects, depending on the timing of its administration relative to cardiac arrest.

Haemodynamic impact of aortic balloon occlusion combined with percutaneous left ventricular assist device during cardiopulmonary resuscitation in a swine model of cardiac arrest.

AIM: To investigate the effect of tandem use of transient balloon occlusion of the descending aorta (AO) and percutaneous left ventricular assist device (pl-VAD) during cardiopulmonary resuscitation in a large animal model of prolonged cardiac arrest. METHODS: Ventricular fibrillation was induced and left untreated for 8 minutes followed by 16 minutes of mechanical CPR (mCPR) in 24 swine, under general anesthesia. Animals were randomized to 3 treatment groups (n = 8 per group): A) pL-VAD (Impella CP®) B) pL-VAD+AO, and C) AO. Impella CP® and the aortic balloon catheter were inserted via the femoral arteries. mCPR was continued during treatment. Defibrillation was attempted 3 times starting at minute 28 and then every 4 minutes. Haemodynamic, cardiac function and blood gas measurements were recorded for up to 4 hours. RESULTS: Coronary perfusion pressure (CoPP) in the pL-VAD+AO Group increased by a mean (SD) of 29.2(13.94) mmHg compared to an increase of 7.1(12.08) and 7.1(5.95) mmHg for groups pL-VAD and AO respectively (p = 0.02). Similarly, cerebral perfusion pressure (CePP) in pL-VAD+AO increased by a mean (SD) of 23.6 (6.11), mmHg compared with 0.97 (9.07) and 6.9 (7.98) mmHg for the other two groups (p < 0.001). The rate of return of spontaneous heartbeat (ROSHB) was 87.5%, 75%, and 100% for pL-VAD+AO, pL-VAD, and AO. CONCLUSION: Combined AO and pL-VAD improved CPR hemodynamics compared to either intervention alone in this swine model of prolonged cardiac arrest.

Therapeutic Effect of Argatroban During Cardiopulmonary Resuscitation and Streptokinase During Extracorporeal Cardiopulmonary Resuscitation in a Porcine Model of Prolonged Cardiac Arrest.

Prolonged cardiac arrest (CA) causes microvascular thrombosis which is a potential barrier to organ reperfusion during extracorporeal cardiopulmonary resuscitation (ECPR). The aim of this study was to test the hypothesis that early intra-arrest anticoagulation during cardiopulmonary resuscitation (CPR) and thrombolytic therapy during ECPR improve recovery of brain and heart function in a porcine model of prolonged out-of-hospital CA. DESIGN: Randomized interventional trial. SETTING: University laboratory. SUBJECTS: Swine. INTERVENTIONS: In a blinded study, 48 swine were subjected to 8 minutes of ventricular fibrillation CA followed by 30 minutes of goal-directed CPR and 8 hours of ECPR. Animals were randomized into four groups (n = 12) and given either placebo (P) or argatroban (ARG; 350 mg/kg) at minute 12 of CA and either placebo (P) or streptokinase (STK, 1.5 MU) at the onset of ECPR. MEASUREMENTS AND MAIN RESULTS: Primary outcomes included recovery of cardiac function measured by cardiac resuscitability score (CRS: range 0-6) and recovery of brain function measured by the recovery of somatosensory-evoked potential (SSEP) cortical response amplitude. There were no significant differences in recovery of cardiac function as measured by CRS between groups (p = 0.16): P + P 2.3 (1.0); ARG + P = 3.4 (2.1); P + STK = 1.6 (2.0); ARG + STK = 2.9 (2.1). There were no significant differences in the maximum recovery of SSEP cortical response relative to baseline between groups (p = 0.73): P + P = 23% (13%); ARG + P = 20% (13%); P + STK = 25% (14%); ARG + STK = 26% (13%). Histologic analysis demonstrated reduced myocardial necrosis and neurodegeneration in the ARG + STK group relative to the P + P group. CONCLUSIONS: In this swine model of prolonged CA treated with ECPR, early intra-arrest anticoagulation during goal-directed CPR and thrombolytic therapy during ECPR did not improve initial recovery of heart and brain function but did reduce histologic evidence of ischemic injury. The impact of this therapeutic strategy on the long-term recovery of cardiovascular and neurological function requires further investigation.

Calcium during cardiac arrest: A systematic review.

Aim: To perform a systematic review of administration of calcium compared to no calcium during cardiac arrest. Methods: The search included Medline (PubMed), Embase, Cochrane, Web of Science, and CINAHL Plus and was conducted on September 30, 2022. The population included adults and children in any setting with cardiac arrest. The outcomes included return of spontaneous circulation, survival, survival with favourable neurologic outcome to hospital discharge and 30 days or longer, and quality of life outcome. Cochrane Risk of Bias 2 and ROBINS-I were performed to assess risk of bias for controlled and observational studies, respectively. Results: The systematic review identified 4 studies on 3 randomised controlled trials on 554 adult out-of-hospital cardiac arrest (OHCA) patients, 8 observational studies on 2,731 adult cardiac arrest patients, and 3 observational studies on 17,449 paediatric in-hospital cardiac arrest (IHCA) patients. The randomised controlled and observational studies showed that routine calcium administration during cardiac arrest did not improve the outcome of adult OHCA or IHCA or paediatric IHCA. The risk of bias for the adult trials was low for one recent trial and high for two earlier trials, with randomization as the primary source of bias. The risk of bias for the individual observational studies was assessed to be critical due to confounding. The certainty of evidence was assessed to be moderate for adult OHCA and low for adult and paediatric IHCA. Heterogeneity across studies precluded any meaningful meta-analyses. Conclusions: This systematic review found no evidence that routine calcium administration improves the outcomes of cardiac arrest in adults or children.PROSPERO Registration: CRD42022349641.

Extracorporeal cardiopulmonary resuscitation for cardiac arrest: An updated systematic review.

OBJECTIVES: To provide an updated systematic review on the use of extracorporeal cardiopulmonary resuscitation (ECPR) compared with manual or mechanical cardiopulmonary resuscitation during cardiac arrest. METHODS: This was an update of a systematic review published in 2018. OVID Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched for randomized trials and observational studies between January 1, 2018, and June 21, 2022. The population included adults and children with out-of-hospital or in-hospital cardiac arrest. Two investigators reviewed studies for relevance, extracted data, and assessed bias. The certainty of evidence was evaluated using GRADE. RESULTS: The search identified 3 trials, 27 observational studies, and 6 cost-effectiveness studies. All trials included adults with out-of-hospital cardiac arrest and were terminated before enrolling the intended number of subjects. One trial found a benefit of ECPR in survival and favorable neurological status, whereas two trials found no statistically significant differences in outcomes. There were 23 observational studies in adults with out-of-hospital cardiac arrest or in combination with in-hospital cardiac arrest, and 4 observational studies in children with in-hospital cardiac arrest. Results of individual studies were inconsistent, although many studies favored ECPR. The risk of bias was intermediate for trials and critical for observational studies. The certainty of evidence was very low to low. Study heterogeneity precluded meta-analyses. The cost-effectiveness varied depending on the setting and the analysis assumptions. CONCLUSIONS: Recent randomized trials suggest potential benefit of ECPR, but the certainty of evidence remains low. It is unclear which patients might benefit from ECPR.

WOMen profEssioNal developmenT oUtcome Metrics in Academic Emergency Medicine: Results from the WOMENTUM Modified Delphi Study.

INTRODUCTION: To address persistent gender inequities in academic medicine, women professional development groups (PDG) have been developed to support the advancement of women in medicine. While these programs have shown promising outcomes, long-term evaluative metrics do not currently exist. The objective of this study was to establish metrics to assess women's PDGs. METHODS: This was a modified Delphi study that included an expert panel of current and past emergency department (ED) chairs and Academy for Women in Academic Emergency Medicine (AWAEM) presidents. The panel completed three iterative surveys to develop and rank metrics to assess women PDGs. Metrics established by the expert panel were also distributed for member-checking to women EM faculty. RESULTS: The expert panel ranked 11 metrics with high to moderate consensus ranking with three metrics receiving greater than 90% consensus: gender equity strategy and plan; recruitment; and compensation. Members ranked 12 metrics with high consensus with three metrics receiving greater than 90% consensus: gender equity strategy and plan; compensation; and gender equity in promotion rates among faculty. Participants emphasized that departments should be responsible for leading gender equity efforts with PDGs providing a supportive role. CONCLUSION: In this study, we identified metrics that can be used to assess academic EDs' gender equity initiatives and the advisory efforts of a departmental women's PDG. These metrics can be tailored to individual departmental/institutional needs, as well as to a PDG's mission. Importantly, PDGs can use metrics to develop and assess programming, acknowledging that many metrics are the responsibility of the department rather than the PDG.

Eligibility of out-of-hospital cardiac arrest patients for extracorporeal cardiopulmonary resuscitation in the United States: A geographic information system model.

BACKGROUND: Recent evidence suggest that extracorporeal cardiopulmonary resuscitation (ECPR) may improve survival rates for nontraumatic out-of-hospital cardiac arrest (OHCA). Eligibility criteria for ECPR are often based on patient age, clinical variables, and facility capabilities. Expanding access to ECPR across the U.S. requires a better understanding of how these factors interact with transport time to ECPR centers. METHODS: We constructed a Geographic Information System (GIS) model to estimate the number of ECPR candidates in the U.S. We utilized a Resuscitation Outcome Consortium (ROC) database to model time-dependent rates of ECPR eligibility and the Cardiac Arrest Registry to Enhance Survival (CARES) registry to determine the total number of OHCA patients who meet pre-specified ECPR criteria within designated transportation times. The combined model was used to estimate the total number of ECPR candidates. RESULTS: There were 588,203 OHCA patients in the CARES registry from 2013 to 2020. After applying clinical eligibility criteria, 22,104 (3.76%) OHCA patients were deemed eligible for ECPR. The rate of ROSC increased with longer resuscitation time, which resulted in fewer ECPR candidates. The proportion of OHCA patients eligible for ECPR increased with older age cutoffs. Only 1.68% (9,889/588,203) of OHCA patients in the U.S. were eligible for ECPR based on a 45-minute transportation time to an ECMO-ready center model. CONCLUSIONS: Less than 2% of OHCA patients are eligible for ECPR in the U.S. GIS models can identify the impact of clinical criteria, transportation time, and hospital capabilities on ECPR eligibility to inform future implementation strategies.

Association of intentional cooling, achieved temperature and hypothermia duration with in-hospital mortality in patients treated with extracorporeal cardiopulmonary resuscitation: An analysis of the ELSO registry.

AIM: To investigate whether intentional cooling, achieved temperature and hypothermia duration were associated with in-hospital death in patients treated with extracorporeal cardiopulmonary resuscitation (ECPR) for refractory cardiac arrest. METHODS: This is a retrospective analysis of the Extracorporeal Life Support Organization Registry. Patients 18-79 years of age who received ECPR between 2010 and 2019 were included. We compared outcomes for intentional cooling versus no intentional cooling. Then, among those who completed intentional cooling, we compared the outcomes between i) achieved temperature ≤ 34 °C, 34-36 °C, and > 36 °C, and ii) duration ≤ 36 °C for < 12 h, 12-48 h, and ≥ 48 h. The primary outcome was in-hospital mortality within 90 days. Cox proportional hazard models were generated with adjustment for covariates. RESULTS: Among 4,214 ECPR patients, 1,511 patients were included in the final analysis. After multivariable adjustment, there was no significant difference in in-hospital mortality between patients with intentional cooling and no intentional cooling (hazard ratio [HR], 1.06 [95% CI 0.93-1.21]; p = 0.394). In the 609 patients who completed intentional cooling, temperature at 34-36 °C had a significantly lower adjusted HR for in-hospital mortality compared with > 36 °C (HR, 0.73 [0.55-0.96]; p = 0.025). Moreover, temperature ≤ 36 °C for 12-48 h had a significantly lower adjusted HR for in-hospital mortality compared with ≤ 36 °C for < 12 h (HR, 0.69 [0.53-0.90]; p = 0.005). CONCLUSION: Intentional cooling was not associated with lower in-hospital mortality in ECPR patients. However, among patients with intentional cooling, achieving temperature of 34-36 °C for 12-48 h was associated with lower in-hospital mortality.

ECPR2: Expert Consensus on PeRcutaneous Cannulation for Extracorporeal CardioPulmonary Resuscitation.

AIM: Extracorporeal cardiopulmonary resuscitation (ECPR) has emerged as a promising resuscitation strategy for select patients suffering from refractory out-of-hospital cardiac arrest (OHCA), though limited data exist regarding the best practices for ECPR initiation after OHCA. METHODS: We utilized a modified Delphi process consisting of two survey rounds and a virtual consensus meeting to systematically identify detailed best practices for ECPR initiation following adult non-traumatic OHCA. A modified Delphi process builds content validity and is an accepted method to develop consensus by eliciting expert opinions through multiple rounds of questionnaires. Consensus was achieved when items reached a high level of agreement, defined as greater than 80% responses for a particular item rated a 4 or 5 on a 5-point Likert scale. RESULTS: Snowball sampling generated a panel of 14 content experts, composed of physicians from four continents and five primary specialties. Seven existing institutional protocols for ECPR cannulation following OHCA were identified and merged into a single comprehensive list of 207 items. The panel reached consensus on 101 items meeting final criteria for inclusion: Prior to Patient Arrival (13 items), Inclusion Criteria (8), Exclusion Criteria (7), Patient Arrival (8), ECPR Cannulation (21), Go On Pump (18), and Post-Cannulation (26). CONCLUSION: We present a list of items for ECPR initiation following adult nontraumatic OHCA, generated using a modified Delphi process from an international panel of content experts. These findings may benefit centers currently performing ECPR in quality assurance and serve as a template for new ECPR programs.

Extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest - who, when, and where?

PURPOSE OF REVIEW: Extracorporeal cardiopulmonary resuscitation (ECPR) is an invasive and resource-intensive therapy used to care for patients with refractory cardiac arrest. In this review, we highlight considerations for the establishment of an ECPR system of care for patients suffering refractory out-of-hospital cardiac arrest (OHCA). RECENT FINDINGS: ECPR has been shown to improve neurologically favorable outcomes in patients with refractory cardiac arrest in numerous studies, including a single randomized control trial. Successful ECPR programs are typically part of a comprehensive system of care that optimizes all phases of OHCA management. Given the resource-intensive and time-sensitive nature of ECPR, patient selection criteria, timing of ECPR, and location must be well defined. Many knowledge gaps remain within ECPR systems of care, postcardiac arrest management, and neuroprognostication strategies for ECPR patients. SUMMARY: To be consistently successful, ECPR must be a part of a comprehensive OHCA system of care that optimizes all phases of cardiac arrest management. Future investigation is needed for the knowledge gaps that remain.

Integration of social media with targeted emails and in-person outreach for exception from informed consent community consultation.

BACKGROUND: Exception from informed consent (EFIC) enables the enrollment of research subjects with emergent conditions to clinical trials without prior consent. EFIC study approval requires community consultation and public disclosure. We hypothesized that the integration of social media with targeted emails and in-person outreach is an effective community consultation strategy. METHODS: We utilized social media with targeted emails and in-person outreach for the community consultation of the ACCESS cardiac arrest trial. Study advertisements were disseminated using Facebook and Instagram, and targeted emails were sent to emergency medicine, prehospital, and cardiology providers. We also interviewed at-risk individuals with cardiac conditions, their caretakers, and patient advocacy groups. Participants were asked to complete a survey about their opinions about the study. RESULTS: We collected 559 surveys over an 8-week period, and 70.5% of the surveys were obtained using social media. The median (IQR) age of survey respondents was 44 (33-57) years; 89.9% were White and 60.1% were women. A total of 91.3% believed ACCESS was an important study. Compared to the in-person group, more from social media (81.8% vs. 63.3%, p < 0.05) and targeted email (77.4% vs. 63.3%, p < 0.05) groups said they would include their loved ones in the study. More from the in-person group believed that their opinion would be considered seriously compared to the social media (75.9% vs. 62.6%, p < 0.05) and targeted email (75.9% vs. 54.5%, p < 0.05) groups. The incorporation of social media and targeted emails for community consultation reduced the cost per survey by fourfold compared to an in-person-only strategy. CONCLUSIONS: The integration of social media with targeted emails and in-person outreach was a feasible and cost-saving approach for EFIC community consultation. Future work is necessary to determine the perception and best utilization of social media for community consultation.

Cardiopulmonary resuscitation and defibrillation for cardiac arrest when patients are in the prone position: A systematic review.

AIM: To perform a systematic review of cardiopulmonary resuscitation (CPR) and/or defibrillation in the prone position compared to turning the patient supine prior to starting CPR and/or defibrillation. METHODS: The search included PubMed, Embase, Web of Science, Cochrane, CINAHL Plus, and medRxiv on December 9, 2020. The population included adults and children in any setting with cardiac arrest while in the prone position. The outcomes included arterial blood pressure and end-tidal capnography during CPR, time to start CPR and defibrillation, return of spontaneous circulation, survival and survival with favorable neurologic outcome to discharge, 30 days or longer. ROBINS-I was performed to assess risk of bias for observational studies. RESULTS: The systematic review identified 29 case reports (32 individual cases), two prospective observational studies, and two simulation studies. The observational studies enrolled 17 patients who were declared dead in the supine position and reported higher mean systolic blood pressure from CPR in prone position (72 mmHg vs 48 mmHg, p < 0.005; 79 ± 20 mmHg vs 55 ± 20 mmHg, p = 0.028). One simulation study reported a faster time to defibrillation in the prone position. Return of spontaneous circulation, survival to discharge or 30 days were reported in adult and paediatric case reports. Critical risk of bias limited our ability to perform pooled analyses. CONCLUSIONS: We identified a limited number of observational studies and case reports comparing prone versus supine CPR and/or defibrillation. Prone CPR may be a reasonable option if immediate supination is difficult or poses unacceptable risks to the patient.

Insights From the Ventricular Fibrillation Waveform Into the Mechanism of Survival Benefit From Bystander Cardiopulmonary Resuscitation.

Background The mechanism by which bystander cardiopulmonary resuscitation (CPR) improves survival following out-of-hospital cardiac arrest is unclear. We hypothesized that ventricular fibrillation (VF) waveform measures, as surrogates of myocardial physiology, mediate the relationship between bystander CPR and survival. Methods and Results We performed a retrospective cohort study of adult, bystander-witnessed patients with out-of-hospital cardiac arrest with an initial rhythm of VF who were treated by a metropolitan emergency medical services system from 2005 to 2018. Patient, resuscitation, and outcome variables were extracted from emergency medical services and hospital records. A total of 3 VF waveform measures (amplitude spectrum area, peak frequency, and median peak amplitude) were computed from a 3-second ECG segment before the initial shock. Multivariable logistic regression estimated the association between bystander CPR and survival to hospital discharge adjusted for Utstein elements. Causal mediation analysis quantified the proportion of survival benefit that was mediated by each VF waveform measure. Of 1069 patients, survival to hospital discharge was significantly higher among the 814 patients who received bystander CPR than those who did not (0.52 versus 0.43, respectively; P<0.01). The multivariable-adjusted odds ratio for bystander CPR and survival was 1.6 (95% CI, 1.2, 2.1), and each VF waveform measure attenuated this association. Depending on the specific waveform measure, the proportion of mediation varied: 53% for amplitude spectrum area, 31% for peak frequency, and 29% for median peak amplitude. Conclusions Bystander CPR correlated with more robust initial VF waveform measures, which in turn mediated up to one-half of the survival benefit associated with bystander CPR. These results provide insight into the biological mechanism of bystander CPR in VF out-of-hospital cardiac arrest.

Rapid Dissemination of a COVID-19 Airway Management Simulation Using a Train-the-Trainers Curriculum.

PROBLEM: The most effective way to train clinicians to safely don and doff personal protective equipment (PPE) and perform aerosol-generating procedures (AGPs), such as intubations, is unknown when clinician educators are unavailable, as they have been during the COVID-19 pandemic. Proper PPE and airway management techniques are critical to prevent the transmission of respiratory illnesses such as COVID-19. APPROACH: In March 2020, the authors implemented a structured train-the-trainers curriculum to teach PPE techniques and a modified airway management algorithm for suspected COVID-19 patients. A single emergency medicine physician trainer taught 17 subsequent emergency medicine and critical care physician trainers the proper PPE and airway management techniques. The initial trainer and 7 of the subsequent trainers then instructed 99 other emergency medicine resident and attending physicians using in situ simulation. Trainers and learners completed retrospective pre-post surveys to assess their comfort teaching the material and performing the techniques, respectively. OUTCOMES: The surveys demonstrated a significant increase in the trainers' comfort in teaching simulation-based education, from 4.00 to 4.53 on a 5-point Likert scale (P < .005), and in teaching the airway management techniques through simulation, from 2.47 to 4.47 (P < .001). There was no difference in the change in comfort level between those learners who were taught by the initial trainer and those who were taught by the subsequent trainers. These results suggest that the subsequent trainers were as effective in teaching the simulation material as the initial trainer. NEXT STEPS: Work is ongoing to investigate clinician- and patient-specific outcomes, including PPE adherence, appropriate AGP performance, complication rate, and learners' skill retention. Future work will focus on implementing similar train-the-trainers strategies for other health professions, specialties, and high-risk or rare procedures.

Extracorporeal Cardiopulmonary Resuscitation for Refractory Out-of-Hospital Cardiac Arrest (EROCA): Results of a Randomized Feasibility Trial of Expedited Out-of-Hospital Transport.

STUDY OBJECTIVE: Outcomes of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest depend on time to therapy initiation. We hypothesize that it would be feasible to select refractory out-of-hospital cardiac arrest patients for expedited transport based on real-time estimates of the 911 call to the emergency department (ED) arrival interval, and for emergency physicians to rapidly initiate ECPR in eligible patients. METHODS: In a 2-tiered emergency medical service with an ECPR-capable primary destination hospital, adults with refractory shockable or witnessed out-of-hospital cardiac arrest were randomized 4:1 to expedited transport or standard care if the predicted 911 call to ED arrival interval was less than or equal to 30 minutes. The primary outcomes were the proportion of subjects with 911 call to ED arrival less than or equal to 30 minutes and ED arrival to ECPR flow less than or equal to 30 minutes. RESULTS: Of 151 out-of-hospital cardiac arrest 911 calls, 15 subjects (10%) were enrolled. Five of 12 subjects randomized to expedited transport had an ED arrival time of less than or equal to 30 minutes (overall mean 32.5 minutes [SD 7.1]), and 5 were eligible for and treated with ECPR. Three of 5 ECPR-treated subjects had flow initiated in less than or equal to 30 minutes of ED arrival (overall mean 32.4 minutes [SD 10.9]). No subject in either group survived with a good neurologic outcome. CONCLUSION: The Extracorporeal Cardiopulmonary Resuscitation for Refractory Out-of-Hospital Cardiac Arrest trial did not meet predefined feasibility outcomes for selecting out-of-hospital cardiac arrest patients for expedited transport and initiating ECPR in the ED. Additional research is needed to improve the accuracy of predicting the 911 call to ED arrival interval, optimize patient selection, and reduce the ED arrival to ECPR flow interval.