bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 184: Racial Disparities in Out-Of-Hospital Cardiac Arrest Interventions and Survival in the Pragmatic Airway Resuscitation Trial
Authors: Lupton Joshua R , Schmicker Robert , Carlson Jestin , Callaway Clifton W , Herren Heather , Aufderheide Tom P , Nichol Graham , Colella Riccardo , Hansen Matthew L , Wang Henry E , DAYA Mohamud R
Published: June 2021

Background:
Prior studies have reported racial disparities in survival from out-of-hospital cardiac arrest (OHCA). However, these studies did not evaluate how emergency medical services (EMS) provider assessment of race impacts OHCA interventions and survival. Our objective was to evaluate racial disparities in OHCA airway management and patient outcomes in the multicenter Pragmatic Airway Resuscitation Trial (PART).

Methods:
We conducted a secondary analysis of adult OHCA patients enrolled in PART. Trial subjects were randomized to initial advanced airway management with laryngeal tube or endotracheal intubation. The primary independent variable was patient race (categorized by EMS as white, black, and other). We used general estimating equations (GEE) to examine the association of race (white or black) with airway attempt success, 72-hour survival, and survival to hospital discharge, adjusting for sex, age, witness status, bystander CPR, initial rhythm, arrest location, and randomization cluster.

Results:
Of 3002 patients, race was 1537 white, 860 black, and 605 other. Median times (min [interquartile range]) from dispatch to arrival (5.4 [2.8] vs. 5.0 [2.3]), arrival to CPR (2.2 [2.7] vs. 2.0 [2.7]), and arrival to airway attempt (12.2 [7.6] vs. 11.0 [7.4]) were longer for black compared to white patients, respectively. Black patients had lower unadjusted odds of shockable rhythms (OR 0.59; 95% CI 0.47, 0.74), bystander CPR (0.47; 0.39, 0.56), and survival to discharge (0.68; 0.50, 0.92) than white patients. After adjustment for confounders, black race was not associated with airway success (OR 1.13; 95% CI 0.9, 1.41), 72-hr survival (1.06; 0.81, 1.30), or survival to discharge (0.82; 0.57, 1.19).

Conclusions:
Although black patients had lower odds of shockable rhythms and bystander CPR, airway success and survival odds were similar to white patients. Further studies are needed to better understand disparities in survival from OHCA.
Abstract 195: Chronic Enhancement of Endogenous Nitric Oxide Production via Whole Body Periodic Acceleration (WBPA) Induces Cardioprotection in 15 Months Diabetic Mice
Authors: Uryash Arkady , Flores Valentina , Kolster Juan , Lopez Jose R , Adams Jose A
Published: June 2021

Background:
Diabetes mellitus (DM) is a major risk factor for the development of cardiovascular disease. Over time, diabetic patients develop cardiomyopathy, referred to as diabetic cardiomyopathy (DCM). The etiology of DCM in part relates to the duration of hyperglycemia. We have previously shown that type 1 diabetic mice (T1D) have abnormally elevated cardiomyocyte diastolic [Ca
2+
]
d
, sodium ([Na
+
]
d
) after 3 months of diabetes. Whole body periodic acceleration (WBPA) is the motion of the supine body headward to footward in a sinusoidal fashion to induce pulsatile shear stress, increasing expression and phosphorylation of endothelial-derived nitric oxide synthase (eNOS, p-eNOS). We have previously shown that WBPA decreases [Ca
2+
]
d
, sodium ([Na
+
]
d
in various models of cardiomyopathy. We hypothesized that WBPA might reverse ion dyshomeostasis in the long term (15-months) hyperglycemia (glucose>250mg/dl) mice.

Methods:
15 C57BL/6J (CONT) and diabetic mice (T1D) were randomized to receive WBPA (480 rpm, 1 hr daily for 20 days). Diastolic [Ca
2+
]
d
, ([Na
+
]
d
) (selective microelectrodes), and ROS production (fluorescent) were determined in isolated cardiomyocytes at day 0 and at upon completion of the treatment (day 20).

Results:
Hyperglycemia produced an increase in [Ca
2+
]
d
, [Na
+
]
d
and ROS production in cardiomyocytes. 20 days of WBPA treatment in established DCM significantly decreased [Ca
2+
]
d
, [Na
+
]
d
, and ROS production toward normal values.

Conclusions:
These findings suggest that WBPA may be a therapeutic strategy to reverse ion dyshomeostasis and oxidative stress in a very established(15mos) DCM
Abstract 196: Cardiac Small Extracellular Microvesicles-Induced Adipogenesis Suppression Contribute to Matabolic Disorders in Heart Failure
Authors: Gan Lu , Xie Dina , Liu Jing , Liu Demin , Zhang Ling , Zhang Zhen , Gao Erhe , LAU Wayne Bond , Lopez Bernard L , Christopher Theodore , Wang Yajing , Ma Xin L
Published: June 2021

Objective:
Local and systemic metabolic disorders during heart failure (HF) affecting the disease progression and prognosis. The long-range organ-to-organ communications mediates the coordination of organs homeostasis and adaptation. However, it remains unknown whether and how the failing heart contributes to the adipose dysfunction.

Method and Results:
6-8 week-old adult wild type (WT) male mice were subjected to myocardial infraction (MI) for 8 weeks. The cardiac function was evaluated by echocardiography. The plasma lipid profiles were evaluated in Sham and HF mice via Alere LDX analyzer. Interestingly, white adipose tissue weight was significantly decreased, TC/HDL ratio and LDL levels were increased in HF mice compared to non-MI sham mice. To determine the possible pathological mediator, the sEV of murine serum, heart tissue perfusate and cardiomyocyte culture medium from HF mice were isolated and incubated with adipocytes (3T3L1). The adipogenesis was significantly inhibited when sEV isolated from three different resources were administrated to 3T3L1 adipocytes. Pathway specific discover-driven approach revealed that Pparg, Cebpa and Cebpd expression were significantly inhibited by sEV derived from HF cardiomyocytes. To determine the specific mediators in sEV, Venn diagraph assay were performed with two databases (the cardiomyocyte-enriched miRNAs and adipocyte development-related miRNAs). The cluster of miR-23-27-24 and the miR-30 family were markedly elevated in serum-derived, heart tissue-derived and cardiomyocyte-derived sEV from MI mice compared to Sham mice. These changes were validated by RT-qPCR assay. Treatment with miR-23-27-24 significantly inhibited adipogenesis.

Conclusion:
Taken together, microRNAs miR-23-27-24 and the miR-30 in cardiac-derived sEV are the key messengers facilitating adipocyte dysfunction after MI. Adiogenesis suppression is regulated by failing myocardium-derived sEV, which results in progressive matabolic disorders in the adipose tissue.
Abstract 198: Metabolic Stress Causes Mitochondrial Dysfunction and Vascular Senescence via Angiotensin II Type I Receptor Signal / Rho Kinase Induced Mitochondrial Fission
Authors: Uchikado Yoshihiro , Ikeda Yoshiyuki , Sasaki Yuichi , Akasaki Yuichi , Ohishi Mitsuru
Published: June 2021

Introduction:
Metabolic stress, such as oxidized low density lipoprotein (ox-LDL) and advanced glycation end products (AGE) cause mitochondrial dysfunction and evoke vascular senescence and atherosclerosis. Mitochondria are highly dynamic organelles that constantly change their morphology to fusion or fission. This study aims to clarify whether mitochondrial dynamics is involved in the etiology of vascular senescence.

Methods:
We used C57BL6 (WT), apolipoprotein E deficient (ApoE KO) and db/db mice. We also conducted in vitro experiments using VSMC and HUVEC.

Results:
The degree of arterial senescence, arterial protein level of Drp1 in mitochondrial fraction and mitochondrial oxidative stress were higher and the number of fused mitochondria and mitochondrial function were lower in either ApoE KO or db/db mice than those of WT mice. Treatment with Drp1-specific inhibitor, mdivi-1, to these mice reduced excessive mitochondrial fission, oxidative stress and attenuated vascular senescence. Administration of either ox-LDL or AGE to cells also induced excessive mitochondrial fission though phosphorylation of Drp1 at Ser616, mitochondrial dysfunction, reactive oxygen species production and cellular senescence. Treatment with mdivi-1 to these cells restored imbalance of mitochondrial dynamics and these detrimental alterations. These results suggest that metabolic stress-induced mitochondrial dysfunction and cellular senescence were derived from Drp1-dependent mitochondrial fission. Treatment with angiotensin II type1 receptor (AT1R) blocker (ARB) to either Apo E KO mice or db/db in in vivo experiments and administration of ARB to cells with ox-LDL or AGE stimulation in in vitro experiments inactivated Drp1 and improved imbalance of mitochondrial dynamics, mitochondrial dysfunction and cellular senescence, suggesting that AT1R signal is involved in regulating metabolic stress-induced mitochondrial fission. Finally, inhibition of Rho kinase ROCK1 successfully attenuated Drp1-mediated mitochondrial fission and cellular senescence derived from metabolic stress.

Conclusion:
Metabolic stress causes cellular and vascular senescence through AT1R signal/Rho kinase-mediated mitochondrial fission.
Abstract 217: Increased Oxidation of Amplex Red in Post-Cardiac Arrest Human and Rat Plasma Can Be Utilized as a Potential Marker of Injury Severity
Authors: Shoaib Muhammad , Iverson Ann , Yin Tai , Becker Lance B , KIM Junhwan
Published: June 2021

Introduction:
Cardiac arrest (CA), an unexpected loss of appropriate electrical signaling in the heart, leads to a loss of blood circulation and decreased oxygen perfusion. Ischemia results in the generation of hydrogen peroxide and other reactive oxygen species (ROS), thereby causing damage to tissues. Currently, there are no available biomarkers to elucidate the severity of ischemic damage. Therefore, oxidation of the Amplex Red (AR) assay by ROS into its fluorescent product, resorufin, may be used as a marker to determine injury severity.

Methods:
Plasma isolated from human CA patients from North Shore University Hospital was obtained to determine ROS generation. A commercially available Amplex Red assay kit was used to measure the amount of resorufin produced after oxidation due to hydrogen peroxide, peroxynitrite, and other ROS. To verify our human findings, we arbitrarily assigned adult male Sprague-Dawley rats into three groups (control, 10 min cardiac arrest, and 20 min cardiac arrest) using our reliable asphyxia-induced cardiac arrest model.

Results:
Despite human variations, our data on human CA patients showed an increased amount of AR oxidation as a result of ischemia. Our 10 min CA rat experimental model verified that Amplex Red is capable of detecting hydrogen peroxide and peroxynitrite formation after ischemia. Rats with 20 mins of ischemia time also produced resorufin, confirming that ischemia induces AR oxidation. Removing horseradish peroxidase and adding catalase controls for hydrogen peroxide and peroxynitrite, which should decrease AR oxidation; however, we observed an increase in AR oxidation. Therefore, we added phenylmethyl sulfonyl acid (PMSF), an inhibitor of carboxylesterase, an enzyme also capable of oxidizing Amplex Red, which resulted in decreased AR oxidation.

Conclusion:
By accounting for peroxide and peroxynitrite species, the increase in Amplex Red oxidation in the plasma of cardiac arrest human patients and rats can be attributed to carboxylesterase activity. Our data corroborates the various mechanisms of AR oxidation in the setting of ischemia-reperfusion allowing the Amplex Red assay to be utilized as a potential tool for assessing the degree of ischemic damage resulting from cardiac arrest.
Abstract 22: Poloxamer 188 Protects Mouse Brain Microvascular Endothelial Cells in an in-vitro Traumatic Brain Injury Model
Authors: Lotze Felicia P , Salzman Michele M , Pille Johannes A , Balzer Claudius , Hees Josephine E , Cleveland William J , Riess Matthias L
Published: June 2021

Introduction:
Traumatic brain injury (TBI), a major cause of severe disability and death, can lead to disruption of the vascular endothelial system and cell membrane integrity, threatening the survival of multiple cell types. Reducing these could improve the clinical outcome of TBI. Poloxamer 188 (P188) has been shown to protect different cell types against ischemia/reperfusion (IR) injury.

Hypothesis:
P188 protects mouse brain microvascular endothelial cells (MBECs) against injury in an in-vitro compression-type TBI model.

Methods:
Confluent MBEC cultures were exposed to normoxic (complete media; 21% O
2
, 5% CO
2
, 74% N
2
; 37°C) or hypoxic (glucose-, serum-free media; 0.01% O
2
, 5% CO
2
, N
2
balance; 37°C) conditions for 5 hrs, with compression (9.81 N / 0.16 cm
2
) added during the first hour of normoxia/hypoxia. All MBECs then underwent 2 hrs of reoxygenation in normoxic conditions ± P188 (10 μM, 100 μM, 1 mM). Samples were assayed for cell number, cytotoxicity (lactate dehydrogenase [LDH] release), and metabolic activity. Statistics: Data are mean ± SEM. Kruskal-Wallis one-way analysis of variance on Ranks, Dunn’s Method; p <0.05, * vs normoxia, † vs hypoxia, ** vs normoxia + compression, †† vs hypoxia + compression; n = 11-19 experiments/group.

Results:
Compared to normoxic cells without compression, cell number and metabolic activity decreased and cytotoxicity increased in cells exposed to hypoxic conditions +/- compression followed by reoxygenation. In hypoxic cells, 1 mM P188 increased cell number and metabolic activity and decreased cytotoxicity, while 100 μM only increased metabolic activity and decreased cytotoxicity and 10 μM only increased metabolic activity. In hypoxic compressed cells, no concentration of P188 improved cell number, however, 10 μM and 100 μM P188 increased metabolic activity, while 1 mM increased metabolic activity and decreased cytotoxicity. There was no difference between normoxic compressed and non-compressed cells in any assay, although all concentrations of P188 tested increased metabolic activity in normoxic compressed cells.

Conclusion:
P188, present during reoxygenation, provides protection to MBECs exposed to simulated IR injury, as well as compression-type TBI.
Abstract 236: Complete Recoil Duration Declines Over the Course of Longer Resuscitations
Authors: Russell James K , Lin Amber , Gonzalez-Otero Digna M , Leturiondo Mikel , Ruiz Jesus M , Daya Mohamud R , Ruiz de Gauna Sofia
Published: June 2021

Introduction:
CPR guidelines call for chest compressions within rate and depth ranges and complete chest recoil. Guidelines development has relied on data from the first 10 minutes of resuscitations. We investigated the influence of rate, depth and chest stiffness on complete recoil duration in longer resuscitations.

Hypothesis:
Decreasing chest stiffness will contribute to reduced complete recoil duration over the course of long resuscitations.

Methods:
Acceleration and force signals were from monitors used in continuous compression CPR during out-of-hospital resuscitations of adults treated by Tualatin Valley Fire & Rescue (Tigard, OR) from 2013 through 2017. Complete recoil was defined as return to within 5 mm of baseline in the absence of leaning (release force > 2.5 kg-f), stiffness as peak force/peak depth. Influences of rate, depth and stiffness on complete recoil duration were modeled with linear mixed effects models with a random intercept and slope clustered by patient.

Results:
A total of 1,076,808 compressions without leaning (93% of compressions) were measured from 616 cases with 1888 ± 1118 compressions/case (mean ± std). Observed increases in rate (7%) and depth (2%) were modest, while stiffness declined markedly (-33%) (Fig 1a). All of these changes tend to reduce the duration of complete recoil (p < 0.001). Mean complete recoil duration decreased 21% (Fig 1a) from 160 ms to 126 ms (Fig 1b). Despite its large relative change, stiffness had little effect on complete recoil duration, as did depth. Increasing rate explained most of the decline in complete recoil duration (Fig 1b).

Conclusions:
Substantial decline in chest stiffness over the course of long resuscitations contributes to reduction of complete recoil duration but little compared to increasing rate. Careful compliance with rate guidelines is paramount in maintaining periods of complete recoil. Depth is relatively well-controlled. Chest molding (decreased stiffness) is of secondary importance.
Abstract 24: Association Between Serum Lactate During Cardiopulmonary Resuscitation and Survival in Adult Out-Of-Hospital Cardiac Arrest: A Multicenter Cohort Study (The Critical Study in Osaka, Japan)
Authors: Nishioka Norihiro , Kobayashi Daisuke , Izawa Junichi , Kiguchi Takeyuki , Kitamura Tetsuhisa , Kawamura Takashi , Iwami Taku
Published: June 2021

Background:
Serum lactate reflects hypoxic insult in many conditions, but its role as prognostic markers after cardiac arrest is still controversial. This study aimed to investigate the association between serum lactate levels during cardiopulmonary resuscitation (CPR) and survival in patients with out-of-hospital cardiac arrest (OHCA).

Methods:
This study analyzed the data of the Osaka Comprehensive Registry of Intensive Care for OHCA Survival, a prospective multicenter observational study of 14 participating institutions in Osaka Prefecture, Japan. We enrolled consecutive patients aged ≥18 years who were transported to the hospital with ongoing CPR from 2013 to 2016. Based on the serum lactate levels, OHCA patients were divided into 4 quartiles: Q1 (lactate ≤10.6 mEq/L), Q2 (10.6< lactate ≤14.1 mEq/L), Q3 (14.1< lactate ≤18.0 mEq/L) and Q4 (lactate >18.0 mEq/L). The relationships between serum lactate level before return of spontaneous circulation (ROSC) and 1-month survival were assessed.

Results:
A total of 3,674 OHCA patients were included in the analysis. Overall 1-month survival was 2.3% (88/3,674). The Q1 group had the highest 1-month survival (4.6% [42/921]), followed by Q2 (2.7% [25/920]), Q3 (1.1% [11/966]) and Q4 (0.6% [5/867]), respectively (p for trend < 0.001). In the multivariable logistic regression analysis, the proportion of 1-month survival in the Q4 group was significantly lower, compared with that in the Q1 group (adjusted odds ratio 0.23; 95% confidence interval 0.09 to 0.60). The adjusted proportion of 1-month survival decreased in a stepwise manner across increasing quartiles (p for trend <0.001). In a subgroup analysis by initial rhythm, there was a significant interaction (p=0.003) between the rhythms: 1-month survival of OHCA patients presented with a non-shockable rhythm decreased when the lactate levels increased (p for trend < 0.001), but in patients with a shockable rhythm the similar trend was not observed (p for trend = 0.574).

Conclusions:
The high serum lactate level before ROSC significantly associated with the worse 1-month survival after OHCA. Serum lactate may be one of the effective prognostic indications for OHCA during CPR, especially with non-shockable initial rhythm.
Abstract 240: Smartphone Application to Provide Real-Time Cardiopulmonary Resuscitation Quality Feedback
Authors: Stumpf Emily , Ambati Ravi , Shekhar Raj , Staffa Steven , Zurakowski David , Sinha Pranava
Published: June 2021

Introduction:
Quality of cardiopulmonary resuscitation (CPR) contributes significantly to morbidity and mortality in both in-hospital and out-of-hospital cardiac arrest. Key parameters that determine the CPR quality are compression rate, compression depth, duration of interruptions, chest recoil factor and respiratory rate. Several studies have demonstrated that real-time audiovisual feedback improves CPR quality in both bystanders and hospital staff. This study aims to develop and validate a smart device (phones and wearable technology) application to provide real-time audiovisual and haptic feedback to optimize CPR quality, by calculating aforementioned chest compression parameters.

Hypothesis:
A mobile application using acceleration sensor data from smart devices can provide accurate real time CPR quality feedback.

Methods:
A mobile application was developed to track the compression depth, compression rate and pause duration in real time using the data captured from the on-device accelerometer. The mobile device was placed on an adult manikin’s chest along the midline close to the point of compressions. Data from the application was compared directly to data obtained from a validated clinical standard CPR quality tool.

Results:
CPR quality parameters were obtained from the app and the standard for 60, 10-second-long sessions. Bland-Altman plot analysis for compression depth showed agreement between the app measurements and standard within +/-3.5mm (Figure 1). The intraclass correlation for agreement in the measurement of compression count was 0.92 (95% CI: 0.88-0.95), indicative of very strong agreement.

Conclusions:
Smart device (phones and wearable technology) applications using acceleration sensor data can accurately provide real-time CPR quality feedback. With further development and validation they can provide a ubiquitous CPR feedback tool valuable for out of hospital arrests and in under-privileged areas worldwide.
Abstract 241: Legal Risk of Bystander Cardiopulmonary Resuscitation
Authors: Murphy Travis , Windermere Sonora , Morris Tareyn , Slish John , Holtzman Liam , Becker Torben
Published: June 2021

Background:
Research has shown disparities between provision of bystander CPR among different race, gender and age groups. Reasons for this disparity have included concern of legal liability by responders. We propose that bystanders are more likely to face litigation for lack of intervention as opposed to providing bystander CPR. This review of the legal literature seeks to quantify the number of cases brought against responders in the USA over the past 30 years.

Methods:
The Westlaw legal research database was searched for jury verdicts, settlements, and appellate opinions from all 50 states from 1989 to 2019, in which the use or non-use of CPR gave rise to a personal injury or wrongful death lawsuit. A total of 274 cases were initially identified and manually reviewed. Outcomes recorded included case jurisdiction, location, date, plaintiff and defendant demographics, bystander training, motivation for the lawsuit, including claims of battery for performing CPR or negligence related to injuries or death following CPR or AED use.

Results:
Preliminary data shows that 41.1% (114 of 274) of all cases screened were directly due to the provision of bystander CPR or lack thereof. Among the relevant cases, 64% (73 of 114) were due to inadequate or untimely bystander CPR. Battery cases due to providing CPR amounted to 32% (32 of 114), but of these, 59.4% (19 of 32) were ruled in favor of the defendant.

Conclusions:
This represents the largest study of legal cases involving bystander CPR in the medical literature, limitations include a lack of a national repository of trial data thus underestimating the total number of cases involving bystander CPR. The likelihood of facing litigation is significantly higher in cases where bystander CPR was delayed or not provided. The authors propose the inclusion of this data and reiteration of protective statutes in all 50 states during CPR training to reassure and encourage trainees.
Abstract 245: Role of the Resuscitation Champion on Survival Outcomes for In-Hospital Cardiac Arrest
Authors: Chan Jesse , Nallamothu Brahmajee K , Tang Yuanyuan , Chan Paul
Published: June 2021

Background:
Hospitals vary markedly in survival rates for their patients with in-hospital cardiac arrest (IHCA). Although many sites have resuscitation champions, whether a resuscitation champion’s clinical background and intensity of engagement distinguishes sites with higher cardiac arrest survival rates remains unknown.

Methods:
We conducted a nationwide survey of adult hospitals participating in GWTG-Resuscitation to elicit detailed information on resuscitation practices, including of their resuscitation champion. Risk-standardized survival rates for IHCA for 2016-2017 were calculated for each hospital, and these were then used to categorize hospitals into quintiles of performance. The association between a resuscitation champion’s clinical background and intensity of engagement (categorized as very active non-physician champion, very active physician champion, and all others) and quintiles of survival was evaluated using multivariable hierarchical proportional odds logistic regression models.

Results:
Overall, 200 of 218 eligible adult hospitals (91.7%) completed the study survey and 190 facilities with
>
10 cases comprised the final study cohort. Risk-standardized survival rates after IHCA varied substantially (median: 24.7%; range: 9.2% to 37.5%). One-third (63/190 [33.2%]) of hospitals had a very active non-physician champion, 29 (15.3%) had a very active physician champion, and the remaining 98 (51.2%) had a resuscitation champion not perceived to be very active or had no champion. Compared to sites with very active non-physician champions, those with a very active physician champion had 5-fold higher odds (adjusted OR, 5.15 [95% CI: 2.13-12.5]) of being in a higher survival quintile category, whereas there was no difference in survival outcomes between sites with less active or no resuscitation champions and very active non-physician champions (adjusted OR, 0.94 [95% CI: 0.52-1.77]) .

Conclusions:
Although most hospitals have resuscitation champions, the background and engagement level of a resuscitation champion is a critical factor in a hospital’s survival outcomes for IHCA. Hospitals with the highest survival rates for IHCA are more likely to have very active physician resuscitation champions.
Abstract 248: Initiation and Assessment of Timekeeping Roles During In-Hospital Cardiac Arrests to Track Rhythm Checks and Epinephrine Dosing
Authors: Crowley Conor , Clardy Peter , McCannon Jessica , Logiudice Rebecca
Published: June 2021

Introduction:
Compliance to ACLS cardiac arrest algorithm is low and associated with worse outcomes from in-hospital cardiac arrests (IHCA). Reasons for non-compliance include reduced communication due to chaotic nature of IHCAs and difficulty timing epinephrine administration and rhythm check intervals.

Hypothesis:
Delegating two separate code team members for rhythm and epinephrine timing will increase adherence to ACLS algorithm during IHCAs.

Methods:
This is a pre-post interventional study of IHCAs at a single academic medical center. Two stopwatches were placed on all code carts and two new timekeeping roles were created. Education was provided to staff regarding the alteration of existing code team member roles for the use of stopwatches. Algorithm adherence was analyzed pre and post implementation of timekeeper roles. Deviation from the 2-minute rhythm check or 3-5-minute epinephrine administration was counted as one deviation. Anonymous surveys were delivered to evaluate providers perceived benefits of timekeeper roles for IHCAs.

Results:
Data from 13 pre intervention IHCAs were compared to 12 IHCAs post intervention. The initial rhythm was PEA/asystole in 69% pre-intervention vs 83% post intervention. Prior to implementation 82 deviations vs. 11 deviations post implementation occurred (p=0.006). The mean time until first dose of epinephrine was administered pre intervention was 2.3 ± 3.3 minutes vs 0.4 ±1 minute post. Pre-implementation ROSC rate was 53.8% vs. 66.7% post intervention. Surveys were delivered to 100% of code team members post intervention, with a 79% response rate. Surveys demonstrate providers felt time keeping roles made it easier to track epinephrine administration and rhythm checks. On a Likert scale, 78% of providers “strongly agree” that the use of timekeeping roles and devices improved code team communication.

Conclusion:
Two separate timekeeper roles during IHCAs improved algorithm compliance, code team function and communication, and was favored by code team members. Timekeeper roles may be associated with improved rates of ROSC and less time until the first dose of epinephrine is administered. This study is limited by its small sample size, single center and requires validation.
Abstract 264: Automatic Detection of Ventilations Using the Thoracic Impedance Signal During Lucas Chest Compressions
Authors: Jaureguibeitia Xabier , Irusta Unai , Aramendi Elisabete , Owens Pamela , Wang Henry E , Idris Ahamed H
Published: June 2021

Introduction:
Resuscitation from out-of-cardiac arrest (OHCA) requires control of both chest compressions and lung ventilation. There are few effective methods for detecting ventilations during cardiopulmonary resuscitation. Thoracic impedance (TI) is sensitive to changes in lung air volumes and may allow detection of ventilations but has not been tested with concurrent mechanical chest compressions.

Hypothesis:
It is possible to automatically detect and characterize ventilations from TI changes during mechanical chest compressions.

Methods:
A cohort of 420 OHCA cases (27 survivors to hospital discharge) were enrolled in the Dallas-Fort Worth Center for Resuscitation Research cardiac arrest registry. These patients were treated with the LUCAS-2 CPR device and had concurrent TI and capnogram recordings from MRx (Philips, Andover, MA) monitor-defibrillators. We developed a signal processing algorithm to suppress chest compression artifacts from the TI signal, allowing identification of ventilations. We used the capnogram as gold standard for delivered ventilations. We determined the accuracy of the algorithm for detecting capnogram-indicated ventilations, calculating sensitivity, the proportion of true ventilations detected in the TI, and positive predictive value (PPV), the proportion of true ventilations within the detections. We calculated per minute ventilation rate and mean TI amplitude, as surrogate for tidal volume. Statistical differences between survivors and non-survivors were assessed using the Mann-Whitney test.

Results:
We studied 4331 minutes of TI during CPR. There were a median of 10 (IQR 6-14) ventilations per min and 52 (30-81) ventilations per patient. Sensitivity of TI was 95.9% (95% CI, 74.5-100), and PPV was 95.8% (95% CI, 80.0-100). The median ventilation rates for survivors and non-survivors were 7.75 (5.37-9.91) min
-1
and 5.64 (4.46-7.15) min
-1
(p<10
-3
), and the median TI amplitudes were 1.33 (1.03-1.75) Ω and 1.14 (0.77-1.66) Ω (p=0.095).

Conclusions:
An accurate automatic TI ventilation detection algorithm was demonstrated during mechanical CPR. The relation between ventilation rate during mechanical CPR and survival was significant, but it was not for impedance amplitude.
Abstract 268: Evaluation of the Abdominal Aortic and Junctional Tourniquet as an Adjunct to Chest Compressions in a Swine Model of Out-Of-Hospital Cardiac Arrest
Authors: Rall Jason , Hewitt Chris , Pombo Matthew , Castaneda Maria , Blough Perry
Published: June 2021

Introduction:
Overall success in treating out-of-hospital cardiac arrest using traditional chest compressions is low. The abdominal aortic and junctional tourniquet (AAJT) is a device with a wedge-shaped air bladder that can be used to occlude the descending aorta at the level of bifurcation. In addition to shunting blood away from the lower extremities, this device may increase pleural pressures by inhibiting movement of the diaphragm during compressions. We have previously shown that the addition of an AAJT to mechanical chest compression leads to an increase in rate of survival in a model of traumatic cardiac arrest.

Hypothesis:
This study was designed to determine if application of the AAJT would lead to more effective chest compressions as measured by an increased rate of return of spontaneous circulation (ROSC) and hemodynamic parameters.

Methods:
Yorkshire swine (n=6 per group) underwent general anesthesia and instrumentation. Ventricular fibrillation was electrically induced using spinal needles placed in contact with the left ventricle. After eight minutes of arrest, chest compressions were initiated. Animals were then allocated into groups with or without the AAJT. Following a total of ten minutes of compressions, the animals entered into a ten-minute advanced cardiac life support phase.

Results:
A ROSC was not achieved in either group. No significant differences were observed with coronary perfusion pressure or end tidal CO
2
. However, the AAJT group had a significantly higher carotid diastolic pressure and higher blood flow in the carotid as compared with repeated-measures ANOVA (p = 0.016 and 0.028 respectively).

Conclusion:
The AAJT did not confer a survival advantage during chest compressions in our swine model of cardiac arrest. However, while the AAJT was in place, improvement was observed in some measures of CPR efficacy.

Disclaimer:
The views expressed are those of the authors and do not reflect the official views or policy of the Department of Defense or its Components. The experiments reported herein were conducted according to the principles set forth in the National Institute of Health Publication No. 80-23, Guide for the Care and Use of Laboratory Animals and the Animal Welfare Act of 1966, as amended.
Abstract 27: Machine Learning Models for Outcome Prediction of Out-Of-Hospital Cardiac Arrest of Presumed Cardiac Cause Using the All-Japan Utstein Registry
Authors: Seki Tomohisa , Tamura Tomoyoshi , Ohe Kazuhiko , Suzuki Masaru
Published: June 2021

Background:
Outcome prediction for patients with out-of-hospital cardiac arrest (OHCA) using prehospital information has been one of the major challenges in resuscitation medicine. Recently, machine learning techniques have been shown to be highly effective in predicting outcomes using clinical registries. In this study, we aimed to establish a prediction model for outcomes of OHCA of presumed cardiac cause using machine learning techniques.

Methods:
We analyzed data from the All-Japan Utstein Registry of the Fire and Disaster Management Agency between 2005 and 2016. Of 1,423,338 cases, data of OHCA patients aged ≥18 years with presumed cardiac etiology were retrieved and divided into two groups: training set, n = 584,748 (between 2005 and 2013) and test set, n = 223,314 (between 2014 and 2016). The endpoints were neurologic outcome at 1-month and survival at 1-month. Of 47 variables evaluated during the prehospital course, 19 variables (e.g.,sex, age, ECG waveform, and practice of bystander CPR) were used for outcome prediction. Performances of logistic regression, random forests, and deep neural network were examined in this study.

Results:
For prediction of neurologic outcomes (cerebral performance category 1 or 2) using the test set, the generated models showed area under the receiver operating characteristic curve (AUROC) values of 0.942 (95% confidence interval [CI] 0.941-0.943), 0.947 (95% CI 0.946-0.948), and 0.948 (95% CI 0.948-0.950) in logistic regression, random forest, and deep neural network, respectively. For survival prediction, the generated models showed AUROC values of 0.901 (95% CI 0.900-0.902), 0.913 (95% CI 0.912-0.914), and 0.912 (95% CI 0.911-0.913) in logistic regression, random forest, and deep neural network, respectively.

Conclusions:
Machine learning techniques using prehospital variables showed favorable prediction capability for 1-month neurologic outcome and survival in OHCA of presumed cardiac cause.
Abstract 282: Cerebral Oximetry to Identify Return of Spontaneous Circulation in Patients Treated With Manual or Mechanical Chest Compressions
Authors: Salaberria Ruth , Larrea Andima , Amas Leyre , Zubia Felix , Zubero Miren Begoña , Alonso Daniel , Irusta Unai , Aramendi Elisabete
Published: June 2021

Background:
Near infrared spectroscopy can be used to monitor cerebral oxygen saturation in out-of-hospital cardiac arrest (OHCA). Brain oxygen saturation increase has been associated to cardiopulmonary resuscitation therapy (CPR), and higher saturation values are observed during return of spontaneous circulation (ROSC) and in survivors. In this study we evaluate cerebral oxygen saturation to identify ROSC, and compare its value for patients treated with manual or mechanical CPR.

Materials and Methods:
A total of 87 OHCA patients treated by the Emergency medical system (EMS) of the Basque Country were included, 32 treated with manual CPR and 55 with the LUCAS-3 device (Stryker). Brain oxygen saturation was measured in the left and right lobes using the NIRO NX-200 (Hamamatsu) in the manual group, and the SenSmart X-100 (NONIN) in the LUCAS-3 group. For each patient the mean value of the left and right lobe saturation in the first minute after the end of chest compressions was computed. Saturation values for the ROSC/no-ROSC groups were compared using the Wilcoxon rank sum test, p<0.01 was considered significant. The area under the curve (AUC) was computed for each CPR group to measure how well brain saturation discriminates ROSC from no-ROSC.

Results:
In the manual CPR group median (IQR) saturation values were 39.2% (33.6-49.7) for the no-ROSC (n=23) and 64.3% (55.2-67.0) for ROSC (n=9) (p<0.01), and the AUC was 0.92. In the LUCAS-3 CPR group saturation values were 41.5% (29.8-50.5) for the no-ROSC (n=37) and 67.0% (61.8-75.0) for ROSC (n=18) (p<0.01), and the AUC was 0.91. No significant differences in saturation were observed between manual and mechanical CPR for both ROSC (p=0.46) and no-ROSC patients (p=0.28).

Conclusions:
Differences in cerebral oximetry were significant between ROSC and no-ROSC patients. No differences were observed in saturation between the manual and mechanical CPR groups, despite using different oximeter models. Cerebral oximetry could be used to predict outcome regardless of the type of CPR.
Abstract 296: Quality Analysis of Cardiopulmonary Resuscitation From Two Emergency Medical Service Systems Using a Feedback Device
Authors: Gao Mengqi , Liu Chenguang , Gehman Stacy , Rea Thomas , Blackwood Jennifer E , Studnek Jonathan R , Vandeventer Steven , Infinger Allison E , Dowbiggin Patricia L , Jorgenson Dawn
Published: June 2021

Background:
High quality cardiopulmonary resuscitation (CPR) plays a critical role in the success of out-of-hospital resuscitation from sudden cardiac arrest (SCA). AHA guidelines provide protocol to achieve recommended targets for CPR quality metrics including chest compression fraction (CCF), percentage of chest compressions (CCs) with full chest recoil, CC rate and CC depth. Our objective was to report the CPR quality of two emergency medical services (EMS) agencies with different basic life support (BLS) CPR protocols.

Methods:
Data from 673 patients, 2015 to 2017, suffering out-of-hospital SCA were obtained from Philips FR3 AEDs. The Philips Q-CPR tool was used for real-time CPR feedback, and CC waveforms were recorded for retrospective CPR analysis using Philips Event Review Pro 5.0 and custom software. The two EMS systems had BLS protocol differences: Site 1(King County, WA, n = 93) applied a compression - ventilation ratio of 30:2, while Site 2 (Mecklenburg County, NC, n = 580) applied 200 compressions in each CPR interval and ventilations were performed during CCs. Analyses were performed comparing CPR metrics between sites and to AHA targets.

Results:
There were 3,460 minutes of resuscitation data analyzed, representing the initial phase of resuscitation prior to ALS. The proportion of cases with shocks was 21.5% (20 of 93) for site 1 and 16.9% (98 of 580) for site 2 (p = 0.3). Both sites achieved guideline metrics though there were statistical differences (Table 1). Compared to site 1, site 2 was associated with a higher CCF, faster CC rate, but less CC depth on average (p < 0.001).

Conclusions:
High quality CPR defined by AHA guidelines was achieved with both sites during the early phase of AED resuscitation though some differences were observed. Additional investigation should identify equipment, or rescuer characteristics that are important to consistently achieve high quality CPR and how the combination might be tailored to optimize individual patient outcome.
Abstract 30: Targeted Temperature Management at 33 versus 36 Degrees: Outcomes After Real-World Implementation
Authors: Johnson Nicholas J , Danielson Kyle R , Counts Catherine R , Ruark Katelyn , Scruggs Sue , Hough Catherine L , Maynard Charles , Sayre Michael , Carlbom David
Published: June 2021

Objective:
To determine the association between targeted temperature management (TTM) goal temperature of 33 versus 36°C and neurologic outcome after out-of-hospital cardiac arrest (OHCA).

Methods:
This was a retrospective, before-and-after, cohort study conducted at an urban, academic, Level 1 trauma center from 2010-2017. We included adults with non-traumatic OHCA who received TTM. Our primary exposure was TTM goal temperature, which was changed from 33 to 36°C in April of 2014 at the study hospital. Primary outcome was neurologically-intact survival to discharge. Secondary outcomes included hospital mortality and care processes. We used univariate analysis and multivariate logistic regression to examined the association between TTM goal and outcome.

Results:
Of 782 OHCA patients transported to the study hospital, 453 (58%) received TTM. Of these, 258 (57%) were treated during the 33°C period (TTM33) and 195 (43%) were treated during the 36°C period (TTM36). Patients treated during TTM33 were older (57 vs. 52 years, p<0.05) and had more arrests of cardiac etiology (45 vs. 35%, p <0.05), but otherwise had similar baseline characteristics, including initial rhythm. 40% of patients treated during TTM33 survived with favorable neurologic outcome, compared with 30% in the TTM36 group (p<0.05). After adjustment for demographic and cardiac arrest characteristics, TTM33 was associated with increased odds of neurologically-intact survival to discharge (OR 1.79, 95% CI 1.09-2.94). TTM33 was not associated with significantly improved hospital mortality. TTM was implemented faster (1.9 vs 3.5 hours from 911 call, p<0.001) and more frequently in the emergency department during the TTM33 period. (87 vs. 55%, p<0.001)

Conclusion:
Comatose, adult OHCA patients treated during the TTM33 period had higher odds of neurologically-intact survival to hospital discharge compared with those treated during the TTM36 period. Our findings may be explained by earlier and more aggressive TTM implementation during the TTM33 period, secular changes in patient characteristics or care, or a biological effect of lower temperature not detected in recent trials.
Abstract 301: Identifying Critical Care Unit Organizational Factors That Impact Cardiac Arrest Incidence and Outcomes: A Report From the Pediatric Cardiac Critical Care Consortium
Authors: Lasa Javier J , Alten Jeffrey A , Banerjee Mousumi , Zhang Wenying , Schumacher Kurt , Gaies Michael G
Published: June 2021

Introduction:
Patient factors leading to cardiac arrest (CA) in the pediatric cardiac critical care unit (CICU) are well understood, but may be unmodifiable. Our understanding of the impact of CICU organizational factors (OFs) such as staffing models, health care provider education, and CICU bed management is limited. The association between these potentially modifiable CICU OFs on CA prevention and rescue outcomes is unknown.

Hypothesis:
CICU OFs associate with CA prevention and rescue.

Methods:
Retrospective analysis of Pediatric Cardiac Critical Care Consortium (PC4) clinical registry including data for all patients admitted to CICUs from August 2014 to March 2019. Prevention was defined as the prevalence of subjects not suffering CA. Rescue was defined as survival after CA. CICU OFs were captured via questionnaire distributed to PC4 participants in 2017 (100% response). Stratified, multivariable regression was used to evaluate associations between OFs and outcome in medical and surgical admission subgroups: competing time-to-events framework (to assess prevention) and multinomial regression (to assess rescue), accounting for clustering of patients within hospitals.

Results:
We analyzed 54,521 CICU admissions (59% surgical, 41% medical) from 29 hospitals with 1398 CA events (2.5%). We studied 12 OFs that varied across centers after accounting for collinearity. For both surgical and medical admissions, lower average daily occupancy (<80%) was associated with better arrest prevention for all admissions, and better rescue in the surgical cohort. Increased proportion of nurses with >2 years experience, increased proportion of nurses with critical care certification, % of full-time intensivists, % of intensivists with critical care training, dedicated respiratory therapists, quality/safety resources, and annual CICU admission volume were not associated with improved prevention or rescue.

Conclusion:
Our multi-institutional analysis suggests that lower average CICU occupancy was the only consistent OF evaluated that was associated with CA prevention and rescue. CICUs that have average daily occupancy >80% may need specific strategies to mitigate the risks of CA.
Abstract 31: Low versus High Blood Pressure Targets After Out-Of-Hospital Cardiac Arrest
Authors: Jakkula Pekka , Ameloot Koen , De Deyne Cathy , Dens Jo , Reinikainen Matti , Pettilä Ville , Hästbacka Johanna , Skrifvars Markus
Published: June 2021

Introduction:
The optimal level of blood pressure after out-of-hospital cardiac arrest (OHCA) is unknown. Hypotension may aggravate cerebral hypoperfusion exacerbating the post-anoxic brain injury. On the other hand, excessive vasopressor support may increase myocardial oxygen consumption and induce arrhythmias. We aimed to evaluate the effects of different blood pressure targets on the extent of brain injury and neurological outcome in patients resuscitated from OHCA.

Methods:
We performed a pooled
post hoc
analysis of OHCA patients randomised in the Neuroprotect (NCT02541591) and COMACARE (NCT02698917) trials to either mean arterial pressure (MAP) 65 mmHg or 80/85-100 mmHg targets for the first 36 h after ICU admission. We compared the serum neuron-specific enolase (NSE) concentrations between the groups at 24, 48 and 72 h after cardiac arrest and the neurological outcome according to the Cereberal Performance Category (CPC) scale at 6 months. We defined CPC 1-2 as good outcome and CPC 3-5 as poor outcome. In addition, we conducted a two-way analysis of variance to assess the effects of the MAP target and previous chronic hypertension on NSE concentrations.

Results:
All 224 patients included in the original studies were included in the analysis. Of these, 111 patients were randomised to the MAP 80/85-100 mmHg group and 113 patients to the MAP 65 mmHg group. Patients assigned to the higher MAP target had significantly higher blood pressure levels (p<0.001). We did not find any statistically significant difference in NSE concentrations (Figure 1) or good neurological outcome (50% in the lower MAP group vs. 56% in the higher MAP group, p=0.417) between the intervention groups. We did not observe statistically significant interaction between the MAP target and chronic hypertension for NSE (p=0.437).

Conclusion:
Targeting MAP 65 mmHg vs. MAP 80/85-100 mmHg after OHCA did not affect the extent of brain injury as determined by NSE concentration or neurological outcome at 6 months.