bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 168: Relation Between the Prehospital Administrated Doses of Epinephrine and the Acquisition of Return of Spontaneous Circulation in Patients With Cardiopulmonary Arrest
Authors: Oshima Kiyohiro , Aoki Makoto , Murata Masato , Nakajima Jun , Sawada Yusuke , Isshiki Yuta , Ichikawa Yumi , Fukushima Kazunori , Aramaki Yuto
Published: June 2021

Introduction:
The efficacy of epinephrine (Ep) administration to cardiopulmonary arrest (CPA) patients is still controversial, and correlation between plasma Ep levels of and prognosis in CPA patients is unclear.

Hypothesis:
We hypothesized that the more EP is administered, the higher the rate of ROSC becomes in CPA patients. The purpose of this study is to evaluate whether a dose of Ep influenced the prognosis in CPA patients.

Methods:
This was a prospective, observational clinical study, approved by the ethics committee of Gunma University Hospital (IRB #14-13). CPA patients transferred to our hospital were enrolled prospectively between July 2014 and July 2017. The levels of Ep in the plasma were measured using blood samples immediately obtained at the time of arrival to our hospital. Patients were divided into the four groups based on the prehospital administered dose of EP; patients without prehospital Ep administration (group Z), prehospital administration of 1mg Ep (group O), 2mg Ep (group T) and 4mg Ep (group F). The plasma Ep levels and the conditions of resuscitation were compared among those groups. The IBM SPSS Statistics 25 software was used for statistical analysis. Data are shown as median (Q1, Q3). The Kruskal-Wallis or chi-square tests were used to conduct the comparisons among four groups. P<0.05 denoted statistical significance.

Results:
We analyzed 150 patients. There were 96 patients in group Z, 38 in group O, 11 in group T and 5 in group F. There was no significant difference in prehospital resuscitation time among 4 groups, and the level of Ep in the plasma obtained immediately after arrival at hospital was the highest in the group F with a significant difference {286.0 (247.2, 424.9) ng/ml in group F, 244.0 (22.1, 620.3) ng/ml in group T, 1.6 (0.5, 4.5) ng/ml in group O and 2.0 (0.4, 4.5) ng/ml in group Z, respectively, p<0.001}. However, the ratio of ROSC acquisition was the lowest in the group F with a significant difference (0 in group F, 18.2% in group T, 15.8% in group O and 35.4% in group Z).

Conclusions:
Our results suggest that the prehospital administered dose of Ep is not relates with the acquisition of ROSC in patients with CPA.
Abstract 172: Ultra-Fast Cooling Through Total Liquid Ventilation is Safe and Feasible in Non-Human Primates
Authors: Kohlhauer Matthias , Boissady Emilie , Lidouren Fanny , Faucher Estelle , Nadeau Mathieu , Ghaleh Bijan , Micheau Philippe , Tissier Renaud
Published: June 2021

Introduction:
Total liquid ventilation (TLV) with temperature-controlled perfluorocarbons (PFC) provides ultra-rapid and protective cooling in animal models of cardiac arrest. However, the ideal ventilatory parameters still need to be determined for a perfectly safe translation of the procedure in humans, especially regarding expiratory residual volume (RV) and tidal volume of PFC (TV) during TLV.

Hypothesis:
We hypothetised that TLV with low RV and TV of PFC is safe and efficient for ultra-fast cooling induction in non-human primates.

Method:
We enrolled two 13-years monkeys (
Macaca Fascicularis
) weighting 10.6 and 11.7 kg, respectively. Lung functional residual capacity (FRC) was measured by CT-scan and 3D-reconstruction of the lung. Two weeks later, animals were anesthetised and submitted to 20 min of TLV with end-expiratory volume of ≈50% of the FRC and TV = 8 ml/kg. The respiratory rate was set to 8/min and the target temperature was 33°C. After the TLV procedure, animals were weaned by prolonged exhalation followed by 6 hours under conventional mechanical ventilation (PEEP = 5 mmHg) before awakening. Three weeks later, they were ansthestized again for blood gases measurement and CT-scan examination for evaluation of the lung parenchyma integrity.

Result:
The initial CT-scan revealed a FRC of 26 and 32 ml/kg in the two animals, respectively. RV was then set at 15 ml/kg for TLV in both animals. During TLV, gas exchanges were normal (arterial partial pressure of CO
2
was 34 and 43 mmHg, respectively). Pulse oxymetry also remained above 97% throughout TLV. The target temperature of 33°C was achieved in the entire body within 15 min for both animals. Additionally, lung static compliance was not altered during or after TLV. After animal weaning, no any sign of respiratory discomfort was evidenced despite careful clinical monitoring. After three weeks, CT-scan examination revealed no structural abnormality of the lung parenchym and arterial partial pressure of CO
2
was normal (35 and 46 mmHg). Based on their excellent health status, animals were transferred to a rehabilitation center.

Conclusion:
Total liquid ventilation below FRC is feasible and safe, without any impairement of the cooling performance in a clinically relevant non-human primate model.
Abstract 175: Cerebral and Myocardial Mitochondrial Injury Differ in a Rat Model of Cardiac Arrest
Authors: Ji Xianfei , Bradley Jennifer , Zheng Guanghui , Ge Weiwei , Xu Jing , He Fenglian , Peberdy Mary Ann A , Ornato Joseph P , Chen Qun , Lesnefsky Edward J , Tang Wanchun
Published: June 2021

Introduction:
Neurologic and myocardial dysfunction after successful resuscitation is prominent and mitochondrial dysfunction is predicted to be a key determinant of poor outcomes. Mitochondria contribute a critical role as effectors and targets of reperfusion injury. However, the onset and severity of mitochondrial dysfunction during cardiac arrest (CA) is not fully understood. The present study was done to explore whether changes in cerebral and myocardial mitochondria differ after cardiac arrest and cardiopulmonary resuscitation (CPR).

Hypothesis:
Mitochondrial injury is more severe in the brain compared to the heart during and following cardiac arrest and CPR.

Methods:
Sprague-Dawley rats weighing between 450 - 550 g were randomized into 4 groups (n=6): 1) sham (surgery, no ventricular fibrillation (VF) or CPR), 2) VF (VF 8 mins, no CPR); 3) VF and CPR (VF 8 mins and CPR 8 mins, no defibrillation); ROSC 1 h (VF 8 mins, CPR 8 mins, defibrillation, and observe 1 h after ROSC). VF was induced through a guide wire advanced from the right jugular vein into the right ventricle. Brain and heart mitochondria were extracted by differential centrifugation and used to measure oxidative phosphorylation and calcium retention capacity (CRC).

Results:
Compared with sham, brain mitochondrial CRC in VF, VF+CPR and ROSC 1 h were decreased (110±11 vs. 70±13, 62±24, 50±6 nmol Ca
2+
/mg protein, p<0.05). However, the CRC of the heart mitochondria was decreased only 1 h after ROSC compared to sham (1000±150 vs. 1000±84, 993±78, 600±76 nmol Ca
2+
/mg protein). Brain mitochondrial oxidative phosphorylation with complex I substrate glutamate in VF, VF+CPR and ROSC 1 h were all decreased compared to sham (127
+
8 vs 92±17, 84±12, and 92±15, p<0.05). This contrasted myocardial mitochondria oxidative phosphorylation which had no impairment (324±3 vs 338±46, 379±29, and 323±45).

Conclusions:
Mitochondria in the brain are more sensitive to injury during CA and CPR compared to heart mitochondria. With markedly decreased CRC, mitochondria are likely to contribute to cerebral reperfusion injury during CPR and ROSC. Preservation of cerebral mitochondrial activity and mitochondrial function during cardiac arrest may improve post-resuscitation neurological function.
Abstract 176: Genetic Ablation of Cyclophilin-D in Mice Increases Physical and Cognitive Performance During Hypoxia
Authors: Radhakrishnan Jeejabai , Baetiong Alvin , Kaufman Harrison , Huynh Michelle , Leschinsky Angela , Gazmuri Raul J
Published: June 2021

Introduction:
We previously reported that silencing of the mitochondrial peptidyl-prolyl isomerase Cyclophilin-D (Cyp-D) in HEK 293T cells reduces oxygen consumption (VO
2
).
In vivo
Cyp-D ablation using constitutive Cyp-D knockout (KO) mice also reduced VO
2
while paradoxically increased exercise endurance, thus demonstrating increased oxygen utilization efficiency. Therefore, we hypothesized that Cyp-D KO mice will display improved physical and cognitive performance during hypoxic conditions.

Methods:
Two groups of 9 mice each, age and gender-matched, representing wild-type (WT) and Cyp-D KO were subjected to treadmill running first under normobaric normoxic conditions (20.9% O
2
, simulating ground level O
2
levels), and the next day under normobaric hypoxic conditions (8% O
2
simulating 7,600 meters altitude O
2
levels). Total running time and distance, V
max
, and work performed were measured. A separate set of 9 mice each (Cyp-D KO and WT), were subjected to behavioral assessments; a pole test to assess motor function and an elevated plus-maze test to assess anxiety levels. The tests were conducted first under normoxia and then under hypoxia.

Results:
Cyp-D KO mice exposed to 8% O
2
displayed increased treadmill work (12±1
vs
8±1 Joules;
p
=0.02) demonstrating increased exercise capacity, shorter pole-climbing time (21±3
vs
37±4 sec;
p
=0.006) demonstrating increased agility and cognitive function, and increased elevated plus-maze open arm time (91±31
vs
23±12 sec;
p
=0.046) demonstrating anti-anxiety like behavior.

Conclusions:
Cyp-D KO mice demonstrated increased exercise capacity, improved motor function, decreased anxiety, and improved cognitive function under hypoxia. Thus, targeting Cyp-D and modulating its activity may impact several acute and chronic conditions in which oxygen availability is limited. The increased cognitive performance could be helpful when working at low environmental O
2
levels (e.g., high-altitude, underground caves, etc.).
Abstract 179: Effects of Necrosulfonamide on Post-Resuscitation Survival and Neurological Function in a Rat Model of Cardiac Arrest
Authors: He Fenglian , Zheng Guanghui , Hu Juntao , Ge Weiwei , Ji Xianfei , Xu Jing , Moore Christine , Bradley Jennifer , Peberdy Mary Ann A , Ornato Joseph P , Tang Wanchun
Published: June 2021

Introduction:
Gasdermin D (GSDMD), a previously unknown protein, serves as a key effector in pyroptosis and its inhibition has protective effects during cerebral ischemia and reperfusion. Necrosulfonamide (NSA) specifically blocks the mixed lineage kinase domain-like pseudo kinase (MLKL), which directly binds to GSDMD preventing pyroptotic cell death and interleukin-1 (IL-1) release. In this study, we investigated the effects of NSA on survival and neurological function after cardiac arrest and resuscitation.

Hypothesis:
Administration of NSA following cardiopulmonary resuscitation (CPR) will improve survival and neurological function in a rat model of cardiac arrest.

Methods:
Twelve male Sprague-Dawley rats weighting between 450-550g were utilized. Ventricular fibrillation was induced and untreated for 6 min followed by defibrillation after 8 min of CPR. Animals were then randomized into two groups: NSA and control. NSA (10mg/kg) or vehicle was administered 5 minutes after restoration of spontaneous circulation (ROSC) by intraperitoneal injection. Duration of survival and neurological deficit scores were recorded at 24, 48, and 72 hours after ROSC.

Results:
All animals were resuscitated successfully. Duration of survival was significantly longer in the NSA group compared to control (p<0.05, Figure 1). The severity of post-resuscitation cerebral dysfunction was significantly reduced in the NSA group compared to control (p<0.05, Figure 2).

Conclusion:
Administration of NSA after ROSC improves post-resuscitation survival and neurological function in a rat model of cardiac arrest.
Abstract 197: Metabolic Syndrome Severely Alters Major Metabolic Pathways in the Pig Myocardium
Authors: Karimi Maryam , Ziegler Olivia , Feng Jun , Usheva Anny
Published: June 2021

Introduction:
Obesity and metabolic syndrome (MetS) are rapidly expanding worldwide. One of the most concerning implications of this trend is the association between MetS and the increased risk of
cardiovascular disease (CVD)
. There is a little data on cross-talk between metabolomics alterations and myocardial functionality.

Hypothesis:
Because of the pleiotropic nature of CVD and of MetS, it is unlikely that single metabolite or metabolic pathway underlies the development of CVD in MetS. Understanding the global metabolic state of the MS myocardium using high throughput metabolomics and transcriptomics may provide novel insights.

Methods:
Yorkshire swine received obesogenic diet (MetS). Control (LD) animals received regular chow. Tissue samples from identical myocardial left ventricular territories are analyzed by: targeted LC/MS-MS for LV polar metabolites, MetaboAnalyst 4.0; RNA-seq.

Results:
MetS vs LD demonstrates: elevated blood fasting glucose, triglycerides, LDL, cholesterol, blood pressure. LC-MS-MS shows diet impact on 287 metabolites availability in MetS together with altered gene expression of traditional enzymes that are involved in C - glycolysis, fatty acids metabolism, ketone body formation, transport, and utilization.

Conclusions:
Transcriptionally controlled fuel gauge in the MetS heart enzymatically turns down glucose and fatty acids oxidation and activates nutritional ketolysis. This study represents a significant step towards characterizing the metabolic state of the heart in MetS and provides potential avenues for therapeutic advance.
Abstract 207: The Association of Academia With Neurological Outcome Among Out-Of-Cardiac Arrest Patients Who Undergo Extracorporeal Cardio-Pulmonary Resuscitation
Authors: Okada Yohei , Kiguchi Takeyuki , Kitamura Tetsuhisa , Kawamura Takashi , Iwami Taku
Published: June 2021

Background:
Our study aim was to identify the association of acidemia with neurological outcome among the out-of-hospital cardiac arrest patients who undergo extracorporeal cardio-pulmonary resuscitation (E-CPR).

Method:
We analyzed the data from multi-institutional prospective cohort study (CRITICAL study: Comprehensive Registry of Intensive Cares for out-of-hospital cardiac arrest Survival) including 14 emergency departments in Osaka, Japan. We included adult out-of-hospital cardiac arrest patients aged ≥18 years who undergo E-CPR. The exposure of interest was serum pH measured before start to E-CPR on admission, and it was divided to tertiles. The primary outcome was 30-days favorable neurological outcome defined as cerebral performance category 1 or 2. We calculated the adjusted odds ratio (OR) with 95% confidence intervals (CI) using logistic regression model, adjusted by age, sex, witness of collapse, by-stander CPR, cardiac rhythm on hospital arrival, and time to hospital arrival.

Results:
Among 9,822 patients in Critical study database, 303 patients were included in the analysis. The median (interquartile range) of the age was 62 (48-71) years-old. The range of serum pH in each tertile was as below; Tertile 1[ pH≥7.02, (n=101)], Tertile 2 [pH 6.87-7.02, (n=100)], Tertile 3 [pH <6.87, (n=102)]. The adjusted OR with 95%CI of tertile2, and 3 for favorable neurological outcome were 0.23 (0.09 to 0.58), and 0.18 (0.06 to 0.52) referred to Tertile 1, respectively.

Conclusion:
Among the out-of-hospital cardiac arrest patients who undergo E-CPR, severe acidemia (pH < 7.02) on arrival was associated with 30-days poor neurological outcome. Serum pH measurement might be useful to consider the indication of E-CPR.
Abstract 209: Does ECPR for the Younger Patients Who Has Long Downtime Improve Neurological Outcome?
Authors: Ijuin Shinichi , Inoue Akihiko , Igarashi Nobuaki , Matsuyama Shigenari , Kawase Tetsunori , Ishihara Satoshi , Nakayama Shinichi
Published: June 2021

Introduction:
It have reported previously that extracorporeal cardiopulmonary resuscitation (ECPR) for out of hospital cardiac arrest should induct within 45 minutes from collapse. However, We often encounter patients with favorable neurological outcome who had longer time interval from collapse to induction of V-A ECMO (Downtime: DT). We analyzed that relation about neurological outcome and DT for patients undergone ECPR.

Methods:
In this single center retrospective study, from January 2010 to April 2019, we identified 147 patients who underwent ECPR. Of these, 87 patients (59%) had shorter DT (≦45min:Group S), and 60 patients (41%) had longer DT (≧46min:Group L). We compared neurological outcome between two groups. Glasgow-Pittsburgh Cerebral Performance Category (CPC) 1-2 was defined as favorable neurological outcome, CPC3-5 was defined as unfavorable outcome at 3 months. Results were expressed as Median (IQR).

Results:
Patient characteristics were not different between the two groups. DT were 37 min (32-42: Group S) and 57 min (50-64: Group L). 51 % of the patients in Group S (46 patients) were alive at 3 month, as compared with 35% in Group L (21 patients) (p: 0.05). At the 3 month follow up, Group S had a higher rate of favorable neurological outcome than Group L (39% (34 patients) vs 28% (17 patients) (p:0.18 ). In younger patients (≦65y.o), the rate of favorable neurological outcome were roughly equal in each groups (Group S: 41% (20/48 patients) vs 37% (11/30 patients) ) (p:0.51).

Conclusions:
Because it is possible younger patients with cardiac arrest had a favorable neurological outcome, even if they had longer DT, it should consider the expanded adaptation of ECPR.
Abstract 210: Effects of Indication for Veno-Arterial Extracorporeal Membrane Oxygenation on Predictive Value of Save Score
Authors: Kosmopoulos Marinos , Bartos Jason A , Yannopoulos Demetris
Published: June 2021

Introduction:
Veno-Arterial Extracorporeal Membrane Oxygenation (VA ECMO) has emerged as a prominent tool for management of patients with Inability to Wean Off Cardiopulmonary Bypass (IWOCB), extracorporeal cardiopulmonary resuscitation (eCPR) or refractory cardiogenic shock (RCS). The high mortality that is still associated with these diseases urges for the development of reliable prediction models for mortality after cannulation. Survival After VA ECMO (SAVE) Score consists one of the most widely used prediction tools and the only model with external validation. However, its predictive value is still under debate.

Hypothesis:
Whether VA ECMO indication affects the predictive value of SAVE Score.

Methods:
317 patients treated with VA ECMO in a quaternary center (n= 52 for IWOCB, n=179 for eCPR and n=86 for RCS) were retrospectively assessed for differences in SAVE Score and their primary outcomes. The Receiver Operating Characteristic (ROC) curve for SAVE Score and mortality was calculated separately for each VA ECMO indication.

Results:
The three groups had significant differences in SAVE Score (p<0.01) without significant differences in mortality (p=0.176). ROC Curve calculation indicated significant differences in predictive value of SAVE Score for survival among its different indications. (Area Under the Curve= 81.69% for IWOCB, 53.79% for eCPR and 69.46% for RCS).

Conclusion:
VA ECMO indication markedly affects the predictive value of SAVE Score. Prediction of primary outcome in IWOCB patients was reliable. On the contrary, routine application for survival estimation in eCPR patients is not supported from our results.
Abstract 247: Development and Evaluation of Standardized Communication for In-Hospital Resuscitation
Authors: Lauridsen Kasper G , Watanabe Ichiro , Nishisaki Akira , Berg Robert A , Niles Dana E , HUNT Elizabeth A , Duval-arnould Jordan M , Good Grace L , Cheng Adam , Løfgren Bo , Nadkarni Vinay M
Published: June 2021

Background:
Recommendations for “standardized” communication during cardiopulmonary resuscitation (CPR) events to reduce interruptions in chest compressions (CCs) are lacking. We aimed to achieve consensus on standardized communication during in-hospital CPR, evaluate feasibility and potential to decrease CC pauses, mental task load, and frustration.

Methods:
Modified Delphi consensus surveys of International Liaison Committee on Resuscitation taskforce members to identify preferred communication for in-hospital cardiac arrest teams. Consensus was reached after-survey teleconference resolution by a team of interdisciplinary experts in communication and CPR. Feasibility was tested in 8 simulated CPR scenarios with physician team leaders randomized (1:1) to ‘standardized’ communication vs. “usual best practice”, closed loop communication. Team leaders watched a 3-min video and received a 10-min training on the assigned intervention before the CPR scenario. NASA task load index questionnaires were used to assess mental task load and frustration (0=lowest to 100=highest).

Results:
Modified Delphi consensus on standardized communication included: 1) preparing the team 15-30 seconds before interrupting CCs, 2) countdown for interruption synchronized with 5 CCs, 3) action words for stopping and resuming CCs, 4) action words for intubation and defibrillation. Among 8 CPR teams (4 standardized, 4 usual communication), median (Q1; Q3) CC interruption duration for rhythm check was significantly shorter, 5.3 (4.8; 6.8) vs. 9.4 (6.4; 13.0) sec for standardized vs. closed loop communication [p=0.02]. Median (Q1; Q3) scores of mental task load were 63 (33; 70) vs 85 (70; 96), [p=0.10] and frustration 10 (5; 34) vs 40 (26; 50) [p=0.11] for standardized vs. closed loop communication. Trained team leaders adhered to standardized phrases 77% of the time.

Conclusion:
Expert consensus for standardized communication during in-hospital CPR was achieved. Pilot simulation implementation of standardized communication demonstrated feasibility of team leader adherence, significantly decreased duration of CC interruption during rhythm checks, and a tendency to reduce team leader task load and frustration.
Abstract 253: The Efficacy of Left Ventricular versus Traditional Chest Compressions During Selective Aortic Arch Perfusion to Treat Traumatic Cardiopulmonary Arrest in a Swine Model
Authors: Barringer Benjamin , Castaneda Maria , Rall Jason , Anderson Kenton
Published: June 2021

Introduction:
Recent evidence has demonstrated that closed chest compressions (CC) directly over the left ventricle (LV) during traumatic cardiopulmonary arrest (TCPA) improve hemodynamics and return of spontaneous circulation (ROSC) when compared to traditional chest compressions. Selective Aortic Arch Perfusion (SAAP) is also able to improve hemodynamics as well as control hemorrhage during TCPA.

Hypothesis:
We hypothesized that LV compressions would increase ROSC when compared to traditional compressions in an animal model of TCPA where SAAP was being used. We also compared LV and Traditional compressions with SAAP to historical controls that received compressions without SAAP.

Methods:
Transthoracic echo was used to mark the location of the aortic root and the center of the left ventricle on animals (n=24, 12 in each arm) which were randomized to receive chest compressions in one of the two locations. One third of each animal’s blood volume was removed and ventricular fibrillation (VF) was induced to simulate traumatic cardiac arrest. After a period of ten minutes of VF, basic life support (BLS) with mechanical CPR was initiated and performed for ten minutes followed by advanced life support (ALS) and blood transfusion for an additional ten minutes. The SAAP balloon was inflated at minute 6 of BLS. Hemodynamic variables were averaged every two minutes. The same model was used for historical controls (n=26, 13 in each arm) without the use of SAAP, so comparisons were treated as a single study with a factorial design.

Results:
There were no differences in hemodynamic variables, ROSC (p=0.67) or survival (p=0.64) between SAAP groups. However, when the LV animals were compared to historic controls without SAAP, LV animals had higher ROSC (p=0.02) and survival rates (p=0.04) than Traditional animals.

Conclusions:
SAAP does not appear to show a synergistic effect with LV compressions, however, SAAP combined with LV compressions improves ROSC and survival when compared to Traditional compressions in our swine model of TCPA. More investigation into SAAP and compression position should be studied to improve treatment of TCPA.
Abstract 254: Synchronized Chest Compressions for Pseudo-PEA: Proof of Concept and Synching Algorithm
Authors: Marill Keith , Menegazzi James J , Koller Allison C , Sundermann Matthew , Salcido David D
Published: June 2021

Introduction:
Pulseless electrical activity (PEA) is a common rhythm in cardiac arrest with a persistently poor outcome. This report describes our successful development of a synchronized compression device and algorithm to treat PEA with or without intrinsic myocardial contractions.

Methods:
We adapted our previously developed signal-guided CPR system to provide synchronized compressions in a porcine model of cardiac arrest. We describe the first comparison of unsynchronized to synchronized compressions in a single animal as a proof-of-concept. We developed an algorithm to provide optimal synchronized chest compressions regardless of intrinsic heartrate while simultaneously maintaining the chest compression rate within a desired range. We tested the algorithm with computer simulations measuring the proportion of intrinsic and compression beats that were synchronized, and the compression rate and its standard deviation, as a function of intrinsic heartrate and heartrate jitter.

Results:
We demonstrate and compare unsynchronized versus synchronized chest compressions in a single porcine model with an intrinsic rhythm and hypotension. Synchronized, but not unsynchronized, chest compressions were associated with increased blood pressure and coronary perfusion pressure (Figure). Our synchronized chest compression algorithm is able to provide synchronized chest compressions to over 90% of intrinsic beats for most heartrates while maintaining an average compression rate between 95 and 135 BPM with relatively low variability.

Conclusion:
Synchronized chest compression therapy for pulseless electrical rhythms is feasible. A high degree of synchronization can be maintained over a broad range of intrinsic heart rates while maintaining the compression rate within a satisfactory range. Further investigation to assess benefit for treatment of PEA is warranted.
Abstract 256: Active Compression Decompression CPR With 5 Centimeters Lift and an Impedance Threshold Device Significantly Improves All Markers of Cerebral and Cardiovascular Hemodynamics and Blood Flow After 8 Minutes of Standard CPR
Authors: Lick Michael , Berger Paul S , Gould Jeff R , Metzger Anja
Published: June 2021

Introduction:
Active compression decompression (ACD) CPR performed along with the use of an impedance threshold device (ITD) has been shown to improve cerebral and coronary hemodynamics compared to standard CPR (SCPR). In this study, we demonstrate that ACD+ITD provides significant benefits even when initiated after 8 minutes of SCPR as measured by cerebral and cardiovascular perfusion pressures, cerebral oximetry, and blood flow as determined by neutron-activated microsphere analysis.

Methods:
Ventricular fibrillation was induced in 10 female Yorkshire farm pigs (40.6 ± 0.7 kg) and left untreated for 6 minutes. All animals then received 8 minutes of SCPR, followed by ACD+ITD for an additional 6 minutes. CPR was performed at a rate of 100 compressions/minute at a depth of 20% (~ 5 cm) of anteroposterior chest height. During ACD there was also an active lift component of 5cm beyond resting chest position. Microspheres were injected 4 minutes after starting SCPR and 2 minutes after starting ACD+ITD. Millar catheters were placed to measure right atrial, aortic, and intracranial pressures and NIRS was used to assess regional cerebral oxygenation. 3 minute averages obtained prior to the end of each intervention were compared with Student’s t-test and reported as mean ± SEM.

Results:
Mean coronary perfusion pressure and cerebral perfusion pressures were significantly improved during ACD+ITD (p<0.002, Fig 1). ACD+ITD also resulted in a 7% increase in cerebral oxygenation (47 ± 2 vs 50 ± 2%, p<0.001), a 30% increase in cerebral blood flow (0.3 ± 0.1 vs 0.4 ± 0.1ml/min/gm, p<0.004), and a 30% improvement in coronary blood flow (0.6 ± 0.1 vs. 0.9 ± 0.1ml/min/gm, p<0.004).

Conclusion:
This study reveals the significant benefit of ACD+ITD as measured by currently available invasive and non-invasive blood flow measurements following 8 minutes of SCPR. Initiating ACD+ITD earlier can only result in further improvement of these parameters and offer a higher likelihood of survival.
Abstract 267: Injuries Associated With Mechanical Chest Compressions in Patients With Out-Of-Hospital Cardiac Arrest: A Comparison of LUCAS 2 and LUCAS 2 Active Decompression
Authors: Petrovich Polina , Berve Per-Olav , Turowski Gitta Erika , Stray-Pedersen Arne , Kramer-Johansen Jo , Wik Lars
Published: June 2021

Background:
Skeletal injuries (rib or sternum fractures) are common complications after cardiopulmonary resuscitation (CPR). Visceral injuries are also reported. During manual chest compressions, incidence of rib fractures is reported to be 13-97% and sternal fractures 1-43%. Studies on active compression decompression (AD) devices report incidence on rib fractures ranging from 4-87% and sternal fractures 0-93%. The aim of the present study is to describe and compare injury patterns caused by two mechanical, piston-based chest compression devices; LUCAS 2 and LUCAS 2AD in patients with out-of-hospital cardiac arrest.

Method:
In the randomized clinical trial comparing standard LUCAS 2 with LUCAS 2AD, patients who died were eligible for medical or forensic autopsy. The pathologists described injury pattern in each patient focusing on CPR-related injuries, but was blinded for the device used. We used Pearson X
2
test with an alpha level of 0.05 to evaluate our findings.

Results:
Of the 221 patients included between April 2015 and April 2017, 204 patients died of whom 115 were autopsied, LUCAS 2 n=62 and LUCAS 2 AD n=53. Median age was 63 (range: 19-91) and men represented 70%. CPR related rib fractures occurred in 70%, and sternal fractures in 45% of all patients. When comparing LUCAS 2 to LUCAS 2AD we found no difference in incidence of rib fractures (69% vs. 70%; p-value: 0.9) or in sternal fractures (44% vs. 47%; p-value: 0.7). Most frequent non-skeletal complication was bleeding in pleura (25), pericardium (13), mediastinum (7), abdomen (5), and ventricle (3). Many patients had bleedings reported from more than one location, but the amount of blood was mostly small and considered to not contribute to the cause of death. A total of 10 patients had injuries on internal organs such as lungs (6), liver (2), spleen (1), and diaphragm (1).

Conclusion:
Comparing LUCAS 2 with LUCAS 2AD we found no difference in rib- or sternal fractures. CPR related injuries on internal organs were rare. We conclude that LUCAS 2AD do not cause more skeletal or non-skeletal injuries compared to LUCAS 2.
Abstract 285: Analysis of Neurological Prognosis After Cardiac Arrest Patients by Using Cerebral Regional Oxygen Saturation Monitoring
Authors: Tachino Jotaro , Shiozaki Tadahiko , Takegawa Ryosuke , Sakai Tomohiko , Nakao Shunichiro , Ohnishi Mitsuo , Shimazu Takeshi
Published: June 2021

Objective:
To clarify the neurological prognosis of post-resuscitation hypoxic encephalopathy patients on the basis of cerebral autoregulation.

Methods:
We conducted a prospective, observational cohort study of patients admitted to our urban emergency and critical care center in Japan between 2017 and 2019. Cerebral regional oxygen saturation (rSO
2
) was measured in patients with cardiopulmonary arrest on hospital arrival or return of spontaneous circulation (ROSC) before hospital arrival. Included in the analysis were patients aged ≥16 years who were transported to our hospital. Patients dying within 24 h of hospitalization were excluded. Immediately after arrival, the cerebral rSO
2
sensor was attached to the patient’s forehead and continuous monitoring was started. Continuous monitoring of cerebral rSO
2
and mean arterial pressure (MAP) was conducted until extubation or 96 hours after ROSC. We divided the patients into the good neurological prognosis group (cerebral performance category: CPC 1, 2) and poor neurological prognosis group (CPC 3-5) and compared them.

Results:
Among the 37 patients with a mean age (± SD) of 68.9 (± 14.8) years, 12 had a good neurological prognosis and 25 had a poor neurological prognosis. In the good neurological cases, we found that the cerebral rSO
2
value showed biphasic changes followed by a long plateau around the lower limit of the normal rSO
2
range from 12 h after ROSC. However, in the poor neurological prognosis cases, we observed that the cerebral rSO
2
value was unstable. In addition, our data showed that the cerebral rSO
2
values in the good neurological prognosis cases remained almost constant even if MAP changed (Figure).

Conclusions:
We observed the transition of cerebral rSO
2
and its characteristics after resuscitation in cases with good neurological prognosis. Focusing on the cerebral autoregulation may be useful to predict neurological prognosis in post-resuscitation hypoxic encephalopathy.
Abstract 286: Cerebral Microstructure Disruptions are Associated With Poor Neurologic Outcomes in Comatose Cardiac Arrest Patients
Authors: Wu Ona , Rosenthal Eric S , Cudeumus-Deseda Gaston , Mills Brittany , Edlow Brian , Kimberly W. Taylor , Ning Ming Ming , Amorim De Cerqueira Filho Edilberto , Westover M B , Hancock Brandon L , Copen William A , Schaefer Pamela , Giacino Joseph T , Greer David M
Published: June 2021

Background:
For cardiac arrest survivors who are initially comatose after restoration of spontaneous circulation, the extent of brain injury and expected recovery are crucial for management decisions. Advanced diffusion imaging approaches may provide additional insight into microstructural integrity and potential for arousal recovery (AR).

Methods:
Multi-shell diffusion imaging was acquired in a prospective study. Neurite orientation dispersion (OD), intracellular volume fraction (ICVF), free water fraction (ISO), mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) and fractional anisotropy (FA) were calculated (see Figure). Median whole-brain values in patients with AR by discharge were compared with those with no AR and to controls (ANOVA, post-hoc 2-tailed Wilcoxon test). Multivariable backward stepwise logistic regression was performed to predict AR.

Results:
19 patients (mean ±SD 48±23 y, 42% men) and 5 controls (37±19 y, 40% men) were analyzed (10 patients with AR, 9 without). Median [IQR] time-to-MRI was 5 [4-8] days. Patients with no AR had higher AK (P=0.037), and RK (P=.045) than those with AR. Controls exhibited higher FA than either AR (P=.009) or no AR (P=.02), lower MK than no AR (P=.02), lower AK than no AR (P=.02), lower RK than no AR (P=0.02), lower OD than no AR (P=.008), and lower ICVF than no AR (P=.046). AK (P=.049) and ICVF (P=.01) were found in multivariable regression to be significant predictors of AR with 81% area under the receiver operating curve (AUC).

Discussion:
Advanced diffusion imaging metrics, AK and ICVF, were able to predict which patients were likely to regain consciousness, with 81% AUC. Despite the small sample size, we note statistically significant differences using more sensitive measures of microstructural injury compared to more commonly used diffusivity metrics. Further investigation of advanced diffusion imaging methods is warranted.
Abstract 290: Association Between Hourly Call Volume in Emergency Medical Dispatch Center and Dispatcher -Assisted Cardiopulmonary Resuscitation Instruction Time in Out-Of-Hospital Cardiac Arrest
Authors: Kim Jong Hwan , Kim Tae Han , Shin Sang Do , Hong Ki Jeong , Park Jeong Ho , Lee Sun Young , Pak Jieun
Published: June 2021

Objectives:
cardiac arrest recognition, ambulance dispatch and dispatcher assisted CPR by emergency medical dispatch (EMD) is crucial for good outcome of out-of-hospital cardiac arrest (OHCA).In EMD, crowding is caused by mismatch between numerous emergency calls and dispatchers per duty available Crowding in emergency department has been shown to decrease the performance and outcome, however little is known about effect of crowding in EMD. We aimed to evaluate incidence of crowding in emergency medical dispatch center and effect of emergency call crowding on dispatcher assisted CPR instruction performance in OHCA calls.

Methods:
We used nationwide OHCA database from 2013 to 2016, consisted of patients with presumed cardiac origin and dispatched by Seoul EMD. Main exposure was hourly number of total incoming emergency calls to EMD. Number of hourly calls were categorized into quartile (~4o calls, 41~51 calls, 52 ~61 calls and ~62 calls). Primary outcome was successful DA-CPR instruction provision within 120 seconds. Adjusted ratios (AORs) and 95% confidence intervals (CIs) were estimated to evaluate association between EMD crowding and outcome in multivariable logistic regression model.

Results:
Of a total of 12,722 patients, proportion of successful DA instruction were highest in least crowded quartile and lowest in the most crowded quartile (22.7% vs. 15.o% , p<0.01). The adjusted odds ratios is 0.85 (95% CI 0.74 - 0.98) in most crowded EMD quartile with lesser proportion of DA instruction within 120 seconds. Crowding quartile 4 and quartile 3 was associated lesser favorable neurological outcome in multivariable logistic regression model.(adjusted OR(95% CI) 0.78 (0.60-0.99) and 0.70 (0.54- 0.91) respectively) .

Conclusion:
Crowding in emergency medicine dispatch caused by increased hourly call volume was associated with delayed dispatcher assisted CPR instruction provision. Medical directors might consider strategy approach to solve crowding in EMD according to crowding distribution.
Abstract 293: CPR And AED for Layperson Initiative in a Place of Worship
Authors: Haedar Ali
Published: June 2021

Background:
Lack of recognition of cardiac arrest leads to almost 100% of deaths outside the hospital. Therefore, sudden cardiac arrest management in out-of-hospital setting by laypeople is paramount. Early implementation of high-quality cardiopulmonary resuscitation (CPR) and the use of Automated Eternal Defibrillator (AED) have significantly improved chances of survival. Anyone can save lives and reduce sequelae in sudden cardiac arrest situations if they have the ability to perform CPR and use AED. Nonetheless, laypeople’s knowledge of CPR and AED has been little investigated in Indonesia.

Method:
This study is aimed to explore laypeople’s knowledge, possible barriers and interest regarding CPR-AED. This 2-hour CPR-AED for layperson certification course, comprises instructional presentation and video demo followed by a hands-on practice sequence on how to call EMS 119, perform hands-only CPR, and use an AED. As we conducted in a church, they would understand how important it is to be prepared for every situation that might arise. We collected questionnaires received from laypersons attending CPR and AED training course.

Result:
Of 105 worshippers, only 57 were willing to take the class after Sunday service; 27 (47.37%) were male and 30 (52.63%) were female. The age was ranged from 18 to 76, with average of 49 years old. Less than one tenth of the respondents (n = 51, 89.47%) had never attended a CPR-AED course before. Nearly the whole sample considered the knowledge of CPR-AED important, most of the respondents (n=55, 96.49%) showed a willingness to perform CPR and 54 (94.74%) for AED. The average of correct answers was 80.35%. This value was higher among subjects with higher level of education (85.24%) and lesser among those who reported previous training in CPR-AED (76.67% ± 17.8%).

Discussion:
Laypeople recognized their role in the immediate care given to victims of sudden cardiac arrest situations and had a positive attitude toward CPR, but previous inadequate knowledge and training were found. Maintaining better knowledge and skills retention, regular and refresher training for community are recommended. Teaching CPR-AED in a place of worship is an effective way to develop readiness of laypeople ready for such emergency situation.
Abstract 310: National Institutes of Health Research Investment for the Leading Causes of Disability-Adjusted Life Years in the United States
Authors: Coute Ryan A , Nathanson Brian , Kurz Michael C , Haas Nathan L , McNally Bryan , Mader Timothy J
Published: June 2021

Background:
Cardiac arrest (CA) is a leading cause of disability-adjusted life years (DALY) in the United States (U.S.). The National Institutes of Health (NIH) does not report annual research funding for CA. Our objective was to calculate and compare the NIH research investment for CA to other leading causes of DALY in the U.S.

Methods:
A search within NIH RePORTER for the year 2016 was performed using the following terms: cardiac arrest, cardiopulmonary resuscitation, heart arrest, circulatory arrest, pulseless electrical activity, ventricular fibrillation, or resuscitation. Grants were individually reviewed and categorized as CA research (yes/no) using predefined criteria and the sum of funding for grants meeting inclusion criteria were tabulated. DALY were calculated as the sum of years of life lost (YLL) and years lived with disability (YLD) using all adult non-traumatic EMS-treated out-of-hospital CA (OHCA) from the CARES database for 2016. Total DALY for the study population were extrapolated to a national level. The leading causes of DALY were obtained from the Global Burden of Disease study. Funding data were extracted from the 2016 NIH Categorical Spending Report. Research funding were compared using U.S. dollars invested per DALY as the outcome measure.

Results:
The search yielded 285 NIH-funded grants, of which 65 (22.8%) were classified as CA research. Total NIH funding for CA research in 2016 was $28.5M. A total of 59,752 cases from CARES met study inclusion criteria for the DALY analysis. The total DALY following adult OHCA in the U.S. were 4,354,192 (YLL 4,350,825; YLD 3,365). Per annual DALY, the NIH invested $284 for diabetes, $89 for stroke, $53 for ischemic heart disease, and $7 for CA research in 2016 (FIGURE).

Conclusion:
The NIH investment into CA research is less than other leading causes of death and disability in the U.S. These results should help inform the debate regarding how to best utilize limited resources to improve public health.
Abstract 320: Statewide Implementation of the Prehospital Traumatic Brain Injury Guidelines in Children: The EPIC4Kids Study
Authors: Spaite Daniel W , Bobrow Bentley , Gaither Joshua B , Keim Samuel M , Barnhart Bruce J , Chikani Vatsal , Denninghoff Kurt , Mullins Terry , Adelson David , Rice Amber D , Viscusi Chad , Hu Chengcheng
Published: June 2021

Introduction:
The EPIC Study implemented the national EMS TBI Guidelines in a massive, statewide initiative (>11,000 providers trained, 133 agencies). While implementation was not associated with improved survival to discharge in moderate or critically-severe TBI in the primary (all-age) study, the adjusted odds of survival doubled in severe TBI and tripled in severe, intubated TBI. We now report the preplanned pediatric subgroup analysis (“EPIC4Kids”-NIH R01NS071049).

Methods:
Multisystem, intention-to-treat study using a before/after controlled design in patients with moderate to critically severe TBI. Interventions: Prevention/treatment of hypoxia, hypotension, and hyperventilation by EMS providers. Inclusion: Age<18; CDC Barell Matrix Type 1; 1/07-6/15. Severity subgroups [Head Region Severity Score (IDC-based AIS equivalent)]: Moderate=1-2; Severe=3-4; Critical=5-6. The pre-implementation (P1) and post-implementation (P3) cohorts were compared using logistic regression (Firth’s approach when comparisons had small event numbers), adjusting for risk factors/confounders.

Results:
Included were 2801 cases [P1=2041 (72.9%), P3=760 (27.1%); median age 11 (IQR 2, 15); 62.9% male]. The all-severity P3 vs P1 cohort analysis yielded adjusted odds (aOR) of 1.16 (95%CI 0.697, 1.92, p=0.57) for survival. In severe TBI (P1=1405, P3=605; 80% of P3 cases), but not moderate or critical TBI, adjusted survival was significantly improved after implementation (Figure; p=0.049). Improvement in survival for those with severe, intubated TBI (P1=174, P3=44) approached significance (Fig; p=0.11).

Conclusion:
In the first controlled study of its kind, implementation of the EMS TBI guidelines was independently associated with a dramatic increase in adjusted survival among children with severe TBI. The aOR for survival was even larger than that of the overall (all-age) EPIC Study and supports widespread implementation of the guidelines in children.
Abstract 330: Intra-Arrest Cardioplegia Prevents the Diastolic Dysfunction Induced by Prolonged VF Arrest
Authors: Allen Jason , Riess Matthias , Bartos Jason
Published: June 2021

Introduction:
There are approximately 400,000 out-of-hospital cardiac arrests annually, including one-third with VT/VF as their initial rhythm. Approximately 60% of VF arrests are refractory to initial resuscitation requiring prolonged CPR and transport to an ECPR center where available. Limiting myocardial injury during this time is critical as it contributes CPR efficiency. The aim of this study was to investigate the effect of cardioplegia on preservation of cardiac function during cardiac arrest.

Hypothesis:
Following induction of VF, the administration of potassium-based cardioplegia will reduce energy utilization and prevent diastolic dysfunction with preservation of contractility following washout of cardioplegia.

Methods:
Hearts were isolated from male Brown Norway rats (n=8) and prepared on a Langendorff apparatus in Krebs solution. Left ventricular pressure was measured throughout the study. Hemodynamics were obtained for 15 min prior to 2 min of rapid pacing to induce VF. After 10 min of VF, cardioplegia was induced with a bolus of 160 μeq potassium. After 10 min, the potassium was washed out and the hearts were reperfused with Krebs-Henseleit solution. Hemodynamics were measured for another 60 min.

Results:
Baseline hemodynamics were similar between the control and cardioplegia groups. Cardioplegic hearts had significantly lower left heart pressures at the end of the VF time compared to control hearts (24 vs. 74 mmHg, p<0.05). Following 60 min of reperfusion and cardioplegia washout, diastolic pressures remained lower in hearts receiving cardioplegia (39 vs 10 mmHg, p<0.05). After 60 min of reperfusion, systolic pressures were the same among the groups, and while rate of contraction and relaxation were numerically faster in hearts receiving cardioplegia, these differences were not significant.

Conclusions:
Potassium cardioplegia, given during ongoing VF arrest, was effective at preventing diastolic dysfunction caused by prolonged ischemia. Washout of the cardioplegia at the time of reperfusion allowed for ROSC and preserved left ventricular relaxation. These studies suggest that the use of cardioplegia in refractory VT/VF arrest may be beneficial in reducing myocardial damage and preserving function during prolonged CPR.