bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 02: Association Between Hospital Volume of Cardiopulmonary Resuscitation for In-Hospital Cardiac Arrest and Survival to Hospital Discharge
Authors: Akintoye Emmanuel O , Tomo Ando , Adegbala Oluwole , Alade Adedotun , Briasoulis Alexandros , Egbe Alexander , Afonso Luis
Published: July 2021

Background:
Prior studies have shown that hospital case volume is not associated with survival in patients with out-of-hospital cardiac arrest (OHCA). However, how case volume impact on survival for in-hospital cardiac arrest (IHCA) is unknown

Methods:
We queried the National Inpatient Sample (NIS) in the U.S. 2005-2011 to identify cases in which in-hospital CPR was performed for IHCA. Years > 2011 were excluded due to redesign of NIS that precludes case volume calculation. Restricted cubic spine was used to evaluate the association between hospital annual CPR volume and survival to hospital discharge. Further analysis was conducted with case volume in quartiles.

Results:
Across more than 1000 hospitals in NIS, we identified 137,466 cases (mean age 67, 45% female) of IHCA for which CPR was performed over the study period. Median [Q1, Q3] case volume was 68 [34, 100]. Compared to those in the 1
st
quartile (q1) of case volume, hospitals in the 4
th
quartile (q4) tends to have younger patients (mean=66 vs 68 yrs), higher comorbidities (median Elixhauser score=4 vs 3), large bed size (89 vs 37%), and in low income areas (37 vs 32%). After adjustment for patient and hospital factors, higher hospital case volume was inversely associated with lower rates of survival (Fig1). Risk-adjusted rates of survival from q1 through q4 were: 28.1%, 25.5%, 25.4% and 23.7%. We arrived at similar results when analysis was stratified by age, gender and hospital bed size (not shown) except that the difference across quartiles was more pronounced among small bed size hospitals (survival rate=27.4% in q1 vs 8.1% in q4). However, among those who survived to hospital discharge, nonroutine home discharge was higher among patients in q1 (73.9%) vs q4 (69.6%)

Conclusion:
Unlike OHCA, hospital case volume is inversely associated with survival to hospital discharge in patients undergoing CPR for IHCA. Hence, quality measures to reduce the incidence of CPR/IHCA have the potential to reduce in-hospital mortality
Abstract 102: Inhaled Nitric Oxide Mitigates Pulmonary Hypertension and Improves Cerebral Hemodynamics During Prolonged Cardiopulmonary Pesuscitation in a Swine Model of Pediatric Cardiac Arrest
Authors: Mavroudis Constantine D , Morgan Ryan W , Ko Tiffany S , Hefti Marco M , Landis William P , Boorady Tiffany W , Marquez Alexandra M , Karlsson Michael , Licht Daniel J , Berg Robert A , Nadkarni Vinay M , Sutton Robert M , Kilbaugh Todd J
Published: July 2021

Introduction:
Pulmonary hypertension may play a role in preventing ROSC during prolonged CPR. Targeted pulmonary vasodilation with inhaled nitric oxide (iNO) during CPR may improve pulmonary blood flow and improve outcomes. The purpose of this study was to study the effects of iNO in a randomized, blinded, placebo controlled, pediatric swine model of asphyxial cardiac arrest.

Hypothesis:
Animals treated with iNO will have lower pulmonary artery pressure, improved systemic hemodynamics, and increased cerebral blood flow during prolonged CPR compared to control.

Methods:
Four-week-old piglets (n=10) that underwent seven minutes of asphyxia, induction of VF, and 10 minutes of CPR were randomized to either iNO (20 ppm) or placebo in a blinded fashion starting one min into CPR and needed more than 1 defibrillation attempt. Defibrillation was attempted after 10 minutes of CPR. Animals that did not achieve ROSC by 20 minutes were euthanized. Invasive pulmonary and systemic hemodynamics, and both invasive and noninvasive cerebral hemodynamics were continuously measured. Data described as mean ± SD and compared using a generalized estimating equation regression model.

Results:
All 5 iNO-treated animals and 2/5 placebo-treated animals achieved ROSC. Those treated with iNO had lower mean pulmonary artery pressures (29.5 ± 9.1 vs. 48.3 ± 5.6 mmHg, p=0.04); higher mean aortic pressures (51.9 ± 6.4 vs. 35.5 ± 4.4 mmHg, p=0.01); higher cerebral blood flow (invasive: 230.4 ± 57.4 vs. 28.7 ± 42.1 % baseline, p<0.001; noninvasive: 58.4 ± 10.9 vs. 32.4 ± 8.1 % baseline, p=0.02); and higher cerebral tissue oxygenation (invasive: 33.1 ± 13.0 vs. 1.2 ± 9.8 mmHg, p=0.01; noninvasive: 38.0 ± 4.2 vs. 26.2 ± 3.1%, p=0.005) compared with placebo.

Conclusions:
Treatment with iNO during prolonged CPR results in lower pulmonary artery pressure, improved systemic hemodynamics, and increased cerebral blood flow and oxygenation. Pulmonary vasodilation may have an important role during prolonged CPR for asphyxial cardiac arrests.
Abstract 103: Propofol Infusion in the Early Post-Cardiac Arrest Phase Improves Cerebral Perfusion and Confers Anti-Apoptotic Neuroprotection via Akt-eNOS-NO Signaling
Authors: Chang Wei-Tien , Hsu Min-Hsuan , Wang Woan-Yi , Lee Chunpei , Wang Chih-Hung , Tsai Min-Shan , Hsieh Ming-Ju , Cheng Hsiao-Ju , Huang Chien-Hua , Chen Wen-Jone
Published: July 2021

Introduction:
Neurological outcome after cardiac arrest (CA) and CPR is usually unsatisfactory even in this era of target temperature management (TTM). Propofol is not only a useful sedative drug for TTM but confers neuroprotective effect. We previously showed that propofol combined with TTM improves survival in patients resuscitated from CA. In this study we aimed to explore the underlying mechanism focusing on cerebrovascular circulation and anti-apoptosis signaling.

Hypothesis:
Infusion of propofol in the early post-CA phase improves cerebral perfusion and mitigates neuronal apoptosis via Akt-eNOS signaling.

Methods:
Using an established rat model of asphyxia cardiac arrest and CPR, propofol infusion (20 mg/kg/h) was instituted after return of spontaneous circulation (ROSC) and continued in the first 2 h. Hemodynamics were monitored and the cerebral perfusion was continuously recorded by OxyFLO probe. The arterial blood was regularly sampled for measurement of reactive oxygen species (ROS, chemiluminescence method) and NO (demonstrated by nitrate/nitrite). Two hours after ROSC, the brain was harvested for measurement of casepase-3, endothelial NO synthase (eNOS) and protein kinase B (Akt).

Results:
After CA and CPR, the cerebral perfusion was significantly reduced to ~0.5 folds that of baseline. With the infusion of propofol, the cerebral perfusion was significantly increased from the beginning after ROSC (
P
< 0.01 vs. CPR control). The plasma NO indicated by nitrate/nitrite 2 h post-CPR was significantly increased (
P
< 0.01) while ROS abrogated (
P
< 0.05). The cleaved caspase-3/caspase-3 of the brain was markedly reduced (
P
< 0.001), suggesting anti-apoptotic neuroprotection. When exploring the mechanism, the phosphorylated (p)-eNOS/eNOS and p-Akt/Akt were significantly increased (both
P
< 0.001), indicating activation of Akt-eNOS-NO signaling.

Conclusions:
Infusion of propofol in the early post-CA phase reduces oxidative stress, improves cerebral perfusion, and ameliorates neuronal apoptosis. The protection is, at least in part, mediated via activation of Akt-eNOS-NO signaling.
Abstract 107: The Effects of Hand Placement on Chest Compression Quality in the Pediatric Emergency Department: Findings From the Videography in Pediatric Emergency Research Collaborative
Authors: Sandler Alexis B , O’Connell Karen , Watanabe Ichiro , Hanna Richard , Kerrey Benjamin T , Myers Sage R , Frey Mary E , Donoghue Aaron J
Published: July 2021

Introduction:
Guidelines for infant cardiopulmonary resuscitation (CPR) recommend two finger (2F) technique for one-rescuer chest compressions (CCs) and a two-thumb encircling (2T) for two-rescuers CCs. Pediatric guidelines recommend either a one-handed (1H) or two-handed (2H) technique based on provider judgement. Previous small, single site studies suggest that 2T compressions are more effective for infant CPR than 2F and 1H.

Hypothesis:
To combine video review and monitor-defibrillator CC analysis to determine the effects of hand placement on CC quality in a pediatric emergency department (PED).

Methods:
Data was obtained from the Videography in Pediatric Emergency Resuscitation (VIPER) Collaborative, a prospective observational resuscitation database from 3 tertiary PEDs. Participating sites review resuscitations for quality, safety, and research purposes. Rate and depth for continuous CC segments delivered by a single compressor (epoch) were obtained from Zoll R-series monitor-defibrillator, epoch duration and hand position from video, and patient demographics from medical records. Epochs with analyzable video and CC data were eligible for inclusion. Quality of CC rate and depth were evaluated for adherence to 2015 AHA standards.

Results:
A total of 248 minutes of CCs for 19 patients [14 infants ≤1 year; 5 toddlers 2-4 years] were analyzed. Median CC rates were adherent to AHA standards for toddlers but not infants, where CCs were often too fast (Table 1). CC depth was inadequate in both infant and toddlers. The 2T technique in infants was significantly associated with adherence to AHA standards for rate (

X
2

=4.97;

X
2

=3.64) (Table 1).

Conclusions:
Infant CC rate and depth and toddler CC depth were not adherent to AHA standards. Performing CCs on infants using the 2T technique was most likely to produce CCs at the recommended rate. Further understanding and implementation of techniques to assist with providing high-quality CCs in young patients is needed.
Abstract 114: Association of Serum Potassium Levels With Favorable Neurological Outcome After Out-of-Hospital Cardiac Arrest: The CRITICAL Study in Osaka, Japan
Authors: Shida Haruka , Matsuyama Tasuku , Kitamura Tetsuhisa , Kishimori Takefumi , Kiyohara Kosuke , Okabayashi Satoe , Kawamura Takashi , Iwami Taku
Published: July 2021

Background:
Little is known about the association between serum potassium levels on hospital arrival and favorable neurological outcome after out-of-hospital cardiac arrest.

Objective:
The purpose of this study was to assess whether serum potassium levels on hospital arrival had prognostic indications for patients with out-of-hospital cardiac arrest (OHCA).

Methods:
The prospective, multicenter observational study conducted in Osaka, Japan (the CRITICAL study) enrolled all consecutive OHCA patients transported to 14 participating institutions from July 2012 through December 2015. We included adult patients aged ≥ 18 years with OHCA of cardiac origin who achieved return of spontaneous circulation (ROSC) and whose serum potassium level on hospital arrival was available. Based on the serum potassium level on hospital arrival, patients were divided into five quintiles (Q1-Q5), namely, Q1 (<3.7mEq/l), Q2 (3.7-4.2mEq/l), Q3 (4.2-5.0mEq/l), Q4 (5.0-6.1mEq/l), and Q5 (>6.1mEq/l). The primary outcome was one-month survival with favorable neurological outcome, which was defined as cerebral performance category scale 1 or 2.

Results:
During the study period, a total of 7373 patients were registered and 1148 of them were eligible for our analyses. The highest proportion of favorable neurological outcome was 42.2% (113/268) in the Q1, followed by 37.6% (76/202), 20.6% (50/243), 6.9% (15/216), and 2.7% (6/219) in the Q2, Q3, Q4, and Q5 (p<0.001). In the multivariable logistic regression analysis, the adjusted proportion of favorable neurological outcome decreased as serum potassium level increased (p for trend <0.001). In the subgroup analyses stratified by the first documented rhythm and estimated glomerular filtration rate, the adjusted proportions of favorable neurological outcome indicated similar tendency with those in the main analysis.

Conclusion:
Higher serum potassium level was significantly and independently associated with poor neurological outcome. Serum potassium on hospital arrival may be effective as a prognostic indication for out-of-hospital cardiac arrest achieving ROSC.
Abstract 132: Neurological Favorable Outcome Associated With Number of Prehospital Defibrillation Attempts in Out-of-Hospital Cardiac Arrest Without Return of Spontaneous Circulation on Scene
Authors: Choi Seulki , Kim Tae Han , Hong Ki Jeong , Song Sung Wook , Jeong Joo , Lee Eui Jung , Song Kyoung-Jun , Shin Sang Do
Published: July 2021

Background:
The early and timely defibrillation in shockable rhythm of out-of-hospital cardiac arrest (OHCA) by prehospital EMS providers is crucial for successful resuscitation. In emergency medical service (EMS) system, where advanced cardiac life support could not be fully provided before hospital transport, optimal range of prehospital defibrillation attempts is debatable. We evaluated association between number of prehospital defibrillation attempts and survival outcomes in OHCA patients who were unresponsive to field resuscitation and defibrillations.

Methods:
This is a retrospective observational study using nationwide OHCA registry of Korea from 2013 to 2016. Adult EMS treated OHCA with presumed cardiac origin with shockable initial ECG rhythm were enrolled. Final analysis was performed in patients who did not achieve return of spontaneous circulation (ROSC) on scene before hospital transport. We categorized number of prehospital defibrillation attempt into 3 groups: ≤3 attempts, 4-5 attempts and ≥6 attempts. Primary outcome was favorable neurological outcome at hospital discharge. Multivariable logistic regression modeling was used to evaluate association between neurological outcome and defibrillation attempts.

Result:
Total 6,679 patients were enrolled for final analyzed. Among total ≤3 defibrillations were attempted in 5015 patients (75.1%), 1050 patients (15.7%) for 4-5 attempts, 614 patient. (9.2%) for ≥6 attempts. Although survival to discharge rate was highest in group with ≤3 defibrillation attempts (8.1% vs. 7.0% vs. 2.9%, p<0.01), survival rate with favorable neurological outcome was highest in group with 4-5 defibrillation attempts (3.0% vs. 4.5% vs. 2.1%, p=0.02). As 4-5 attempts group reference, adjusted odds ratio for favorable neurological outcome of ≤3 attempts was 0.66 (95% CI 0.46 - 0.94) and of ≥6 attempts was 0.47 (95% CI 0.25 - 0.89).

Conclusion:
For patients with shockable initial cardiac rhythm who were unresponsive to filed defibrillation and resuscitation, moderate amount of defibrillation attempt was associated with favorable neurological outcome compared to fewer defibrillation attempts and prolonged number of defibrillation attempts on scene.
Abstract 147: Impact of Recording Direction on the Amplitude Spectrum Area of the Ventricular Fibrillation Waveform: A Study on Limb and Precordial ECG-Leads
Authors: Thannhauser Jos , Nas Joris , Rebergen Dennis J , Meinsma Gjerrit , van Royen Niels , Smeets Joep L , Bonnes Judith L , Brouwer Marc A
Published: July 2021

Introduction:
Currently, “smart” automated external defibrillators (AEDs) are under investigation that use the ventricular fibrillation (VF) waveform to guide shock timing. Recent publications show that AED electrode placement varies greatly in clinical practice, which may affect the registered values of VF waveform characteristics. Therefore, we investigated whether recording direction influences the observed value of the most commonly assessed VF-waveform characteristic: the amplitude spectrum area (AMSA).

Methods:
Prospective cohort of patients who underwent defibrillation testing after implantation of an implantable cardioverter defibrillator (ICD) (2010-2013). Four-second segments of induced VF were selected prior to the ICD-shock. AMSA was calculated for bipolar and unipolar ECG-leads (I, II, V3 and V6) and reported as means ± standard deviations. Pairwise comparisons between leads were performed using paired samples t-tests.

Results:
We studied 180 patients, mean age 63 ± 13 years and 134/180 (74%) males. The mean AMSA was the highest in lead V3 (20.1 ± 9.3 mVHz) and the lowest in lead I (7.9 ± 3.5 mVHz). Significant differences in AMSA between ECG-leads were found between lead I and lead II, between lead I and leads V3,V6 (all p<.001) and between lead V3 and leads II,V6 (both p<.001) (Figure). No other differences were found.

Conclusion:
VF-waveform characteristics vary greatly with the recording direction of ECG electrodes. In an era where “smart” defibrillators are under investigation using specific cut-off values of the AMSA, these findings are of great importance. Future studies on VF-guided shock delivery should use standardized paddle placement.
Abstract 16: Spatiotemporally-Controlled Ultrasound-Triggered Release of Nitric Oxide Using Nano Au-Polymersomes/S-Nitrosoglutathione Mitigates Post-Resuscitation Cerebral Vasoconstriction and Neuronal Apoptosis via Reciprocating Akt-eNOS-NO Signaling
Authors: Chang Wei-Tien , Wang Woan-Yi , Hsu Min-Hsuan , Kao Po-Tsung , Wang Chih-Hung , Tsai Min-Shan , Cheng Hsiao-Ju , Huang Chien-Hua , Chen Wen-Shiang , Liau Ian , Yeh Chen-Sheng , Chen Wen-Jone
Published: July 2021

Introduction:
Cerebral vasoconstriction in the post-resuscitation phase worsens neurological outcome. Nitric oxide (NO) plays important roles mediating vasodilatation and anti-apoptotic protection. We therefore designed an Au-polymersomes/S-nitrosoglutathione (Au-PLGA/GSNO) nanoparticle that can be triggered by ultrasound (US) to release NO, and investigated its roles in mitigating cerebral vasoconstriction and neuronal apoptosis post-CPR.

Hypothesis:
Spatiotemporally controlled, US-triggered NO release by Au-PLGA/GSNO improves post-CPR cerebral perfusion and confers anti-apoptotic neuroprotection.

Methods:
Using an established rat model of asphyxia cardiac arrest and CPR, Au-PLGA/GSNO (7500 PPM, 0.4 ml) was infused with simultaneous US (1 MHz) stimulation at the brain 10 min after ROSC. Brain tissue perfusion was continuously recorded by OxyFLO probe and cerebral vasculature videoed by CytoCam. The blood was sampled 2 h post-CPR for measurement of nitrate/nitrite, and the brain harvested for measurement of casepase-3, endothelial NO synthase (eNOS) and protein kinase B (Akt). In a subgroup the brain was harvested at 24 h for TUNEL stain.

Results:
After CPR, marked cerebral vasoconstriction was noted on CytoCam while brain perfusion significantly reduced to ~0.5 folds that of baseline. After Au-PLGA/GSNO infusion and US stimulation, cerebral vasoconstriction was ameliorated and the brain perfusion significantly enhanced (
P
< 0.05 vs. CPR control). The plasma NO indicated by nitrate/nitrite 2 h post-CPR was significantly increased (
P
< 0.01) while cleaved caspase-3/caspase-3 of the brain markedly reduced (
P
< 0.001). TUNEL stain of the hippocampus CA1 and CA3 regions were also remarkably abrogated, suggesting anti-apoptotic neuroprotection. Specifically, the phosphorylated (p)-eNOS/eNOS and p-Akt/Akt were also increased (
P
< 0.01 and 0.001, respectively), indicating reciprocating activation of Akt-eNOS signaling upstream of NO.

Conclusion:
Spatiotemporally controlled US-triggered NO release by Au-PLGA/GSNO mitigates cerebral vasoconstriction, improves brain perfusion and confers anti-apoptotic neuroprotection post-CPR via reciprocating Akt-eNOS-NO signaling.
Abstract 164: Comparison of Tracheal Intubation vs. Supraglottic Airway Following Pediatric Out of Hospital Cardiac Arrest
Authors: Naim Maryam Y , Griffis Heather , Berg Robert A , Bradley Richard N , Hansen Matthew L , Markenson David , McNally Bryan F , Nadkarni Vinay M , Vellano Kimberly , Rossano Joseph W
Published: July 2021

Introduction:
There are few data comparing Tracheal Intubation (TI) and SupraGlottic Airway (SGA) following pediatric out of hospital cardiac arrest (OHCA).

Hypothesis:
TI is associated with improved outcomes compared to SGA following pediatric OHCA.

Methods:
Analysis of the Cardiac Arrest Registry to Enhance Survival database. Inclusion criteria were age ≤ 18 years, non-traumatic OHCA from 2013 through 2017, resuscitated by Emergency Medical Services (EMS). To adjust for covariate imbalance, propensity score matching and entropy balancing were utilized; variables included age category, sex, bystander CPR, and initial rhythm. Primary outcome was neurologically favorable survival defined as a cerebral performance category scale of 1 or 2. Secondary outcome was survival to hospital discharge.

Results:
Of 2653 cardiac arrests evaluated, 2178 (82.1%) had TI and 475 (17.9%) had SGA placed during OHCA. 835 (31.2%) arrests were resuscitated by agencies used bag valve mask (BVM) and TI and 1818 (68.0%) arrests had agencies that used all 3 airway types (BVM/TI/SGA). Overall, unadjusted favorable neurological survival was 5.7% for TI and 5.3% for SGA, p=0.67 and survival to hospital discharge was 7.9% for TI and 7.5% for SGA, p=0.73. In multivariable analysis (adjusting for age, sex, race/ethnicity, bystander witness, bystander CPR, initial rhythm, AED use, year of arrest, and agency category), SGA was associated with lower neurologically favorable survival compared to TI (adjusted proportion 3.7% vs. 6.3%, OR 0.49, p=0.01), and lower survival to hospital discharge (5.5% vs. 8.5%, OR 0.57, 95% CI 0.36, 0.89). These results were robust on tests for unmeasured confounding and covariate balance; propensity analysis neurologically favorable survival 4.4% vs.7.6% (OR 0.54, 95% CI 0.30, 0.96), survival to hospital discharge 6.6% vs.10.5% (OR 0.58, 95% CI 0.35, 0.95); and entropy balance neurologically favorable survival 5.0 % vs. 9.7% for ETI (OR 0.44, 95% CI 0.27, 0.72), survival to hospital discharge 7.3% vs.12.5% (OR 0.51, 95% CI 0.34, 0.78).

Conclusion:
In pediatric OHCA, TI, compared with SGA advanced airway management is associated with improved neurologically favorable survival and survival to hospital discharge.
Abstract 180: Nursing Roles for In-Hospital Cardiac Arrest Response: A Qualitative Study
Authors: Guetterman Timothy C , Kellenberg Joan , Krein Sarah , Lehrich Jessica , Harrod Molly , Kronick Steven , Chan Paul S , Girotra Saket , Iwashyna Theodore J , Nallamothu Brahmajee K
Published: July 2021

Introduction:
Survival and favorable clinical outcomes for in-hospital cardiac arrest (IHCA) are highly dependent on a skilled resuscitation team, prompt initiation of high quality CPR and defibrillation, and organizational structures to support resuscitation care. While nurses are generally involved in resuscitation efforts, the purpose of this study was to examine their specific roles and factors that affect their contributions during an IHCA response.

Methods:
We conducted a qualitative study at 9 hospitals participating in the AHA Get-With-The-Guidelines Resuscitation registry. Purposeful sampling was used to select hospitals that vary in terms of geography, academic status, and risk-standardized IHCA survival. Participants included nurses, physicians, respiratory therapists, pharmacists, quality improvement staff, hospital administrators, and other staff, yet discussion of the nursing function was prominent across all stakeholder groups. Qualitative thematic text analysis was used to identify the distinct types of nursing roles in relation to IHCA and how these roles were supported across sites.

Results:
We conducted semi-structured interviews with 158 individuals at 9 hospitals. Nurses were identified as an integral part of the IHCA response at all sites, with three major IHCA nursing roles identified: bedside first responder, rapid response or code team member, and leader. There were distinct differences across sites in support for nurses in these different roles with regard to educational training and competency, organizational engagement, and empowerment (Table).

Conclusion:
Nurses are a critical component of effective IHCA response and processes, including diverse roles as bedside first responders, code team members, and leadership for resuscitation care. Mentoring and empowering frontline nurses and ensuring that clinical competency and training needs for IHCA care specific for nurses is essential for resuscitation care.
Abstract 183: Public-Access Automated External Defibrillator Pad Application and Favorable Neurological Outcome After Out-of-Hospital Cardiac Arrest in Public Locations; A Prospective Population-Based Propensity-Score Matched Study
Authors: Kishimori Takefumi , Kiguchi Takeyuki , Kiyohara Kosuke , Matsuyama Tasuku , Shida Haruka , Hayashida Sumito , Kitamura Tetsuhisa , Kawamura Takashi , Iwami Taku
Published: July 2021

Background:
Randomized control trials or observational studies showed that the use of public-access automated external defibrillator (AED) was effective for patients with out-of-hospital cardiac arrest (OHCA). However, it is unclear whether public-access AED use is effective for all patients with OHCA irrespective of first documented rhythm. We aimed to evaluate the effect of public-access AED use for OHCA patients considering first documented rhythm (shockable or non-shockable) in public locations.

Methods:
From the Utstein-style registry in Osaka City, Japan, we obtained information on adult patients with OHCA of medical origin in public locations before emergency-medical-service personnel arrival between 2011 and 2015. The primary outcome was one-month survival with favorable neurological outcome. Multivariable logistic regression analysis was used to assess the association between the public-access AED pad application and favorable neurological outcome after OHCA by using one-to-one propensity score matching analysis.

Results:
Among 1743 eligible patients, a total of 336 (19.3%) victims received public-access AED pad application. The proportion of patients who survived one-month with favorable neurological outcome was significantly higher in the pad application group than in the non-pad application group (29.8% vs. 9.7%; adjusted odds ratio [AOR], 2.85; 95% confidence interval [CI], 1.73-4.68, AOR after propensity score matching, 2.83; 95% CI, 1.40-5.72). In a subgroup analysis, the AOR of patients with shockable or non-shockable rhythms was 3.36 (95% CI, 1.78-6.35) and 2.38 (95% CI, 0.89-6.34), respectively.

Conclusions:
Public-access AED pad application was associated with better outcome among OHCA patients with shockable rhythm and the trend was the same among those with non-shockable rhythm.
Abstract 191: Effects of Anesthetic Agents on Blood Parameters in Rats With Acute Hemorrhagic Shock
Authors: Shi Jianru , Dai Wangde , Carreno Juan , Hale Sharon L , Kloner Robert A
Published: July 2021

Background:
Recent studies in our laboratory indicate that isoflurane (ISO) has protective properties including improved survival in rats with hemorrhagic shock compared to ketamine and xylazine (K/X) anesthesia. The effects of these two anesthetic agents upon blood counts, gases and chemistries in the setting of hemorrhagic shock is unknown. The purpose of the present study was to examine the effects of these two commonly used anesthetic regimens on blood parameters in rats with acute hemorrhagic shock.

Methods and Results:
Sprague Dawley rats (both genders) were anesthetized with either intraperitoneal K/X (90mg/kg and 10mg/kg; n=12) or with isoflurane (5% isoflurane induction and 2% maintenance in room air; n=12). Rats were intubated and ventilated with room air. After heparinization, hemorrhagic shock was induced by withdrawing blood to a fixed mean blood pressure of 30 mmHg for one hour and then shed blood was reinfused. Arterial blood samples were collected at 1 hour after resuscitation with shed blood. We found that K/X was associated with lower PH and lower level of standard bicarbonate concentration (SBC) and oxygen saturation (SO
2
%) and more negative base excess; and had a significantly elevated anion gap, potassium, sodium and chloride levels compared to isoflurane (Table). Platelet counts were preserved and there was less elevation of white blood cell (WBC) in ISO (Table). There were no significant differences in PO
2
, PCO
2
, hematocrit, hemoglobin, glucose and lactate levels between the two types of anesthesia.

Conclusions:
The anesthesia influenced the levels of blood counts, gases and chemistries in rats with acute hemorrhagic shock, favoring ISO over K/X. Blood parameters remained essentially normal in ISO group, which may help explain the protective role of ISO in hemorrhagic shock.
Abstract 192: Pressure Methods for Primary Hemorrhage Control
Authors: Charlton Nathan P , Solberg Robert , Rizer Justin , Singletary Eunice , Woods William
Published: July 2021

Introduction:
Hemorrhage is the primary cause of death in 35% of traumatic mortalities. However, guidelines give little guidance regarding the best method of applying direct pressure including the mechanics of applying the pressure.

Hypothesis:
The purpose of this study is to compare the force generated using different techniques of force application. Additionally, we aimed to measure the pressure generated by a pressure wrap using two commonly used types of bandages in comparison to manual pressure.

Methods:
In this IRB approved study, subjects were recruited as a convenience sample of medical providers during a weekly medical conference. A standardized bleeding simulator (Z-Medica) with a flat force sensitive resistor was used in this study to measure force. Subjects were randomized to application order of each of the following techniques: the finger pads of 3 digits of the right hand, 3 fingers of the right hand with the opposing hand applying counter pressure, or 3 digits of each of two hands on top of the other. The subjects were asked to hold pressure at each application for 10 seconds and all completed each method sequentially. Subjects then applied a compression wrap using either an elastic wrap or self-adhesive wrap. Researchers were not blinded during data collection, but data analysts were blinded to the groups.

Results:
Thirty-three subjects were enrolled and all had data available for analysis. Twenty-two were residents, 11 attending physicians, 22 were male, and the average age was 34.2 years (range 26-63). Two hand pressure application generated the most amount of force averaging a constant of 3.75 (SD 1.54) lbs. This was statistically different from one hand application which generated an average of 3.00 (SD 1.29) lbs of force (p <0.001). Comparison of opposing hands to single hand and two hands to opposing hands did not reach statistical significance. Neither pressure wrap technique generated a comparable amount of force to that of manual pressure [0.70 (SD 0.49) lbs vs 1 hand with 10 4x4” gauze pads (p <0.001)].

Conclusions:
In this model of bleeding, medical personnel generated the most force when two hands were used to apply pressure over the wound. This study also demonstrated direct manual pressure generated much higher pressures than a pressure dressing.
Abstract 205: Blood Flow Backward into the Vein During Chest Compression; The Correlation Between the Vessel Pressure and Return of Circulation in Out-of-Hospital Cardiac Arrest
Authors: Koyama Yasuaki , Matsuyama Tasuku , Hoshino Tetsuya , Shimojo Nobutake , Kawano Satoru , Inoue Yoshiaki
Published: July 2021

Introduction:
Little is known about the hemodynamic flow during chest compression (CC) for patients with cardiac arrests; some previous studies reported blood may flow backward into vein and oxygenated blood may not forward into artery during CC. We set out to describe the pattern of the hemodynamic flow during CC and identify the relationship between the pattern and their outcome.

Method:
We prospectively enrolled out-of-hospital cardiac arrest (OHCA) patients admitted to our emergency department (ED) and for whom femoral arterial and venous pressure were successfully measured from May 2017 to April 2018. The exclusion criteria was those with traumatic OHCA, who received extracorporeal membrane oxygenation or who aged <15 years. We inserted a 4Fr catheter both in femoral artery and vein. The standard advanced cardiac life support was provided with manual or mechanical CC. We defined the case that the artery pressure was higher than the venous pressure as the A group, and the opposite case as the V group. The proportion of ROSC in both groups was statistically evaluated by chi-square test.

Results:
Total 70 patients were transported to our ED during the study period. Of the 25 patients for whom femoral arterial and venous pressure were tried to measure, 22 patients (90%) were successful and included in our final analysis. Each group had 11 patients. In A group, seven out of 11 patients achieved ROSC, whereas no patients did in V group (p=0.006).

Conclusion:
In this study, half of the patients predominantly showed the backward flow during CC and no patients could achieve ROSC in this group. This suggests that blood flowing backward into venous may be associated with the lower quality of CC during CPR.
Abstract 223: Pilot Study of s Rewarming Rate of 0.15c/h vs. 0.25c/h and Outcome in Post Cardiac Arrest Patients
Authors: Chae Minjung K , Cho Eunhye , Park Eunjung , Lee Seung Eun , Cho Eunsom
Published: July 2021

Introduction:
Cerebral hemodynamic and metabolic changes may occur during the rewarming phase of targeted temperature management (TTM) of post cardiac arrest patients. Yet, studies of different rewarming rates and patient outcomes are limited. The researchers would like to perform a pilot study to investigate post cardiac arrest patients, who were rewarmed with different rewarming rates after 24 hours of hypothermia and their association to neurologic outcomes.

Method:
The researchers investigated post cardiac arrest patients treated with TTM and rewarmed with a rewarming rate of 0.15°C/h and 0.25°C/h. The association of rewarming rate and poor neurologic outcome(CPC3-5) was investigated.

Result:
A total of 63 patients were analyzed (0.15°C/h N=33, 0.25/h N=30). When comparing the neurologic outcomes of 0.15°C/h versus 0.25°C/h, the neurologic outcome did not significantly differ between the two rewarming rates (22(66.7) vs. 20 (66.7), p=1.00). Rewarming rate of 0.15°C/h was not associated with one-month neurologic outcomes, after adjusting confounding factors in the multivariate analysis (OR 1.19 (0.31-4.54), p=0.80).

Conclusion:
Although the sample size was limited, findings of this pilot study showed that rewarming rates of 0.15°C/h and 0.25°C/h were not associated with different neurologic outcomes in the post cardiac arrest patients.
Abstract 234: The Variability of Visual Assessment of Traditional Capillary Refill Measurement
Authors: Shinozaki Koichiro , Saeki Kota , Jacobson Lee , Falotico Julianne , Li Timmy , Becker Lance B
Published: July 2021

Objective:
Capillary refill time (CRT) measured at the bedside is widely promulgated as an acceptable method to identify patients in shock. However, inter-observer reliability of CRT visual assessments is questionable. To investigate the variability that occurs when healthcare providers (HCP) visually assess CRT, we conducted a study in the emergency department (ED) that simultaneously measured CRT while recording the change in the patients’ fingertip color by video.

Methods:
Three HCPs were selected to perform manual CRT assessments at the bedside to classified patients as having either normal (≤2 seconds) or abnormal (>2 seconds) CRT. An attending ED physician, blinded from the HCP classification, quantitatively measured CRT using a chronograph (
visual CRT
). A video camera was mounted on top of the hand tool in order to obtain a digital recording of the change in color, as the fingertip was compressed. The videos were thereafter used to calculate CRT via image software analysis (
image CRT
). Additionally, nine HCPs, including the ED physician, reviewed the videos in a separate setting to visually assess CRT while blinded from any patient information (
video assessment CRT
).

Results:
Thirty ER patients were enrolled in the ED. The ED physician identified 10 patients with abnormal CRT (> 2.0 seconds), while only two patients were identified by HCPs. Mean visual CRT was 2.0±0.9 (range: 1.2-4.4) seconds; mean image CRT, 2.4±2.1 (range: 0.5-8.0); mean video assessment CRT by the ED physician, 1.8±0.6 (range: 1.0-2.7). The correlation between visual CRT and image CRT was strong (r=0.648, p=0.002), while it was weak between visual and video assessment CRT (r=0.312, p=0.18). Inter-observer reliability of video assessment CRT among HCPs was low (intra correlation coefficient: 0.15, 95% CI 0.05-0.33).

Conclusions:
Inter-observer reliability of visual CRT assessment is low. The reliability of skilled physician in a real clinical situation increases and it infers that a reliable CRT test may only be capable if other patient information is available at the bedside, such as patient’s background, distressed appearance, cold peripheral temperature etc.
Abstract 236: Lactate Level at the Scene of Injury can Accurately Predict the Need for Massive Transfusion
Authors: Ogura Takayuki , Okada Mio , Kanehata Keita
Published: July 2021

Introduction:
The lactate has been widely recognized as a marker of tissue hypoxia/hypoperfusion. Hyperlactatemia is common among patients requiring critical care, and lactate levels and their trend may be reliable markers of illness severity and mortality. Elevated plasma lactate levels have been recommended as a parameter for hemodynamic resuscitation. The aim of this study is to investigate the predictive value of the lactate levels at the scene of injury for the need for Massive Transfusion (MT).

Patients and Methods:
A single-center retrospective diagnostic study was conducted. The records of the emergency medical service (EMS) between Sep. 2012 and Apr. 2017 were reviewed and adult high-energy trauma patients transported by the EMS were included. The data about the lactate levels and the need for MT (10 units or more of packed red blood cells transfusion within 24 hours of injury) was collected, and the predictive value of the lactate levels at the scene of injury was analyzed by the area under the receiver operating characteristic curve (AUROC). Our EMS system is always with specialized emergency physician, and lactate level was measured by portable equipment.

Results:
1039 patients were enrolled and 1025 patients were analyzed after exclusion of 14 patients with insufficient data. The mean age was 55.0 years, 77.6% male, 98.1% blunt trauma, and 6.6% underwent MT. The AUROC of the lactate levels at the scene of injury for MT was 0.91 [95% confidential interval; 0.90-0.93].

Conclusion:
The lactate levels at the scene of injury can accurately predict the need for Massive Transfusion. The further investigation is warranted.
Abstract 238: In-Hospital Cardiac Arrest: The Dynamic Clinical Course During Advanced Cardiac Life Support
Authors: Skogvoll Eirik , Buckler David G , Nordseth Trond , Brønstad Maria , Eftestøl Trygve , Kvaløy Jan T , Irusta Unai , Abella Benjamin S
Published: July 2021

Background:
Sudden cardiac arrest may present with one of three clinical states (rhythms): Ventricular fibrillation/tachycardia (VF/VT), Pulseless Electrical Activity (PEA), or Asystole (ASY). During Advanced Cardiac Life Support (ACLS), the patient may also transition between the other states or reach temporary ROSC (defined as an organized electrical rhythm without chest compressions >= 1 min). Finally, either sustained ROSC or death will ensue. The aim of study was to investigate and quantify the dynamic characteristics of this process and compare with previous studies.

Methods:
As part of a CPR quality assessment initiative, we prospectively registered the development of clinical states using defibrillators that records the ECG as well as ongoing chest compressions. These recordings were analyzed in a multi-state statistical framework. Instantaneous transition rates were obtained by smoothing the Nelson-Aalen estimator of cumulative intensities.

Results:
We analyzed 201 episodes in 168 patients between 2008 and 2009 at the Hospital of the University of Pennsylvania (51% women; median age 60, IQR 49-73 years). Most episodes (62%) took place in the Medical ICU, and represented multiple etiologies. PEA was the most frequent presenting rhythm (69%); VF/VT and ASY contributed with 15 % each. In the 191 episodes with complete information about the clinical course, the transition rate from PEA to ROSC was 0.11 episodes/min (approximately 11%), the rate of PEA recurring from temporary ROSC was 0.12/min. These transition rates are both about 40 % higher than observed earlier. The prevalence of sustained ROSC was 0.6 (60%) at about 25 min (figure: 0 to 45 min of CPR).

Conclusion:
We provide quantitative overview of the dynamic process of clinical state transitions during in-hospital cardiac arrest in adults. Compared to earlier studies from American and Norwegian Hospitals, we found higher transition rates between PEA to ROSC, and a high prevalence of sustained ROSC.
Abstract 239: Frequency of Advanced Cardiac Life Support Medication Use and Association With Survival During In-Hospital Cardiac Arrest
Authors: Benz Paul , Brenner Nicole , Woo Stephanie , Chong Stephen , Wilson Matthew , Heinrichs Dorothy , Dubin Jeffrey , Goyal Munish
Published: July 2021

Introduction:
Resuscitation medication shortages are widespread across the US. We sought to determine the frequency and quantity of meds used during IHCA.

Methods:
Retrospective, single center, chart review at a large, urban teaching hospital. Adults over 18 who suffered IHCA between Jan 2017 and Mar 2018 were identified. Trained and supervised research assistants used a standardized data tool to extract data from the EMR. Primary outcome was the frequency and quantity of ACLS meds used during IHCA. Secondary outcomes included evaluating the association of med administration with ROSC and survival as well as the use of sodium bicarb with survival in patients with pre-existing end stage renal disease.

Results:
Criteria were met for 181 IHCA events. Demographics: 71% (128 of 181) black; mean age 65; and 46% (83 of 181) women. Epi was given in 86.7% (157 of 181) cases, with average cumulative dose of 4.2 mg, sodium bicarb given in 63.5% (115 of 181), average dose of 1.9 amps, calcium chloride given in 39.2% (71 of 181), average dose of 1.9 amps, amiodarone was given in 30.9% (56 of 181), average dose of 311.8 mg, and atropine was given in 13.8% (25 of 181), average dose of 1.3 amps. Administration of sodium bicarb was associated with lower rates of ROSC (OR 0.31, 95% CI 0.18 to 0.83) and lower survival (OR 0.31, 95% CI 0.13 to 0.73). Administration of mag sulfate was associated with lower rates of ROSC (OR 0.33, 95% CI 0.13 to 0.83), but no difference in survival (OR 0.34, 95% CI 0.10 to 1.14). Administration of epi, amiodarone, calcium, dextrose, or atropine was not associated with a change in rates of ROSC or survival. In patients with pre-existing ESRD (45 of 181), 73.3% (33 of 45) received sodium bicarb, with 51.5% (17 of 33) achieving ROSC, and 12.1% (4 of 33) surviving to discharge. In patients without ESRD (136 of 181), 60.3% (82 of 136) received sodium bicarb, with 65.9% (54/82) achieving ROSC, and 22.0% (18 of 82) surviving to discharge. (12.1% vs 22.0% p = 0.224).

Conclusions:
Substantial amounts of drugs with known recent shortage are used in IHCA with no significant increase in ROSC or survival to discharge. Administration of sodium bicarb during IHCA is associated with lower rates of ROSC and survival. These results may be due to confounders such as code duration.
Abstract 273: Alpha-Delta Ratio Peak Appears Early After Return of Spontaneous Circulation in the Continuous Electroencephalogram of Patients With Good Outcome After Cardiac Arrest
Authors: Oh Joo Suk , Oh Sang Hoon , Park Kyu Nam
Published: July 2021

Introduction:
Several studies have shown that the alpha-delta ratio (ADR) is associated with ischemic brain injury. Recently, an animal study has revealed that the ADR reaches the maximum point at 11 hours after ROSC, followed by downward curve (ADR peak) in the continuous EEG recordings of the rats with good outcome after cardiac arrest. We examined the existence of the early ADR peak after cardiac arrest in human.

Methods:
This is a prospective, observational study. Forty patients who survived out-of-hospital cardiac arrest underwent 33°C-targeted temperature management. We induced 33°C within 5 hours after ROSC and maintained for 24 hours, followed by 12 hours of rewarming period. All patients received sedative and paralytic agents until the restoration of normothermia. We started continuous EEG monitoring within 20 hours after ROSC until 72 hours after ROSC or mental recovery. We calculated alpha (8 - 13 Hz) and delta (0.5 - 4 Hz) frequency bands and computed ADR in the bifrontal channel (F3 - F4), bicentral channel (C3 - C4) and biparietal channel (P3 - P4). We did not remove artifact nor seizure events. Therefore, the whole continuous recordings were analyzed. Good neurologic outcome was defined as cerebral performance category 1 and 2 one month after ROSC.

Results:
Twenty-five patients showed poor outcome, while 15 patients showed good outcome. The figure is showing mean ADR ± SD change over time. The ADR reaches its highest amplitude 10 hours after ROSC and gradually decreases in the patients with good outcome regardless of the recording channel. However, the 10-hour ADR was not significantly different between the groups due to the large variances.

Conclusions:
Similar to the rats, the ADR peak appears early in the human patients with good outcome. However, due to the highly variable trend, application of ADR peak as a prognostic marker is limited. Regardless, the ADR implicates the crucial window of brain recovery time and remains an important subject requiring further study.
Abstract 286: Chance of Bystander Defibrillation According to Number of Nearby Automated External Defibrillators in Out-Of-Hospital Cardiac Arrests
Authors: Karlsson Lena , Sun Christopher , Malta Hansen Carolina , Wissenberg Mads , Lippert Freddy , Torp-Pedersen Christian , Chan Timothy , Folke Fredrik
Published: July 2021

Introduction:
Use of automated external defibrillators (AEDs) for early defibrillation in out-of-hospital cardiac arrest (OHCA) substantially increases chance of survival.

Aim:
To examine the relationship between number of nearby accessible AEDs and chance of bystander defibrillation.

Methods:
All OHCAs (2008-2016), and all publicly available AEDs (2007-2016) in Copenhagen were identified. The route distances between OHCAs and AEDs were calculated to determine the number of accessible AEDs ≤100m of an OHCA (OHCA coverage). Multiple logistic regression was performed to identify the adjusted Odds Ratios (ORs) of OHCA characteristics, including the number of AEDs covering an OHCA, on bystander defibrillation. The regression model was evaluated using receiver operator characteristics (ROC). Multiple logistic regression was also used to determine the predicted probability (through a 2000 iteration bootstrap approach) of bystander defibrillation for public vs. residential OHCAs, according to the number of accessible AEDs covering the OHCA, defined as covered by 0, 1 or >1 AED.

Results:
There were 1830 AEDs registered in Copenhagen. Of 2500 OHCAs, 75.2% (n=1879) occurred in residential locations of which 98.1% were not covered by an AED, 1.7% were covered by 1 AED only, and 0.2% were covered by >1 AED. The corresponding figures for public OHCAs (n=621, 24.8%) were 87.5%, 9.0%, and 3.5%, respectively. Overall, the number of accessible AEDs covering the OHCA, public location, bystander witnessed arrest and bystander CPR were significantly associated with bystander defibrillation (OR (95%CI): 1.75 (1.24-2.46); 4.25 (2.75-6.57); 3.12 (1.84-5.27); 2.33 (1.44-3.75), respectively. (ROC=82%)). The predicted probability of bystander defibrillation for public OHCAs was 12.2% (95%CI: 9.5-14.9) with no AED covering the OHCA, 24.7% (95%CI: 18.2-31.3) with 1 AED, and 39.8% (95%CI: 23.4-56.7) with >1 AED. The corresponding figures for residential OHCAs were 2.1% (95%CI: 1.5-2.8), 4.3% (95%CI: 2.5-6.8), and 4.0% (95%CI: 0.9-10.8), respectively.

Conclusions:
Rates of bystander defibrillation significantly improved with increasing number of accessible AEDs covering the OHCA, especially for public OHCAs.