bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract Or115: Execution of Transesophageal Echocardiography in Cardiopulmonary Resuscitation for Patients with Out-of-hospital Cardiac Arrest (EXECT-CPR): A Clustered Randomized Clinical Trial
Authors: Chu Sheng-En , Sun Jen-Tang , Cheng Chiao-Yin , Ma Matthew , Chiang Wen-Chu
Published: November 2024

Background:
Current cardiopulmonary resuscitation (CPR) guidelines recommend chest compressions at "the center of the chest." However, studies have shown that over half of patients with out-of-hospital cardiac arrest (OHCA) experience aortic valve (AV) compression following this recommendation, which may worsen outcomes. We hypothesized that using transesophageal echocardiography (TEE) to guide chest compressions in adult OHCA patients, avoiding AV compression and targeting the left ventricle (LV), would improve outcomes compared to the conventional site.

Methods:
The EXECT-CPR trial was a single-center cluster randomized clinical trial enrolling adults (≥20 years old) with non-traumatic OHCA presenting to the emergency department (ED). Exclusion criteria included return of spontaneous circulation (ROSC) before ED arrival, extracorporeal CPR, pre-existing contraindications for TEE, do-not-resuscitate orders, or obvious signs of death. Patients were assigned to the TEE-guided or conventional group using biweekly cluster randomization. Both groups received standard advanced life support, except the intervention group's compression site, which was initially conventional then rapidly adjusted by TEE. The primary outcome was sustained ROSC (≥20 mins). Secondary outcomes included survival to ICU and discharge with favorable neurological outcomes. The sample size was estimated at 66/group. Analyses were performed on intention-to-treat (ITT) and per-protocol (PP) basis.

Results:
From June 26 to November 15, 2023, a total of 262 OHCA patients were sent to the ED, and 132 were enrolled in the final analysis (mean age 65 years, 66% male), with 66 in each group. In the TEE-guided group, TEE was successfully imaged in 53 patients (5.3 mins after arrival at the ED). Due to clinical situations, only 46 patients completed the assigned TEE-guided interventions. Of these, 35 patients, who were initially not compressed at the LV, had their compression sites successfully adjusted (9.2 mins after arrival at ED). In ITT analysis, the primary outcome was 29/66(43.9%) in the TEE-guided group and 26/66(39.4%) in the conventional group (odds ratio[OR] 1.21, P=0.60), while in PP analysis it was 20/46(43.5%) and 26/66(39.4%) (OR 1.18, P=0.67; adjusted OR 1.63, P=0.28). Secondary outcomes showed no significant differences.

Conclusion:
Among adults with non-traumatic OHCA, TEE-guided CPR with an adjusted compression site in the ED did not result in different outcomes compared to conventional CPR.
Abstract Sa1007: Chest Compressions to the Left of the Sternum are Associated with Higher Systolic Blood Pressure than to the Lower Sternum
Authors: Frank Kevin , cohen allison , Haddad Ghania , Berruti Alaina , Li Timmy , Young Elizabeth , Becker Lance , Jafari Daniel , Rolston Daniel
Published: November 2024

Introduction/Background:
Despite over 60 years of cardiopulmonary resuscitation (CPR), there is a paucity of evidence assessing the optimal location to perform chest compressions during cardiac arrest. Some recent imaging studies with transesophageal echocardiography (TEE) and computed tomography (CT) show that the left ventricular outflow tract (LVOT) is often the site of maximum compression with CPR, if using the AHA recommended site of the lower half of the sternum.

Research Questions/Hypothesis:
We hypothesize that chest compressions performed to the left of the sternum, where the left ventricle is more likely to be located, will be associated with higher systolic blood pressure (SBP) than those performed at the AHA-recommended lower half of the sternum.

Goals/Aims:
Our primary aim was to compare the highest SBP, measured on a femoral arterial line, during a chest compression (CC) interval at the AHA recommended location (Zone 1, Figure) versus those performed to the left of the sternum (Zone 2, 3, or 4, Figure). Secondarily, we compared the highest end-tidal CO2 (ETCO2) for chest compression intervals performed at Zone 1 vs. Zone 2, 3, or 4.

Methods/Approach:
We conducted a retrospective cohort study of video-recorded, adult, cardiac arrest resuscitations with changes in chest compression location in a quaternary care Emergency Department (ED) from 3/9/2021 to 2/20/2024. We excluded chest compressions at Zone 5 or 6. Wilcoxon rank sum tests were used to assess differences in SBP and ETCO2 among chest compressions performed at Zone 1 vs. Zones 2, 3, or 4.

Results/Data:
24 patients had SBP or ETCO2 recordings, 11 patients with SBP recordings, 18 patients with ETCO2 recordings, and 5 patients with both. For SBP, there were 28 CC intervals in Zone 1 and 32 CC intervals in Zone 2 or 4. The median SBP for Zone 1 was 67 mmHg (IQR 52.25-86.75 mmHg) vs. 103 mmHg (IQR 79-125 mmHg) for Zone 2 or 4 (p<0.001). For ETCO2, there were 44 CC intervals for Zone 1 and 32 for Zone 2, 3, or 4. The median ETCO2 in Zone 1 was 16 mmHg (IQR 12.75-23.75 mmHg) vs. 17.5 mmHg (IQR 13-31.25 mmHg) in Zone 2, 3, or 4 (p=0.517).

Conclusions:
Chest compressions to the left of the sternum are associated with higher SBP than compressions at the AHA recommended lower half of the sternum. ETCO2 was similar regardless of chest compression location.
Abstract Sa107: Course and Outcomes of Prehospital Advanced Airway Management Efforts in the Pragmatic Airway Resuscitation Trial (PART)
Authors: Moeller Kim , Powell Jonathan , Gage Christopher , Panchal Ashish , Wang Henry
Published: November 2024

Background:
Prehospital advanced airway management may be associated with important complications, such as failed insertion attempts or the need to replace a successfully inserted airway. Only limited data describe the course and outcomes of these efforts.

Objective:
Describe the reasons for abandoning or replacing advanced airway management devices in the Pragmatic Airway Resuscitation Trial (PART).

Methods:
Secondary analysis of PART, a multicenter trial comparing airway management in adult out-of-hospital cardiac arrests (OHCA). Paramedics performed laryngeal tube (LT) and endotracheal intubation (ETI) per study protocol. For unsuccessful advanced airway management, paramedics reported the reasons for abandoning further airway insertion attempts. For successful advanced airway events, paramedics reported the reasons for removing the device. We further determined the reasons for the emergency department (ED) removal of successfully placed prehospital airway devices. We analyzed the data using descriptive techniques, including frequency (%).

Results:
Of 3,004 patients, first airway techniques were LT 1,423, ETI 1,227, and BVM 354. First-effort success rates in advanced airways were LT 90.3% and ETI 51.6%. For the second effort, airway switches were LT to ETI [62 (45.0)] and ETI to LT [454 (76.4)]. Of 1,317 total ETI efforts, reasons for abandoning airway insertions were difficulty visualizing vocal cords [243 (18.5)], view obstructed by blood/vomit [(51 (3.9)], and difficult anatomy [50 (3.8)]. Of 1,928 total LT efforts, reasons for abandoning airway insertion were ventilation/device difficulties [39 (2.0)], uncertain placement [27 (1.4)], and obstruction by blood/vomit [20 (1.0)]. Reasons for removing successfully placed airways were ventilation/device difficulties [LT 37 (1.9); ETI 7 (0.5)], displacement [LT 19 (1.0); ETI 26 (2.0)], obstruction by blood/vomit [LT 20 (1.0); ETI 7 (0.5)], and uncertain placement [LT 17 (0.9); ETI 11 (0.8)]. Among 684 LTs transported to the ED, reasons for LT removal were unknown [416 (60.8)], physician discretion [194 (28.4)], and local protocol requirements [47 (6.9)].

Conclusion:
Abandonment of airway insertion was more common with ETI, mainly due to poor vocal cord visualization. Successfully placed airways were replaced infrequently. EDs replaced a large portion of prehospital LTs. These data highlight the challenges of placing and maintaining advanced airway devices.
Abstract Sa202: Detection of Spontaneous Circulation During Chest Compressions with Hands-Free Carotid Doppler. An Animal Study.
Authors: Faldaas Bjoern , Storm Benjamin , Lappegård Knut Tore , How Ole-jakob , Nilsen Bent Aksel , Kiss Gabriel , Skogvoll Eirik , Nielsen Erik , Torp Hans , Ingul Charlotte
Published: November 2024

Background:
During cardiopulmonary resuscitation (CPR), identifying the return of spontaneous circulation (ROSC) is challenging. Methods such as manual palpation, end-tidal carbon dioxide, and point-of-care ultrasound to detect ROSC are inaccurate, time-consuming, or intermittent. They may also require halting or prolonging no-compression time to identify signs of circulation. Maintaining a high compression fraction is associated with an increased likelihood of achieving ROSC.

Aim:
This study aimed to investigate if using a novel continuous hands-free carotid Doppler system (RescueDoppler (RD)) could identify ROSC during chest compressions by distinguishing between spontaneous and chest compression-generated carotid blood flow velocity.

Methods:
We used a porcine cardiac arrest model to investigate the RD. The RD probe was positioned and fixated over the carotid artery. An invasive blood pressure catheter was inserted in the contralateral carotid artery. An implantable cardioverter defibrillator (ICD) was utilized to induce sequences of ventricular fibrillation followed by defibrillation and chest compressions (cardiac arrest sequences). Compressions were administered manually at a rate of 100 or 50 compressions per minute or using a mechanical chest compression device (LUCAS). Doppler blood flow velocity curves were retrospectively analyzed for signs of ROSC by examining both spontaneous and/or compression-generated velocities (Fig. 1,2). We combined color M-mode and Doppler spectrum (Fig. 1) to differentiate between chest compression and spontaneous velocities.

Results:
Data from eight animals (mean weight 30 kg) and 56 cardiac arrest sequences were included. In the analysis, chest compressions were identified as tissue movements through the whole spectrum of the color M-mode, in the spectral display (Fig. 1), or both. Spontaneous velocities were identified in a specific carotid depth of the color M-mode and between compression-generated peak velocities in the Doppler specter (Fig. 1). ROSC was confirmed by pausing chest compressions and evaluating ECG and invasive blood pressure. We identified spontaneous circulation during manual and mechanical chest compressions in 55 of 56 sequences.

Conclusions:
In a porcine cardiac arrest model, with ROSC, we could differentiate between spontaneous circulation and chest compression-generated blood flow velocity of the carotid artery using RescueDoppler.
Abstract Sa205: Resuscitation and Antiarrhythmic Effects of Artificial Oxygen Carrier of HbV in Perioperative Severe Hemorrhagic Shock during Total Pneumonectomy Model
Authors: Takase Bonpei , Higashimura Yuko , Masaki Nobuyuki , Kinoshita Manabu , Adachi Takeshi , Nagata Masayoshi , Sakai Hiromi
Published: November 2024

Perioperative bleeding is fetal complication of thoracic surgery (0.3-1.8% of all lung resection). We reported effects of Liposome-encapsulated hemoglobin vesicle (HbV) in hemorrhagic shock. Phase I clinical trial of HbV was successfully performed. For future clinical trials, we investigated resuscitation and antiarrhythmic effects of HbV in pneumonectomy model by using optical mapping analysis (OMP) with Langendorff's method. Left total pneumonectomy was performed in SD rats (N=30). Immediately after pneumonectomy, repetitive 50% blood hemorrhage and resuscitation were conducted. HbV-administration (HbV-group), washed red blood cell-administration (wRBC-group), and 5% albumin-administration (ALB-group) were studied. Right mean ventricular pressure (RMVBP) and systemic mean blood pressure (SMBP) were measured. OMP including lethal arrhythmia (SVT/VF) induction by electrophysiological study (EPS) was performed. Ventricular arrhythmia (PVC/NSVT) numbers were counted. Blood chemistry of ALT, AST, CPK, Cr, troponin I (TnI) and lactate (LT) were measured. Tissue HIF1alpha expression were examined in heart, lung, liver, kidney and spleen. RMVBP increased to 20±4 to 45±3 mmHg by pneumonectomy, presumably worsening systemic circulation and proarrhythmic effect. Observation for 40 min after resuscitation showed that SMBP remained normal in HbV-group and wRBC-group, but not in ALB-group (Fig. 1). SVT/VF induction and PVC/NSVTs were observed in ALB-group, but suppressed in HbV-group and wRBC-group (Fig. 2). The values of action potential duration dispersion (APDd; index of lethal arrhythmias) in LV determined by OMP was comparable in the HbV-group and wRBC-group (APDd; HbV-group, wRBC-group vs. ALB-group;12±4,14±3 vs. 24±4* ms, P<0.01, Fig. 3). ALT, CPK, TnI and LT were increased in ALB-group only, but not those in HbV- and wRBC-group (values after resuscitation, HbV-group, wRBC-group vs. ALB-group; ALT, 28±8, 24±6 vs. 72±6* U/L; CPK, 241±61,154±76 vs. 732±175* U/L; TnI, 0.21±0.07, 0.21±0.06 vs. 3.54±0.84*ng/mL; LT, 0.8±0.2, 1.1±0.1 vs. 2.6±0.6* mmol/L; *P<0.01). HIF1alpha staining was observed in heart, liver and kidney only in ALB-group, but not in HbV- and wRBC-groups. Conclusions: HbV effectively preserves cardiac circulatory function due to anti-shock effect even in RVMBP overload, and it has anti-hypoxic effect leading to prevent lethal arrhythmias in perioperative hemorrhagic shock following total lung resection, which is useful finding in future HbV trials.
Abstract Sa207: Early Nebulized Inhaled Nitroglycerin Enhances Carotid Blood Flow Without Compromising Coronary Perfusion Pressure During CPR in a Swine Cardiac Arrest Model
Authors: Youngquist Scott , Kelly Christopher , Palatinus Helen , Ewer Nicole , Hoareau Guillaume , Johnson Michael
Published: November 2024

Introduction/Background:
Pulmonary vasodilators reduce pulmonary vascular resistance and may improve blood flow during CPR. However, most are not available outside of an ICU setting. Nitroglycerin is an inexpensive pulmonary vasodilator that EMS widely uses to treat chest pain.

Research Questions/Hypothesis:
We hypothesized that nebulized, inhaled nitroglycerin (NIN) would improve carotid blood flow (CBF) without reducing coronary perfusion (CPP) or arterial pressures.

Goals/Aims:
The principal aim of this investigation was to assess the hemodynamic effects of NIN administered during CPR in a swine model of cardiac arrest.

Methods/Approach:
N=17 Mixed breed Yorkshire swine (54
+
5 kg) were sedated, intubated, and placed under isoflurane general anesthesia. Following instrumentation with arterial and right atrial pressure catheters as well as a carotid flow probe, the fraction of inspired oxygen (FiO
2
) was titrated to achieve a PaO
2
of 80-100 mmHg. Ventricular fibrillation (VF) was then induced with a pacing catheter, and the ventilator turned off. After 7 minutes of untreated VF, mechanical chest compressions with a LUCAS device were initiated. Three minutes later, mechanical ventilation was resumed at prearrest settings with 100% FiO
2
. Two minutes later, 5 mL of either nebulized normal saline (NNS controls, n=9) or 10 mg of nitroglycerin (NIN treatment, n=8) was delivered through a nebulizer placed in line with the endotracheal tube, by random allocation. After 4 minutes of nebulized treatment, IV epinephrine (0.15 mg/kg) was administered, followed 2 minutes later by defibrillation. NIN or nebulized NS was continued until the volume was fully delivered, while standard ALS resuscitation proceeded until ROSC or 40 min of arrest had elapsed. Data were analyzed using mixed effects models.

Results/Data:
Prearrest hemodynamic and blood gas variables were similar between groups. There were no statistically significant differences in systolic or diastolic arterial pressures or CPP. However, there was a statistically significant increase in CBF following NIN (Figure). After 4 minutes of treatment, CBF in NIN-treated animals was approximately double that of NNS controls: 85 mL/min (95% CI 63-108 mL/min) vs 41 mL/min (95% CI 21-61 mL/min), respectively. ROSC was achieved in 3/9 (33%) NNS controls and in 5/8 (63%) of NIN-treated animals (p=0.23).

Conclusions:
In this small study, early NIN treatment resulted in superior CBF without decreasing arterial pressures or CPP.
Abstract Sa309: The Effect of Active Thoracic Deconstriction on Circumferential Constriction Cardiopulmonary Resuscitation
Authors: Paradis Aidan , Gaddy David , Moodie Karen , Mader Timothy , Dufresne Alexandre , Couturier Christine , Dufresne Simon , Davis Daniel , Sims Christopher , Paradis Norman
Published: November 2024

Introduction:
Active thoracic deconstriction (
ATD
) is an impactful addition to standard closed-chest CPR, thought to increase perfusion pressure (CPP) by augmenting venous return. Most studies of ATD, however, have been conducted using piston-based sternal compression CPR (
PBSC-CPR
), which can cause significant thoracic skeletal trauma. In contrast, circumferential constriction CPR (
CC-CPR
) does not cause significant structural damage, possibly preserving the thoracic-recoil-based venous return mechanism. If that is the case, CC-CPR would not benefit from ATD.

Hypothesis:
ATD has no effect on CC-CPR hemodynamic parameters.

Methods:
Ventricular fibrillation was induced in Yorkshire swine (n = 3
,
~30 kg). CPR was provided by a custom pneumatic CC-CPR system. ATD during CC-CPR was achieved by active deflation against a hard outer shell, called a cuirass, using Velcro interfaces between the animal, the belt, and the cuirass. CC-CPR was alternated in 45-second epochs between active pneumatic deflation with and without a rigid cuirass. Aortic (
Ao
) and right atrial (
RA
) pressures were measured, and coronary perfusion pressure (
CPP
) derived. ETCO2 and carotid flow were also measured. Results from all experiments were grouped by treatment type and subjected to Analysis of Variance.

Results:
39 epochs in three studies were included. There were no statistically significant differences (P < 0.1) in CPP, ETCO2, or carotid flows between treatment types (Table).

Conclusion:
Because of its much larger contact surface area, the total possible decompression force during CC-CPR is greater than during PBSC-CPR. Despite this, the presence or absence of the rigid cuirass—and thus active deconstriction—appeared to have no impact on hemodynamic parameters. This finding suggests that the benefit of ATD during PBSC may derive from compensating for the damaged thoracic recoil mechanism, not enhancement of an extant mechanism. If the skeletal trauma of PBSC-CPR devices is avoided, the apparent benefit of ATD might be lessened. Further study to test this potentially important hypothesis is indicated.
Abstract Sa401: Bystander Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest Cases in Chicago
Authors: Khosla Shaveta , Del Rios Marina , Kotini-Shah Pavitra , Schwerin O'Reilly Courtney , Froelich Elizabeth , Fokum Brenice , Campbell Teri , Markul Eddie , Tataris Katie , Weber Joseph , Vanden Hoek Terry
Published: November 2024

Introduction:
Bystander cardiopulmonary resuscitation (CPR) improves survival in out-of-hospital cardiac arrest (OHCA) cases. Nationally and locally, consistent efforts have been made in increasing awareness and training the public in CPR. In this study, we assessed the changes in bystander CPR rates over time, overall and by sex and race/ethnicity in Chicago.

Methods:
We analyzed OHCA cases served by Chicago Emergency Medical Services from 2014-2023. We excluded trauma cases, pediatric cases, cases that were missing bystander CPR information, cases from nursing homes and healthcare facilities, and cases from international airports. Average annual change was assessed along with a p-value for trend.

Results:
Of the 21,862 OHCA cases reported from 2014-2023, 58% were Black, 14% Hispanic and 24% White, and the remaining were categorized as other. Overall, the bystander CPR rate increased from 12.4% in 2014 to 43.9% in 2023. Yearly rates of bystander CPR improvement were initially inconsistent, but the rates have risen consistently since 2018 (with an average annual change of +5%, p=0.003).

Similar trends have been seen by race/ethnicity and sex. In White cases, the bystander CPR increased from 19% to 47% from 2014 to 2023 (average annual change of +6.2% from 2020 onwards, p=0.047). In Hispanic cases, the bystander CPR increased from 17% to 51% from 2014 to 2023; however, the increase was not consistent from year to year. During the same time period, bystander CPR increased in Black cases from 8% to 41% (average annual change of +5.4% from 2018 onwards, p=0.001). From 2014 to 2023, bystander CPR increased from 15% to 44% (annual change of +4.8% from 2018 onwards, p=0.005) in males, and from 9% to 43% (annual change of +5.4% from 2018 onwards, p=0.004) in females.

Conclusion:
Bystander CPR rates have improved significantly in Chicago. Since 2020, sharp increase in bystander CPR rates is coinciding with overall improvement in OHCA survival in Chicago. The impact of bystander CPR on survival in different racial/ethnic groups requires further study.
Abstract Sa402: CPR Coaches Improve Cardiopulmonary Resuscitation Guideline Adherence in Pediatric In-Hospital Cardiac Arrest
Authors: Jensen Savannah , Zhang Bin , Paff Zachary , Ely Kelly , Collins Kelly , Gibson Abigayle , James Kyesha , Loeb Daniel , Lautz Andrew , Zackoff Matthew , Tegtmeyer Kenneth , Gray James , Dewan Maya
Published: November 2024

Introduction:
Despite advances in resuscitation science and training, the quality of CPR performed during pediatric IHCA remains suboptimal in many cases. CPR coaches provide real-time guidance on CPR performance metrics to improve chest compression depth, rate, and fraction using a defibrillator with audiovisual feedback. While studies in simulation show improved guideline adherence with CPR coaches, there remains a gap in clinical data for IHCA.

Hypothesis:
CPR coaches using Zoll feedback defibrillators improve adherence to CPR quality metrics in IHCA patients in the PICU.

Methods:
This was a retrospective single center study at Cincinnati Children’s Hospital Medical Center of chest compression quality before and after CPR coach implementation for PICU patients with IHCA from August 2017 to October 2022. Study population included all patients <18 years of age who had a cardiac arrest occurring entirely within the PICU. Measured CPR quality metrics included chest compression rate, depth, and fraction obtained using data collected from the Zoll defibrillator. Statistical analysis used Student’s t-test for continuous variables and chi-square or Fisher’s exact test for categorical variables. Compliance was defined as the average depth, rate, and fraction over the entire event meeting guideline recommendations.

Results:
During the study period, there were 93 IHCA patients, 12 patients were excluded due to incomplete data. Of the remaining 81 events, 29 were pre-CPR coach implementation and 52 patients were post-CPR coach.

Depth compliance improved from 14% pre-CPR coach to 56% post-CPR coach (p <0.001). Improvement in depth compliance was most noticeable for IHCA events >20 minutes, 0% pre-CPR coach to 62% post-CPR coach (p=0.006). Compression rate improved from 76% to 89% (p=0.206), and compression fraction improved from 72% to 81% (p=0.386). Return of spontaneous circulation increased from 38% to 69% with the implementation of CPR coaching (p=0.006).

Total CPR duration was similar between the pre (25 ± 28 minutes) and post-CPR coach groups (18 ± 18 minutes, p=0.218). The average age for the pre-CPR coach group was lower (4.2 ± 5 years) compared to the post-CPR coach (6.8 ± 6 years, p= 0.05). Immediate causes of CPR were similar between the two groups.

Conclusion:
CPR coach presence was associated with improved adherence to CPR depth guidelines.
Abstract Sa405: Unlocking the Potential of Mechanical CPR: The Role of Real-Time Feedback Before Device Application
Authors: Miyazato Mitsuyuki , FUJITA KENSUKE , Douno Eri , Hagiwara Yoshihiro , Ogura Takayuki
Published: November 2024

Background:
Current AHA guidelines do not recommend routine use of Mechanical CPR devices due to the decline in CPR quality during their preparation and application. However, Manual chest compressions during transport can reduce CPR quality. In situations where maintaining high-quality CPR is challenging, Mechanical CPR devices are essential. We hypothesized that real-time feedback (RF) could help maintain the quality of Manual CPR before Mechanical CPR devices are activated.

Objectives:
To investigate the impact of RF on the quality of Manual CPR before the activation of Mechanical CPR devices.

Methods:
This retrospective observational study included OHCA cases where Mechanical CPR using the LUCAS 3® device was performed between May 2023 and February 2024. We compared chest compression quality parameters, including Depth Achievement Rate (≥5cm) (%), Depth (cm), Rate Achievement Rate (100-120/min) (%), Rate (/min), Longest Interruption (s), and Chest Compression Fraction (CCF) (%) during Manual chest compressions before the application of the Mechanical CPR device between two periods, using the ZOLL X Series® monitor. During the first 5 months, RF was not used, and EMS teams could not see RF data, but chest compression quality parameters were recorded. During the subsequent 5 months, RF was displayed, and the same parameters were recorded.

Results:
The results are summarized in the attached figure. There were 10 cases without RF and 37 with RF. The RF group showed significant improvements in depth achievement rate (≥5cm) and compression depth. The rate achievement rate (100-120/min) and compression rate were similar between groups. The longest interruption time was shorter in the RF group, and the CCF was higher, although these differences were not statistically significant. The median duration of Manual CPR before applying the Mechanical CPR device was longer in the RF group [382s, IQR 110-654] compared to the non-RF group [156s, IQR 67-283], p=0.065.

Conclusions:
RF significantly improved the depth achievement rate and compression depth during Manual CPR before applying Mechanical CPR devices. Trends towards shorter interruption times and higher CCF in the RF group suggest RF may help maintain CPR quality. However, the retrospective nature and limited sample size may affect the generalizability of the results.
Abstract Sa407: Chest Compression Oscillations and Computed Airway Opening Index during CPR Depend on Waveform Capnography Measurement Approach.
Authors: Leturiondo Mikel , Uriguen Jose Antonio , Daya Mohamud , Johnson Nicholas , Bhandari Shiv , Blackwood Jennifer , Ruiz de Gauna Sofia
Published: November 2024

Introduction:
Chest compressions during CPR cause oscillations in capnography waveforms. The airway opening index (AOI) was proposed to measure the amplitude of these oscillations. Studies indicate that AOI is inversely correlated with the change in intrathoracic pressure and that lower AOI values may reflect airway closure. However, little has been reported about how different waveform capnography approach may affect the appearance or amplitude of these oscillations.

Aim:
Quantify the differences in AOI values obtained from mainstream and sidestream waveform capnography.

Methods:
We retrospectively analyzed 25 monitor-defibrillator recordings having both concurrent mainstream and sidestream waveform capnography and spirometry-based tidal volume and inspiratory flow. Ventilations were automatically detected in the volume signal. Each ventilation was characterized by the end-tidal carbon dioxide (ETCO
2
) values measured using both tracings and annotated for the presence of chest compression oscillations. If the latter were found, oscillation amplitudes were measured in absolute value (mmHg) and AOI was computed as the average difference between each pair of peaks and troughs normalized to the ETCO
2
value of that ventilation.

Results:
A total of 3,275 ventilations were annotated with concurrent mainstream and sidestream capnography signal. From these, 695 had oscillations (21.2%) captured by either technology or both. All the oscillations were captured by the mainstream technology, but only 660 (95%) appeared in the sidestream recordings. The median (IQR) oscillation amplitude was 21.8 (7.5, 33.5) mmHg and 14.0 (5.0, 20.0) mmHg (
p
< 0.001), for mainstream and sidestream, respectively; and the AOI was 45.7% (31.3%, 62.8%) and 29.5% (12.9%, 41.8%), (
p
< 0.001).

Conclusion:
Oscillations in the capnogram generated by chest compressions during CPR were almost always larger when measured with mainstream technology, and 5% were missed entirely when measured by sidestream capnography. Likewise, calculated AOI values were also greater most of the time. Therefore, in the context of monitoring the quality of CPR through oscillations present or not in the capnogram, as well as regarding their amplitudes, waveform capnography approach should be considered.
Abstract Sa501: Neurological Prognostication in Cardiac Arrest Survivors: Correlation Between Biomarker Molecular Weight and Blood-Brain Barrier Disruption.
Authors: Jeon So Young , Park Jung Soo , Kang Changshin , You Yeonho , Min Jin Hong , Jeong Wonjoon , Ahn Hong Joon
Published: November 2024

Aims:
This study evaluated the association between blood-brain barrier (BBB) disruption and the molecular weights of biomarkers in predicting neurological outcomes in out-of-hospital cardiac arrest (OHCA) survivors who received targeted temperature management (TTM) and lumbar drainage therapy.

Methods:
This observational study used data from a prospectively collected TTM registry at a tertiary academic hospital.Serum levels of neuron-specific enolase (NSE, 47 kDa) and S100 calcium-binding protein B (S100B, 21 kDa) were measured immediately, 24 h, 48 h, and 72 h after return of spontaneous circulation (ROSC). To assess the extent of BBB disruption, the albumin quotient (Q
A
) was calculated at each time point of serum biomarker measurement using the formula: Q
A
= albumin [cerebrospinal fluid] / albumin [serum]. Degrees of BBB disruption were categorized as follows: a Q
A
value less than 0.007 was considered normal; a value within 0.007–0.01 indicated mild disruption; a value within 0.01–0.02 indicated moderate disruption; and a value greater than 0.02 indicated severe disruption. Prognostic performances were evaluated using the areas under receiver operating characteristic curves (AUC). The primary outcome was poor neurological outcome 6 months after ROSC defined as Cerebral Performance Category scores of 3–5.

Results:
A total of 562 serum biomarker levels (371 NSE and 191 S100B) in 106 patients (59% poor neurological outcome) were evaluated. Serum levels of NSE and S100B showed no statistically significant difference in prognostic performance for poor neurological outcomes (AUC 0.85 [0.81–0.88] vs. 0.83 [0.80–0.87], P=0.43). Serum NSE levels showed differences in prognostic performance depending on BBB integrity (AUC 0.65 [intact BBB] vs AUC 0.87 [disrupted BBB]), compared with S100B (AUC 0.83 [intact BBB] vs. 0.79 [disrupted BBB]) (Figure 1). In particular, serum NSE levels had higher predictive performance when the BBB was moderately or severe disrupted compared to when it was intact (Figure 2). Additionally, serum NSE levels demonstrated better predictive performance when BBB is disrupted (P< 0.001), whereas serum S100B levels demonstrated better predictive performance when BBB is intact (P = 0.004) (Figure 3).

Conclusions:
In this cohort study, the relationship between molecular weights of biomarkers and BBB intact/disruption demonstrated good prognostic performance for OHCA survivors. Prospective multicenter studies are needed to generalize our findings.
Abstract Sa504: Association between Dispatch-Performance and Outcomes after Out-of-Hospital Cardiac Arrest in North Carolina: A registry analysis
Authors: Yonis Harman Gailan Hassan , Kaltenbach Lisa , Blewer Audrey , Starks Monique , Powell Stephen , Monk Lisa , Jollis James , Al-Khalidi Hussein , Al-Khatib Sana , Mark Daniel , Malta Hansen Carolina , Vandeventer Steve , McNally Bryan , Granger Christopher , Krychtiuk Konstantin
Published: November 2024

Introduction:
Each year in the U.S., over 350,000 people experience out-of-hospital cardiac arrests (OHCA), with a survival rate of just 10%. Most do not receive bystander CPR before professional rescuers arrive. Telecommunicator CPR (T-CPR) allows dispatchers to guide callers in performing CPR, a practice recommended by the American Heart Association (AHA). This study investigates the association between T-CPR and time to first compression and clinical outcomes.

Methods:
This analysis included all OHCAs in North Carolina (NC) from July 1, 2022, to December 31, 2023, with data from the RACE-CARS trial embedded in the Cardiac Arrest Registry to Enhance Survival (CARES) dispatch module. Exclusions were pediatric, traumatic, EMS-witnessed arrests, cases in healthcare facilities, and cases where CPR was already in progress or data on dispatcher recognition of need for CPR were missing. The primary outcome was survival to hospital discharge with good neurological function (cerebral performance category 1 or 2).

Results:
Overall,1,903 OHCA cases met the inclusion criteria. Median (25
th
- 75
th
percentiles) age was 64 (50-75) years, 29.0% were Black, and 37.6% were female. Dispatchers recognized the need for CPR in 81.6% of cases and chest compressions were initiated in 63.0%. Median times from call receipt were: 87 sec (52-158) to recognition of cardiac arrest, 137 sec (88-215) to T-CPR instructions, and 213 sec (151-293) to first compression. Of the 997 cases with information available, 24.6% met the AHA-recommended time of <150 sec from call to first chest compression. Among patients meeting those criteria, there was a trend towards higher survival with good neurological outcomes compared to those that did not meet the benchmark (10.2% vs. 8.3%, p=0.4).

Conclusions:
In this contemporary OHCA population in NC, the AHA benchmark of median time from call to recognition of <90 sec was met while the benchmark for time from call to first chest compression <150 sec was not met in most cases. In patients with time to first chest compression of <150 sec, a numerically higher survival rate with good neurological outcome was observed but this was not statistically significant. These results emphasize the need for enhanced strategies to overcome barriers and improve T-CPR performance as part of the comprehensive strategy to improve cardiac arrest survival. Further analyses with adjustments for confounders are necessary to fully understand the implications of these findings.
Abstract Sa507: Neurological prognostication by gray-white matter ratio on dual-energy brain computed tomography for extracorpeal cardiopulmonary resuscitation patients
Authors: Li Boyangzi , Bentho Oladi , Bartos Jason , Fridman Renee , Mello Gregory , Dahiya Garima , Singh Rahul , Tandon Rishabh , Gutierrez Alejandra , Yannopoulos Demetris , Elliott Andrea
Published: November 2024

Introduction:
Gray-white matter ratio (GWR) on non-contrast head computed tomography (HCT) is a helpful tool in neuro-prognostication in post-cardiac arrest patients. Its usage is unclear for those with angiography due to residual contrast.

Hypothesis:
GWR remains valid for neuro-prognostication in comatose patients undergoing extracorporeal cardiopulmonary resuscitation (ECPR) followed by coronary angiography (CAG) after out-hospital cardiac arrest (OHCA).

Methods:
We performed a retrospective study of comatose OHCA adults post ECPR and CAG at University of Minnesota from January to June 2022 with dual energy HCT within 12 hours. GWR was measured at basal ganglia, centrum semiovale, and high convexity levels. Gray matter areas of interest included caudate nucleus, putamen, thalamus, and medial cortex. The white matter areas of interest included the genu of the corpus callosum, posterior limb of the internal capsule, and medial white matter. Circular regions of interest (ROI, 10-15 mm
2
) were placed bilaterally in corresponding areas to record the average attenuation in Hounsfield unit (HU). The basal ganglia, cerebrum, and overall GWRs were calculated as the ratio of average HU between the gray and white matter ROIs within the area. Primary outcome was inpatient death, further categorized by the primary cause being neurological or not. Logistic regression followed by receiver operating characteristic (ROC) curves was used to validate GWR in predicting death. All data analysis was performed by StataCorp Software (STATA 14).

Result:
25 patients were included in the study. 18 (72%) were male with a median age of 60 (interquartile range (IQR): 45-67). The initial HCT was obtained at 2.08 hours (median, IQR: 1.37–2.43) post ECPR cannulation. 7 (28%) patients died from brain death or herniation and 15 (60%) died from non-neurological causes. None had intracranial bleeding. 1 patient had unilateral hypodensity on initial HCT, suggesting an acute embolic infarct. Patients who died had lower GWRs on initial HCT (Figure 1). ROC regression showed all GWRs demonstrated good prognostic performance on inpatient death with area under the curve (AUC) of 0.6970 (basal ganglia), 0.8485 (cerebrum), and 0.7576 (overall) (Figure 2).

Conclusions:
GWR in early HCT has prognostic value in predicting neurological outcomes despite residual contrast. It may be used as a risk stratification tool for comatose OHCA patients undergoing ECPR and angiography.
Abstract Sa602: Novel gas mixture combined with an auto-transfusion tourniquet enhances cerebral O
2
transport and hemodynamic indices in CPR swine
Authors: Gavriely Noam , Rasanen Jukka , Abadi Saar Sharon sofia , Lamhaut Lionel , Hutin Alice , lidouren fanny , Abi Zeid Daou Yara , Tissier Renaud
Published: November 2024

Background:
The cognitive outcome of CPR is poor. This study aims to evaluate if enhancing blood flow to the brain and oxygen dissociation from the hemoglobin, improve cerebral O
2
delivery during CPR in cardiac arrest swine.

Methods:
Standard swine-CPR model of induced VF and recovery was treated with an auto-transfusion tourniquet (A-TT®; HemaShock® (HS) Oneg HaKarmel Ltd. Israel) and ventilation with a novel mixture of Oxygen – 30%, CO
2
– 5%, and Argon 65% (COXAR™). Five swine received the study treatment and 5 controls standard therapy. All animals were anesthetized, ventilated, and instrumented for blood draws and pressure measurements. Five minutes of no-CPR arrest were followed by 10 minutes of mechanical CPR with and without COXAR-HS enhancement followed by defibrillation and 45 minutes post ROSC follow-up of.

Results:
All 5 COXAR-HS™ animals were resuscitated successfully as opposed to 3 of the control animals (p=0.09 NS).
Hemodynamic indices:
Systolic (p<0.05), and diastolic (p<0.01) blood pressures, coronary (p<0.001) and cerebral (p<0.05) perfusion pressure were higher in the COXAR-HS group after ROSC, as well as cerebral flow and O
2
delivery (p<0.05). Blood pressure maintenance after ROSC required dose of norepinephrine in the 3 control animals that had ROSC vs the 5 COXAR-HS animals (p<0.05). PO
2
and SO
2
in the jugular vein exceeded 50 mmHg and 50%, respectively with COXAR-HS.

Discussion:
The COXAR-HS group hemodynamic and gas exchange were significantly superior post ROSC compared to the control. The higher PjvO
2
and SjvO
2
indicate enhanced O
2
delivery to the brain mitochondria, while limb compression by the HS counteracts the vasodilatory effect of the CO
2
. The much lower and less toxic F
I
O
2
in the COXAR-HS group was sufficient and there were no adverse effects of Argon.

Conclusions:
The combination of the HemaShock peripheral vasoconstrictive effect with the COXAR vasodilative effect enhance ROSC and brain oxygen delivery.
Abstract Sa707: The role of gender in conversations about suspected cardiac arrest with 9-1-1 callers and telecommunicators
Authors: Blewer Audrey , Hart Lauren , Joiner Anjni , Powell Stephen , Van Vleet Lee , Starks Monique , Siddiqui Fahad , Yoon Sungwon , Wee Glenda , Gonzalez Angel , Ostbye Truls , PrvuBettger Janet , King Heather
Published: November 2024

Introduction:
Women receive bystander cardiopulmonary resuscitation (BCPR) less frequently than men in public. Studies have demonstrated that the gender of the person calling 9-1-1 may influence receipt of BCPR for female patients with out-of-hospital cardiac arrests (OHCA). It is unknown how the tone, or the way a person speaks to someone else, and gender of the caller impact receipt of BCPR by gender of the patient.

Objectives:
We sought to understand whether the tone of the caller varies by gender of the caller and whether the tone impacts receipt of BCPR by gender of the patient.

Methods:
We performed a multiple methods retrospective analysis of 9-1-1 calls for suspected non-traumatic OHCAs in Durham, NC (08/2022-1/2024). Calls were professionally transcribed. We excluded pediatric arrests and those that occurred in a healthcare facility. We identified the gender of the caller and gender of the patient as well as receipt of BCPR. Using qualitative analysis, we coded a full range of tones through the transcripts and listening to the audio. Two team members double coded transcripts (AG, LH) and audio (LH, GW) until they reached interrater reliability. Theme matrix techniques were used to facilitate data analysis and presentation. Quantitative data were analyzed using descriptive statistics.

Results:
We included 170 total suspected OHCA calls. Mean age of patients was 56±20; 35% were women. Of these, 23% occurred in public and 50% received BCPR. When women called about women patients (16%), 50% received BCPR. When women called about men patients (42%), 51% received BCPR. When women were the callers, the primary tone was distressed (e.g.,
“Oh, my God. Give me one second, give me one second. I’m trying to think”)
, independent of patient gender
.
When men called about women patients (19%), 50% of women patients received BCPR. In contrast, when men called about men patients (21%), 53% of men patients received BCPR. When the caller was a man, the primary tone was assertive
(“Ma’am, she needs an ambulance!”
), independent of patient gender. Distressed or uncertain were also common tones for men callers
(“I really rather a paramedic go up there and do that.”; "Yes, yes, please! I don’t have time to talk!").

Conclusion:
Further research is needed to understand these interactions, including what types of interventions could improve equity and receipt of BCPR particularly for women.
Abstract Sa803: Duration of cardiopulmonary resuscitation and survival for pediatric patients with out-of-hospital cardiac arrest
Authors: Okubo Masashi , Komukai Sho , Izawa Junichi , Ramgopal Sriram , Callaway Clifton , Berg Robert
Published: November 2024

Background:
Prior studies have reported that a longer duration of prehospital cardiopulmonary resuscitation (CPR) before return of spontaneous circulation (ROSC) is associated with poor patient outcomes for adults with out-of-hospital cardiac arrest (OHCA). The association of CPR duration with survival has not been fully investigated for pediatric patients.

Aim:
To quantify the time-dependent probability of survival as a function of CPR duration among pediatric patients with OHCA.

Methods:
We conducted a secondary analysis of the Resuscitation Outcomes Consortium Epidemiologic Registry, a prospective multicenter OHCA registry at 10 sites in the US and Canada from 2011 through 2015. We included pediatric patients (<18 years) with emergency medical services (EMS)-treated OHCA. We estimated the time-dependent probability of subsequently surviving to hospital discharge if patients without prehospital ROSC at each minute of CPR duration received further CPR beyond the time point. The numerator was the number of patients without ROSC at each minute and subsequently survived to hospital discharge. The denominator was the number of patients without ROSC at each minute, excluding those who had termination of resuscitation before or at each minute.

Results:
Of 1,313 eligible pediatric patients (median [IQR] age, 1 [0-9] year; 773 [58.9%] were male), 236 (18.0%) achieved prehospital ROSC. The median interval from initiation of CPR by EMS clinicians to ROSC was 10 minutes (IQR 5-16 minutes). The time-dependent probabilities (95% CIs) of survival to hospital discharge among patients without ROSC were 7.9% (6.4%-9.4%) at 1 minute, 5.6% (4.3%-6.9%) at 5 minutes, 2.6% (1.6%-3.5%) at 10 minutes, 1.1% (0.4%-1.8%) at 15 minutes, and 0.6% (0.02%-1.3%) at 20 minutes of CPR duration. The point estimate of the probability became less than 1% at 17 minutes of CPR duration.

Conclusions:
In this analysis of a large multicenter OHCA registry, we quantified the time-dependent probability of survival to hospital discharge in each minute of CPR duration for pediatric OHCA. These findings provide EMS clinicians, patients, and their surrogates with insights into the likelihood of survival if pediatric patients without ROSC continue to receive further CPR.
Abstract Sa901: In-Hospital Cardiac Arrest After Cardiac Surgery: Incidence, Prognostic Features, and Outcomes at a Single Institution From 2011-2024
Authors: Goodman James , Fielding-Singh Vikram , Vogelsong Melissa
Published: November 2024

Introduction:
In the United States, the incidence of in-hospital cardiac arrest (IHCA) ranges from 0.1-0.5% and most larger studies report about 20% of patients survive to hospital discharge. IHCA after cardiac surgery is unique because patients are often monitored closely and arrest etiologies are frequently reversible. This may contribute to improved survival, however current data on cardiac arrest outcomes that reflect the rapidly evolving landscape of cardiac surgery and intensive care are lacking.

Aims:
To identify the incidence, prognostic features, and outcomes of cardiac arrest following cardiac surgery at a single high-volume academic center.

Methods:
We identified all adult (≥18 years) patients who underwent cardiac surgery and experienced in-hospital cardiac arrest at our institution from 2011-2024 in our local Society of Thoracic Surgery database. The primary outcome was the incidence of cardiac arrest after cardiac surgery. In an exploratory analysis, we fit a multivariable logistic regression for death before discharge, adjusting for variables noted in Tables 1 and 2. All analyses were performed in R (Version 2024.04.1+748). A p value < .05 was considered significant. No adjustment for the family-wise error rate was made – all analyses should be considered hypothesis-generating.

Results:
Of 10,152 surgeries, 263 cases (2.6%) of postoperative cardiac arrest were identified. Survival to discharge occurred in 123 (50%) of cases. Median age was 67 (IQR 57-75) and 103 (39%) patients were female (Table 1). In adjusted analyses, death before discharge was significantly associated with use of extracorporeal membrane oxygenation (OR 3.52, CI 1.51-8.23, p=0.003), postoperative dialysis (OR 3.27, CI 1.57-6.77, p=0.001), pre-operative stroke (OR 2.28, CI 1.17-4.46, p=0.016), post-operative stroke (OR 3.01, CI 1.04-8.73, p=0.042), and age (OR 1.03, CI 1.01-1.05, p=0.016) (Figure 1). Survival to discharge was associated with placement of permanent pacing device (OR 0.30, CI 0.11-0.81, p=0.017).

Conclusions:
Incidence of IHCA after cardiac surgery is much higher than in the general inpatient population. However, survival to discharge is also common, suggesting that cardiac surgical patients have distinctly different outcomes after IHCA compared to other inpatient populations. In an exploratory analysis, we identified several factors associated with survival to hospital discharge after cardiac arrest which can be examined in future studies.