bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 223: Association Between Covid-19 Pandemic Related Anxiety and Advanced Care Planning Desire in Cardiac Arrest Survivors
Authors: Meyer Benjamin J , Jacobson Samuel , Roh David , Park Soojin , Claassen Jan , Agarwal Sachin
Published: November 2020

Introduction:
Patients with cardiovascular disease conditions are at high risk for direct and indirect impacts of COVID-19 on morbidity and mortality. In light of this, we aimed to assess the extent to which COVID-19-related anxiety in patients with a history of cardiac arrest (CA) correlates with the desire to change or discuss advanced directives.

Methods:
Between May 15-28, 2020, a month after the New York City (NYC) COVID-19 pandemic peak, CA survivors from a prospective cohort were invited to participate in a telephone-based assessment of the pandemic’s impact on psychological and other survivorship dimensions. COVID-19-related anxiety was measured by the Generalized Anxiety Disorder-3 scale, which asks how often respondents felt (1) anxious, (2) unable to stop worrying, and (3) excessively worried over two weeks, and was keyed to the COVID-19 pandemic. Desire to discuss or to change financial and/or health-related advanced directives were reported on a yes-or-no basis.

Results:
100 approached, 69 CA survivors participated (53% male; age 61±15 years; 44% White, 20% Black, and 31% Latinx). A majority, 58 of 69 (84%), had no COVID-19 symptoms and/or were not tested. Only 12 of the 69 respondents (17%) showed interest in discussing or changing advanced directives. There were no significant differences in the age, sex, race, or COVID-19 symptoms status between those who showed desire versus those who did not. Desire to change advance directives was significantly associated with increased COVID-19-related anxiety (OR 1.5, CI 95% [1.2-1.9] p<0.002).

Conclusions:
In CA survivors, a desire to change financial or healthcare-related advanced directives during the COVID-19 outbreak was associated with increased pandemic-related anxiety. The causality and directionality of this relationship require further, qualitative study.
Abstract 234: Validation of a Termination-of-resuscitation Rule for Patients with Refractory Out-of-hospital Cardiac Arrest at an Emergency Department in Japan
Authors: Funada Akira , Goto Yoshikazu , Takamura Masayuki
Published: November 2020

Introduction:
In Japan, emergency medical service (EMS) providers are prohibited from cardiopulmonary resuscitation (CPR) termination in the field and must transport all out-of-hospital cardiac arrest (OHCA) patients to a hospital, regardless of the return of spontaneous circulation (ROSC). We previously developed a termination of resuscitation (TOR) rule for emergency department physicians (ED-TOR) treating OHCA patients using data from the All-Japan Utstein Registry between 2005 and 2009, when CPR was performed according to the 2005 guidelines. The ED-TOR rule recommends CPR termination when patients in the emergency department meet all of the following criteria: initial unshockable rhythm, arrest unwitnessed by bystanders and no prehospital ROSC.

Hypothesis:
We aimed to validate the ED-TOR rule using more recent data, where CPR was performed according to the 2010 and 2015 guidelines, comparing the relevance of the ED-TOR rule with the universal basic life support TOR (BLS-TOR) rule, which consists of the following criteria: no prehospital ROSC, unwitnessed arrest by EMS providers and no shock received.

Methods:
We analysed 552,554 OHCA patients (age ≥ 18 years) treated by EMS providers. OHCA patients witnessed by EMS providers were excluded. Data were obtained from a prospectively recorded All-Japan Utstein Registry from 2013 to 2017. The study endpoints were specificity and a positive predictive value (PPV) for predicting 1-month mortality after OHCA with the ED-TOR and BLS-TOR rules.

Results:
The overall 1-month survival rate was 4.3% (23,733/552,554). The proportions of OHCA patients who fulfilled the ED-TOR and BLS-TOR criteria were 59.6% and 83.8%, respectively. The specificity and PPV of the ED-TOR and BLS-TOR rules for predicting 1-month mortality were 93.2% (95% confidence interval [CI], 92.8%-93.5%) and 99.5% (95% CI, 99.5%-99.5%) and 82.6% (95% CI, 82.1%-83.1%) and 99.1% (95% CI, 99.1%-99.1%), respectively.

Conclusions:
The ED-TOR rule was successfully validated using more recent data from a Japanese registry where CPR was performed according to the 2010 and 2015 guidelines. The ED-TOR rule was slightly superior to the BLS-TOR rule in Japanese EMS systems showing high specificity and PPV for predicting 1-month mortality.
Abstract 235: The Covid-19 Pandemic in Dallas: Increased Out-of-hospital Cardiac Arrest and Death
Authors: Guo Lin , Owens Pamela , Isaacs Marshal , Kayea Tami , McKee Lu Ann , Mody Purav , Idris Ahamed H
Published: November 2020

Introduction:
Since March, the CDC has reported weekly excess deaths of up to 40% in the US. Spikes in excess deaths were associated with spikes in COVID-19 cases. In Texas, 55% of excess deaths from March 1 to May 30, 2020 were unattributed to COVID-19. One possible source of this unaccounted excess death is out-of-hospital cardiac arrest, which corresponds to a notable decline in hospitalizations for acute cardiovascular events.

Objective:
To compare the number of out-of-hospital cardiac arrest (OOHCA) and dead-on-scene cases in Dallas, Texas in years prior to and during the COVID-19 pandemic.

Methods:
The Dallas-Fort Worth Center for Resuscitation Research Cardiac Arrest Registry provided data for this IRB-approved study. Eligible cases were non-traumatic OOHCAs who received cardiopulmonary resuscitation (CPR) from emergency medical services (EMS) providers. We compared monthly case numbers in 2017, 2018, and 2019 with case numbers in 2020 at the time of the COVID-19 pandemic in Dallas, TX. Additionally, we compared the numbers of non-traumatic deaths (declared dead on scene without receiving CPR from EMS providers) in the same timeframes.

Results:
While total counts of out-of-hospital cardiac arrest during the months of March to June decreased from 2017 to 2019 by 9.2% and 1.2% respectively, the number of cardiac arrest cases rose dramatically by 47.9% in 2020 (p < 0.05).(Table) The percentage of OOHCAs with an initial rhythm of asystole increased as well, from 50.1% in 2018 and 2019 to 60.4% in 2020. The total number of dead-on-scene cases was also higher in March to June 2020 than in 2017 to 2019 (NS).

Conclusion:
Increased out-of-hospital cardiac arrest is likely contributing to the unattributed excess deaths noted during the months of the COVID-19 pandemic in Dallas, TX. The rise in cases may be indirectly attributable to COVID-19 as cardiovascular events go untreated or treated too late.
Abstract 241: Analysis of Characteristics and Mortality by the Level of Hospital in the Patients with Cardiac Arrest; A Nation-wide Population-based Study
Authors: Lee Sijin , Kim Su Jin , Lee Sung Woo , Han Kap Su , Lee Eui Jung
Published: November 2020

Objectives:
We intended to determine the association between hospital-level and mortality, and reveal differences in patient characteristics and potential resource utilization using the National health Insurance Service database.

Methods:
We selected adult patients (>20 years old) with non-traumatic cardiac arrest from 2006 to 2015 using the national database. The patients were categorized into ‘Tertiary’, ‘Secondary’ and ‘Primary’ groups by the level of hospital where they were treated. Demographics, insurance type, urbanization level, previous disease, medical therapies and hospital costs were analyzed among the groups. Primary end-points were mortality rate within 30 days, 6 months and 1 year. Multiple logistic regression analysis was utilized for determining the association between hospital-level and mortality (SAS ver 9.4).

Results:
Tertiary, Secondary and Primary groups accounted for 32.6%, 49.6% and 17.8% of total 337,042 patients. Tertiary and Secondary groups showed the higher proportion of younger age, male patients, coverage by national health insurance, urban residents and lower Charlson Comorbidity Index than Primary group. After adjusting characteristics and pre-existing diseases in multiple logistic regression analysis, the higher hospital level was negatively associated with mortality (Adjusted Odds ratio[aOR]: 0.372 and 0.419 at 30-days, aOR: 0.504 and 0.568 at 6-months, aOR: 0.538 and 0.604 at 1-year in Tertiary and Secondary groups). Advanced treatments like PCI, CABG, ECMO, EEG and therapeutic hypothermia were provided more in the higher level hospital. With regard to guideline change in 2010, there was a downturn in use of atropine and an increment in post-resuscitation care treatments in Tertiary and Secondary groups.

Conclusions:
Significant variability in cardiac arrest mortality exists across hospital levels, and this variation persists despite adjustment for measured patient factors. These findings suggest that higher level hospital provided more advanced procedures and post-resuscitation care, which leaded to higher hospital cost especially in acute period, and showed good adherence to guideline updates. (NRF-2017R1A2B100 5037)
Abstract 245: Dispatcher Assisted Cardiopulmonary Resuscitation in Patients Not in Cardiac Arrest: A Multi-Center, Observation Study
Authors: Ng Julia YX , Sim Zariel J , Siddiqui Fahad J , Shahidah Nur , Leong Benjamin SH , Tiah Ling , Ng Yih Yng , Arulanandam Shalini , Ho Andrew FW , Ong Marcus E
Published: November 2020

Background:
Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) can increase bystander CPR rates and improve outcomes in out-of-hospital cardiac arrest (OHCA). Protocols used by dispatchers are designed to provide a quick assessment for prompt initiation of CPR. However, there are instances where non-cardiac arrest cases are falsely recognised by dispatchers to be in cardiac arrest. These patients may go on to receive chest compressions and potentially suffer from complications of unnecessary CPR, though the clinical implications of starting DA-CPR on these non-cardiac arrest cases have not been studied. Hence, the objectives of this study are to find the prevalence and clinical outcomes of DA-CPR in patients not in cardiac arrest in the Singapore population.

Methods:
This was a multi-center, observational study of all dispatcher-recognized cardiac arrests cases between January to December 2017 involving three tertiary hospitals in Singapore. Data was collected through audio review of dispatch calls from the national emergency ambulance service and information about patients’ clinical outcomes were prospectively collected from health records.

Results:
During the study period, dispatchers recognised 821 patients as having cardiac arrest. Of these, 40.0% (328/ 821) were not in cardiac arrest. 52.7% (173/ 328) of the non-cardiac arrest patients had chest compressions initiated under dispatcher assistance. No complications from chest compressions were reported. The top diagnoses of non-cardiac arrest patients found were cerebrovascular accidents (CVA), syncope and infection. A multiple logistic regression model with estimates adjusted for the presence or absence of chest compressions revealed that only final diagnoses of CVA (OR 20.68), infection (OR 17.34) and myocardial infarction (OR 32.19) were associated with in-hospital mortality.

Conclusion:
In this study, chest compressions initiated due to false recognition of cardiac arrest by dispatchers did not result in any reported complications and was not associated with in-hospital mortality. This provides reassurance for the continued implementation of DA-CPR.
Abstract 257: Adherence to the Termination Recommendations in the Universal Termination of Resuscitation Rule and Survival After Out-of-hospital Cardiac Arrest
Authors: Okubo Masashi , Wallace David J , Grunau Brian E , Daya Mohamud R , Callaway Clifton W
Published: November 2020

Introduction:
Survival after out-of-hospital cardiac arrest (OHCA) varies across emergency medical services (EMS) systems, but the EMS practices that contribute to the outcome variation are unclear. We evaluated the association between EMS agency variation in adherence to the termination recommendations in the Universal Termination of Resuscitation (TOR) rule and survival after OHCA.

Methods:
We conducted a secondary analysis of the Resuscitation Outcomes Consortium Epistry, a prospective multicenter OHCA registry in North America. We included adults (≥ 18 years) with OHCA for whom EMS providers attempted resuscitation from 2011 through 2015. The main exposure was proportion of patients meeting the Universal TOR rule (not EMS-witnessed arrest, no return of spontaneous circulation prior to transport,
and
no shock delivery prior to transport) among those who had prehospital TOR at the level of EMS agency. We categorized EMS agencies into quartiles based on the adherence to the Universal TOR rule. Our primary outcome was survival to hospital discharge. We used multilevel modified Poisson regression model, including patient-level and EMS-level covariates with patients nested within EMS agencies.

Results:
We included 43,656 EMS-treated OHCAs from 112 EMS agencies. The median adherence to the Universal TOR rule was 75.6% (interquartile range [IQR] 67.5-83.7) across EMS agencies. Compared with patients resuscitated at EMS agencies in the quartile of the lowest adherence (median adherence 62.5% [IQR 58.9-65.7]), survival to hospital discharge was inversely associated with treatment at EMS agencies in the second quartile (median adherence 72.6% [IQR 70.2-74.7]) (adjusted risk ratio [aRR] 0.83, 95% confidence interval [CI] 0.71-0.96), the third quartile (median adherence 80.6% [IQR 78.5-81.9]) (aRR 0.71, 95% CI 0.60-0.85), and the fourth quartile (median adherence 90.6% [IQR 86.2-93.7]) (aRR 0.68, 95% CI 0.58-0.80).

Conclusions:
In this large cohort study of adult patients with OHCA, we observed variation in the adherence to the Universal TOR rule’s termination recommendations across EMS agencies, and an association between higher EMS-level adherence and worse survival to hospital discharge after OHCA.
Abstract 260: Regional Routing for Extracorporeal Membrane Oxygenation to Increase Survival From Refractory Ventricular Fibrillation/Ventricular Tachycardia Out-of-Hospital Cardiac Arrest
Authors: Bosson Nichole E , Kaji Amy H , Niemann James T , Schlesinger Shira , Shavelle David , Tolles Juliana , Gausche-Hill Marianne
Published: November 2020

Introduction:
Extracorporeal membrane oxygenation (ECMO) is increasingly used to support patients with refractory ventricular fibrillation/ventricular tachycardia (rVF/VT) out-of-hospital cardiac arrest (OHCA). Los Angeles County (LAC) operates a regional system of care for 10.2 million persons, routing patients with OHCA to the closest cardiac receiving center. The purpose of this study was to determine 1) the number of patients eligible and 2) the potential for increased neurologically intact survival routing patients with rVF/VT OHCA to ECMO-capable cardiac centers.

Methods:
This was a retrospective study utilizing LAC quality improvement databases. Patients 18-75 years treated by EMS from 2011-2017 for rVF/VT OHCA, defined as persistent VF/VT after 3 defibrillations, were included in the analysis. Actual survival with good neurologic outcome, defined as cerebral performance category (CPC) 1 or 2, was abstracted from the LAC OHCA Registry. Theoretical patient outcome with routing directly to an ECMO-capable center was determined by applying outcomes as described by the Minnesota Resuscitation Consortium (MRC) for rVF/VT transported for ECMO. Assumptions included the availability of ECMO within a 30-minute transport time, and similar proportions of patients meeting criteria for transport/cannulation and surviving with CPC 1-2 as the MRC cohort, 78% and 40% respectively. For the remaining patients, we assumed no change in outcome. We compared the actual to the theoretical outcome with regional ECMO to determine the annual increase in survival with good neurologic outcome.

Results:
During the 7-year study period, there were 1862 patients with rVT/VT OHCA with outcomes available for 1454 (78%) patients. Median age was 59 years (IQR 51-66); 76% were male. Actual survival with CPC 1-2 was 13% (187 patients). Theoretical survival with CPC 1-2 in a regional ECMO-capable system was 34% (495 patients); OR 3.5 (95%CI 2.9-4.2), p<0.0001 with ECMO routing versus without.

Conclusion:
Assuming ECMO availability within a 30-minute transport time throughout the regional system, routing patients with rVF/VT to ECMO-capable centers could improve survival with CPC 1-2 nearly three-fold and result in 44 additional patients/year with meaningful survival.
Abstract 268: Combined Use of VA-ECMOecmo and Impella (ECPELLA) Improves Outcome of Patients with Out of Hospital Cardiac Arrest or Cardiac Arrest at the Emergency Room
Authors: Tamura Yudai , Unoki Takashi , Nakayama Tomoko , Kametani Motoko , Takagi Daisuke , Konami Yutaka , Suzuyama Hiroto , Inoue Masayuki , Yufu Tetsuo , Kodama Kazuhisa , Yamamuro Megumi , Taguchi Eiji , Sawamura Tadashi , Nakao Koichi , Sakamoto Tomohiro
Published: November 2020

Background:
Extracorporeal CPR (E-CPR) is a lifesaving method for refractory cardiac arrest (CA), and IABP has been often used as the additional circulatory support. However, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) increase damaged left ventricular (LV) afterload. The percutaneous microaxial pump, IMPELLA, can reduce damaged LV preload and afterload with circulatory support. Concomitant use of VA-ECMO and IMPELLA (ECPELLA) may have significant effect on clinical outcome.

Objective:
This study is to evaluate the effects of ECPELLA on clinical outcome of patients with out of hospital cardiac arrest (OHCA) or CA at the emergency room (ERCA) who underwent E-CPR.

Method:
We retrospectively reviewed 140 consecutive patients who underwent E-CPR from January 2012 through May 2020 in our institute. Seventy-four in-hospital CA patients were excluded, and 66 patients with OHCA or ERCA were recruited. Patients were divided into three groups ECEPLLA (n=13), ECMO with IABP (n=40), and ECMO alone (n=13). The primary endpoint was 30-day mortality. Secondary endpoint was good neurological outcome at hospital discharge defined as cerebral performance categories (CPC) of 1 or 2.

Result:
There were no significant differences in age, sex, OHCA, acute coronary syndrome in all three groups. The rate of shockable rhythm was higher in the ECPELLA and ECMO with IABP groups than ECMO alone. ECPELLA had the shortest time from CA to ECMO support compared with other groups. The 30-day survival and favorable neurological prognosis rates were significantly higher in the ECPELLA group, compared with other groups (ECPELLA: 61% vs. IABP: 18% vs. ECMO alone: 15%; P=0.008, ECPELLA: 38% vs. IABP: 8% vs. ECMO alone: 8%; P=0.03). Multivariate cox regression analysis including age, sex, time from CA to ECMO support and ECPELLA revealed that age (hazard ratio [HR], 1.36 (10 years increase), 95% confidence interval [CI], 1.11-1.67, P=0.04), male (HR, 2.42, 95%CI, 1.04-5.66, P=0.04), time from CA to ECMO support (HR, 1.01, 95%CI, 1.01-1.03, P=0.04), and ECPELLA (HR, 0.35, 95%CI, 0.13-0.91, P=0.03) were significantly associated with 30-day mortality.

Conclusion:
ECPELLA could improve 30-day mortality and neurological outcome in OHCA or ERCA patients who underwent E-CPR.
Abstract 271: Care Patterns for Out Of Hospital Cardiac Arrest Differ From Other Emergency Care Sensitive Conditions
Authors: Buckler David G , Wiebe Douglas , Sims Sarah , Doorley Ronan , Zebrowski Alexis , Carr Brendan
Published: November 2020

Background:
Understanding utilization patterns for out of hospital cardiac arrest (OHCA) is critical to organizing regional systems of care as recommended by the American Heart Association. We examined the agreement between regional utilization patterns for out-of-hospital cardiac arrest (OHCA) and other emergency care sensitive conditions (ECSCs).

Methods:
We used Medicare fee-for-service outpatient and inpatient claims from 2013-2014 to describe geographic utilization patterns for 5 emergency care conditions as has been done previously. We compared these regional clusters developed for OHCA to similarly created clusters for other emergency cardiovascular (ECV) conditions (by adding STEMI and stroke). Regional ZIP code attributions were compared using a modified Jaccard index, measuring the agreement between region membership. We also calculated patient-level risk-adjusted survival probabilities (controlling for patient age, sex, race and presenting condition) and summarized for each region as an observed-to-expected (O:E) ratio. O:E ratios higher than 1 indicate better than expected survival. Each region was ranked based on its O:E ratio and ranks between the two sets of conditions were compared.

Results:
The analysis included 3,279,013 ECSC claims containing 246,342 OHCA and 1,037,472 ECV claims grouped into 234 OHCA regions and 343 ECV regions. When comparing OHCA only to all ECV utilization (clusters), agreement was 64%. O:E survival to hospital discharge for OHCA regions showed greater variability compared to ECV regions (OHCA: 0.53-2.2 vs. ECV: 0.90 - 1.10). In comparing ranked O:E outcomes between OHCA and ECV regions, we found 72% discordance in quartile rankings (κ = 0.28).

Conclusion:
Care utilization pattern and risk-adjusted survival for OHCA in older adults vary greatly when compared to other emergency cardiovascular conditions and should be benchmarked separately. Further research is needed to understand the role strong regionalization of care policies could play in improving outcomes and streamlining care processes.
Abstract 272: Differences in Out-of-hospital Cardiac Arrest Survival Between Inner-city and Suburban Areas in New York
Authors: Sayeen Nagarajan Mohanapriya , Owens Casey , Haddad-Essaihi Ghania , Li Timmy , Becker Lance B , Rolston Daniel
Published: November 2020

Introduction:
Previous studies have shown that survival from out-of-hospital cardiac arrest (OHCA) is higher in urban settings than in rural settings. However, few studies have assessed survival differences in inner-city areas compared to suburban areas. We assessed differences in survival to admission and survival to discharge between OHCA patients treated at inner-city hospitals and those treated at suburban hospitals.

Method:
We conducted a retrospective analysis of adult atraumatic OHCA patients presenting to 12 hospitals in 2018 and 2019 within a healthcare system in the downstate New York area. Hospitals were classified as either inner-city or suburban using the urban-rural classification system of the National Center for Health Statistics, according to hospital addresses. We modified the LACE score to create a measure of the Charlson Comorbidity Index and number of ED visits in the past 6 months (termed “CE score”) to represent comorbidities and overall health. Two multivariable logistic regression models were developed to assess the association between location (inner city vs suburban) and survival to admission and discharge, after controlling for relevant covariates.

Results:
A total of 3,035 patients were included in this analysis; 1,350 patients (44%) presented to inner-city hospitals and 1,685 (56%) presented to suburban hospitals. Overall median age was 75 years, 59% were male, and 63% were White. Controlling for race, age, and CE score, inner-city hospital patients had higher odds of survival to admission (adjusted OR: 1.84; 95% CI: 1.57, 2.15) and higher odds of survival to discharge (adjusted OR: 1.35; 95% CI: 1.13, 1.60) compared with suburban hospital patients.

Conclusion:
Patients treated at inner-city hospitals had significantly higher odds of both survival to admission and survival to discharge compared with those treated at suburban hospitals. Further studies are needed to determine the relevant factors and inform public health interventions to increase survival from OHCA in suburban areas.
Abstract 292: Detection of Return of Spontaneous Circulation in Pseudo-Pulseless Electrical Activity Using Trans-thoracic and Trans-abdominal Bioimpedance
Authors: Hunckler William J , Lindqwister Alexander L , Murphy Ethan K , Klein Samuel B , Moodie Karen L , Hamlin Alexandra P , Anderson Justin E , Minichiello Joseph M , Paradis Norman A
Published: November 2020

Introduction:
Pseudo-Pulseless Electrical Activity (p-PEA) is a lifeless form of profound cardiac shock characterized by measurable cardiac mechanical activity without clinically detectable pulses. Patients in pseudo-PEA carry different prognoses than those in true PEA and may require different therapies. Noninvasive technologies capable of detecting return of spontaneous circulation (ROSC) are needed to guide transition therapy from ACLS to critical care. Electrical impedance (EI) measurements across the thorax and abdomen may reflect the state of the cardiovascular system and change with ROSC.

Hypothesis:
EI measured across the chest wall or abdomen can detect ROSC in p-PEA.

Methods:
Female swine (N = 14) under intravenous anesthesia were instrumented with aortic and central venous micromanometer catheters. EI was measured with cutaneous belts around the chest and abdomen (Swisstom). p-PEA was induced by ventilation with 6% oxygen in 94% nitrogen and was defined as a systolic aortic pressure < 40 mmHg. Experiments in which ROSC occurred within 20 seconds of starting 100% FiO
2
were studied. EI waveforms were analyzed with fast fourier transforms, and the dominant frequencies of p-PEA and ROSC signals were subtracted to create a difference distribution.

Results:
With onset of ROSC, there was a characteristic frequency increase in EI measurable across both chest and abdominal bands. Fourier transform analysis demonstrated a significant difference in dominant frequencies between resuscitation and p-PEA. The median difference between resuscitation and p-PEA dominant frequencies were 5.49 in the thorax [95% CI 3.48 - 7.50] and 6.65 in the abdomen [95% CI 3.63 - 9.67].

Conclusions:
There appear to be characteristic EI frequency patterns and changes in p-PEA and ROSC. If confirmed clinically, this indicates that EI may be a promising technology for non-invasive monitoring in cardiac arrest.
Abstract 293: Detection of Pseudo-Pulseless Electrical Activity with Electrical Impedance Tomography
Authors: Lindqwister Alexander L , Wu Weiyi , Ivanov Alexander , Murphy Ethan K , Klein Samuel B , Hassanpour Saeed , Moodie Karen L , Hamlin Alexandra P , Minichiello Joseph M , Anderson Justin E , Paradis Norman A
Published: November 2020

Introduction:
Pseudo-Pulseless Electrical Activity (p-PEA) is a lifeless form of profound cardiac shock characterized by measurable cardiac mechanical activity without clinically detectable pulses. p-PEA may constitute up to 40% of reported cases of cardiac arrest and its management may be different from ventricular fibrillation or even true-PEA. Currently, diagnosis of p-PEA requires either echocardiography or intravascular catheterization, neither of which are ideal in the prehospital setting. Electrical impedance tomography (EIT) uses skin surface electrodes to generate images based on cross sectional resistance. We investigated the ability of EIT and machine learning (ML) to detect p-PEA.

Methods:
Female swine (N = 14) under intravenous anesthesia were instrumented with aortic and central venous micromanometer catheters. p-PEA was induced by ventilation with 6% O
2
in 94% N
2
, defined as a systolic aortic pressure less than 40 mmHg. Continuous EIT renderings were obtained from circumferential thoracic and abdominal electrode arrays. A deep learning model was utilized to detect p-PEA using EIT sequences. Twelve pigs were randomly selected as training data and 2 pigs as a test set. EIT images were saved as 30 second clips, resulting in 3033 clips generated. To increase generalizability, random epochs ranging from 30 - 100% of the total clip length were generated, resulting in a model capable of detecting this disease state with limited video fragments.

Results:
This technique yielded a receiver operator characteristic curve - area under the curve (ROC-AUC) of 0.91 for detection of p-PEA in the testing dataset (Figure 1), with 84% accuracy, 88% sensitivity, and 84% specificity.

Conclusions:
EIT combined with machine learning may be able to reliably delineate p-PEA in a hypoxic porcine model. This approach may be promising for non-invasive operator-independent p-PEA detection.
Abstract 295: Deep Learning and Electrical Impedance Tomography in the Prediction of Interventions Needed to Resuscitate From Hypoxic Pseudo-Pulseless Electrical Activity
Authors: Lindqwister Alexander L , Wu Weiyi , Klein Samuel , Murphy Ethan K , Moodie Karen L , Hassanpour Saeed , Hamlin Alexandra P , Minichiello Joseph M , Anderson Justin E , Paradis Norman A
Published: November 2020

Introduction:
Pseudo-Pulseless Electrical Activity (p-PEA) is a form of profound cardiac shock defined as measurable cardiac activity without clinically detectable pulses. p-PEA has a distinct physiology and etiology from VF and true-PEA, and may constitute up to 40% of reported cases of cardiac arrest. Electrical impedance tomography (EIT) uses cutaneous electrodes to generate images based on cross sectional resistance. We utilized EIT to predict the number of interventions required to achieve ROSC from p-PEA.

Methods:
Female swine (N = 14) under intravenous anesthesia were instrumented with aortic and central venous micromanometer catheters. p-PEA was induced by ventilation with 6% oxygen in 94% nitrogen and was defined as a systolic aortic pressure less than 40 mmHg. Continuous EIT renderings were obtained from circumferential cutaneous thoracic and abdominal electrode arrays. A deep learning model was utilized to detect features within the EIT video clips of the p-PEA disease state to predict the number of treatments required to achieve ROSC. Twelve pigs were randomly selected as training data and 2 pigs as a test set. EIT images were saved as 30 second clips, resulting in 1630 clips generated. To increase generalizability, random epochs ranging from 30 - 100% of the total clip length were generated, resulting in a model capable of detecting this disease state with limited video fragments. Data were labeled based on the number of interventions required to achieve ROSC (100% O
2
, 100% O
2
+ CPR, 100% O
2
+ CPR + Epi, ROSC not achieved).

Results:
This approach yielded receiver operator characteristic curves - area under the curve (ROC-AUC, Figure 1) values of 0.75 for micro (weighted) AUC and 0.78 for macro (unweighted) AUC on a 4 class prediction model.

Conclusion:
EIT combined with machine learning may differentiate the required treatments needed to achieve ROSC in p-PEA.
Abstract 301: Aortic and Central Venous Pressure Wave Synchronization in Pseudo-Pulseless Electrical Activity
Authors: Lindqwister Alexander L , Klein Samuel B , Raelson Colin , Moodie Karen L , Stanko Kevin M , Paradis Norman A
Published: November 2020

Introduction:
Pseudo-Pulseless Electrical Activity (p-PEA) is a lifeless form of profound cardiac shock characterized by measurable cardiac mechanical activity without clinically detectable pulses. p-PEA may constitute up to 40% of reported cases of cardiac arrest and its etiologies and physiology are distinctly different from ventricular fibrillation or even true-PEA. In the normal physiologic state, there is an expected delay between the central venous (CV) and aortic (Ao) pressure waveforms corresponding to atrial kick and ventricular systole, respectively. We studied this relationship in hypoxic porcine p-PEA.

Hypothesis:
Development of p-PEA may be associated with changes in Ao and CV waveform synchronization.

Methods:
Female swine (N = 14) under intravenous anesthesia were instrumented with Ao and CV micromanometer catheters. ECG and ET-CO
2
were measured continuously. p-PEA was induced by ventilation with 6% oxygen in 94% nitrogen, and was defined as a systolic aortic pressure less than 40 mmHg. After 2 min. of p-PEA, 100% O
2
, CPR, and epinephrine were administered in a stepwise progression until ROSC was achieved.

Results:
One min. before the onset of hypoxia, the mean CV to Ao waveform delay was 0.161 sec. (SE ± 0.0015) across 52 experiments (n = 4797). This delay shortened during development of the p-PEA disease state (Figure 1), where the average delay decreased to 0.057 seconds (SE ± 0.0012) across 52 experiments (n = 3969, P < 10-6). There were statistically significant differences (P < 10-6) in waveform delays in between cohorts of animals who required more interventions to achieve ROSC, with shorter delay periods in both baseline and disease states correlating strongly with greater interventions.

Conclusions:
Development of the hypoxic p-PEA state may be associated with a loss of the normal CV to Ao pressure waveform delay. The degree of this loss may be associated with the severity of p-PEA disease state and predictive of the therapy required for ROSC.
Abstract 302: First of It's Kind Capillary Refill Monitoring Device to Guide Resuscitation
Authors: Sheridan David C
Published: November 2020

Background:
Capillary refill is an early reflection of decreased end organ perfusion resulting in shunt of blood from the extremities to vital organs. Physicians rate this as the most important factor to guide therapeutic resuscitation efforts. However, literature shows that providers have significant variability in their bedside measurement of capillary refill.

Objective:
The objective of this study was to develop and evaluate a novel technology to detect capillary refill in a noninvasive and rapid manner through an iterative, problem-based innovation approach.

Methods:
This was a prospective study at a level 1 tertiary care hospital of patients presenting to an emergency department. The research team used in a new technology that utilizes light transmission and pressure to objectively quantify extremity capillary refill time. This measurement was compared to manual refill time performed by a trained study provider.

Results:
Through an iterative approach the team developed a platform technology and enrolled 63 subjects in this prospective trial. 9 subjects had inadequate data and so the final cohort consisted of 54 subjects with both manual capillary refill time and the new novel technology measurement. The device measured capillary refill time showed a high degree of correlation to manual estimate of capillary refill time with a Pearson coefficient of 0.7.

Conclusions:
Novel technology to measure capillary refill time can significantly improve the treatment and care of multiple medical conditions that rely on timely diagnosis and initiation of resuscitation in the emergency department and other care settings. This study shows a modest correlation of technology with automated signal processing algorithms for noninvasive measurement of capillary refill. Integration of this technology into standard hospital monitors has broad applicability to make capillary refill a standard vital sign.
Abstract 310: Validation of the Cardiac Arrest Hospital Prognosis (CAHP) Score in an American Out-of-hospital Cardiac Arrest Cohort: Results From a Large Single Center Cardiac Arrest Registry
Authors: Grady Jason J , Atwell Katie A , Oshimura Tomo , Ghasemzadeh Nima
Published: November 2020

Background:
The cardiac arrest hospital prognosis (CAHP) score has been shown in French studies to predict neurologic outcomes in patients who suffer an out-of-hospital cardiac arrest (OHCA), but this score has not been studied in an American cohort. We aimed to validate the CAHP score in an independent, single center, large cardiac arrest registry.

Methods:
Between January 2015 to June 2020 there were 925 patients who suffered OHCA and were transferred to Northeast Georgia Medical Center out of whom 450 patients survived to hospital admission. Cerebral Performance Category (CPC) score was used for assessment of neurologic outcome at discharge ranging from 1-5. The primary endpoint was poor neurologic outcome defined as CPC 3-5. Logistic regression was performed to identify independent predictors of poor neurologic outcome.

Results:
Included patients were mostly male 57% (256 of 450) with a mean age of 52±15. STEMI was present on 11% (51 of 450) and a shockable rhythm on 35% (150 of 450) of patients. Targeted temperature management (TTM) and a mechanical compression device (MCD) were used in 72% (327 of 450) and 74% (336 of 450) respectively. 76% (344 of 450) had a CPC of 3-5 at discharge. After adjusting for covariates, including gender, BMI, serum lactate level, witnessed arrest status, STEMI on ECG, and use of MCD and TTM, the only independent predictors of a CPC of 3-5 were CAHP score (p<0.001), witnessed cardiac arrest, (p=0.039, OR: 0.45) and STEMI on admission ECG (P=0.001, OR: 0.22). Compared with CAHP< 150, CAHP 150-200 and CAHP>200 were associated with a 12-fold (p<0.00001) and 79-fold (p<0.00001) increased risk of poor neurologic outcome. Area under ROC curve for CAHP score predicting neurologic outcome was 0.92 (95% CI: 0.89-0.94).

Conclusion:
Here we show, for the first time, in an independent, large American cardiac arrest registry that CAHP score predicts neurologic outcomes in patients with OHCA. Further research is needed to assess how this prognostication tool would help clinicians decide on early vs. delayed invasive strategy in patients with OHCA admitted to hospitals across the U.S.
Abstract 325: Resuscitation Practices in Pediatric Hospitals: Insights From Get with the Guidelines-Resuscitation
Authors: Chan Jesse L , Tang Yuanyuan , Roberts Joan S , Chan Paul S
Published: November 2020

Background:
Resuscitation practices for adult in-hospital cardiac arrest (IHCA) vary widely, based on setting and size. Resuscitation practices in pediatric hospitals have not been examined in detail, and whether practices differ between free-standing pediatric hospitals and combined hospitals (which care for adults and children) is unknown.

Methods:
We conducted a survey of U.S. hospitals that submit data on pediatric IHCA to GWTG-Resuscitation, a large national registry of IHCA, to elicit detailed information on resuscitation practices. Hospitals were categorized as free-standing pediatric hospitals and combined hospitals, and rates of resuscitation practices were compared.

Results:
A total of 33 hospitals with at least 5 IHCA events between 2015-2019 completed the survey, of which 9 (27.3%) were freestanding pediatric hospitals and 24 (72.7%) were combined hospitals. Overall, 18 (54.5%) hospitals used a device to measure chest compression quality, 2 (6.1%) used a mechanical device to deliver chest compressions, 6 (18.2%) routinely monitored diastolic pressures during resuscitations, 16 (48.5%) had a staff member monitor chest compression quality, 10 (30.3%) used lanyards or hats to designate leaders during a resuscitation, 16 (48.5%) routinely conducted immediate code debriefings, and 7 (21.2%) conducted mock codes at least quarterly and 17 (51.5%) reported no set schedule. Freestanding pediatric hospitals were more likely to employ a device to measure chest compressions (88.9% vs. 41.7%; P=0.016), conduct code debriefing always or frequently after resuscitations (77.8% vs. 37.5%, P=0.044), use lanyards or a hat to designate the code team leader during resuscitations (66.7% vs. 16.7%, P=0.006), and allow nurses to defibrillate using an AED (77.8% vs. 29.2%, P=0.01). There were no differences in simulation frequency or other resuscitation practices between the 2 hospital groups.

Conclusions:
Across hospitals caring for pediatric patients, substantial variation exists in resuscitation practices. For some resuscitation practices, there were differences between freestanding pediatric hospitals and hospitals which care for both adults and children.
Abstract 329: Predicting Survival from Out-of-hospital Cardiac Arrest
Authors: Drennan Ian , Thorpe Kevin , Cheskes Sheldon , Mamdani Muhammad , Scales Damon , Morrison laurie
Published: November 2020

Introduction:
Prognostication is a significant challenge early in the post-cardiac arrest period. Common prognostic factors for neurological survival are unreliable (high false positive rates) until 72 hours post-cardiac arrest. It is not known whether there are a combination of factors that can be utilized earlier in the post-cardiac arrest period to accurately predict patient outcome. Our objective was to predict neurological outcome utilizing a novel combination of patient factors early in the post-cardiac arrest period.

Methods:
We conducted a retrospective cohort study using data from our local registry. We included adult patients who obtained a return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA). We excluded patients who did not survive for at least 24 hours post-ROSC and those who had a do not resuscitate (DNR) order within 2 hours of ROSC. We performed an ordinal regression analysis using the proportional odds model to predict neurological outcome (modified rankin score (mRS)). We included a good neurological outcome (mRS 0-2), poor neurological outcome (mRS 3-5), and dead (mRS 6) as an ordinal outcome. We included a number of patient demographics, intra- and post-cardiac arrest factors as covariates in our model. The predictive performance of our model was analyzed using receiver operating characteristic (ROC) curves for discrimination and Brier statistic for calibration.

Results:
We included 3448 patients in our analysis. We found that an initial shockable rhythm (odds ratio (OR) 4.1; 95% confidence interval (CI) 3.6, 5.4), the absence of pupillary reflexes (OR 3.5; 95% CI 2.4,4.8) and maximum motor score on the Glasgow Coma Scale (GCS) (OR 1.5; 95% CI 1.4,1.6) had the greatest association with improved neurologic outcome. Longer duration of resuscitation was associate with worse outcomes (OR 0.84, 95% CI 0.82,0.87). The overall performance of our model was excellent with an area under the ROC curve of 0.89 and a Brier statistic of 0.13.

Conclusion:
Our model predicted good neurological outcome with a high rate of accuracy, however external validation of the model is required. This model may be useful to provide risk stratification of patients in clinical practice and future research on post-cardiac arrest care.
Abstract 332: Long-term Post-discharge Survival and Healthcare Utilization Following Out-of-hospital Cardiac Arrest: Insights From a Novel Province-wide Linkage
Authors: Fordyce Christopher B , Grunau Brian E , Guan Meijiao , Lee May K , Hawkins Nathaniel M , Helmer Jennie , Wong Graham C , Humphries Karin H , Christenson Jim
Published: November 2020

Introduction:
Out-of-hospital cardiac arrest (OHCA) is associated with poor short-term outcomes. However, the impact of pre- and in-hospital factors on long-term outcomes is ill-defined, mainly related to challenges combining disparate data sources.

Methods:
We linked adult non-traumatic EMS-treated OHCAs from the British Columbia Cardiac Arrest Registry (Jan 2009 - Dec 2016) to provincial datasets describing co-morbidities, medications, procedures, mortality, and hospital admission and discharge. Among hospital-discharge survivors, we examined the 3-year composite endpoint of mortality ± all-cause readmission using the Kaplan-Meier (KM) method and multivariable Cox model for predictors.

Results:
Of 10,876 successfully linked OHCAs, 1325 survived to hospital discharge: mean age 62.8 years, 77.9% male, 72.6% shockable rhythms, 60.1% non-public locations, 69.1% bystander CPR, and 30.3% STEMI. During admission, 78.6% required mechanical ventilation, 69.1% received coronary angiography (37.5% PCI, 10.3% CABG), and 24.8% received an ICD. At 3 years post-discharge, the estimated KM event rates were 15.9% (95% CI 13.9%, 19.3%) for mortality and 68.2% (95% CI 65.3%, 71.0%) for mortality and readmission, which differed by age, initial rhythm, and arrest location (
Figure
). Following multivariable analysis, patients with a history of HF [HR 1.62 (95% CI 1.34 - 1.96)], age >75 [1.62 (1.35, 1.96)], anticoagulation use [2.55 (1.36, 4.79)], non-shockable rhythm [1.29 (1.07, 1.55)] and non-public arrest location [1.21(1.04, 1.40)] were more likely to experience the composite endpoint; those receiving coronary angiography were less likely [0.79 (0.64, 0.98)].

Conclusions:
The long-term death or readmission risk persists even among OHCA hospital-discharge survivors, and is associated with both pre- and in-hospital factors. An enriched, linked dataset detailing the entire OHCA “journey” may be a promising tool to identify care and treatment gaps.
Abstract 340: Analysis of Post Cardiac Arrest Recovery Services
Authors: Stegamat Nassim , Elmer Jonathan , Callaway Clifton W , Doshi Ankur A
Published: November 2020

Introduction:
Cardiac arrest survivors may suffer sustained functional, psychiatric and cognitive impairments . Survivors’ perspectives on outpatient services necessary for recovery are unknown.

Hypothesis:
Survivors rate the usefulness of certain outpatient services more highly than others.

Methods:
We performed a structured phone interview of patients treated from 2010 to 2018 at a single center after cardiac arrest who survived at least one year. We asked survivors or their proxies about their experiences with physician, rehabilitation and care coordination services. Survivors rated usefulness of each resource on a Likert scale (1 “not useful” to 4 “essential”) and identified the single most useful resource.

Results:
We interviewed 25 survivors. All received outpatient physician services (24 primary care (PCP); 19 cardiologist, 7 neurologist, and 7 other). Subjects identified PCP (12/25, 48%) and cardiologist (12/25, 48%) services most useful. Seventeen (68%) subjects received outpatient rehabilitation (13 physical therapy; 9 occupational therapy; 8 speech therapy; 8 cardiac rehab; and 1 pulmonary rehab). Subjects considered physical therapy (9/17, 53%) and cardiac rehab (6/17, 35%) most useful. Nine (36%) subjects received care coordination (5 psychological; 4 case management; 3 home nursing). Median rating of usefulness for all services was 3. Only three subjects rated either cardiologist, physical therapy or psychological services as non-useful.

Conclusion:
Cardiac arrest survivors may require multiple and varied outpatient services. The most beneficial services include PCP, cardiologist and physical therapy. Survivors vary in their needs, and care should be tailored to the individual.