bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 217: Chest Compression on Aortic Valve Decreases Chance of Return of Spontaneous Circulation for Patients Experiencing Out-of-Hospital Cardiac Arrest
Authors: Chu Sheng-En , Sun Jen-Tang , Ma Matthew H , Chin Kuan-Chen , Tsai Min-Shan , Chiang Wen-chu
Published: December 2023

Background:
Current CPR guidelines recommend applying chest compression at "the center of the chest" for patients undergoing out-of-hospital cardiac arrest (OHCA). However, studies revealed that following this recommendation, around half of OHCA patients would receive compressions on the aortic valve (AV), potentially obstructing blood flow and worsening prognosis.

Hypothesis and Aim:
We aimed to use transesophageal echocardiography (TEE) during cardiopulmonary resuscitation (CPR) to test the hypothesis of the impact of AV compression vs AV non-compression on adult OHCA patients' outcomes.

Methods:
This prospective cohort study included OHCA patients receiving TEE exams during CPR. Exclusion criteria were the return of spontaneous circulation (ROSC) before TEE, unidentifiable compression site, or unqualified TEE image. Patients were divided into AV-compressed or non-compressed groups based on initial TEE findings. Patient characteristics, TEE recordings, resuscitation data, and critical time points were analyzed. Primary outcome was sustained ROSC. Secondary outcomes included any ROSC, survival to admission, survival to discharge, and favorable neurological outcomes upon discharge defined by MRS ≤ 2. The sample size was pre-estimated as 37 patients per group.

Results:
A total of 76 patients from October 2020 to January 2023 were enrolled for analysis, with 39 in the AV non-compressed group and 37 in the AV-compressed group. Baseline characteristics were similar between groups. Compared to the compressed group, the non-compressed group had a better chance of sustained ROSC [adjusted odds ratio (aOR) 4.72, p=0.010], any ROSC (aOR 3.30, p=0.033), and survival to admission (aOR 6.74, p=0.010). The main results were tabulated as below.

Conclusions:
CPR with compressed AV decreased the chances of ROSC among OHCA patients.
Abstract 218: Effect of Airway Pressure and Localized Sternal Compression Upon Hemodynamics During Cardiopulmonary Resuscitation
Authors: Clark Lyra , Harvey Brian , Lampe Joshua W , Beck George , Moodie Karen L , Paradis Norman A
Published: December 2023

Background:
During cardiopulmonary resuscitation (CPR), chest compression (CC) and mechanical ventilation are cyclic in nature and each modulate the intrathoracic pressure (ITP). ITP is increased during the compression phase of CC, causing an increase in aortic pressure (AoP) and right atrial pressure (RAP) to drive forward blood flow. Similarly, positive pressure ventilation increases ITP during the inspiratory phase as pressure is transmitted through the lungs, which also has an impact on hemodynamics. The purpose of this analysis was to examine differences in hemodynamics during ventricular fibrillation (VF) arrest due to ventilation alone and during localized sternal CC of varying depths in a porcine model of cardiac arrest.

Methods:
Domestic swine (n = 8) underwent electrically induced VF with ten-minute downtime, followed by resuscitation with mechanical ventilation and CC with active lift to neutral chest position. Mechanical ventilation was delivered using pressure-controlled synchronized intermittent mandatory ventilation (SIMV) mode (Vt 10 mL/kg, 10 bpm, trigger -6 cmH
2
O, PEEP 5 cmH
2
O, FiO
2
100). CPR was initiated with three minutes of ventilation only, followed by one minute of break-in CC at 1.0 in and 1.5 in prior to increase to depth of 2.0 in. AoP, RAP, esophageal pressure (Pes), and airway pressure (Paw) were examined over the ventilation cycle to determine the effect of each treatment upon parameters.

Results:
Positive pressure ventilation caused similar changes to the Pes, RAP, and AoP values (3-5 mmHg). CC caused similar changes to Pes (3-5 mmHg), but much larger changes to the RAP and AoP (10-130 mmHg) depending on compression depth.

Conclusions:
The ITP is not uniform during CC, creating only modest changes to Pes. This suggests that CC generate blood pressures, and presumably flows, through mechanisms other than ITP modulation. Understanding this interaction could improve our understanding of blood flow during CPR.
Abstract 220: Association Between Initial Defibrillator Pad Position And Outcomes For Out-of-hospital Cardiac Arrest Patients Presenting With Shockable Rhythms
Authors: Lupton Joshua , Newgard Craig , Dennis David , Nuttall Jack , Sahni Ritu , Jui Jonathan , Neth Matthew R , Daya Mohamud R
Published: December 2023

Background:
Ventricular fibrillation (VF) or ventricular tachycardia (VT) are the most treatable causes of out-of-hospital cardiac arrest (OHCA). Yet, it remains unknown if defibrillator pad position, placement in the anterior-posterior (AP) or anterior-lateral (AL) positions, impacts patient outcomes in VF/VT OHCA.

Aim:
Evaluate the association between initial defibrillator pad placement (AP vs. AL) and OHCA outcomes for patients presenting with VF/VT.

Methods:
This was a prospective observational study of non-traumatic OHCA patients with initial VF/VT on EMS rhythm analysis treated by a single EMS agency in the Portland Cardiac Arrest Epidemiologic Registry (PDX Epistry) from July 1st, 2019 through October 15th, 2022. Our primary outcome was return of spontaneous circulation (ROSC) at any time and secondary outcomes were ROSC at emergency department (ED) arrival, survival to admission, survival to discharge, and functional survival (cerebral perfusion category score of ≤2). We performed t-tests, chi-squared tests, and multivariable logistic regressions adjusting for age, sex, witness status, bystander interventions, arrest location, 911 call to EMS arrival time, and year of arrest.

Results:
A total of 243 OHCA patients met inclusion criteria and 232 (95.5%) had initial pad positioning documented (133 AP and 99 AL). Patients with AP placement had higher rates of ROSC at any time (72.2% vs. 47.5%, p<0.001), survival to admission (56.4% vs. 41.4%, p=0.024), survival to discharge (36.1% vs. 24.2%, p=0.050), and functional survival (36.1% vs. 21.2%, p=0.012) compared to AL, with no difference for ROSC at ED arrival (52.6% vs. 40.4%, p=0.065). AP versus AL placement showed higher adjusted odds (aOR [95% CI]) for ROSC at any time (2.76 [1.55-4.93]) and functional survival (2.06 [1.05-4.05]), but not ROSC at ED arrival (1.50, [0.85-2.64]), survival to admission (1.69 [0.96-2.96]) or survival to discharge (1.68 [0.86-3.27]). Among patients with ROSC at ED arrival, patients with AP placement, had shorter times from 911 call to sustained ROSC (21.0 vs. 28.4 min, p=0.013).

Conclusions:
Initial AP pad placement, compared to AL, was associated with higher ROSC, a reduction in time to sustained ROSC, and higher functional survival for patients with VF/VT OHCA.
Abstract 233: Out-of-Hospital Cardiac Arrest Survival When CPR is Initiated by First Responders
Authors: El-Zein Rayan , Kennedy Kevin , Chan Paul S
Published: December 2023

Background:
In most patients with out-of-hospital cardiac arrest (OHCA), life-saving cardiopulmonary resuscitation (CPR) is initiated by first responders (non-transporting firefighters or police) or emergency medical service (EMS) personnel. Whether survival outcomes differ when CPR is initiated by first responders vs. EMS is unclear.

Research Question: Do survival outcomes differ when CPR is initiated by first responders vs. EMS personnel for OHCA?

Methods:
Within the Cardiac Arrest Registry to Enhance Survival, we identified 162,896 patients with a OHCA in whom CPR was initiated by first responders or EMS. Using multivariable hierarchical logistic regression to adjust for demographics, cardiac arrest characteristics and time to first CPR, we compared rates of survival to hospital admission and to discharge between patients in whom CPR was initiated by first responders and EMS.

Results:
CPR was initiated by first responders in 70,889 (43.5%) and by EMS in 92,007 (56.5%) patients. Time to first CPR was shorter when first responders initiated CPR (median: 8.0 [5.0-13.0] vs. 10.0 minutes [IQR: 6.0-14.0]; standardized difference 16.1%). The likelihood of survival to hospital admission was similar when CPR was initiated by first responders (27.1% [first responders] vs. 26.8% [EMS]; adjusted OR: 0.98 [0.96, 1.01], P=0.15) whereas survival rates to hospital discharge were higher with CPR initiated by first responders (9.4% [first responders] vs. 7.7% [EMS]; adjusted OR: 1.17 [1.02- 1.21], P<0.001). After adjustment for time to first CPR, rates of survival to discharge were similar between the first responder and EMS groups (adjusted OR: 1.04 [1.00-1.08]; P=0.07).

Conclusions:
CPR initiated by first responders for OHCA is associated with higher overall survival rates and was explained by earlier response times.
Abstract 254: Patients With Signs of Life on Hospital Arrival Have a Higher Chance of Survival and Favorable Neurological Outcomes Following Traumatic Cardiac Arrest
Authors: obara Takafumi , Hongo Takashi , Nojima Tsuyoshi , Yumoto Tetsuya , Naito Hiromichi , Nakao Atsunori
Published: December 2023

Introduction:
The clinical impact of signs of life (SOL) in traumatic cardiac arrest (TCA) remain to be elucidated. A previous study compared TCA patients with pulseless electrical activity (PEA) to those with asystole, but survival was not significantly different between the groups. Other obvious SOL (i.e., fine extremity/eye movement, light reflection, agonal respiration) have not yet been examined in TCA.

Hypothesis:
We hypothesized that TCA patients with SOL on hospital arrival have a higher chance of survival and good neurological outcomes.

Aim:
To examine survival and neurological outcomes in TCA patients with or without SOL.

Methods:
Retrospective review of data from the Japan Trauma Data Bank (2019-2021). The inclusion criteria were patients with TCA on arrival. The exclusion criteria were patients with burns, abbreviated injury scale score> 6 in any region, and missing survival or SOL data. SOL was defined as follows: extremity or eye movement, light reflex, gasping, pulseless electrical activity with electrical heart activity > 40 beats per minute. The primary outcome was survival at discharge. The secondary outcome was favorable neurological outcome (Glasgow Outcome Scale score of 4 or 5) at hospital discharge. Patients with and without SOL were compared using univariable analysis. Results were described with odds ratio (ORs) and 95% confidence intervals (CI).

Results:
A total of 2,136 patients (121 with SOL and 2,015 without SOL) were included. The characteristics of patients with or without SOL were as follows: age (median age 60.5 years old [interquartile range: 42-80 years] vs. 55.2 [38-75]), gender (male: 83/121 (68.6%) vs. 1,321/2,015 (65.9%), Injury Severity Score (32.9 [22-43] vs. 33.7 [22-41]), blunt trauma (97/121 (82.2%) vs. 1,711/2,015 (84.9%)), and transportation time (15.1 min [7-18] vs. 13.3 [7-16]). The patients with SOL showed higher survival compared with the patients without SOL (11/121 (8.5%) vs. 24/2015 (1.2%), OR 1.9 [CI 1.38-2.85]). A similar trend was observed for favorable neurological outcomes (5/95 (5.3%) vs. 7/1,440 (0.5%), OR 2.41 [CI 1.26-3.60]).

Conclusions:
TCA patients with SOL at arrival showed higher survival and favorable neurological outcomes at hospital discharge compared with TCA patients without SOL.
Abstract 263: Disparities in Antiarrhythmic Practices for Out-of-Hospital Cardiac Arrest
Authors: Papin Anastasia , Chan Hei Kit , Johnson Anna Maria , Mann N. Clay , Child Angela , Fisher Benjamin , Walter Daniel , Huebinger Ryan
Published: December 2023

Background:
Antiarrhythmics are an important treatment for out-of-hospital cardiac arrest (OHCA) with a shockable rhythm, but little is known about racial and ethnic disparities in antiarrhythmic administration practices.

Objective:
This study aims to investigate the association between community race/ethnicity and antiarrhythmic administration for OHCA.

Hypothesis:
OHCAs in minority communities receive antiarrhythmics less often and with a longer delay.

Methods:
We conducted a retrospective study of a national prehospital database, NEMSIS, linked to Census data. We included all cardiac arrests from 2018-2021 with a shockable rhythm. We stratified patients based on majority (>50%) zip code race/ethnicity (non-Hispanic White (White), non-Hispanic Black (Black), and Hispanic). For patients with a shockable rhythm at any point, we performed a mixed logistic regression model evaluating the association ZIP code race/ethnicity to administration of antiarrhythmic medication. We modeled EMS agency as a random intercept and adjusted for possible confounders. For patients with an initial shockable rhythm, we compared the time from EMS dispatch to first antiarrhythmic administration between strata.

Results:
Of 763,944 cardiac arrests, 203,816 had an initial shockable rhythm at any point during the encounter and 111,778 had an initial shockable rhythm. For patients with a shockable rhythm at any point, the median age was 65 (IQR 54-75), 68.5% were male, 65.9% occurred in a private residence, and 67.1% were bystander witnessed. Majority White (33.9%) received antiarrhythmics at a higher rate than majority Black (31.8%; aOR 0.89, 95% CI 0.85-0.94) and majority Hispanic (28.1%; aOR 0.89, 95% CI 0.84-0.94). For patients with an initial shockable rhythm, the time to antiarrhythmic for White (mean 22.2, SD 10.8, median 19.8 minutes, IQR 15-26.6 minute), was lower than Black (mean 22.6, SD 10.7, median 20.3 minutes, IQR 16.1-26.5 minutes, p=0.02) but higher than Hispanic (mean 20.3, SD 9.7, median 18.1 minutes, IQR 14.3-23.6 minutes, p<0.01).

Conclusion:
While antiarrhythmic administration rate was lower for minority communities and time to antiarrhythmic was higher for Black OHCAs, time to antiarrhythmic administration was lower for Hispanic OHCAs.
Abstract 265: Sex-Based Differences in Clinical Outcomes of Out-of-Hospital Cardiac Arrest Patients
Authors: Imburgio Steven , Alshami Abbas , Upadhyaya Vandan , Dandu Sowmya , Zolezi Sydney , Ramirez Claudia , Patel Palak , Varon Joseph
Published: December 2023

Introduction:
Historically, studies have shown lower overall survival rates for women following out of hospital cardiac arrests (OHCA). Despite advancements in resuscitation care over recent years, it is not clear if sex-based differences in inpatient mortality and postresuscitation outcomes have improved.

Aims:
We aim to investigate if gender disparities still exist in the clinical outcomes of OHCA patients.

Methods:
A national cohort of patients primarily hospitalized for cardiac arrest was identified using the 2019 National Inpatient Sample database. The study cohort was divided into male and female populations. The primary outcome was inpatient mortality. Secondary endpoints assessed length of stay and discharge to home rates (as a surrogate to functional status on discharge).

Results:
A total of 28,890 admissions were identified during the study period. Of them, 63.6% (n = 18,365) were males and 36.4% (n = 10,510) were females. The overall unadjusted inpatient mortality rate was 52.2% (n = 15,065) and was lower in females than males [48% (n = 5,040) vs 54.6% (n = 10,025), p < 0.001]. However, after adjusting for potential confounders in Table 1, the female sex was associated with higher adjusted inpatient mortality (aOR 1.085, 95% CI 1.023-1.150, p = 0.007). The average LOS for those who survived to hospital discharge was 5.0 days (IQR 2-10) and was similar between both groups (p = 0.703). Of those who survived to hospital discharge, disposition to home was significantly higher in males (49.3%, n = 4,940) than in females (41.3%, n = 2,080), (p < 0.001).

Conclusions:
Female sex remains an independent predictor of inpatient mortality in patients admitted with OHCA. Discharge to home after successful resuscitation was lower in females than males, suggestive of worsened functional status on discharge.
Abstract 295: Predicting Outcomes in Adult Patients With Out-of-Hospital Cardiac Arrest; Results From the All-Japan Utstein Registry
Authors: Yagi Tsukasa , Nagao Ken , Yonemoto Naohiro W , TACHIBANA EIZO , Tani Shigemasa , Chiba Nobutaka , Ashida Tadashi , Okumura Yasuo , Tahara Yoshio , Ikeda Takanori ,   The JCS-ReSS Group
Published: December 2023

Background:
The recent cardiopulmonary resuscitation (CPR) Guideline addressed that there was no evidence to clearly define what should constitute selected patients in case of performing invasive CPR, such as extracorporeal CPR, for patients with cardiac arrest (CA). However, emergency physicians often need to determine the treatment strategy immediately upon arrival in emergency departments. The present study aimed to clarify the helpful factor of prehospital care to predict adult CA patients' prognosis using the All-Japan Utstein Registry data, a prospective, nationwide, population-based registry of out-of-hospital CA (OHCA).

Methods:
From the data of this registry, between 2005 and 2020, we included adult OHCA patients due to cardiac etiology. The endpoint was the favorable neurological outcome at 30 days after OHCA. The multivariable logistic regression analysis included potential confounding factors based on biological plausibility and previous studies. We scored based on the odds ratio. Receiver operating characteristic analysis was performed, and the area under the curve (AUC) was calculated for factors of the total score in order to assess the 30-day neurological outcome.

Results:
Of the 1,930,273 patients registered in this Registry, the data of 1,099,908 patients were included in this analysis. The table showed the adjusted odds ratio for 30-day favorable neurological outcomes in OHCA patients in the multivariate analysis, and the score based on the odds ratio. The AUC of the total scores was 0.956 (p < 0.001) with a cutoff value of 7, a sensitivity of 92%, and a specificity of 88%. In the case of this total score of less than 7, the 30-day favorable neurological outcome in CA patients was significantly low (total score < 7 vs. total score > 7 = 0.3% vs. 18.7%: p<0.001).

Conclusion:
This score might be a helpful factor in prehospital care information in CA patients to determine the treatment strategy upon arrival in emergency departments.
Abstract 299: Predictors of Pediatric Response to Peri-Arrest Bolus Epinephrine
Authors: Sorcher Jill L , Mehta Shivani , Grossestreuer Anne V , Kleinman Monica E , Ross Catherine
Published: December 2023

Introduction:
Low-dose vasopressor boluses are commonly used for acute hypotension and prevention of cardiac arrest in the ICU. Recent studies have shown an association between SBP response to initial dosing of peri-arrest bolus epinephrine (PBE) and important clinical outcomes in PICU patients. However, reasons for poor response to PBE are not well understood.

Aim:
To explore clinical characteristics associated with response to initial dosing of PBE.

Hypothesis:
We hypothesized that more profound hypotension and lower pH would be associated with poor response to PBE.

Methods:
Cohort study of PICU patients <18 years old who received PBE from April 2022 to March 2023. Change in SBP was measured within 5 minutes before and after PBE. Non-responders were defined as change in SBP ≤10 mmHg. The degree of hypotension was calculated (PALS cutoff for hypotension by age minus lowest SBP prior to PBE). Additional clinical characteristics were abstracted, including pH levels within 2 hours prior to PBE. Given the small subset of patients with pH data, the current dataset was combined with an historical cohort to increase power (Ross, 2018).

Results:
Of 75 patients who received PBE, 53 (71%) were responders and 22 (29%) were non-responders. Overall, the mean increase in SBP was 31 mmHg (95% CI: 24, 37, p<0.0001). Responders and non-responders were similar ages (median 3.7 years [IQR: 0.4, 10.9] vs. 1.6 years [IQR: 0, 5.4], p=0.11) and received similar initial PBE doses (median 0.26 mcg/kg [IQR: 0.11, 0.43] vs. 0.20 mcg/kg [IQR: 0.17, 0.38], p=0.75). Non-responders had less profound pre-PBE hypotension than non-responders (-15± 10 mmHg vs. –21±12 mmHg, p=0.03). In the combined dataset, 83 responders and 34 non-responders had pH data. Non-responders had lower median pH (7.23; IQR, 7.07, 7.33) than responders (7.32; IQR: 7.23, 7.37; p=0.004).

Conclusion:
In PICU patients who receive PBE for acute hypotension, poor SBP response was associated with lower pre-event pH, which may reflect known negative effects of acidosis on hemodynamic response to catecholamines. However, contrary to our hypothesis, non-responders had less severe pre-PBE hypotension. Further work is needed to understand factors affecting response to PBE in PICU patients.
Abstract 327: Implementation of Bronchoalveolar Lavages as a Quality Improvement Initiative in Out-of-Hospital Cardiac Arrest Patients
Authors: Jonsson Andrea , Roach David , Rohan Thomas , Weissman Alexandra
Published: December 2023

Patients who suffer OHCA are at risk for early onset pneumonia due to loss of airway protection, emergency airway access and intubation, CPR, mechanical ventilation, among other complications. It is difficult to accurately diagnose early onset pneumonia post OHCA due to multi-organ dysfunction post arrest and radiography findings confounded by non-infectious inflammation from CPR and aspiration. As a result, a substantial number of patients receive empiric antibiotics. A bronchoalveolar lavage (BAL) can screen for the presence of bacteria in the lungs and aid in identifying the incidence of early onset pneumonia after OHCA. We implemented a quality improvement (QI) initiative to collect a BAL on initial patient presentation to our hospital in May 2018. We conducted an observational, retrospective study to assess the impact of BAL implementation on empiric antibiotic prescribing. We used a rigorous study definition of pneumonia requiring at least two of the following positive within the same 24-hour period: BAL, chest radiography, and/or a fever >38°C. We compared rates of antibiotic prescription in the first 7 days of hospitalization for patients receiving a BAL to those without, as well as rates of antibiotic prescriptions before and after implementation of the BAL QI initiative. Implementation of initial BAL collection was successful and resulted in a 66% increase of BALs (from 44 to 73 BALs) collected compared to an average from the prior 2 years. We hypothesized rates of antibiotic prescription would decrease post-implementation of BAL collection; however, there was no statistically significant change in rate of antibiotic prescription (Figure 1) over the initial 7-day hospitalization period

X
2

(
Df
= 1,
N =
3247) = 0.68,
p =
0.54. Over 80% of patients with pneumonia received antibiotics, roughly 60% of OHCA patients received antibiotics despite no pneumonia diagnosis by any definition. Further study is needed to alter these practices and reduce antibiotic overuse.
Abstract 328: Identification of In-Hospital Cardiac Arrest Using Administrative Billing Codes
Authors: Kaviyarasu Aarthi , Mitchell Oscar J , Thomas Sunil , Batugo Ashley , Mowery Danielle L , Abella Benjamin S
Published: December 2023

Introduction:
In-hospital cardiac arrest (IHCA) is experienced by approximately 200,000 patients annually in the US. While individual care teams can readily identify IHCA at the bedside, subsequent event identification for research or quality improvement (QI) purposes is challenging and often relies on the use of administrative billing codes. Prior research has shown that the use of administrative codes from International Classification of Diseases-9 (ICD-9) was both insensitive and nonspecific for identification of IHCA events. However, the performance of this approach using updated ICD-10 codes has not been established.

Hypothesis:
ICD-10 codes can be used to identify IHCAs in a QI database of IHCA events with high sensitivity.

Methods:
We performed a retrospective cohort study of all adult IHCA patients (
>
18 years old) at the Hospital of the University of Pennsylvania from 06/2018-03/2022. True IHCA events were confirmed by a research coordinator and a physician through detailed encounter-level chart review of clinical records. We searched for four individual ICD-10 diagnostic codes: ICD I46.2 - cardiac arrest due to underlying cardiac condition; ICD I46.8 - cardiac arrest due to other underlying condition; ICD I46.9 - cardiac arrest, unspecified; and ICD I49.01 - ventricular fibrillation. ICD-identified IHCA was defined as the presence of any of these codes from a hospital stay but not present on hospital arrival.

Results:
Of 466 patients with a confirmed IHCA event contained within the QI database, the median age was 65 (54-73), 43% (199/466) were female, and 69% (323/466) had sustained return of spontaneous circulation (ROSC) at the end of their code. The use of billing codes identified 318 patients as having IHCA, corresponding to a sensitivity of 68%. The most used ICD-10 code in this cohort was ICD I46.9 (141/466, 30%).

Conclusions:
The use of ICD-10 codes has a low sensitivity for identification of IHCA events. These findings are consistent with previously published work using older ICD iterations and suggests significant limitations with using administrative codes to identify IHCA events. Novel approaches (e.g., natural language processing and machine learning algorithms) to identify IHCA may facilitate more accurate research and QI efforts.
Abstract 336: Bystander CPR Maintains Shockable Rhythm in Sudden Cardiac Arrest Across EMS Response Times
Authors: Reinier Kyndaron , Holmstrom Lauri , Chugh Harpriya , Uy-Evanado Audrey , Norby Faye L , Jui Jonathan , Chugh Sumeet S
Published: December 2023

Introduction:
Presentation with shockable rhythm markedly improves survival from out-of-hospital sudden cardiac arrest (SCA). Shockable rhythms (ventricular fibrillation/tachycardia; VF/VT) are known to deteriorate to asystole or pulseless electrical activity (PEA) over time, but little population-based data is available regarding this phenomenon. Also, bystander CPR (BCPR) improves survival from SCA but its association with maintenance of shockable rhythms is unclear.

Hypothesis:
With longer EMS response time, the proportion of EMS-assessed shockable initial rhythms will decrease. BCPR may influence this association.

Methods:
We analyzed EMS-assessed initial rhythm of SCA cases from the Oregon SUDS study in the Portland, OR metro area (pop ~1 million). For this analysis, we included bystander-witnessed SCA cases (2002-2018) aged ≥18 with resuscitation attempted by EMS. SCA was defined as a sudden, unexpected pulseless condition of likely cardiac origin. We assessed initial rhythm proportions across EMS response times using Cochran-Armitage trend tests.

Results:
Among 3,309 SCA cases, 1,748 (53%) were bystander-witnessed, and of these, 706 (40%) received BCPR. Response time was 7.3 ± 3.4 minutes for cases with BCPR and 6.8 ± 3.1 minutes without BCPR (p=0.01). In the group receiving BCPR, the proportion with shockable rhythm remained near 60% across response times from <3 to ≥12 minutes (Figure, solid line; p=0.88), and proportions of PEA and asystole remained stable. In the group without BCPR, shockable rhythm declined from 70% at <3 minutes to 44% at ≥12 minutes response time (Figure, dashed line; p<0.001), while non-shockable rhythms increased.

Conclusions:
Among community-based SCA cases who received bystander CPR, there was no significant decrease in shockable rhythm as response time increased. In contrast, among SCA cases without bystander CPR, longer response times were associated with a lower proportion of shockable rhythms.
Abstract 363: Endothelial Nitric Oxide Mediates Protection of Isolated Cardiomyocytes by Poloxamer 188 Against Hypoxia Reoxygenation Injury
Authors: Li Zhu , Barajas Matthew , Oyama Takuro , Riess Matthias L
Published: December 2023

Background:
Poloxamer (P) 188, a copolymer-based cell membrane stabilizer, has been suggested to alleviate myocardial ischemia/reperfusion injury through cell membrane stabiliztion. Recent studies found that cell-to-cell interactions between endothelial cells (ECs) and cardiomyocytes (CMs) can further protect CMs: data from our co-culture model showed that ECs, at an appropriate density, promoted protection by P188 against hypoxia/reoxygenation (HR) injury evidenced by reduced release of lactate dehydrogenase (LDH) from CMs; however, the mechanism of interaction was yet to be explored. In the present study, we examined whether L-NAME, a nitric oxide (NO) synthase inhibitor, abrogates LDH release and/or Ca
2+
overload in CMs in the presence or absence of P188 and ECs.

Methods:
Mouse coronary artery ECs, plated at densities of 25,000 per insert, were co-cultured with mouse CMs plated at confluency on the bottom of the corresponding well. Normoxic controls were kept under normal O
2
and media conditions for 24 hours while HR groups underwent 24 h hypoxia at 0.01% O
2
in serum- and glucose-free media, followed by 2 hr reoxygenation in normal media. P188 (300 uM), L-NAME (40 mM) or vehicle were administered upon reoxygenation. Intracellular Ca
2+
and LDH release were measured by standard kits. Statistics: ANOVA and SNK, alpha = 0.05.

Results:
Consistent with previous observations, ECs at this low density did not affect HR-triggered LDH release or increased Ca
2+
in CMs by themselves; in the presence of P188, however, ECs were able to reduce LDH and Ca
2+
after HR (panel 1A, 2A) synergistically. L-NAME abrogated CM protection by P188 & ECs in both assays (panels 1B, 2B). Neither intervention had any effect under normoxic conditions (all panels).

Conclusion:
The current data in this co-culture model suggest that protection of CMs by P188 is mediated through endothelial NO release.
Abstract 374: Modified Physiologic Criteria for the Field Triage Scheme: Efficacy of Major Trauma Recognition in Different Age Groups Across Asia
Authors: Lin HaoYang , Chien Yu-Chun , Ko Ying-Chih , Tsai Min-Shan , Chin Kuan-Chen , Ma Matthew , Chiang Wen-chu ,   The PATOS Clinical Rsch Network
Published: December 2023

Introduction:
Identifying patients with major trauma in prehospital settings by Field Triage Scheme (FTS) is of paramount importance. The goal of the FTS was set with a sensitivity (Sn) of 95% and specificity (Sp) of 50% to identify patients with major trauma, although many studies showed it unachievable. A simplified FTS (sFTS) may offer a more rapid prehospital triage of patients. However, evidence of its accuracy remains unclear.

Hypothesis:
We examined the performance of identifying patients with major trauma by triage tools of sFTS, modified sFTS, and adding shock index (SI) in different age groups.

Methods:
We conducted a multinational retrospective cohort study involving a total of 51,622 adult trauma patients in the studied countries from 2016 to 2020, using data from the Pan-Asia Trauma Outcomes Study. We tested (1) sFTS comprising only physiological and anatomical criteria, (2) modified sFTS defined by fine-tuning the physiological criteria of GCS score < 15, respiratory rate <10 or ≥ 24 beats/minute, and systolic blood pressure < 110 mmHg, and (3) sequentially added a SI of ≧0.8, to compare their performance in identifying patients with major trauma. Major trauma was defined by injury severity score ≥ 16. The cubic-spline method was used to smooth the curves of Sn/Sp across ages.

Results:
The overall sensitivity and specificity of the sFTS, modified sFTS, and adding SI of 0.8 to modified sFTS were, 80.6%, 82.8%, 84.3%, and 58.5%, 53.7%, 49.2%, respectively. The trade-off of Sn/Sp was illustrated in Figure 1. The top Sn/Sp of the three triage tools was constantly at patients’ age of 50, with rapidly declining in both younger and older patients. The modified sFTS showed increasing sensitivity with more pronounced changes in the younger group. Adding the shock index further increased sensitivity in both younger and older groups.
Abstract 397: Hydrogen Inhalation in Combination With Hypothermic Temperature Control Improves Survival After Out-of-Hospital Cardiac Arrest
Authors: Minami Koji , Tamura Tomoyoshi , Narumiya Hiromichi , Suzuki Masaru ,   HYBRID II Study Group
Published: December 2023

Background:
In a randomized trial, we demonstrated that hydrogen (H
2
) inhalation improves the outcomes after cardiac arrest (CA). All patients underwent target temperature management (TTM) in this trial, but the selection of a target temperature between 32 and 36 °C varied per institutional protocol. This study aimed to investigate the interaction of H
2
and hypothermic TTM on survival after CA.

Methods:
This post-hoc analysis of a randomized controlled trial (HYBRID II Trial; jRCTs031180352) included comatose patients after cardiogenic out-of-hospital CA (OHCA). They received either 2% H
2
mixed oxygen (H
2
group) or oxygen alone (control group) for 18 hours under hypothermic TTM (<35°C) or normothermic TTM (35-36°C). A target temperature was reached quickly, maintained for 24 hours, and rewarmed over 48 hours. The survival rate was compared between the H
2
and control groups under hypothermic or normothermic TTM.

Results:
The analysis included 72 patients with outcome data (39 and 33 patients in the H
2
and control group, respectively). Hypothermic TTM was implemented in 25 (64%) and 24 (73%) patients in the H
2
and control group, respectively (P=0.46). Under hypothermic TTM, the 90-day survival rate was 88% (22/25) and 46% (11/24) in the H
2
and control group, respectively (P=0.01). In contrast, under normothermic TTM, 78% (7/9) and 79% (11/14) of patients survived 90 days in the H
2
and control group, respectively (P=0.93). The interaction between H
2
and hypothermic TTM was independently associated with 90-day survival in a multivariable logistic regression model (adjusted odds ratio 7.79 [95%CI: 1.46-41.6]), however, it was marginally significant in the Cox proportional hazards model (adjusted hazard ratio 0.33 [95%CI: 0.10-1.17]) after adjusting for confounding factors including age, sex, witness status, bystander CPR implementation, shockable rhythm, CA duration, and time from the return of spontaneous circulation to gas inhalation, respectively.

Conclusions:
H
2
in combination with hypothermic TTM improved 90-day survival after OHCA but not under normothermic TTM.
Abstract 406: Texas Out of Hospital Cardiac Arrest Disparities for Rural Patient Care From Statewide Out-of-Hospital Cardiac Arrest Data Registry - The Texas Cares Project
Authors: Karfunkle Benjamin L , Huebinger Ryan , Schulz Kevin , Gill Joseph , Bakunas Carrie A , Waller-Delarosa John , Witkov Richard , Panczyk Micah , Villa Normandy W , Bobrow Bentley
Published: December 2023

Introduction:
Out-of-hospital cardiac (OHCA) arrest victims from rural settings suffer worse outcomes. We evaluated the association between rural setting and post-arrest care and outcomes.

Hypothesis:
Receiving treatment for OHCA at a rural hospital will be associated with a lower rate of post OHCA care and lower rate of favorable neurologic outcomes (cerebral performance score 1 or 2).

Methods:
We performed a retrospective analysis of the Texas Cardiac Arrest Registry to Enhance Survival (CARES) from 2014-2021. We included adult OHCAs not listed as DNR. We defined hospital urbanicity as the proportion of OHCAs originating from rural census tracts. We defined hospitals as rural if more than 25% of included OHCAs were rural. We evaluated the association between rural hospital status and patient and prehospital care characteristics - age, race, initial rhythm, response time, bystander CPR - and hospital care characteristics - targeted temperature management (TTM) and percutaneous coronary intervention (PCI) rates. We evaluated the association between rural hospital status and favorable neurological outcomes with logistic regression, adjusted for patient and prehospital factors, hospital care, and census tract median household income.

Results:
We included 31,569 encounters with OHCA at 161 unique hospitals. The rural hospital group included 1,213 OHCA encounters (3.8%) at 25 hospitals (15.5%). Patient factors between groups were similar other than a higher rate of white patients in the rural group. Rates of angiography (16.1% non rural, 17.1% rural), PCI (8.2%, 8.7%), and TTM (30.6%,34.7%) were not statistically different. Treatment at rural hospitals was not associated with a statistically significant decreased odds of good neurological outcome (aOR 1.02, 95%ci 0.83-1.24).

Conclusion:
Treatment for OHCA at rural hospitals was not associated with a lower rate of post OHCA care or lower rate of favorable neurologic outcome
YKL-40 as a biomarker in various inflammatory diseases: A review
Authors: Hrabar Davor , Bakula Dejan , Vrkljan Nikolina , Ratkajec Valentina , Glavcic Goran , Miler Marijana , Pelajic Stipe , Rogic Dunja , Blazevic Nina , Pavic Tajana
Published: December 2023

YKL-40 or Chitinase-3-Like Protein 1 (CHI3L1) is a highly conserved glycoprotein that binds heparin and chitin in a non-enzymatic manner. It is a member of the chitinase protein family 18, subfamily A, and unlike true chitinases, YKL-40 is a chitinase-like protein without enzymatic activity for chitin. Although its accurate function is yet unknown, the pattern of its expression in the normal and disease states suggests its possible engagement in apoptosis, inflammation and remodeling or degradation of the extracellular matrix. During an inflammatory response, YKL-40 is involved in a complicated interaction between host and bacteria, both promoting and attenuating immune response and potentially being served as an autoantigen in a vicious circle of autoimmunity. Based on its pathophysiology and mechanism of action, the aim of this review was to summarize research on the growing role of YKL-40 as a persuasive biomarker for inflammatory diseases’ early diagnosis, prediction and follow-up (e.g., cardiovascular, gastrointestinal, endocrinological, immunological, musculoskeletal, neurological, respiratory, urinary, infectious) with detailed structural and functional background of YKL-40.
Paraoxonase and arylesterase activity of paraoxonase 1 and oxidative stress parameters in cervical intraepithelial neoplasia
Authors: Rajković Marija Grdić , Rašić Dubravka , Stojanović Ivana , Turčić Petra , Miletić Tomislav , Tomašković Andrea Hulina , Kačkov Maslać Sanja , Ćelap Ivana , Butorac Dražan
Published: December 2023

IntroductionParaoxonase 1 (PON1) is the enzyme that removes carcinogenic radicals from lipids. The aim of the study was to investigate the differences in PON1 activity and oxidation stress parameters between patients with cervical intraepithelial neoplasia (CIN) and healthy controls. Materials and methodsThe study included 65 women with CIN and 109 healthy women. Lipid parameters were determined on Cobas Integra 400 plus (Roche, Mannheim, Germany). Tiols and reduced glutathione (GSH) were determined spectrophotometric using Eliman reagent. Activity of PON1 was assessed with two substrates, paraoxon and phenylacetate by spectrophotometric method. Malondialdehyde (MDA) was determined by high performance liquid chromatography (Shimadzu Corporation, Kyoto, Japan). Mann-Whitney-test, t-test, χ2-test, correlation and logistic regression was used in statistical analysis. P < 0.05 was considered statistically significant. ResultsThe basal (P = 0.929) and NaCl-stimulated (P = 0.985) PON1 activity and activities standardised on the concentration of high-density lipoprotein (HDL; P = 0.076; P = 0.065, respectively) and apolipoprotein AI (apo AI; P = 0.444; P = 0.499, respectively) as well as PON1 phenotypes (P = 0.842) did not differ significantly between the groups. The PON1 arylesterase activity (53±19 kU/L vs. 77±17 kU/L; P < 0.001) and HDL-standardized activity (37 (28-44) kU/mmol vs. 43 (37-50) kU/mmol; P < 0.001) and apoAI (29±11 kU/g vs. 44±11 kU/g; P < 0.001) was significantly reduced in the CIN group. The concentration of the thiol groups was similar (P = 0.519), of MDA was lower (0.39 (0.27-0.55) µmol/L vs. 0.76 (0.57-1.15) µmol/L; P < 0.001) and of GSH was higher (112.0 (66.0-129.6) µg/mL vs. 53.4 (34.8-134.4) µg/mL; P < 0.001) in the CIN group. ConclusionReduced PON1 arylesterase activity, lower MDA and higher GSH concentration were observed in CIN patients.
Elevated plasma pyruvate kinase M2 concentrations are associated with the clinical severity and prognosis of coronary artery disease
Authors: Huang Yu , Zhang Jing-kun , Wu Xue , Ma Hang-hao , Zhang Xin-tao , Xu Yi-wei , Zhao Zi-wen
Published: December 2023

IntroductionPyruvate kinase M2 (PKM2) was involved in the pathophysiology of atherosclerosis and coronary artery disease (CAD). We tested whether plasma PKM2 concentrations were correlated with clinical severity and major adverse cardiovascular events (MACEs) in CAD patients. Materials and methodsA total of 2443 CAD patients and 238 controls were enrolled. The follow-up time was two years. Plasma PKM2 concentrations were detected by enzyme-linked immunosorbent assay (ELISA) kits (Cloud-Clone, Wuhan, China) using SpectraMax i3x Multi-Mode Microplate Reader (Molecular Devices, San Jose, USA). The predictors of acute coronary syndrome (ACS) were assessed by logistic regression analysis. The association between PKM2 concentration in different quartiles and MACEs was evaluated by Kaplan-Meier (KM) curves with log-rank test and Cox proportional hazard models. The predictive value of PKM2 and a cluster of conventional risk factors was determined by Receiver operating characteristic (ROC) curves. The net reclassification improvement (NRI) and the integrated discrimination improvement (IDI) were utilized to evaluate the enhancement in risk prediction when PKM2 was added to a predictive model containing a cluster of conventional risk factors. ResultsIn CAD patients, PKM2 concentration was the independent predictor of ACS (P < 0.001). Kaplan-Meier cumulative survival curves and Cox proportional hazards analyses revealed that patients with a higher PKM2 concentration had higher incidence of MACEs compared to those with a lower PKM2 concentration (P < 0.001). The addition of PKM2 to a cluster of conventional risk factors significantly increased its prognostic value of MACEs. ConclusionBaseline plasma PKM2 concentrations predict the clinical severity and prognosis of CAD.
A case of functional vitamin B12 deficiency after recreational nitrous oxide use
Authors: Leleu Damien , Denimal Damien
Published: December 2023

The recreational use of nitrous oxide as laughing gas becomes a real public health issue among adolescents and young adults. Chronic use is deleterious and can lead to severe neurological disorders. Nitrous oxide inactivates vitamin B12, and the functional defect of vitamin B12 plays a major role in the pathogenesis of nitrous oxide-related neurological disorders. Here we report the case of a 22-year-old woman who came to the hospital after an unexplained loss of consciousness. She exhibited typical features of vitamin B12 or folate deficiency such as macrocytic anemia and hypersegmented neutrophils. However, serum concentrations of folate and vitamin B12 were normal. In contrast, circulating concentrations of total homocysteine and methylmalonic acid were significantly increased. These results clearly indicated a defect in vitamin B12 functions. The reason for this defect was clarified when she revealed that she had been consuming nitrous oxide recreationally for over a year. The present case points out the challenges in diagnosing vitamin B12 deficiency in the context of nitrous oxide abuse due to normal concentrations of total serum vitamin B12 in a significant proportion of cases. The medical community should be aware of how difficult it can be to interpret B12 status in this specific population.
Detecting the interferences in adrenocorticotropic hormone measurement - three cases reinforcing the efficiency of the complementary clinical and laboratory audit
Authors: Yetkin Ilhan , Karakoc Mehmet Ayhan , Akturk Mujde , Altinova Alev Eroglu , Gulbahar Ozlem , Osmanov Zakir , Yalcin Mehmet Muhittin , Barlas Tugba , Toruner Fusun Balos
Published: December 2023

Accurate measurement of adrenocorticotropic hormone (ACTH) is crucial in the evaluation of pituitary and adrenal disorders. Although great progress has been achieved in ACTH measurement with immunometric assays, interference may occur and adversely affect the clinical management. The report contributes to compiling the evidence on the clinical challenges with the management of the interferences in the ACTH measurement by presenting three cases: two with clinically overt hypercortisolism and discrepant ACTH concentrations within the reference interval; the third case describes the falsely elevated ACTH in a patient with secondary adrenal insufficiency. In all patients, the results obtained with the two immunometric platforms, chemiluminescence (CLIA) immunoassay (Siemens, Immulite) and electrochemiluminescence (ECLIA) immunoassay (Roche, Cobas), were discordant. Serial dilution of plasma samples revealed nonlinearity. After polyethylene glycol (PEG) precipitation recoveries were less than 22%, 26%, and 3%, respectively, supporting interference. Moreover, a decrease in ACTH concentration after incubation in a heterophile antibody-blocking tube was observed in the second case. In the first case, misinterpretation of ACTH led to inferior petrosal sinus sampling (IPSS), whereas timely detection of assay interference prevented further investigations in other cases. Increasing awareness regarding ACTH interference and comprehensive approach in evaluation could allow timely detection, helping to prevent unnecessary testing and perplexing clinical outcomes.
BIKAS: Bio-Inspired Knowledge Acquisition and Simulacrum—A Knowledge Database to Support Multifunctional Design Concept Generation
Authors: Velivela Pavan Tejaswi , Zhao Yaoyao Fiona
Published: December 2023

A detailed acquisition, analysis, and representation of biological systems exhibiting different functions is required to develop unique bio-inspired multifunctional conceptual designs and methods. This paper presents BIKAS: Bio-inspired Knowledge Acquisition and Simulacrum, a knowledge database of biological systems exhibiting various functionalities, developed based on case-based bio-inspired examples from literature. The knowledge database represents the biological features, their characteristics, and the function exhibited by the biological feature as a combination of its integrated structure and structural strategy. Furthermore, this knowledge database is utilized by the Expandable Domain Integrated Design (xDID) model that works on classifying, mapping, and representing biological features into their respective geometric designations called Domains. The combination of features from the Domains results in the generation of multifunctional conceptual designs. In addition, Meta-level design factors are proposed to aid designers in filtering the biological features and their respective functions having a similar structural strategy, thus aiding designers in rapidly selecting and emulating biological functions.