bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 220: Public Defibrillator Accessibility and Mobility Trends During the Covid-19 Pandemic in Canada
Authors: Leung K.H. Benjamin , Alam Rejuana , Brooks Steven , Chan Timothy C
Published: November 2020

Introduction:
The COVID-19 pandemic has led to widespread closures of non-essential businesses and buildings. The impact of such closures on public automated external defibrillator (AED) accessibility compared to mobility trends is unknown.

Methods:
We identified all publicly available online AED registries in Canada last updated May 1, 2019 or later. AEDs were classified by location type using addresses and registry notes, and deemed completely inaccessible, partially inaccessible, or unaffected using government-issued closure orders as of May 1, 2020. We mapped AED location types to categories used by Google’s COVID-19 Community Mobility Reports and calculated the median percent change in daily traffic between Feb. 15 - May 1, 2020 (excluding Apr. 10-12). We compared the percent of completely inaccessible AEDs to the median percent change in traffic for each category.

Results:
We identified three provincial (British Columbia, Alberta, Nova Scotia) and two municipal (Mississauga and Toronto in Ontario) online AED registries, collectively covering 13.1 million people. Of the 5,845 AEDs identified, 69.9% were completely inaccessible, 18.8% were partially inaccessible, and 11.3% were unaffected. AEDs in parks (n=141), almost all retail and recreational locations (n=1,539), and two-thirds of workplaces (n=3,633) were completely inaccessible, grocery and pharmacy-based (n=173) AEDs were partially inaccessible, and transit station (n=277) and residential (n=85) AEDs were unaffected. The largest discrepancies between AED accessibility and mobility occurred in parks (100% completely inaccessible vs. 10.5% traffic decrease), retail and recreation (99.0% completely inaccessible vs. 48.0% traffic decrease), and transit stations (100% unaffected vs. 63.0% traffic decrease).

Conclusion:
Government-mandated closures due to the COVID-19 pandemic have led to a greater reduction in AED accessibility than mobility in many locations across Canada.
Abstract 232: Delayed Administration of Epinephrine is Associated with Worse Neurological Outcomes in Patients with Out-of-hospital Cardiac Arrest and Initial Pulseless Electrical Activity
Authors: Enzan Nobuyuki , Hiasa Ken-ichi , Ichimura Kenzo , Nishihara Masaaki , Iyonaga Takeshi , Shono Yuji , Kitazono Takanari , Tsutsui Hiroyuki
Published: November 2020

Background:
Delayed administration of epinephrine has been proven to worsen the neurological outcomes of patients with out-of-hospital cardiac arrest (OHCA) and initial shockable rhythm. We aimed to investigate whether delayed administration of epinephrine might also worsen the neurological outcomes of patients with witnessed OHCA and initial pulseless electrical activity (PEA).

Methods:
The Japanese Association for Acute Medicine - out-of-hospital cardiac arrest (JAAM-OHCA) Registry is a multicenter, prospective, observational registry including 34,754 OHCA patients between 2014 and 2017. The present study assessed the impact of the time to epinephrine administration on neurological outcomes in patients with witnessed non-traumatic OHCA with initial rhythm of PEA. The primary outcome was defined as Cerebral Performance Categories (CPC) Scale 1-2 at 30 days after OHCA. The association between the odds ratio for the primary outcome and the time from witnessed OHCA to epinephrine administration was assessed with a restricted cubic spline analysis.

Results:
Out of 34,754 patients with OHCA, 3,050 patients with OHCA and initial PEA who received epinephrine were included in the present study. Mean age was 73.7 years and 1836 (60.2%) was male. After adjusting for potential confounders, the time from witnessed OHCA to epinephrine administration was associated with lower likelihood of favorable neurological outcomes (odds ratio [OR] 0.92; 95% confidence interval [CI] 0.89-0.96; P<0.001). The restricted cubic spline analysis demonstrated that delayed epinephrine administration could decrease the likelihood of a favorable neurological outcome; this was significant within the first 10 minutes.

Conclusions:
Delayed administration of epinephrine was associated with worse neurological outcomes in patients with witnessed OHCA patients with initial PEA.
Abstract 239: The Relationship Between Duration of Chest Compression and Traumatic Thoracic Injuries in Out-of-hospital Cardiac Arrest Patients
Authors: Katasako Aya , Kawakami Shoji , Ikee Takashi , Shojima Yoko , Maezono Akihiro , Furukawa Shoichiro , Oga Yasuhiro , Takahara Yusuke , Inanaga Keita , Imamura Yoshihiro , Yamada Tetsuhisa , Miura Nobutoshi , Inoue Shujiro
Published: November 2020

Background:
Recent guidelines emphasized that high-quality chest compression is essential for improving the survival in out-of-hospital cardiac arrest (OHCA) patients. However, it may lead to critical traumatic injuries.

Method:
Between June. 2018 to Mar. 2019, we collected Utstein-style data on 130 consecutive adult patients with non-traumatic OHCA who were transferred to our hospital without return of spontaneous circulation (ROSC). Patients with aortic dissection and aortic aneurysmal rupture were excluded. Full-body CT scan was performed in all patients and chest compression-induced thoracic injuries were defined as rib fracture, sternum fracture, hemopneumothorax, mediastinal emphysema or intrathoracic hematoma. We identified the possible predictors for thoracic injuries and evaluated the relation between traumatic thoracic injuries and 30-day survival.

Results:
Patients with thoracic injuries were 105 (81%). The duration of chest compression in patients with thoracic injuries was significantly longer than that in patients without thoracic injuries (30 vs 38min, p<0.01). ROC analysis identified a duration of chest compression of 35 minutes as the optimal cutoff point for predicting thoracic injuries (sensitivity 0.59, specificity 0.83, area under the curve 0.71). Multivariate analysis revealed that age and duration of chest compression were predictors of thoracic injuries (OR 1.05, 1.07, p≦0.01, respectively). The rates of 30-day survival in patients with thoracic injuries was significantly lower than those without thoracic injuries (1 % vs 16 %, p<0.01).

Conclusion:
The duration of chest compression was one of the independent predictors for thoracic injuries in non-traumatic OHCA patients. Prolonger duration of chest compression are potential candidates for CT scan to diagnose thoracic injuries.
Abstract 246: Therapeutic Hypothermia Mimicking Peptide Administration During Cardiopulmonary Resuscitation Improved Cardiac Arrest Survival in Swine
Authors: Oberdier Matt , Li Jing , Ambinder Dan , Zhu Xiangdong , Fink Sarah , Halperin Henry R , VandenHoek Terry
Published: November 2020

Background:
Out-of-hospital sudden cardiac arrest is a leading cause of death in the United States, affecting over 350,000 people per year with an overall survival rate around 10%. CPR, defibrillation, and therapeutic hypothermia are common resuscitation strategies, but hypothermia is difficult to implement timely to achieve survival benefit. A cell-permeable peptide TAT-PHLPP9c has been shown to alter metabolic pathways similar to hypothermia, and decreases the release of two biomarkers, taurine and glutamate, during the high osmotic stress of heart stunning and brain injury in a mouse arrest model.

Hypothesis:
TAT-PHLPP9c, given during CPR, enhances 24-hour survival in a swine ventricular fibrillation (VF) model.

Methods:
In 14 (8 controls and 6 treated) sedated, intubated, and mechanically ventilated swine, after 5 min of VF, ACLS with vest CPR and periodic defibrillations was performed. Venous blood samples were collected at baseline, after 2 min of CPR, and at 2 and 30 min after return of spontaneous circulation (ROSC). The animals were survived up to 24 hrs and plasma samples were analyzed for glutamate and taurine in 2 controls and 1 animal given peptide.

Results:
Three of the control animals had ROSC, but none survived for 24 hrs, while 4 of 6 treated animals achieved neurologically intact survival at 24 hrs (p < 0.02). Compared to baseline, both taurine and glutamate plasma concentrations increased in the control group, but the increase was reduced substantially by the peptide treatment at 30 min after ROSC (Figure).

Conclusion:
The use of the cooling mimicking peptide TAT-PHLPP9c administered during CPR significantly improved 24-hour survival in this swine model of cardiac arrest. It reduced the increase of cerebral and myocardial metabolic biomarkers, which encourages utilizing a strategy of cell-permeable peptides for intravenous administration for more rapid onset of hypothermia-like salutary effects than are possible with current CPR cooling devices.
Abstract 248: When Does Expiration End? Comparison of Two Criteria for Measuring End-tidal Co
2
Authors: Gutierrez Jose Julio , Ruiz De Gauna Sofia , Ruiz Jesus , Azkarate Izaskun , Sandoval Camilo L , Leturiondo Luis A , Russell James K , Daya Mohamud R
Published: November 2020

Aim:
End-tidal CO2 is defined as the partial pressure of carbon dioxide in exhaled air at the end of expiration. During CPR with manual ventilation, end-tidal CO2 is generally measured as the maximum CO2 value during the expiratory plateau of the capnogram. Transthoracic impedance (TTI) acquired through defibrillation pads also allows for tracking inspiratory and expiratory phases during CPR. Our aim was to compare the CO2 value measured at the end of the TTI expiration with the maximum CO2 value in the capnogram plateau.

Materials and methods:
Fifteen out-of-hospital cardiac arrest defibrillation recordings (Tualatin Valley Fire & Rescue, Oregon, USA) containing concurrent TTI and capnogram were analyzed. TTI signal was filtered to isolate the fluctuations caused by ventilations from those caused by chest compressions or spontaneous circulation. Inspiratory and expiratory intervals per ventilation were marked in the TTI. Values of CO2 at the end of the TTI expiratory interval and the maximum value in the capnogram expiratory plateau were annotated.

Results:
A total of 3559 ventilations were analyzed. Median (IQR) ventilation rate was 17.1 (11.2, 22.9) min-1. Median ventilation duration was 2.4 (2.1, 2.9) s, and inspiration represented the 45.5 (40.2, 49.9) % of the ventilation duration. CO2 value at the end of TTI expiration was 24.5 (14.7, 34.1) mmHg. Difference with respect to the maximum capnogram CO2 was 2.1 (0.7, 4.4) mmHg. More importantly, we found differences higher than 7.5 mmHg (29.1%) in 10% of the annotated ventilations. In the figure, both values match in the first ventilation but not in the second, where the difference between CO2 values is 15.4%.

Conclusion:
Median differences between CO2 concentration at the end of the TTI expiratory phase and the maximum tidal value in the capnogram were small. However, the observed important differences require further exploration.
Abstract 269: The Design of an Adaptive Clinical Trial - The Extracorporeal Cardiopulmonary Resuscitation for Refractory Out of Hospital Cardiac Arrest (EROCA) Project
Authors: Tolles Juliana , Kidwell Kelley , Broglio Kristine , Graves Todd , Meurer William J , Lewis Roger J , Neumar Robert W
Published: November 2020

Introduction:
Extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) is promising but unproven. We developed a concept for a randomized Bayesian adaptive clinical trial to define the interval after arrest during which patients derive benefit.

Hypotheses:
We hypothesized that the simulated design characteristics of the adaptive design would efficiently confirm or refute the existence of a therapeutic window for ECPR in a future trial.

Methods:
Through iterative simulation and design modification, we developed a Bayesian adaptive trial of ECPR for adults with OHCA. The goals of the trial design were to address the uncertainty surrounding the OHCA-to-ECPR interval within which clinical benefit might be preserved and the difference in prognosis between patients with non-shockable vs shockable rhythms. The treatment effect was defined as the mean 90-day utility-weighted Modified Rankin Scale (uwmRS) for each rhythm subgroup and estimated CA-to-ECPR interval. The trial adaptively lengthens or contracts the estimated CA-to-ECPR eligibility window depending on the probability of benefit from ECPR. We simulated trial performance under six potential ECPR efficacy scenarios. We compared the adaptive design to a fixed design.

Results:
The trial had 91-100% power to detect a benefit from ECPR for non-shockable rhythms and 69-98% power for shockable rhythms under the scenarios simulated (figure). The design had a high probability of identifying the maximum CA-to-ECPR interval within which ECPR produces a clinically significant benefit of 0.2 on the uwMRS. In null scenarios, the 97-99% of the simulated trials ended early declaring futility.

Conclusions:
The adaptive trial design helps to ensure the patient population most likely to benefit from treatment—as defined by rhythm subgroup and estimated CA-to-ECPR interval—are enrolled. The design also promotes early termination of the trial if continuation is likely to be futile.
Abstract 274: Drugs and Cardiac Arrest: Suffocate the Brain, Spare the Body?
Authors: Uzendu Anezi , McIntyre Mark , Suara Habeeb , Alabre Alisha , Boateng Emmanuel , Charles Lawrence , Gumbs Edvard , Ruz Patrick , Anaba Uzoma , Carter Rebecca , Okafor Henry , Dezfulian Cameron , Guha Avirup , Addison Daniel
Published: November 2020

Background:
Nearly 70,000 people die of a drug overdose every year. Yet, how drug induced cardiac arrests differ from presumed cardiac etiology cardiac arrests is not well described. In animal models, asphyxial arrests resemble drug induced arrests, demonstrating better hemodynamic profiles yet worse neurologic recovery. Theoretically, this is caused by hypoxemic but preserved perfusion prior to ultimate arrest. But, this has not been studied in humans. We hypothesize that drug induced cardiac arrests will have higher incidence of return of spontaneous circulation (ROSC) in all comers, yet worse neurologic recovery among hospitalized patients.

Methods:
From a large institutional dataset capturing all patients with out-of-hospital cardiac arrests admitted from 2011 to 2019, we assess the prevalence and outcomes of cardiac arrests, by drug-use status. Patients were excluded if the arrest was trauma induced, occurred in an extended care facility/nursing home, or if treatment was initiated at another medical center. The primary outcome was ROSC in all comers, and the secondary outcome was favorable neurologic function among those surviving to admission. Multivariable logistic regression was used to assess factors associated with differences in outcomes, accounting for traditional cardiac risk factors and arrest characteristics.

Results:
In total, 436 patients (57±10 years, 31.7% female, 58.5% non-white, 49.3% hypertensive, 28.4% diabetics, and 21.1% preceding coronary disease) were identified, including 94 (21.6%) with drug induced cardiac arrest. Of that total group 101 (23.2%) survived, to admission, 26.6% of the drug induced group and 22.2% of the presumed cardiac cohort, demonstrating no difference in ROSC (P=0.32). Among those that survived to admission, 8% (2/25) of the drug induced group had a favorable neurologic outcome, compared to 29.0% (22/76) of the cardiac induced group (P= 0.03). Following adjustment, the presence of presenting drug induced cardiac arrest remained associated with lower rates of neurologic recovery [OR 7.3 (1.03-51.6) P= 0.04]. There was no difference in survival to discharge.

Conclusion:
Drug induced cardiac arrest is associated with worse neurologic outcomes than presumed cardiac etiology cardiac arrests.
Abstract 276: The Effects of Peep and Blood Pressure on Cerebral Tissue Oxygen Saturation During Hemorrhage in Swine
Authors: Gould Jeff R , Lampe Joshua W , Clark Lyra , Beck George , Harvey Brian C , Moodie Karen L , Paradis Norman A
Published: November 2020

Introduction:
Positive end-expiratory pressure (PEEP) is used to increase oxygen delivery by preventing end-expiratory alveolar collapse. However, the associated increased intrathoracic pressure can lead to an increase in right atrial pressure, and a decrease in venous return and cardiac output. Near infrared spectroscopy (NIRS) can be used as a non-invasive tool to continuously monitor cerebral tissue oxygen saturation. In this pilot study, we examined the effects of PEEP on cerebral oxygen saturation during a controlled hemorrhage.

Methods:
Four female, domestic swine (~30 kg), were bled to 3 target levels of mean arterial pressure (MAP; 55, 45, and 35 mm Hg). At each MAP target, 3 levels of PEEP were applied using a mechanical ventilator (5, 10, and 15 cm H
2
O) for ~10 minutes each. Following the reinfusion of shed blood and a recovery period, these interventions were repeated. Measurements included invasive aortic pressure and cerebral oxygen saturation using a commercially available tissue oximeter. A total of 61 epochs were entered into the following regression model: cerebral oxygen saturation = MAP + PEEP + animal number. Each epoch contained data from the last ~2 minutes of each MAP target and PEEP level.

Results:
The regression model yielded a coefficient of 0.30 for MAP (
P
< 0.001) and -0.08 for PEEP (
P
= 0.09) and overall, explained 94% of the variance in cerebral oxygenation (adjusted

R
2

= 0.94,
P
< 0.001). While MAP was a stronger predictor in the model, higher PEEP levels appear to result in lower levels of cerebral oxygenation (see figure).

Conclusions:
Cerebral tissue oxygen saturation declines with lower mean arterial pressures and increased levels of PEEP. NIRS to measure cerebral oxygen saturation may be a useful clinical tool to ensure adequate cerebral oxygenation in patients with hypotension related to hemorrhage, particularly in those patients that require greater than physiologic PEEP to maintain central oxygenation.
Abstract 277: Discrepancies Between Non-invasive Blood Pressure Monitor Data and Ems Provider Documentation in Major Traumatic Brain Injury: Are We Missing Hypotension?
Authors: Spaite Daniel W , Barnhart Bruce J , Helfenbein Eric , Jorgenson Dawn B , Babaeizadeh Saeed , Gaither Joshua B , Rice Amber D , Keim Samuel M , Bradley Gail , Hu Chengcheng
Published: November 2020

Background:
Recent studies have shown that prehospital systolic blood pressure (SBP) is strongly associated with mortality across a remarkably wide range (far above 90 mmHg) in traumatic brain injury (TBI). Furthermore, in TBI research, trial enrollment and risk-adjustment are highly dependent upon accurate documentation of BP. Our preliminary work identified potential discrepancies between EMS-documented vs. actual measured BP.

Objective:
In major TBI, evaluate concordance between SBP documented in EMS patient care records (PCR) and actual, monitor-recorded SBP.

Methods:
A subset of major TBI cases (mod/severe/critical) in the EPIC TBI Study (NIH 1R01NS071049) were analyzed (3/13-7/18). Cases from 6 EMS agencies reporting continuous monitor data (Philips MRx™) were included. All monitor data available for this analysis were displayed and accessible to the providers during EMS care. We compared the lowest PCR-documented SBP to the monitor-recorded value in each patient.

Results:
Included: 210 cases (median age: 52, 67% male). In 152 cases (72%), the lowest PCR-documented SBP was exactly concordant with the monitor. When concordance was defined by a difference of ≤5 mmHg, 171 (81%) were concordant. Among the 27 cases with monitor-identified hypotension (<90 mmHg), only 18 (67%) were documented by EMS. EMS documentation also failed to record 20% (3/15) of “near-hypotensive” cases (90-99 mmHg).

Conclusions:
Significant disparities existed between monitor-recorded and PCR-documented SBP. PCRs failed to reflect 33% of monitor-documented hypotensive cases. It appears that ongoing care responsibilities and scene distractions may cause providers to miss important BP readings. These findings identify a potential hidden contributor to poor outcomes if hypotension goes unrecognized and untreated, rather than simply not being documented. Furthermore, case ascertainment, trial enrollment, confounding, and risk-adjustment in TBI studies may be substantially impacted when these processes are based on EMS documentation. When possible, QI and research projects should utilize monitor data to identify hypotensive patients. Development of real-time audiovisual monitor feedback technology might improve provider recognition of hypotension.
Abstract 281: The Association of Left and Right Atrial Volume Indices on Survival Time Post-cardiac Arrest
Authors: Ibrahim Sami H , Miller Matt S , Blazek Olivia J , Strickling Jarred E , Elumogo Comfort , Laja Olusola , Mohammadi Sahar , Ahmad Syed , Bilchick Kenneth C , Mazimba Sula
Published: November 2020

Introduction:
Left and right atrial volume indices (LAVI and RAVI) are markers of cardiac remodeling. LAVI and RAVI are associated with worse outcomes in other cardiac conditions. This study aimed to determine the association of LAVI and RAVI with survival time post-cardiac arrest.

Hypothesis:
Atrial volumes are associated with survival time post-cardiac arrest.

Methods:
This was a single center, retrospective study of patients with a cardiac arrest event during index hospitalization from 2014-2018. LAVI was calculated using the biplane Simpson’s method, while RAVI was calculated using a single plane summation in the 4-chamber view. Patients were further stratified into either having a Vfib/pulseless VT (pVT) event or a PEA arrest/asystole event. Survival time was measured in days from event to death date. Kaplan-Meier plots were used to evaluate differences in survival time for patients based on mean LAVI and RAVI.

Results:
Of 305 patients studied (64 +/- 14 years, 37% female (112 out of 305)), 162 had a reliable LAVI measurement with a mean of 34.1 mL/m
2
(SD=15.8) and 163 had a reliable RAVI measurement with a mean of 25.1 mL/m
2
(SD=15.5). In patients who had sustained a VFib/pVT event, those with reduced LAVI (p=0.045) and RAVI (p=0.041) values below the mean had significantly improved survival time. No association was found in the PEA/asystole subgroup. KM plots of patient survival for both LAVI and RAVI compared to mean are presented in figures 1a and 1b.

Conclusion:
Among patients presenting with Vifb/pVT arrest, increased LAVI and RAVI were associated with decreased survival time. More studies are needed to better prognosticate cardiac arrest using atrial volumes.
Abstract 287: Expediency and Accuracy of Identifying the “Resuscitation Line” Using a Visual-Tactile Marker in a Critical Care Setting
Authors: Wampler David A , Dillard Elizabeth , Miller Larry
Published: November 2020

Background:
Most medications have some type of compatibility conflict with other medications. Emergency medication delivery is time dependent, delays required to identify a saline-only intravenous line may negatively impact patient outcomes. In this study, a tactile/visual IV tubing marker was evaluated for time to medication delivery as compared to standard identification methods.

Methods:
This was a mixed methods study. Method 1: Prospective randomized crossover study compared the administration of simulated Midazolam IV to a simulated critically ill patient using either the standard tape labeled IV-line or a new visual tactile marker (‘GoTo Tag’) to identify the correct saline IV through which to give the drug. Recorded time began when the participant entered the room and ended when the medication was delivered into the IV line. Subjects then left, and repeated with the opposite identification methods after a minimum 10-minutes. The normal saline IV line was moved to a different location between the attempts. Method 2: An exit questionnaire was utilized to obtain subjective data and to obtain open-ended comments.

Results:
Twenty-four participants, (4 physicians, 9 nurses and 11 paramedics) were recruited. The mean time to medication delivery was 28.3 ± 15.6 seconds. The visual tactile marker was statistically faster (22 ± 14 sec vs 35 ± 15 sec; p=0.002). The paramedic subgroup was also faster using the visual tactile marker (23 ± 14 sec vs 37 ± 12 sec; p=0.019). Overall, nurses identified the saline line modestly faster (25 ± 18) than paramedics (40 ± 14) or physicians (31 ± 14) regardless of the identification method. Comments by the participants clearly favored the ‘GoTo Tag’ over traditional tape labeled markers in terms of ease of resuscitation line identification and the potential to improve patient safety.

Conclusion:
The GoTo tag reduced the time to medication delivery, and was a preferred method to identify the resuscitation line by critical care providers.
Abstract 305: Contemporary Analysis of Percutaneous Intraaortic Balloon Pump Therapy as a Bridge to Orthotopic Heart Transplant
Authors: Bakir Nadia H , Finnan Michael J , Schilling Joel D , Ewald Gregory A , Vader Justin M , Kotkar Kunal D , Itoh Akinobu , Moon Marc R , Masood Muhammad F
Published: November 2020

Objective:
Intra-aortic balloon pump (IABP) support has been used as a bridge to transplant (BTT) therapy for acutely deteriorating patients awaiting orthotopic heart transplantation (OHT). Given recent changes to the heart allocation algorithm which have expanded IABP use for BTT, the evaluation of device strategy, complications, and near-term survival is warranted.

Methods:
Patients bridged with IABP who underwent OHT between October 2018 and January 2020 at our institution were retrospectively reviewed (n=21). Chart review was conducted to assess IABP insertion site, timing of support, device-related complications, removal strategy, and thirty-day post-transplant mortality.

Results:
Patients were bridged with femoral (n=6), axillary (n=9), or femoral with axillary conversion (n=6) approaches for IABP insertion. Common complications included pump malposition (n=5), hematuria (n=4), pump exchange (n=9), and insertion site bleeding (n=2). Median duration of IABP support was 12 [7, 18] days and median time to removal after OHT was 1 [1, 2] day. IABP removal occurred at the bedside with direct pressure application for all femoral pumps (n=6). Among axillary pumps (n=15), 11 were removed at the bedside with direct pressure, 3 were removed in the operating room, and 1 was removed in the catheterization lab with device closure. There was no thirty-day mortality following OHT.

Conclusion:
Following the changes to the heart allocation algorithm, IABP has become the most common method of temporary mechanical circulatory support for patients awaiting OHT at our center with excellent early survival and acceptable complication rates. In addition to allowing patients to ambulate while on IABP, we find that axillary insertion did not result in excess bleeding complications and that bedside removal with direct pressure was a safe method for postoperative decannulation.
Abstract 308: Automated Detection of Patients with Return of Spontaneous Circulation in the Retrospective Analysis of Resuscitation Episodes
Authors: Elola Andoni , Aramendi Elisabete , Irusta Unai , Wang Henry E , Idris Ahamed H
Published: November 2020

Introduction:
Retrospective analysis of out-of-hospital cardiac arrest episodes is important to evaluate the performance of resuscitation teams, and to advance research. Large numbers of electronic files are compiled in cardiac arrest registries and identifying patients with return of spontaneous circulation (ROSC) is expensive and time-consuming. The aim of this study was to analyze the feasibility of automatically annotating ROSC using the signals recorded by defibrillators.

Materials and methods:
A set of 893 patients (261 with ROSC, of which 127 were transient) recorded by the Dallas-Fort Worth Center for Resuscitation Research using Philips HeartStart MRx devices were included. Every record contained the ECG and the thoracic impedance (TI) signals. ROSC was automatically identified as follows: 1) chest compression pauses longer than 60 s were identified using either the TI or the compression depth signals. 2) Organized ECG rhythms were identified using a comercial defibrillator's algorithm. 3) Pulsatile rhythms were identified using a published machine learning algorithm based on the ECG or the ECG and TI signals. The model uses up to 9 features, extracted from both the ECG (6) and the TI (3) signals. ROSC was identified when a 10s-interval was classified as pulsatile and the ROSC onset was set at the beginning of the pause. The performance was assessed in terms of Sensitivity (Se, ROSC patients), Specificity (Sp, no ROSC patients) and overall F1-score. Error in the ROSC onset was calculated comparing the automatically detected onset to the reviewed time of the clinical annotation of ROSC.

Results:
The algorithm based exclusively on ECG showed Se, Sp and F1 scores of 90.0%, 92.7% and 90.5%, respectively. The algorithm that included both ECG and TI improved scores to 91.2%, 94.3% and 92.1%. For the set of patients with transient ROSC the algorithm showed a Se of 81.9% (95.6% for permanent ROSC) using the ECG and TI signals. The median (IQR) absolute error on the time of first ROSC onset was 0.8 (0.6-8.2) s.

Conclusions:
An accurate algorithm to automatically identify patients with ROSC is demonstrated. This technique could be useful for retrospective analysis of cardiac arrest registries.
Abstract 314: Cardiac Arrest Related Cognitive Activity
Authors: Keshavarz Shirazi Tara , Gonzales Anelly M. , Dickinson Analise , Parnia Sam
Published: November 2020

Background:
Few studies have examined the psychological outcomes of cardiac arrest (CA) survivors. While some negative outcomes including post-traumatic disorder, anxiety and depression have been reported in ~50%, interestingly, ~10-20% of CA survivors have reported lucid, well-structured thought processes during CA associated with positive psychological outcomes and transformation post CA. We aimed to characterize the themes describing the cognitive experiences recalled by survivors.

Method:
In a qualitative study 118 self-reported cases were extracted from a CA survivor registry, coded the data using thematic analysis to identify emerging themes followed by descriptive statistics to identify frequencies of identified themes.

Results:
Analysis of 69 in-hospital and 45 out-of-hospital CA events led to identification of 10 major and 64 sub-themes describing the breadth of CA survivors’ cognitive experiences. Most predominate features included having no sense of pain during on-going CPR (18%), perception of being separate from the body (46%), observing the body from a point outside (40%), travelling through a tunnel towards a destination (16%) and having a life review (19%). Interestingly, in the life-review category 87% perceived the life-review to be an educational experience focused on their actions and intentions towards others, 38% described reliving of certain actions with a sense of shame, and 18% perceived to examine life events from others’ perspective. In addition, another category of cognitive experiences were also described that appeared to relate to events during recovery of consciousness around the time of return of spontaneous circulation (ROSC) where 14% of survivors sensed the pressure of CPR and 18% woke up with pain.

Conclusion:
CA survivor’s memories appear to reflect two categories: 1) a life review and perception of observing themselves during CPR without pain, which is felt to be educational, positive and peaceful and 2) memories related to the recovery phase around the time of ROSC. These include sensing CPR related events such as pain, chest pressure and distress. While the former category may explain the long-term positive transformation, the latter may explain the long-term occurrence of PTSD and anxiety in CA survivors.
Abstract 315: Time Adaptive Model for Real-time Cardiopulmonary Resuscitation Outcome Prediction: A Nationwide Out-of-hospital Cardiac Arrest Study
Authors: Kim Ji Woong , Ha Juhyung , Hwang Sung Yeon , Kim Taerim , Cha Wonchul
Published: November 2020

Background:
OHCA patients use lots of hospital resources, and predicting prognosis is important in decision making for patient treatment. However, no algorithm can predict survival to hospital discharge rates in real-time.

Aim:
This study aimed to develop and validate the time adaptive model for real-time outcome prediction of OHCA patients.

Methods:
We performed a retrospective observational study using data from the Korea OHCA Registry in South Korea. In this study, we exclude patients with trauma, experienced ROSC before arriving in the ED, and patient who did not execute CPR in ED to select patients who executed CPR in ED. To develop the time adaptive prediction model, we organize training dataset as ongoing CPR patients by the minute. We used XGBoost as a machine-learning method and find the area under the receiver operating characteristic curve (AUROC) and predict the probability of the time adaptive prediction model.

Results:
The entire study population is 67270 and the majority were male patients (64%) with a median age of 70 years (IQR 23 years); 2632 (4.0%) had a shockable first documented rhythm at the ED. The subject was split into derivation and validation datasets at a ratio of 8 to 2. The AUROC of the model is 0.72 when the CPR starts, 0.68 after 30 minutes, and 0.62 after 60 minutes. Prediction probability of the time adaptive prediction model is shown in Fig. 1.

Conclusions:
We developed and validated the time adaptive prediction model by training ongoing CPR patients by minute to predict the CPR outcome of OHCA patients in real-time. This study showed the potential of a machine-learning-based algorithm model for decision making of patients about the termination of resuscitation.
Abstract 321: Illness Perceptions and Readiness for Discharge Are Associated with Psychological Symptoms in Cardiac Arrest Survivors with Good Neurologic Recovery
Authors: Presciutti Alex , Perman Sarah M , Newman Mary M , Shaffer Jonathan
Published: November 2020

Introduction:
Understanding the development of psychological symptoms post-arrest is a major research gap. In qualitative studies, cardiac arrest survivors report being poorly equipped to face the numerous sequelae upon returning home, which could in turn exacerbate acute psychological symptoms from the initial cardiac arrest event. In this study, we examined associations between illness perceptions (i.e. cognitive and emotional appraisals of illness and recovery), readiness for discharge, and provider-patient communication with psychological symptoms in cardiac arrest survivors with good neurologic recovery.

Methods:
We distributed an online survey to cardiac arrest survivors who were members of the Sudden Cardiac Arrest Foundation. Survivors completed the Brief Illness Perception Questionnaire (B-IPQ), Readiness for Hospital Discharge Scale (RHDS), Questionnaire for the Quality of Provider-Patient Interactions (QQPPI), PTSD Checklist-5 (PCL-5), and Patient Health Questionnaire-4 (PHQ-4) which has anxiety and depression subscales. Three multiple regression models examined associations between B-IPQ, RHDS, and QQPPI scores with PCL-5 and PHQ-4 anxiety and depression sores, adjusted for age, sex, time since arrest, self-reported understanding of cardiac arrest and post-arrest symptoms at discharge, self-reported memory at discharge, functional status via the Lawton Instrumental Activities of Daily Living scale, pre-arrest Charlson Comorbidity Index, and income.

Results:
We obtained full data from 163 survivors (mean age: 50.1 years, 50.3% women, 95.5% white, mean time since arrest: 63.9 months). More threatening illness perceptions (β: .57, p < .01) and lower readiness for discharge (β: -.22, p = .01) were associated with greater posttraumatic stress symptoms. More threatening illness perceptions was associated with greater anxiety (β: .53, p < .01) and depression (β: .5, p < .01) symptoms.

Conclusions:
Illness perceptions and readiness for discharge were associated with psychological symptoms in cardiac arrest survivors. Future studies should examine the feasibility of in-hospital assessment of survivors’ illness perceptions, readiness for discharge, and psychological symptoms.
Abstract 324: Assessment of Optimal Chest Compression Depth to Optimize Cardiopulmonary Resuscitation: A Randomized Controlled Trial
Authors: Bruckner Marlies , Kim Seung Yeun , Shim Gyu Hong , Neset Mattias , Cheung Po-yin , Lee Tze-Fun , O'Reilly Megan , Schmölzer Georg
Published: November 2020

Introduction:
Neonatal chest compression (CC) should be performed to a 1/3 anterior-posterior (AP) chest diameter depth, however, the optimal AP depth is unknown.

Hypothesis:
We hypothesized that in asphyxiated neonatal piglets a 40% AP depth compared to 1/3, or 1/4 AP depth will reduce time to achieve return of spontaneously circulation and improve survival.

Methods:
Newborn piglets (n=8/group) were anesthetized, intubated, instrumented, and exposed to 45-minute normocapnic hypoxia followed by asphyxia and cardiac arrest. Piglets were randomly allocated to four intervention groups (“AP 12.5% depth”, “AP 1/4 depth”, “AP 1/3 depth” or “AP 40% depth“). CCs were performed using an automated CC machine with a rate of 90/min. Hemodynamic and respiratory parameters were continuously measured.

Results:
Median (IQR) time to return of spontaneously circulation was 70 (60-117), 85 (72-90), 90 (90-130), and 600 (600-600) sec with AP 40% depth, AP 1/3 depth, AP 1/4 depth, AP 12.5% depth, respectively. No piglet in the AP 12.5% depth group achieved ROSC while the short-term survival (1h) in the other groups was 100%. Systolic and diastolic blood pressure, central venous pressure, carotid blood flow, tidal volume, and minute ventilation increased with increasing AP depth.

Conclusions:
Time to return of spontaneously circulation and survival was similar between 1/4, 1/3, and 40% AP depth, while 12.5% AP depth did not result in return of spontaneously circulation. Hemodynamic and respiratory parameters improved with increasing AP depth suggesting that 40% AP depth might provide improved organ perfusion and oxygen delivery.
Abstract 328: Aversive Cognitions and Engagement in Physical Activity at Hospital Discharge and 1 Year After Cardiac Arrest
Authors: Diaddigo Sarah , Chee Michelle , Roh David , Park Soojin , Claassen Jan , Edmondson Donald , Agarwal Sachin
Published: November 2020

Introduction:
We have shown that cardiac arrest-induced psychological distress is associated with an increased risk of cardiovascular disease (CVD) events and death. Low physical activity (PA) is a known risk factor for recurrent CVD events. We hypothesize that aversive cognitions about PA due to fear of trauma-related bodily sensations may lead to poor engagement in PA after cardiac arrest (CA).

Methods:
We prospectively enrolled 58 adults with a return of spontaneous circulation after in-hospital or out-of-hospital CA between 9/2015-8/2018 at a high-volume, major academic center. We studied 58 patients who survived CA and were discharged from Columbia University. Aversive cognitions about PA were measured with the following items: 1) “I am anxious when I think about doing PA at home;” 2) “I worry that doing PA at home will trigger another cardiac event;” 3) “I fear that I won’t know what is and isn’t safe;” 4) “I worry that I will die.” Patients responded using a 4-point Likert scale and “extremely” or “moderately” responses were classified as having aversive cognitions for each item. Items were adapted from the Anxiety Sensitivity Index.

Results:
Of 58 patients included (50% women, 52% minorities, average age 55±17 years) greater than 2/3 of the respondents reported at least one of the concerns about PA both at discharge and 12 months after discharge. Many (62% at discharge and 65% at 12 months) are not engaged in recommended levels of physical activity. Patients who reported at least 1 concern were almost 4 times more likely to have NOT engaged in PA at home (vs those who reported no concerns) since the CA event (OR= 4 (1.3-14) P=0.01), after adjusting for age, sex, and time since the event. Fear of death was independently associated with low engagement after adjusting for age, sex, and time since the event (OR 1.9 (1-3.7) P=0.05). Of all 58 participants, 71% at discharge and 76% at 12 months reported feeling that any PA done at home without medical supervision was either “not safe at all” or “only somewhat safe.”

Conclusion:
Survivors of CA frequently experience PA-induced anxiety and avoid PA because of the fear of recurrence or death. PA avoidance as an underlying mechanism by which psychological distress worsens prognosis in CA patients should be tested prospectively.
Abstract 339: Relationship Between Post-arrest Care Hemodynamics and Cerebral Oxygen Saturation in Comatose Survivors of Out-of-hospital Cardiac Arrest: Insights From the CAPITAL-RETURN Trial
Authors: Russo Juan J , Boland Paul , Parlow Simon , Bernick Jordan , Mathew Rebecca , So Derek Y , Hibbert Benjamin M , Osborne Christina , De Roock Sophie , Fordyce Christopher , Van Diepen Sean , Le May Michel R
Published: November 2020

Introduction:
Comatose survivors of OHCA develop a post cardiac arrest syndrome (PCAS) characterized by myocardial dysfunction and cerebrovascular dysregulation. Hemodynamic derangements related to PCAS can jeopardize cerebral oxygen delivery and therefore impair neurologic recovery. However, optimal hemodynamic targets to ensure adequate cerebral oxygen delivery following OHCA remain undefined. Accordingly, we examined the relationship between cardiac index (CI), mean arterial pressure (MAP), and regional cerebral oxygen saturation (rO
2
%) following OHCA.

Methods:
CAPITAL-RETURN was a prospective, single-center observational study examining hemodynamics in comatose survivors of OHCA undergoing targeted temperature management after an initial shockable rhythm. Between August 2016 and December 2017, comatose survivors of OHCA underwent continuous, blinded, non-invasive monitoring of CI and rO
2
% using bioimpedance (Cheetah Medical, Portland, OR, USA) and near-infrared spectroscopy (Covidien, Boulder, CO, USA), respectively, for 96 hours after intensive care unit admission. In the present study, we examined the relationship between CI, MAP, and rO
2
% using multivariable linear regression.

Results:
In 56 patients in this analysis, the mean CI and MAP during the first 96 hours of intensive care unit admission were 3.2±0.5 L/min/m
2
and 76±6 mmHg, respectively (Figure). The mean rO
2
% was 63±9% and increased over time (+0.1% per hour; p<0.001). Higher CI was associated with improved rO
2
% (+3.2% per L/min/m2 increase in CI; p<0.0001). There was no association between MAP and rO
2
% (p=0.42). After adjustment for MAP, the association between CI and rO
2
% remained significant (+3.1% per L/min/m2 increase in CI; p<0.0001).

Conclusion:
In comatose survivors of OHCA with an initial shockable rhythm, a higher CI is associated with improved rO
2
%. Further studies are needed to determine whether CI targets improve rO2% and neurologic outcomes following OHCA.
Abstract 344: Comparing the Efficacy of Real-Time Audiovisual Feedback Devices and Active Compression-Decompression Devices in Out-of-Hospital Cardiac Arrest: A Network Meta-Analysis
Authors: Sood Nitish , Sangari Anish , Hauger Joseph A
Published: November 2020

Introduction:
Nearly 350,000 out-of-hospital cardiac arrest (OHCA) cases occur annually in the United States, with a fatality rate nearing 90%. Quality of cardiopulmonary resuscitation (CPR) is known to significantly influence survival. Randomized controlled trials (RCT) on real-time audiovisual feedback (RTAVF) and active compression-decompression (ACD) devices show both provide substantial advantages to standard CPR. We conducted the first network meta-analysis comparing the efficacy of RTAVF and ACD devices in OHCA based on a literature review.

Methods:
Studies examining the efficacy of RTAVF or ACD devices to standard CPR by emergency medical personnel in OHCA cases were identified in PubMed, SCOPUS, Cochrane, Google Scholar, and Embase. Outcomes of interest were return of spontaneous circulation (ROSC), survival to hospital discharge (SHD), and favorable neurological recovery. Both a frequentist and Bayesian network meta-analysis were conducted. The p-values, P-scores and Surface under the Cumulative Ranking (SUCRA) scores were computed to analyze significance and effect size.

Results:
The search yielded 31 eligible studies (n = 35,575). RTAVF devices significantly improved ROSC (Risk Ratio (RR) 1.15, 95% CI: 1.09 - 1.22, p < 0.001, P-score > 0.999) and SHD (RR 1.16, 1.07 - 1.26, p < 0.001, P-score > 0.91), but did not significantly improve favorable neurological recovery (RR 1.05, 0.92 - 1.19, p > 0.05). ACD devices did not report significant improvement in either ROSC (RR 1.03, 0.99 - 1.08, p > 0.05) or SHD (RR 1.10, 0.99 - 1.21, p > 0.05), but did report significant benefits in favorable neurological outcome (RR 1.30, 1.07 - 1.58, p < 0.01, P-score > 0.97). Similar findings were also seen in SUCRA scores.

Conclusion:
We found RTAVF devices increased ROSC and SHD, while ACD devices increased favorable neurological recovery. Our meta-analysis supports the adoption of RTAVF devices, but an RCT directly comparing RTAVF with ACD devices is recommended.
Abstract 351: Current Barriers for College Students to Perform Cardiopulmonary Resuscitation on Strangers and Family Members
Authors: Dluzynski Daniela , Baird Trey , Short Trevor , VanScoy Rachel , Panchal Ashish R
Published: November 2020

Background:
As opioid associated cardiac arrests increase on US college campuses, there is a need for students to learn and perform CPR. These arrests are respiratory in origin and require provision of compressions with rescue breathing (conventional CPR) over hands-only CPR. Unfortunately, only some college students will provide rescue breaths as mouth to mouth contact is a leading barrier to initiate CPR. The objective of this study was to evaluate the barriers of college students to performing conventional CPR on strangers and family members.

Methods:
Undergraduate students at The Ohio State University were recruited from Jan 2018 to Dec 2019 to participate in a survey. Respondents’ demographic data were collected, and they were asked about their attitudes concerning performing conventional CPR on strangers and family. This was followed by identifying their potential barriers to performing conventional CPR. Inclusion criteria were age > 17 and missing < 10% of survey data. Barriers were compared between respondents who were unlikely to perform CPR (unlikely) and those likely to perform CPR (likely). Descriptive statistics were calculated.

Results:
A total of 883 surveys were included in the analysis (response rate 74%). Of these respondents, 495 (56%) were likely to perform CPR on a stranger and 743 (84%) were likely to perform CPR on a family member. When performing CPR on a stranger, the barriers of fear of an incorrect method (unlikely: 81% vs likely: 61%, P<0.001) and mouth to mouth contact (unlikely: 31% vs likely: 24%, p=0.03) were different between groups while facing legal risk and causing harm to the victim were not. In contrast, when performing CPR on a family member, there were no differences between groups except for the fear of applying an incorrect method, which persisted as a larger barrier for those unlikely to perform CPR (unlikely: 72% vs likely: 62%, p<0.05).

Conclusion:
There are many barriers that influence college students’ intention to perform CPR. Surprisingly, the most significant barrier reported by both groups was fear of performing CPR incorrectly, while the fear of mouth-to-mouth contact was not as prevalent. Further evaluation is necessary in the post-COVID-19 era to understand the impact of increased fear of infectious diseases.