bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 21: Effects of the Selective NLRP3-Inflammasome Inhibitor MCC950 on Post-Resuscitation Myocardial and Cerebral Function in a Rat Model of Cardiopulmonary Resuscitation
Authors: Zheng Guanghui , Xu Jing , He Fenglian , Hu Juntao , Ge Weiwei , Ji Xianfei , Bradley Jennifer , Peberdy Mary Ann A , Ornato Joseph P , Jiang Longyuan , Wang Tong , Toldo Stefano , Tang Wanchun
Published: June 2021

Introduction:
NLRP3 inflammasome mediated pyroptosis has been demonstrated to increase myocardial and cerebral ischemia/reperfusion injury. MCC950 is a newly developed highly selective inhibitor of the NLRP3 inflammasome.

Hypothesis:
MCC950 administered following resuscitation will reduce the severity of post-resuscitation myocardial and cerebral dysfunction and improve duration of survival in a rat model of CPR.

Methods:
15 male Sprague-Dawley rats weighting between 450-550 g were randomized into three groups: 1) MCC950 2) Control 3) Sham. Ventricular fibrillation (VF) was induced and untreated for 6 min. CPR was then initiated and continued for 8 min. Resuscitation was attempted with a 4 J defibrillation. Either MCC950 (10mg/kg) or vehicle was administered intraperitoneal (IP) in line with cardiac injury animal studies immediately after return of spontaneous circulation (ROSC). Sham underwent the same surgical procedure without VF and CPR. Sublingual microcirculation was measured at baseline (BL), 3, 6 and 48 hrs after ROSC. Ejection fraction (EF) was measured at BL, 1, 3, 6 and 48 hrs after ROSC. Neurologic Deficit Score (NDS) was recorded at 48 hrs after resuscitation.

Results:
Post-resuscitation ejection fraction and perfused sublingual vessel density were greater in MCC950 compared to control (p<0.05). NDS was also improved in MCC950 compared to control (110 vs 425, p<0.05). Survival at 48 hrs after ROSC was greater in MCC950 (4/5 vs 1/5, p<0.05).

Conclusion:
Administration of MCC950 following ROSC mitigates post-resuscitation myocardial and cerebral dysfunction, improves sublingual microcirculation and duration of survival in a rat model of CPR.
Abstract 216: Therapeutic Hypothermia Alone and in Combination With Preconditioning Improves Long Term Survival During Resuscitation of Hemorrhagic Shock
Authors: Dai Wangde , Shi Jianru , Carreno Juan , Kloner Robert A
Published: June 2021

Background:
We investigated the effects of hypothermia treatment alone and in combination with experimental bilateral lower limb remote ischemic preconditioning (RIPC) in rats undergoing experimental hemorrhagic shock. Previously we showed that RIPC alone improved survival.

Methods:
In the hypothermia alone study, adult Sprague Dawley rats (both genders) were randomized to hypothermia (n=16) or control group (n=15); in a combination study, rats were randomized to hypothermia plus RIPC (n=11) or control group (n=10). Rats were anesthetized with intraperitoneal ketamine/xylazine. Therapeutic hypothermia (Thermosuit) was started at 5 minutes after mean blood pressure (MBP) reached 30 mmHg. Core temperature was maintained at ~ 32 °C until blood volume was fully restored. RIPC was induced by 4 cycles of inflating small bilateral pressure cuffs to 200 mmHg around the femoral arteries for 5 minutes, followed by 5 minute deflation of the cuffs prior to hemorrhagic shock. In the control group, body temperature was maintained at 37 °C during the procedure. Hemorrhagic shock was induced by withdrawing blood from the carotid artery. Target mean blood pressure of 30 mmHg was maintained for 30 minutes followed by reinfusion of shed blood within the next 30 min. Rats were allowed recovery and the primary endpoint was survival rate at 6 weeks.

Results:
In the setting of hypothermia alone, 4 of 15 (26.7 %) rats in the control group and 11 of 16 (68.8 %; p = 0.032) rats in the hypothermia group survived at 6 weeks. In the combination study, 1 of 10 (10 %) rats in the control group and 7 of 11 (63.6 %; p = 0.024) rats in the hypothermia plus RIPC group survived at 6 weeks. Kaplan Meier Survival Curves are shown in Fig1.

Conclusions:
Hypothermia alone and combination with RIPC significantly improved long term survival in rats subjected to hemorrhagic shock. Hypothermia and RIPC did not show survival rates greater than hypothermia alone.
Abstract 218: Therapeutic Hypothermia Alone and Combination With Preconditioning Blunt Inflammation in Experimental Hemorrhagic Shock
Authors: Shi Jianru , Dai Wangde , Carreno Juan , Hale Sharon L , Kloner Robert A
Published: June 2021

Background:
Recent studies by our group indicate that preconditioning, therapeutic hypothermia (TH) and TH combined with preconditioning improved long-term survival during resuscitation of hemorrhagic shock. The neutrophil-to-lymphocyte ratio (NLR) is a marker of inflammation associated with increased mortality in patients with severe hemorrhage shock. The aim of this study is to evaluate the effects of these three therapies on NLR level in rats with acute hemorrhagic shock.

Methods and Results:
In the preconditioning study, Sprague Dawley rats (both genders) were randomized to preconditioning (n=26) or control group (n=27); in the hypothermia study, rats were randomized to TH (n=16) or control group (n=15); in a combination study, rats were randomized to TH plus preconditioning (n=11) or control group (n=10). Rats were anesthetized with intraperitoneal Ketamine and xylazine. After heparinizing, hemorrhagic shock was induced by withdrawing blood to a fixed mean blood pressure (MBP) of 30 mmHg for 30 minutes and then shed blood was reinfused. Preconditioning was induced by 4 cycles of inflating small cuffs around the femoral arteries to 200 mmHg for 5 minutes, followed by 5-minute deflation of the cuffs prior to hemorrhagic shock. TH started at 5 minutes after MBP reached 30 mmHg. Core temperature was maintained at ~32 °C until blood volume was fully restored. In the control group, body temperature was maintained at ~ 37°C. Arterial blood samples were collected 1 hour after resuscitation. The NLR is an easily accessible biomarker, which is calculated by dividing the absolute neutrophil count by the absolute lymphocyte count. The NLR was significantly lower in TH group (0.20 ± 0.02) compared with the control group (0.32 ± 0.03; p=0.003). Similarly, the NLR level was significantly decreased in TH plus preconditioning group (0.19 ± 0.02) versus the control group (0.33 ± 0.02; p= 0.001). There was no difference in NLR level between the preconditioning group (0.41 ± 0.04) and the control group (0.41 ± 0.04; p=0.984).

Conclusions:
NLR is widely recognized inflammation marker associated with poor prognosis in severe hemorrhagic shock. TH alone and TH combined with preconditioning blunt the inflammation by decreasing the NLR level in experimental hemorrhagic shock.
Abstract 226: Increasing Accidental Death in Elderly, Drawing in Bathtub and Foreign Body Airway Obstruction, Should Be Prevent in Japan
Authors: Hanada Hiroyuki , Ito Katsuhiro , Yaguchi Shinya , Ishizawa Yoshiya , Kita Kaoru , Saito Kyoji , Sato Yuta
Published: June 2021

Background:
Japan is facing upcoming unprecedented population problems, proportion of elderly person is increasing year by year. It is expected that 1 in 2.5 people will be 65 years old and over, and 1 in 4 will be 75 years old and over by 2060. All Japan Utstein style registry of out of hospital cardiac arrest (OHCA) from 2005 to 2014 showed that the percentage of patients with OHCA aged 80 years old and more were increasing from 37.1% in 2005 to 47.8% in 2014 by 1% each year. Although cardiogenic cardiac arrests were more frequent than non-cardiogenic, there are specific problems of non-cardiogenic arrests in Japan.

Methods:
Data analysis using All Japan Utstein style registry from 2005 to 2014, and mortality statistics from Ministry of Health, Labor and Welfare Japan.

Results:
During 2014 in an age group 80 years old and more, this Utstein style registry reported that 885 OHCA by traffic accidents and 3594 OHCA by drowning happened, and Ministry of Health, Labor and Welfare Japan reported that 6470 death by air way obstruction (AWO). Because it is not common for Japanese elder people to swimming and very common to taking hot bathing every day at home, drowning commonly occurs in bathtub. Among all 7915 case of OHCA by drowning in all aged groups, 155 case was reported to be alive with good neurological status at one month after OHCA. Initial shockable cardiac rhythms were reported in 266 out of 7915 cases (3.4%). All of good neurological survivors showed shockable rhythm initially. In an aged group 80 years old and more, only 2 cases survived to be a good neurological status at one month after OHCA by drawing. Because Utstein style registry did not show any details about OHCA by AWO, we could not report initial rhythm nor yes or no of bystander CPR

Conclusion:
As OHCA in bathtub and by AWO could being preventable accidental death, we Japanese should have new campaigns nationwide to prevent.
Abstract 229: What is the Real Incidence of Out-Of-Hospital Cardiac Arrest in Norway
Authors: Tjelmeland Ingvild B , Larsen Morten , Skogvoll Eirik , Kramer-Johansen Jo
Published: June 2021

Purpose of the study:
The Norwegian Cardiac Arrest Registry (NorCAR) is a mandatory national registry of resuscitation attempts that monitors the population incidence, care and outcome for cardiac arrest. Previously, substantial differences in the number of included patients per 100 000 inhabitants were observed in some “atypical” health trusts (HT). It was not known if this is a problem with data collection or reflected genuine population differences. The purpose of this study was to identify all patients that fill NorCAR’s inclusion criteria among these HTs, by imposing consistent methods for data collection.

Materials and methods:
The registry implemented consistent, standardised and rigorous data collection methods including targeted audits in four “atypical” health trusts, two with a high and two with a low reported population incidence. Registrations from January to March 2019 was compared with similar results from 2018.

Results:
In 2018, the observed nationwide annual incidence of out-of-hospital cardiac arrest was 64 per 100 000 inhabitants, varying from 40 to 102. At the four study sites the observed population incidence was stable among HT with high incidence (88 and 110) but apparently increased in the two HTs with previous low incidence after implementation of standardised collection method (from 48 to 56, and 46 to 54).

Conclusions:
The previously “atypical” low incidence probably reflected a problem with data collection. To achieve full coverage of the population, all data collectors need to collect data using the same method with a concise and thorough investigation of ambulance-, air ambulance-, dispatch-, and hospital records. Data collectors need to have a close relationship with ambulance and dispatch, and constant reminders and feedback on reported results are important. Implementing a new method for data collection takes time, and results need to be evaluated over time.
Abstract 249: The Costs and Acute Outcomes Following Pulmonary Vein Isolation for Atrial Fibrillation in Elderly Patients a Comparison Between Cryoballoon and Radiofrequency Ablation
Authors: Chen Chao-Feng
Published: June 2021

Backgroup:
Limited comparative data exist regarding catheter ablation (CA) of atrial fibrillation (AF) using second-generation cryoballoon (CB-2) ablation versus radiofrequency (RF) ablation in elderly patients (>75 years ). This study aims to compare the
costs
and periprocedural outcomes in elderly patients using these two strategies.

Methods:
Elderly patients (>75years) with symptomatic drug-refractory AF were included in the study. Pulmonary vein isolation (PVI) was performed in all patients by CB or RF. The
costs
and periprocedural outcomes of the two strategies are compared using SPSS 22.

Results:
324 elderly patients with symptomatic drug-refractory paroxysmal/short-lasting persistent AF received PVI using RF (n=176) and CB-2 (n=148) from September 2016 to April 2019. The CB-2 was associated with shorter procedure duration and left atrial dwell time (128.9±18.3 vs. 152.8±18.9 minutes, P<0.001; 89.4±18.4 vs. 101.9± 22.2minutes,
P
<0.001), but greater fluoroscopy utilization (24.3±10.9 vs. 19.2±7.5 minutes,
P
<0.001). Periprocedural complications occurred in 3.4% (CB-2) and 9.1% (RF) of patients (P=0.037). There was no significant difference between 2 groups for AF/atrial tachycardia (AT) recurrence until discharge (16.2 vs. 18.7%,
P
= 0.552). The length of stay after ablation was shorter, but the costs were greater in the CB-2 group (
P
<0.001).

Conclusions:
Both CB-2 and RF ablation appear to be safe and effective for AF in elderly patients (>75 years). In addition, CB-2 is associated with shorter procedure time, left atrial dwell time, and length of stay after ablation, as well as lower complication rates, but its costs and fluoroscopy time are greater than those of the RF group.
Abstract 255: A Novel and Accurate Method for Assessing Recoil During CPR Training
Authors: Dantu Ram , Sarma Satyam , Dokendorf Mark , ranasinghearachchilage Ishan , Hearn Samuel , Idris Ahamed H
Published: June 2021

Introduction:
In addition to accurate measurement depth and rate of each compression, accurate measurement of full recoil, after each compression, is mandatory for the CPR training. Permitting complete chest recoil during the decompression phase of CPR is essential for refilling the lungs and for adequate myocardial perfusion. Complete chest recoil is important but not evaluated during CPR training. Currently, the recoil is measured based on the residual force when the rescuer releases the hands. Recent clinical research shows the recoil measurements need to consider the release time, release velocity and release height.

Hypothesis:
With a commercially available smartphone providing real-time feedback (placed on an armband of the subjects), trainees will improve recoil performance using proper release velocity, release time and release height.

Methods:
Using a previously validated smartphone application utilizing the smartphone’s accelerometer, gyroscope and magnetometer, we measured these 3 variables. Total of ten sessions was recorded. Each individual CPR session was recorded in the application (acceleration streams, detected pumps with annotations, and the generated feedback). Audio and visual feedback was provided about the measured depth, rate, and recoil quality. Each session has 30 CPR pumps. The scripted patterns consisted of alternating (recoil on and off) window lengths of either 5 or 10 pumps, and the patterns varied between sessions. Recoil was considered to be good if releases velocity is >= 400mm/sec and release time is <=120ms and release height is >= 2 inches.

Results:
Using the output of a bayesNet classifier on the manually-annotated dataset, 84% true positives (success) was achieved for all the three metrics.

Conclusions:
With guided feedback recoil efficiency improved.
Abstract 257: Ventricular Fibrillation Amplitude Spectral Area to Assess the Myocardial Effect of Hemodynamic and Metabolic Interventions During Cardiac Resuscitation in a Rat Model
Authors: Aiello Salvatore , Lamoureux Lorissa , Baetiong Alvin , Radhakrishnan Jeejabai , Gazmuri Raul J
Published: June 2021

Introduction:
The amplitude spectral area (AMSA) of ventricular fibrillation (VF) has been shown to track the myocardial energy state and to predict the effect of defibrillation. We measured AMSA in a rat model of VF and assessed the effects of α-methylnorepinephrine (α-MNE) - a selective peripheral α
2
-adrenoreceptor agonist - given to increase the coronary perfusion pressure without myocardial β
1
-adrenoceptor stimulation and the effects of zoniporide (ZNP) - an inhibitor of the sodium-hydrogen exchanger isoform-1 - given to protect mitochondrial bioenergetic function from reperfusion injury.

Methods:
VF was electrically induced in 48 rats and left untreated for 8 minutes. Chest compression was then started and defibrillation attempted 8 minutes later. Rats were randomized to receive a 3-mg/kg bolus of ZNP or 0.9% NaCl control (Ctr) before starting chest compression and a 100-μg/kg bolus of α-MNE or 0.9% NaCl control (Ctr) at 2 minutes of chest compression yielding four groups of 12 rats each; ZNP/α-MNE, ZNP/Ctr, Ctr/α-MNE, and Ctr/Ctr.

Results:
AMSA (mV·Hz; mean±SEM) was 34.9±1.5 at minute one after induction of VF and decreased to 2.6±0.2 at minute eight. With chest compression, AMSA gradually increased attaining different levels among groups (p<0.001). At minute seven of chest compression, AMSA was the highest with ZNP/α-MNE (29.9±2.5; p=0.012 vs Ctr/α-MNE and p<0.001 vs Ctr/Ctr) followed by ZNP/Ctr (24.1±2.5; p=0.016 vs Ctr/Ctr), Ctr/α-MNE (18.9±2.3), and Ctr/Ctr (12.9±2.6). Survival at 240 minutes differed among groups (p=0.007) with the highest survival with ZNP/α-MNE. Analysis of the independent effects of the interventions revealed that AMSA at minute seven was significantly higher with ZNP (27.2±2.6 vs 16.2±1.6; p<0.001) but not with α-MNE (22.9±2.1 vs 18.6±2.8; p=1.000). Survival was significantly higher with ZNP (18/24 vs 7/24; p=0.004) but not with α-MNE (12/24 vs 13/24; p=1.000).

Conclusions:
AMSA was the highest when ZNP was combined with α-MNE; a combination that also resulted in the highest 240-minute survival. This effect was primarily linked to ZNP without excluding a positive interaction with α-MNE. Accordingly, AMSA may also serve to assess the myocardial effects of metabolic interventions during cardiac resuscitation.
Abstract 272: Dose Optimization of Early High-Dose Valproic Acid for Neuroprotection After Cardiac Arrest
Authors: Hsu Cindy H , Tiba Mohamad H , McCracken Brendan M , Colmenero Carmen I , Pickell Zachary , Leander Danielle C , Weitzel Anne M , Jinka Tulasi , Cummings Brandon C , Pai Manjunath P , Ward Kevin R , Neumar Robert W
Published: June 2021

Introduction:
High-dose valproic acid (VPA) has been shown to improve the survival and neurologic outcomes in preclinical brain injury models including asphyxial cardiac arrest (CA) in rats. However, its pharmacokinetics, pharmacodynamics, and safety profiles in large animal CA models are unknown.

Hypothesis:
High-dose VPA can be safely administered after return of spontaneous circulation (ROSC) and cross the blood-brain barrier dose-dependently in a swine CA model.

Methods:
After 8 minutes of untreated ventricular fibrillation CA, male Yorkshire swine [43.3 (3.0) kg] were resuscitated for up to 16 minutes until ROSC. They were randomized to receive placebo, 75 mg/kg, 150 mg/kg, or 300 mg/kg VPA as 90-minute intravenous infusion (n=5 per group) beginning 20 minutes after sustained ROSC. Animals were monitored for 2 additional hours after infusion ended and then euthanized. Experimental operators were blinded to the treatments.

Results:
The mean total cardiac arrest duration was 15.0 (1.6) minutes, with no significant differences between groups. At end of infusion, the serum free VPA concentration increased dose dependently, from 139.2 (10.1) mcg/mL [75 mg/kg VPA] to 287.2 (24.6) mcg/mL [150 mg/kg VPA] to 565.6 (36.5) mcg/mL [300 mg/kg VPA] (p<0.05). This corresponded to a dose-dependent decrease in the fraction of serum protein-bound VPA, from 41.8% (1.8) [75 mg/kg VPA] to 23.4% (3.8) [150 mg/kg VPA] to 14.4% (3.8) [300 mg/kg VPA] (p<0.05). Brain total VPA concentrations at end of experiment were 26.1 (3.1) mcg/g [75 mg/kg VPA], 72.5 (18.9) mcg/g [150 mg/kg VPA], and 212.3 (33.4) mcg/g [300 mg/kg VPA] (p<0.05). There was a strong linear correlation between serum free VPA and brain total VPA concentrations (R
2
=0.98). All animals survived until euthanasia, although the 300 mg/kg group required more epinephrine to maintain mean arterial pressure greater than or equal to 80 mmHg and had higher lactic acidosis.

Conclusion:
Brain VPA concentrations correlate strongly with serum free VPA when high-dose intravenous VPA is given after ROSC in a swine CA model. These results provide the foundation for dose-optimization studies of high-dose VPA as a neuroprotective therapy following resuscitation from CA.
Abstract 287: Bimodal Brain Monitoring Using Portable EEG and Cerebral Oximetry During Cardiopulmonary Resuscitation (CPR): A Pilot Study
Authors: Parnia Sam , Roellke Emma , Dupont David , Williams Tori , Tarpey Thaddeus , Qian Yingzhi , Spiegel Rebecca
Published: June 2021

Background:
There is a need to monitor brain resuscitation during CPR. Furthermore, 10% of CA survivors report cognitive activity and 2-3% report consciousness during CPR.

Methods:
Using data from a prospective study (AWARE-II) with bimodal brain monitoring during CPR (EEG, [Massimo] and regional cerebral oxygenation [rSO2 normal 60-80%]) using cerebral oximetry [Nonin]), we sought to identify EEG rhythms, their progression over time, and underlying rSO2 thresholds. Inclusion criteria: In hospital CA, ≥ 18 years. Raw EEG data were captured as images (1/second) during CPR pauses, while rSO2 was captured continuously.

Results:
38 patients were recruited; mean age 69±16 with duration of CPR (10-60 mins). We captured 362 EEG images. 91 (25%) were artifacts. Among the 271 interpretable images, there were 13 EEG rhythms placed into 6 groups based on their association with normal/near normal, seizures, coma, absence of cortical activity as follows: Group 1 (Non-epileptogenic): Theta, Delta, Alpha, Group 2 (Epileptogenic/Spike and Wave): Generalized Rhythmic Delta Activity (GRDA) + Spike (S), Delta + S, Theta + S, Burst Suppression with GRDA + S, Group 3 (Flat-line): Marked Voltage Attenuation (MVA), Group 4 (Coma State): Burst Suppression (w/ GRDA, Delta, and/or Theta), Group 5: GRDA, Group 6: Generalized Periodic Discharges (GPD). MVA/absence of activity was observed throughout CPR time and across all rSO2 ranges. Normal/near normal (non-epileptogenic) including alpha rhythms (which to our knowledge is described for the first time), and epileptogenic rhythms were observed with rSO2>30%

Conclusions:
While unclear whether non-epileptogenic rhythms are associated with transient periods of ROSC, however real-time bimodal brain monitoring provides insights regarding brain resuscitation and its dynamic interaction with patient factors. While ischemia may cause epileptogenic activity, there are periods of normal/near-normal cortical activity despite prolonged CPR >45-60 mins. A minimal threshold of brain oxygen delivery (rSO2>30%) may be required for cortical activity. These data raise questions regarding assumptions of irreversible brain damage with prolonged CPR, as well as the possibility of consciousness and cognitive activity during CPR.
Abstract 294: Different Effect of Bystander CPR According to Dispatcher-Assistance on Neurologic Outcome in Out-Of-Hospital Cardiac Arrest
Authors: Pak Jieun , Kim Tae Han , Kim Min Woo , Kim Jong Hwan , Hong Ki Jeong , Shin Sang Do
Published: June 2021

Introduction:
Bystander CPR is an important prognostic factor for outcome in out-of-hospital cardiac arrest (OHCA). Dispatcher-assisted(DA) CPR program have shown to successfully increase rate of bystander CPR in communities. However DA-CPR is usually targeted for bystanders with no or lower level of CPR training compared to bystanders who are able to perform CPR without dispatcher assistance. We evaluated the effect of bystander CPR separately according to presence of dispatcher assistance on neurologic outcome.

Methods:
Retrospective analysis was performed using nationwide OHCA database from 2014 to 2017. Adult EMS treated OHCA with presumed cardiac origin were enrolled. EMS witnessed arrest and arrest occurred during ambulance transport were excluded. Bystander CPR was classified into 2 groups according to presence of DA-CPR instruction from emergency medical dispatch center. Rate of favorable neurologic outcome (CPC 1 or 2) was compared according to type of bystander CPR. Multivariable logistic regression model was used to estimate effect of bystander CPR type on outcomes.

Results:
Total of 72,314 eligible OHCA were enrolled for final analysis. Proportion of patients with favorable neurologic outcome was highest in bystander CPR without dispatcher assistance. (8.6% for bystander CPR without DA, 5.0% for bystander CPR with DA and 2.9% for no bystander CPR, p<0.01). Bystander CPR with DA was associated with higher chance of good neurological recovery than no bystander CPR, effect on neurologic outcome was significantly different than bystander CPR without DA(adjusted OR with 95% CI (bystander CPR with DA as reference): 0.61[0.55-0.67] for no-bystander CPR , 1.24[1.14–1.36] for bystander CPR without DA)

Conclusion:
Bystander CPR with DA showed positive effect on neurologic outcome compared to no-bystander CPR. However bystander CPR with DA was less effective than bystander CPR performed without dispatcher assistance. To improve quality of bystander CPR with dispatcher assistance, strategy to monitor and give feedback bystander CPR during dispatcher assistance should be developed and implemented in dispatch center.
Abstract 311: Trajectory of Risk-Standardized Survival Rates for In-Hospital Cardiac Arrest
Authors: Qazi Abdul H , Zhou Yunshu , Chan Paul , Girotra Saket
Published: June 2021

Introduction:
Risk-standardized survival rate (RSSR) for in-hospital cardiac arrest (IHCA) has emerged as an important metric to measure and incentivize resuscitation quality at a hospital-level. We examined whether hospital performance on the RSSR metric was generally stable year-over-year.

Methods:
We used data from 81,795 adult patients with an IHCA from 163 hospitals with continuous participation in Get With The Guidelines-Resuscitation from 2012 to 2017. A two-level hierarchical regression model was used to compute RSSRs for 2 time intervals (baseline: 2012-13; follow-up: 2014-17). Hospitals were classified as top-, middle- and bottom-performing if they ranked in the top 25%, middle 50%, and bottom 25% on the RSSR metric during 2012-2013. We examined the trajectory of top, middle, and bottom-performing hospitals’ RSSR during 2014-2017 (follow-up).

Results:
During 2012-2013, 41 hospitals were identified as top-performing (median RSSR 31.9%), 81 as middle-performing (median RSSR 24.9%) and 41 as bottom-performing (median RSSR 18.5%). During 2014-2017, more than 3/4
th
(75.6%) of top-performing hospitals remained in the top 50% and 53.7% remained in the top 25% (Table). In contrast, most (81.5%) bottom-performing hospitals ranked in the bottom 50%, and 56.1% remained in the bottom 25% during 2014-2017. Performance of middle-performing hospitals on the RSSR metric was variable. Importantly, rankings improved by at least 1 quartile (
>
25 percentile points) at 26.8% and by at least 2 quartiles (
>
50 percentile points) at 12.2% bottom-performing hospitals (Table). Likewise, rankings at 31.7% and 19.5% of top-performing hospitals worsened by at least 25 and 50 percentile points during 2014-2017, respectively.

Conclusion:
Hospital performance on RSSR during a baseline period was generally consistent with their performance during follow up. However, percentile rankings changed markedly over time at a small proportion of top- and bottom-performing hospitals.
Abstract 314: The Impact of City-Level Public Health Interventions on Increased Bystander Cardiopulmonary Resuscitation
Authors: Blewer Audrey L , Ho Andrew F , Binte Ahamad Nur Shahidah , White Alexander E , Pek Pin Pin , Ng Yih Yng , Mao Desmond Ren Hao , Tiah Ling , Chia Michael Yih-Chong , Leong Benjamin Sieu-Hon , Cheah Si Oon , Tham Lai Peng , Kua Phek Hui Jade , Arulanandam Shalini , Ostbye Truls , Bosworth Hayden B , Ong Marcus E
Published: June 2021

Introduction:
Bystander cardiopulmonary resuscitation (B-CPR) may increase a victim’s chance of survival from sudden cardiac arrest (SCA), but B-CPR rates are low in many communities. Few studies have examined the association of city-wide public health interventions on B-CPR.

Objectives:
We sought to assess whether there is variation in B-CPR by intervention and location of arrest. We hypothesized that implementation of dispatch-assisted CPR (DA-CPR), CPR/AED training, and a first responder mobile application (myResponder) would increase B-CPR by two-fold.

Methods:
We conducted a retrospective study of adult, non-traumatic SCAs from the Singapore registry (4/2010-12/2016). Interventions included DA-CPR (7/2012 - present), CPR/AED training (04/2014 - present), and myResponder (4/2015 - present). Using logistic regression, we modeled the likelihood of receiving B-CPR by increased number of interventions over time. We examined these effects together, in the home, and public accounting for patient-level confounding.

Results:
From 2010-2016, the Singapore registry contained 12,546 SCA events. Excluding pediatric, EMS witnessed, and healthcare facility arrests, 7,476 were analyzed. Of these, mean age was 66±15 and 68% were male. B-CPR was administered in 45% of the events and varied by location (home: 43% v public: 52%). With implementation of DA-CPR, likelihood of B-CPR increased (OR: 3.5 (2.9-4.2) p<0.01) compared to no intervention; with implementation of CPR/AED training, likelihood of B-CPR increased compared to no intervention (OR: 5.8 (4.8-7.0), p<0.01). Lastly, implementation of myResponder resulted in a 7.09 increased likelihood of B-CPR compared to no intervention (OR: 7.1 (5.9-8.4), p<0.01). Variation was seen when examining likelihood of B-CPR by all interventions compared to no intervention, in the home (OR: 8.7 (7.0-10.7)) and the public (OR: 4.0 (2.9-5.6)). Survival increased, corresponding to the increase in B-CPR.

Conclusion:
City-level public health interventions increased the likelihood of layperson B-CPR, while variation was seen in the home and public. Understanding the impact of public health interventions may shed light on strategies to increase B-CPR and inform targeted initiatives to improve survival from SCA.
Abstract 316: Missing Data and the SOFA Score in Cardiac Arrest Research: A Scoping Review
Authors: Grossestreuer Anne V , Yankama Tuyen , Moskowitz Ari , Ngo Long H , Donnino Michael
Published: June 2021

Introduction:
The Sequential Organ Failure Assessment (SOFA) score is often used as an outcome or exposure in cardiac arrest studies. SOFA requires lab values and vital signs at certain time points which often results in missing data. How this missing data is handled is unknown.

Methods:
We performed a scoping review of PubMed, EMBASE, and Web of Science. English language peer-reviewed manuscripts were included. Titles/abstracts were screened by two independent reviewers to assess if they met inclusion criteria. Studies that met inclusion criteria were retrieved in full; those that did not were excluded. Disagreements between reviewers were resolved by a third reviewer.

Results:
The initial search provided 408 abstracts, 142 underwent full-text review (kappa: 0.91), and 66 were included (5 randomized controlled trials, 26 prospective and 25 retrospective studies). The studies had a median of 151 (IQR: 55, 278) subjects. SOFA was used as an outcome in 36 (55%) and a primary outcome in 10 (15%). Only 27 (41%) studies reported a method to handle missing SOFA data. The most common method was to exclude subjects with missing data (81%). Other methods were use of maximum SOFA while subjects were alive (11%), modified SOFA after excluding subjects who died prior to the timepoint (11%), and earlier and later SOFA to impute values (4%). When SOFA was the primary outcome, 4 (40%) reported a method; 3 (75%) excluded subjects and one (25%) used modified SOFA. Two studies conducted sensitivity analyses to test assumptions used to handle missing SOFA (one imputed values for death/discharge, one adjusted for mortality difference prior to SOFA measurement). Only 9 studies (14%) mentioned quantity of missing SOFA, ranging from 0-76% (median: 10% [IQR: 6%, 42%]). In the 50 studies using SOFA at time points after baseline, only 11 (22%) mentioned mortality prior to SOFA measurement; when mentioned, it ranged from 3%-76% with a median of 12% (IQR: 6%-35%).

Conclusion:
Missing data for SOFA scores used in cardiac arrest studies is pervasive yet often not acknowledged and/or handled with described or consistent methods. These findings illustrate that studies using SOFA may exhibit substantial bias and results could be misinterpreted, particularly if patients with missing data are excluded.
Abstract 32: Chest Compression Fraction Increased When Police Used AED That Analyses Heart Rhythm During CPR
Authors: de Graaf Corina , Beesems Stefanie G , Stickney Ronald E , Chapman Fred W , Koster Rudolph W
Published: June 2021

Introduction:
Conventional automated external defibrillators (AED) prompt rescuers to stop cardiopulmonary resuscitation (CPR) for ECG analysis during cardiac arrest (CA), but pauses in CPR are associated with worse outcome. A new AED algorithm, cprINSIGHT™ Analysis Technology, analyses the ECG while rescuers continue chest compressions.

Hypothesis:
Compared to conventional AEDs, AEDs with the cprINSIGHT algorithm will lead to fewer and shorter interruptions of chest compressions for ECG analysis and, thereby, a higher chest compression fraction (CCF).

Methods:
Amsterdam Police used conventional AEDs in 2016 (LIFEPAK® 1000 defibrillator) and AEDs with cprINSIGHT in 2018 (LIFEPAK CR2 AED); in the CR2 AED, cprINSIGHT is activated after the first conventional analysis. We analysed AED data from control CA cases in 2016 and intervention CA cases in 2018, comparing pre-shock pause, median CCF and CCF categories. CCF was defined as the proportion of time with chest compressions in the period from the start of CPR after analysis 1 to the start of CPR after analysis 2. The CCF analysis included only cases where CPR was provided with a ratio of 30 compressions to 2 ventilations.

Results:
Data from 111 control and 87 intervention cases were analysed. The initial recorded rhythm was shockable in 42 control cases (38%) and 36 intervention cases (41%). Rhythm during analysis 2 was shockable in 28/103 (27%) control and 19/80 (24%) intervention cases; 15 cases had no second analysis. In 67/80 (84%) intervention cases, analysis 2 reached a decision without prompting for a CPR pause. Intervention cases had a significantly shorter pre-shock pause than control cases (7 sec vs 22 sec, p < 0.001) and significantly higher median CCF (87% vs 77%, P<0.001). CCF was ≥90% in 38% of intervention cases and 10% of control cases (figure).

Conclusion:
The use of the cprINSIGHT algorithm in AEDs leads to a shorter pre-shock pause, fewer analysis pauses and an increase in CCF compared to conventional AEDs.
Abstract 321: Pediatric Transfusion Score Predicts Transfusion Requirements for Children With Trauma
Authors: Komori Akira , Abe Toshikazu , Deshpande Gautam A , Aoki Makoto , Naito Toshio
Published: June 2021

Introduction:
Trauma is a leading cause of death in young populations. Transfusion is often a key life-saving element in cases of children with trauma. Nonetheless, clinicians may hesitate to use transfusion in children given the risks of complications.

Hypothesis:
A pediatric transfusion score can accurately predict 24-hour transfusion requirement in pediatric trauma patients.

Methods:
This is a retrospective cohort study using a nationwide registry of trauma patients (Japan Trauma Data Bank). All patients under 16 years of age with blunt or penetrating trauma between 2004 and 2015 were included. A pediatric transfusion score was developed based on previous literature and clinical relevance. One point was given for each of the following criteria: systolic blood pressure ≤ 90 mmHg; heart rate ≥ 120/min; Glasgow Coma Scale (GCS) < 15; and positive result on focused assessment with sonography for trauma (FAST) scan. For sensitivity analysis, age-adjusted pediatric transfusion score was also developed using cut off points for different age categories (infant, toddler, preschool age, school age, and adolescent).

Results:
Of the eligible 5,976 pediatric trauma patients, 550 patients had transfusion within 24 hours after trauma. In-hospital mortality rate was 2.6% (146/5,647). Transfusion increased from 7.7% (113/315) to 35.9% (437/5,661) in those with systolic blood pressure ≤ 90 mmHg (1 point); from 6.2% (280/4,526) to 18.6% (270/1,450) for heart rate ≥ 120/min (1 point); from 4.1% (113/3,220) to 15.1% (417/2,756) for altered mental status with GCS < 15 (1 point); and from 7.5% (403/5,404) to 25.7% (147/572) for FAST positivity (1 point). Pediatric transfusion scores of 0, 1, 2, 3, and 4 points were associated with transfusion rates of 2.2% (48/2,223), 7.5% (199/2,638), 20.3% (187/919), 53.9% (90/167), and 89.7% (26/29), respectively. The area under the curve (AUC) was 0.77 (95% CI, 0.75-0.79). For those without isolate head injury, it was 0.77 (95% CI, 0.75-0.80). After age adjustment, AUC was 0.76 (95% CI, 0.74-0.78).

Conclusions:
The pediatric transfusion score using vital signs and FAST may be helpful in predicting transfusion requirements within 24 hours for children with trauma.
Abstract 325: Characteristics and Outcomes of Hanging Induced Out-Of-Hospital Cardiac Arrest: Insights From the Paris Sudden Death Expertise Center Registry
Authors: Gille Arnaud , Chocron Richard , Ozguler Anna , JOUVEN Xavier , Cariou Alain , Dumas Florence , Marijon Eloi , Bougouin Wulfran , adnet frederic , jost daniel , Lamhaut Lionel , Lecarpentier Eric , Baer Michel , Groizard Charles , Loeb Thomas ,   Paris SDEC Investigators
Published: June 2021

Introduction:
Hanging-induced Out-of-Hospital cardiac arrest (OHCA) is poorly studied and a better understanding of these specific OHCA could be helpful to improve patients’ outcome. The main objective of our study was to describe characteristics and outcomes in patients who had OHCA from hanging injuries.

Methods:
From May 2011 to December 2017 we analyzed a prospectively collected Utstein database for all OHCA adults. All cases due to hanging were included. Utstein style variables were compared for 2 groups of patients: those with a Return of Spontaneous Circulation (ROSC) and those without (non-ROSC). Continuous data are described as means (extremes).

Results:
Among 25 055 OHCA, 500 patients were included. They were 49 (18-100) years old. Seventy-three (14.6%) hanging were witnessed and 58 (11.6%) benefited from a bystander cardiopulmonary resuscitation before Emergency Medical Service (EMS) arrival. No-flow duration was 29.1 (4-180) minutes. Advance life support was initiated by EMS in 299 (59.8%) cases. Low-flow duration was 23.8 (2-79) minutes. Nine patients (1.8%) had a shockable initial rhythm. We observed 83 (16.6%) ROSC. Four (0.8%) patients were discharged alive from hospital. They were all CPC 1.

Table 1 compares characteristics with significant differences between ROSC and non-ROSC groups.

Conclusion:
As expected, younger age, short no-flow and low-flow durations and shockable rhythm on EMS arrival were significantly associated with ROSC. Overall prognosis is dramatically poor when OHCA is due to hanging (<1%), with a very low proportion of shockable rhythm, even if the rare survivors have an excellent CPC at discharge. Indeed, the best method to reduce the mortality rate of hanging is, with no contest, the prevention of suicidal act.
Abstract 326: Prehospital Use of Nasal Cannula End-Tidal CO
2
Monitoring in Non-Intubated Major Traumatic Brain Injury Patients
Authors: Spaite Daniel W , Barnhart Bruce J , Helfenbein Eric , Jorgenson Dawn , Babaeizadeh Saeed , Gaither Joshua B , Rice Amber D , Keim Samuel M , Hu Chengcheng
Published: June 2021

Objective:
Little is known about End-Tidal CO

2

monitoring using nasal cannula sensors (NC-CO

2

) in non-intubated patients.

Objective:
To describe the patterns of NC-CO

2

seen during the EMS care of spontaneously breathing major Traumatic Brain Injury (TBI) patients.

Methods:
Continuous NC-CO

2

data (Philips MRx™ monitors) were evaluated from non-intubated, major (moderate, severe, critical) TBI cases (4/13-5/17) in the EPIC TBI Study (NIH 1R01NS071049). Descriptive statistics were used to evaluate case and NC-CO

2

attributes.

Results:
Included were 92 cases [median age = 50 (range 10-91; 66% male)]. Median respiratory rate (RR) was >15/min in 87% of cases and >20/min in 53%. The highest median RR was 39. Sixteen cases (17%) had a median NC-CO

2

<20 mmHg, 37% (34) were 20-29, 18% (17) were 30-34, 25% (23) were 35-45. Two cases (2%) were 45-50, which has not been noted in this population previously. No case had a median NC-CO

2

>50. Several common NC-CO

2

patterns emerged: 1) while the final level varied among patients, the vast majority of cases (79, 86%) attained a stable “plateau” with relatively small variation after that point; 2) ETCO

2

often “ramped up” from <10mmHg to the plateau during the initial few seconds of monitoring (36; 39%); 3) many patients (40; 43%) had near-normal (30-34 mmHg) or even normal (35-45) ETCO

2

plateaus. In 78% of the cases with normal CO

2

plateaus (35-45mmHg), these levels were maintained despite high RR and/or dramatic variations in RR.

Conclusions:
This initial work identifies that NC-CO

2

monitoring may provide useful information in non-intubated EMS patients. After initial “ramp up,” the vast majority achieved stable readings despite dramatic RR variations. Most patients (53%) were spontaneously hyperventilating at rates more than twice “normal.” Despite this, almost half of them (43%) had ETCO

2

plateaus that were normal/near normal throughout their course. It is unclear whether the “very low” readings (<30mmHg) represent true physiological hypocapnia or simply “washout” due to the sensors being in an open ventilatory space (the naris) with continuous ambient O

2

flow. Future studies comparing NC-CO

2

to measured arterial pCO

2

are needed to identify the correlation and accuracy of NC-CO

2

as a tool for evaluating ventilatory physiology.
Abstract 335: Predicting Pulse Status From the ECG Signal Without Interrupting CPR
Authors: Kwok Heemun , Bhandari Shiv , Blackwood Jennifer E , Coult Jason , Kudenchuk Peter , Rea Thomas
Published: June 2021

Objective:
Currently, cardiac arrest resuscitation requires interruptions in CPR every 2 minutes to assess cardiac rhythm and pulse. A method which analyzed the ECG during CPR to predict whether or not an organized rhythm generated a pulse could help to direct care and limit CPR interruptions. We evaluated a real-time method to predict pulse status from organized rhythm ECG segments with and without CPR.

Methods:
The study cohort received attempted resuscitation by a metropolitan EMS system following out-of-hospital ventricular fibrillation arrest. Two-minute rhythm/pulse checks on the continuous defibrillator recordings were annotated for CPR, rhythm, and pulse status using the ECG, impedance, and accelerometer signals, the audio recording, and EMS record. Pulse was defined by the presence of a palpable pulse by EMS. Paired ECG segments with and without CPR were extracted at each rhythm/pulse check. Using organized rhythm segments from one-third of cases for training, we developed four ECG features using wavelet analysis (median power values in three frequency bands and QRS rate) and a logistic model to predict pulse status. Predictive performances of each ECG feature and the logistic model were measured by AUC in the remaining validation cases with and without CPR.

Results:
There were 238 cases and 911 paired segments with a median of 3 (IQR 2,5) paired segments per case. Among 319 organized rhythm segments in the validation set, AUC for pulse prediction ranged from 0.67 to 0.79 for the individual ECG features (Figure). The logistic model was more predictive than any individual feature (AUC 0.84, 95% CI 0.80-0.89, p < 0.05 for each comparison). The model predicted pulse similarly regardless of CPR activity (p = 0.2).

Conclusion:
ECG features extracted by wavelet analysis were predictive of pulse status among organized rhythm segments with and without ongoing CPR. Further study is required to understand how pulse prediction could guide rescuer actions in real-time.
Abstract 343: Chest Compression Compliance With Guidelines Declines Over the Course of Rescues
Authors: Russell James K , González Otero Digna , Ruiz de Gauna Sofia , Leturiondo Mikel , Ruiz Jesus M , DAYA Mohamud R
Published: June 2021

Introduction:
CPR guidelines recommend limits for rate and depth, and release (avoidance of leaning). Simultaneous compliance with all three recommendations is challenging, sustained compliance more so.

Hypothesis:
Compliance with rate, depth and release guidelines is limited, and will decline over the course of rescues.

Methods:
Acceleration and force signals were extracted from monitor/defibrillators equipped with CPR monitors in 248 adult cases of manual CPR during out-of-hospital resuscitations treated by Tualatin Valley Fire & Rescue (TVF&R, Tigard, OR) during 2016 and 2017. TVF&R personnel delivered continuous compression CPR with real-time feedback available for rate, depth and leaning. Depth was calculated from acceleration. Peak depth, release force, and rate were measured for each compression. Release with force exceeding 2.5 kg-f was counted as incomplete (leaning).

Results:
Cases included 1802 (1055-2683) (median, IQR) compressions (total 481,407 compressions). Compliance with all three recommendations was 25% initially, declining to 19% for the ends of the longest rescues (> 3000 compressions from 48 cases). Depth compliance and complete release varied relatively little (31-36%, 93-95% respectively) and irregularly over the course of resuscitation. Early, 45% of compressions were too shallow (< 50 mm), and 21% were too deep (> 60 mm). Depth exceptions shifted over the course of resuscitation (to 36%, 28% respectively). Rate compliance declined from 73% to 54%. Rates below 100 cpm were 9% initially, declining to 5%. Rates exceeding 120 cpm were 18% early on, but climbed to 41% towards the end of long resuscitations, accounting for most of the decline in compliance with guidelines.

Conclusions:
Compliance with all 3 recommendations for CPR compressions is challenging, and becomes more so as the chest changes in response to compressions. Most problematic is a steady increase in compression rates above 120 cpm.
Abstract 345: Forecasting the Number of Out-Of-Hospital Cardiac Arrest in the Young Using Generalized Additive Model
Authors: Vermeulen Alyssa , Del Rios Marina , Campbell Teri L , Nguyen Hai , Nguyen Hoang H
Published: June 2021

Introduction:
Accurate forecasting could help in resource planning and evaluation of intervention efforts to reduce out-of-hospital cardiac arrest.

Hypothesis:
Generalized additive model can rapidly and accurately forecast the number of OHCA in the young (1-35 years old) when compared to other auto regressive moving average (ARIMA) based models.

Methods:
Data were obtained from CARES in Chicago from May 2013 to December 2017. Monthly forecasts of the number of OHCA were performed using a generative additive model framework using the open source software Prophet and R. The first 50 months served as training and the last 6 months served as testing.

Results:
Figure 1
shows the distribution of the number of cases over the 3-year study period showing yearly seasonality and upward trend.
Figure 2
shows the forecast of the number of arrest (middle line) along with the actual number of arrest (dots). The shaded band represents the 95% confidence interval of the prediction.
Figure 3
show the comparison of the 6-month forecast and actual data. This model has low root mean square error score when compared with other ARIMA based models (2 vs. 4).

Conclusion:
Accurate time series forecasting of the number of OHCA arrests could be achieved. Time series analysis and forecasting are essential tools in evaluating the effectiveness of intervention efforts to reduce OHCA as they allow for causality hypothesis testing.