Return Of Spontaneous Circulation Rate Research Articles

Endovascular aortic occlusion improves return of spontaneous circulation after longer periods of cardiopulmonary resuscitation: A translational study in pigs

IntroductionResuscitative endovascular balloon occlusion of the aorta (REBOA) has emerged as an adjunct to CPR for nontraumatic cardiac arrest (NTCA). This translational study investigated the impact of varying low-flow duration (15- vs 30-mins) on REBOA's hemodynamic performance and ability to achieve return of spontaneous circulation (ROSC) in a porcine model. MethodsThirty-two pigs were anesthetized and placed into ventricular fibrillation. All animals received a 4-min no-flow period before CPR was initiated. Animals were randomized into four groups: 15- vs 30-minutes of CPR; REBOA vs. no-REBOA. After completion of 15- or 30-minute low-flow, ACLS was initiated and REBOA was inflated in experimental animals. ResultsIn the 15-mins groups, there were no differences in the rates of ROSC between REBOA (4/8, 50%) and control (4/8, 50%; p = 0.99). However, in the 30-min groups, the REBOA animals had a significantly higher rate of ROSC (6/8, 75%) compared to control (1/8, 12.5%; p = 0.04). In the 7-mins after REBOA deployment in the 30-min animals there was a statistically significant difference in coronary perfusion pressure (REBOA 42.1 mmHg, control 3.6 mmHg, p = 0.038). Importantly, 5/6 animals that obtained ROSC in the 30-min group with REBOA re-arrested at least once, with 3/6 maintaining ROSC until study completion. ConclusionIn our porcine model of NTCA, REBOA preferentially improved hemodynamics and ROSC after a 30-mins period of low-flow CPR. REBOA may be a viable strategy to improve ROSC after prolonged downtime, however, more hemodynamic support will be required to maintain ROSC.

Epidemiology and outcome of out-of-hospital cardiac arrest in Salt Lake City: Sex-based investigations.

Prior research indicates sex disparities in the incidence and outcomes of out-of-hospital cardiac arrest (OHCA). This study investigates the presence of such differences in Salt Lake City, Utah. We analyzed data from the Salt Lake City Fire Department (2008‒2023). We included adults with non-traumatic OHCA. We calculated the annual incidence of OHCA and examined sex-specific survival outcomes using multivariable logistic regression, adjusting for OHCA characteristics known to be associated with survival. The annual incidence of OHCA was 76 per 100,000 person-years. Among the 894 OHCA cases included in the analysis, 67.5% were males, 37.3% achieved return of spontaneous circulation (ROSC), and 13.6% survived hospital discharge. Unadjusted analysis revealed that males had significantly higher OHCA in public locations (43.9%vs. 28.6%), witnessed arrests (54.5%vs. 47.8%), and shockable rhythms (33.3%vs. 22.9%). Males also showed higher rates of ROSC (37.5%vs. 36.9%), hospital discharge survival (14.5%vs. 11.7%), and neurologically intact survival. After adjusting for the OHCA characteristics, there was no significant differences between males and females in ROSC, survival to hospital discharge, and favorable neurological function with adjusted odds ratios (male vs. female) of 0.92 (95% confidence interval [CI] 0.73‒1.16), 0.85 (95% CI 0.59‒1.22), and 0.92 (95% CI 0.62‒1.40), respectively. Approximately, 128 adults suffer OHCA in Salt Lake City annually. Males initially showed higher crude survival rates, but after adjusting for OHCA characteristics, no significant sex differences in survival outcomes were found. Enhancing OHCA characteristics could benefit both sexes. Investigations into the relationship between sex- and region-specific factors influencing OHCA outcomes are needed.

Infant out-of-hospital cardiac arrest during nights and weekends

BackgroundA growing body of evidence suggests outcomes for cardiac arrest in adults are worse during nights and weekends when compared with daytime and weekdays. Similar research has not yet been carried out in the infant setting. MethodsWe examined the National Emergency Medical Services Information System (NEMSIS), a database containing millions of emergency medical services (EMS) runs in the United States. Inclusion criteria were infant out-of-hospital cardiac arrests (patients <1 years old) taking place prior to EMS arrival between January 2021 and December 2022 where EMS documented whether return of spontaneous circulation (ROSC) was achieved. Cardiac arrests were classified as occurring during either the day (defined as 0800–1959) or the night (defined as 2000–0759) and weekends (Saturday/Sunday) or weekdays (Monday-Friday). Rates of ROSC achievement were compared. ResultsA total of 8549 infant cardiac arrests met inclusion criteria: 5074 (59.4%) took place during daytime compared with 3475 (40.6%) during nighttime, and 5989 (70.1%) arrests occurred on weekdays compared with 2560 (29.9%) on weekends. Rates of ROSC achievement were significantly lower on weekends versus weekdays (16.8% vs. 14.1%; p = 0.00097). A difference in ROSC rates when comparing daytime and nighttime was seen, but this difference was not statistically significant (16.4% vs. 15.3%; p = 0.08076). ConclusionROSC achievement rates for infant out-of-hospital cardiac arrest are significantly lower on weekends when compared with weekdays. Further study and quality improvement work is needed to better understand this.

A novel preclinical model of fentanyl-induced cardiorespiratory collapse to investigate resuscitation outcomes

Introduction: Opioid-related morbidities have become a critical public health concern, with ultrapotent synthetic opioids (UPSO) such as fentanyl contributing to the rise in opioid-related fatalities. Respiratory depression is the cardinal trait of fentanyl overdose, leading to systemic hypoxia and subsequent cardiorespiratory collapse (CRC). There is growing recognition that fentanyl induced CRC (fiCRC) is unique from other forms of sudden CRC. Yet, the consequences of fiCRC and its reversal remain poorly understood. This is due in part to the limited preclinical studies investigating rescue from fiCRC. Objective: using a novel model of fiCRC and subsequent reversal, this ongoing study aims to define the impact of UPSO and naloxone rescue on in vivo survival outcomes. Methods and Results: Male and female C57BL/6J mice were used. UPSO fentanyl i.v. administration (30 to 500 mcg/kg) suppressed breathing and subsequently led to fiCRC. The return of spontaneous circulation (ROSC) was achieved by performing manual chest compressions in combination of epinephrine administration after 8 minutes of fiCRC. In subset of mice, naloxone was administered post ROSC. Outcomes after 72 hours were accessed. The latency of fiCRC (mean arterial pressure at 40 mmHg) exhibited a negative correlation with the doses of fentanyl administered. Resuscitation from fiCRC was unreliable across the dose spectrum, while naloxone consistently rescued the majority of fiCRC animals. Naloxone increased ROSC rate from 54% to 86% when the dose of fentanyl was 30 mcg/Kg (n=22). With naloxone rescue, we compared fiCRC with non-opioid-induced cardiac arrest followed by potassium chloride injection (0.8 mg/g). Both models showed severe lung edema as evidenced by Evans Blue staining. However, the lung wet/dry weight ratio was higher in fiCRC group than in the non-opioid treatment group (5.50±0.05 vs. 6.60±0.60, n=4, p&lt;0.05). Survival in fiCRC group was significantly worse than in non-opioid treatment group (survival rate: 25% vs. 83%, n=17, p&lt;0.05). Conclusions: Our study highlights two important findings. First, the reliable resuscitation of fiCRC necessitates the use of naloxone. Second, the likelihood of injury is significant following successful rescue from fiCRC by naloxone. Our continued work using this fiCRC model will lead to insights that can be leveraged for strategies to mitigate injury and improve survival following fentanyl overdose. R01 HL163965 &amp; R01 DA057767. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Survival After Out-of-Hospital Cardiac Arrest Before and After Legislation for Bystander CPR

The lack of evidence-based implementation strategies is a major contributor to increasing mortality due to out-of-hospital cardiac arrest (OHCA) in developing countries with limited resources. To evaluate whether the implementation of legislation is associated with increased bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use and improved clinical outcomes for patients experiencing OHCA and to provide policy implications for low-income and middle-income settings. This observational cohort study analyzed a prospective city registry of patients with bystander-witnessed OHCA between January 1, 2010, and December 31, 2022. The Emergency Medical Aid Act was implemented in Shenzhen, China, on October 1, 2018. An interrupted time-series analysis was used to assess changes in outcomes before and after the law. Data analysis was performed from May to October 2023. The Emergency Medical Aid Act stipulated the use of AEDs and CPR training for the public and provided clear legal guidance for OHCA rescuing. The primary outcomes were rates of bystander-initiated CPR and use of AEDs. Secondary outcomes were rates of prehospital return of spontaneous circulation (ROSC), survival to arrival at the hospital, and survival at discharge. A total of 13 751 patients with OHCA (median [IQR] age, 59 [43-76] years; 10 011 men [72.83%]) were included, with 7858 OHCAs occurring during the prelegislation period (January 1, 2010, to September 30, 2018) and 5893 OHCAs occurring during the postlegislation period (October 1, 2018, to December 31, 2022). The rates of bystander-initiated CPR (320 patients [4.10%] vs 1103 patients [18.73%]) and AED use (214 patients [4.12%] vs 182 patients [5.29%]) increased significantly after legislation implementation vs rates before the legislation. Rates of prehospital ROSC (72 patients [0.92%] vs 425 patients [7.21%]), survival to arrival at the hospital (68 patients [0.87%] vs 321 patients [5.45%]), and survival at discharge (44 patients [0.56%] vs 165 patients [2.80%]) were significantly increased during the postlegislation period. Interrupted time-series models demonstrated a significant slope change in the rates of all outcomes. These findings suggest that implementation of the Emergency Medical Aid Act in China was associated with increased rates of CPR and public AED use and improved survival of patients with OHCA. The use of a systemwide approach to enact resuscitation initiatives and provide legal support may reduce the burden of OHCA in low-income and middle-income settings.

Use of Initial Endotracheal Versus Intravenous Epinephrine During Neonatal Cardiopulmonary Resuscitation in the Delivery Room: Review of a National Database

To assess whether initial epinephrine administration by endotracheal tube (ET) in newly born infants receiving chest compressions and epinephrine in the delivery room (DR) is associated with lower rates of return of spontaneous circulation (ROSC) than newborns receiving initial intravenous (IV) epinephrine. We conducted a retrospective review of neonates receiving chest compressions and epinephrine in the DR from the AHA Get With The Guidelines-Resuscitation registry from October 2013 through July 2020. Neonates were classified according to initial route of epinephrine (ET vs IV). The primary outcome of interest was ROSC in the DR. In total, 408 infants met inclusion criteria; of these, 281 (68.9%) received initial ET epinephrine and 127 (31.1%) received initial IV epinephrine. The initial ET epinephrine group included those infants who also received subsequent IV epinephrine when ET epinephrine failed to achieve ROSC. Comparing initial ET with initial IV epinephrine, ROSC was achieved in 70.1% vs 58.3% (adjusted risk difference 10.02; 95% CI 0.05-19.99). ROSC was achieved in 58.3% with IV epinephrine alone, and 47.0% with ET epinephrine alone, with 40.0% receiving subsequent IV epinephrine. This study suggests that initial use of ET epinephrine is reasonable during DR resuscitation, as there were greater rates of ROSC compared with initial IV epinephrine administration. However, administration of IV epinephrine should not be delayed in those infants not responding to initial ET epinephrine, as almost one-half of infants who received initial ET epinephrine subsequently received IV epinephrine before achieving ROSC.

Effects of physician-present prehospital care in patients with out-of-hospital cardiac arrest on return of spontaneous circulation: A retrospective, observational study in Saga, Japan.

Emergency medical services for out-of-hospital cardiac arrest (OHCA) vary according to region and country, and patient prognosis differs accordingly. In Japan, physicians may provide prehospital care. However, the effect of physician-present prehospital care on achieving return of spontaneous circulation (ROSC) in patients with cardiac arrest is not clear. Here, we aimed to examine the effect of physician-present prehospital care on the prognosis of patients with OHCA at our hospital compared with physician-absent care. In this retrospective, observational study, patients aged ≥18 years with non-traumatic OHCA from a single center in Saga City, Japan, between April 2011 and December 2019, were included. Patients were divided into two groups, based on prehospital physician presence or absence. Logistic regression analysis was used to determine the association between physician-present prehospital care and ROSC. Of 820 patients with OHCA, 151 had a physician present and 669 did not. Logistic regression analysis with no adjustment showed that the odds ratio (OR) of physician-present prehospital care for an increased ROSC rate was 1.74 (95% confidence interval [CI]: 1.22-2.48, p = 0.002). Logistic-regression analysis adjusted for ROSC-related factors indicated an ORof 1.05 (95% CI:0.47-2.34, p = 0.914) for physician-present prehospital care to ROSC. Physician-present prehospital care may not necessarily lead to increased ROSC rates. However, insufficient data limited our study findings. Further studies involving larger sample sizes are warranted.

Analysis of factors affecting the return of spontaneous circulation in elderly patients with out-of-hospital cardiac arrest

To investigate the factors that influence the return of spontaneous circulation (ROSC) in elderly patients suffering from out-of-hospital cardiac arrest (OHCA). A retrospective study was used to collect the clinical data of OHCA patients admitted to the emergency center of Zhengzhou People's Hospital from July 2016 to July 2019 based on the pre-hospital emergency database of Utstein model. Patients' gender, age, cardiac arrest (CA) etiology, presence or absence of bystander cardiopulmonary resuscitation (CPR), emergency response time, initial cardiac rhythm, ventilation method, use of epinephrine, defibrillation and ROSC were included. The patients were divided into elderly and young groups according to whether age ≥ 60 years old, and the differences in various indicators between the two groups were compared. Univariate Logistic regression analysis was used to analyze the relationship between emergency response time and ROSC in elderly patients and multivariate Logistic regression analysis was used to identify factors influencing ROSC in elderly patients. A total of 3 429 adult OHCA patients were enrolled in this study, including 2 105 elderly patients (61.39%), and 1 324 young and middle-aged patients (38.61%). Compared to the young group, the proportion of females, non-cardiac causes and asystole as the initial rhythm was higher in the elderly group, the emergency response time was shorter, the rate of defibrillation and tracheal intubation, and the success rate of ROSC were lower (all P < 0.05). Among them, the proportion of cardiac arrest as the initial rhythm in elderly male patients was significantly higher than that of young male patients (P < 0.05); the proportion of non-cardiac causes in elderly female patients was significantly higher than that of young female patients, and the proportion of defibrillation was significantly lower than that of young female patients (all P < 0.05). Multivariate Logistic regression analysis showed that cardiac arrest as the initial rhythm was strongly associated with ROSC in elderly male patients [odds ratio (OR) = 0.126, 95% confidence interval (95%CI) was 0.045-0.352, P < 0.05]. Univariate Logistic regression analysis of the relationship between emergency response time and ROSC in elderly patients showed that although there was no significant difference in the ROSC success rate among elderly patients with various emergency response times, an emergency response time within 10 minutes was beneficial for ROSC in elderly patients. The success rate of ROSC is very low in elderly OHCA patients aged ≥60 years. Although the CPR-related indicators of elderly patients are significantly different from those of young patients, there are gender differences. The association between the elderly male patients and cardiac arrest as the initial rhythm is stronger, while OHCA caused by non-cardiac diseases is more common and defibrillable rhythm is less common in elderly female patients. It may be more beneficial for elderly patients to shorten the emergency response time and increase bystander CPR.

Outcomes of in-hospital cardiac arrests during and after office hours in a single tertiary centre in Singapore.

In-hospital cardiac arrest (IHCA) is a significant healthcare burden with a paucity of data in Singapore. Various factors, including time of cardiac arrest, affect survival from acute resuscitation. This was a retrospective cohort study that evaluated the characteristics of patients who sustained an IHCA, including the Cardiac Arrest Survival Post Resuscitation In-hospital (CASPRI) scores, and the impact of arrest time in 220 consecutive cardiac arrests occurring in a tertiary hospital. The primary outcome was rate of return of spontaneous circulation (ROSC) post-IHCA, and the secondary outcome was 90-day survival. The ROSC rate among patients with IHCA out of and during office hours was 69.5% and 75.4%, respectively (odds ratio [OR] 0.74, 95% confidence interval [CI] 0.39-1.42). There were no statistically significant differences between the CASPRI scores of both groups. After adjusted analysis, the OR of ROSC post-IHCA out of office hours as compared to that during office hours was 0.78 (95% CI 0.39-1.53). The 90-day survival rate of patients who had an IHCA out of and during office hours was 25.7% and 34.6%, respectively (OR 0.65, 95% CI 0.32-1.34). The adjusted OR of 90-day survival was 0.66 (0.28-1.59). The results of this observational study did not show an association between the timing of cardiac arrest and the rate of ROSC or 90-day survival.

Dispatchers trained in persuasive communication techniques improved the effectiveness of dispatcher-assisted cardiopulmonary resuscitation

BackgroundEarly recognition of cardiac arrest and early initiation of bystander cardiopulmonary resuscitation can increase the survival of patients with out-of-hospital cardiac arrest (OHCA). We compared dispatcher-assisted cardiopulmonary resuscitation (DACPR) effectiveness before and after using different communication models in the dispatching center. MethodWe analyzed dispatch recordings of non-trauma origin OHCA cases received by the Taichung dispatch center between May 1 to September 30, 2021, and November 1, 2021, to March 31, 2022. The dispatchers underwent an 8-hour training intervention consisting of targeted education using a new communication model for DACPR. Several outcome measures were evaluated, including the sustained return of spontaneous circulation and the time to first chest compression. ResultsWe included 640 cases in the preintervention group and 580 cases in the postintervention group. The return of spontaneous circulation (ROSC) rate, the time to first chest compression, and good neurological outcome were significantly improved in the postintervention group (20.9% vs. 31.0%, p < 0.001;168 seconds vs. 151 seconds, p = 0.004; 2.8% vs. 5.3%, p = 0.024, respectively). In subgroup analyses, the intervention was related to a statistical improvement in ROSC rate among patients whose caller was a family member (18.7% vs. 31.4%, p < 0.001). Among patients whose caller was female, both ROSC and good neurological outcome significantly improved after the intervention (19.8% vs. 36.6%, p < 0.001; 2.7% vs. 7.5%, p = 0.006, respectively). There was a statistical difference between the pre-intervention and post-intervention group with respect to ROSC rate among patients whose caller was family (the adjusted odds ratio:1.78, 95% CI: 0.59–1.25], p < 0.001.) or female (the adjusted odds ratio:3.18,95% CI: 1.77–5.70], p = 0.008.) in the multivariable regression model. ConclusionThe new communication model has enhanced the effectiveness of DACPR in terms of the ROSC rate, particularly when the caller was a family member or female, leading to improved rates of ROSC and favorable neurological outcomes.

Association Between Advanced Airway Management With Adrenaline Injection and Prognosis in Adult Patients With Asystole Asphyxia Out-of-hospital Cardiac Arrest.

The neurological prognosis of asphyxia is poor and the effect of advanced airway management (AAM) in the prehospital setting remains unclear. This study aimed to evaluate the association between AAM with adrenaline injection and prognosis in adult patients with asystole asphyxia out-of-hospital cardiac arrest (OHCA). This study assessed all-Japan Utstein cohort registry data between January 1, 2013 and December 31, 2019. We used propensity score matching analyses before logistic regression analysis to evaluate the effect of AAM on favorable neurological outcome. There were 879,057 OHCA cases, including 70,299 cases of asphyxia OHCAs. We extracted the data of 13,642 cases provided with adrenaline injection by emergency medical service. We divided 7,945 asphyxia OHCA cases in asystole into 5,592 and 2,353 with and without AAM, respectively. After 1:1 propensity score matching, 2,338 asphyxia OHCA cases with AAM were matched with 2,338 cases without AAM. Favorable neurological outcome was not significantly different between the AAM and no AAM groups (adjusted odds ratio [OR] 1.1; 95% confidence interval [CI], 0.5-2.5). However, the return of spontaneous circulation (ROSC) (adjusted OR 1.7; 95% CI, 1.5-1.9) and 1-month survival (adjusted OR 1.5; 95% CI, 1.1-1.9) were improved in the AAM group. AAM with adrenaline injection for patients with asphyxia OHCA in asystole was associated with improved ROSC and 1-month survival rate but showed no differences in neurologically favorable outcome. Further prospective studies may comprehensively evaluate the effect of AAM for patients with asphyxia.

The Impact of Double Sequential Shock Timing on Outcomes During Refractory Out –of-Hospital Cardiac Arrest

BackgroundAnimal studies suggest the efficacy of double sequential external defibrillation (DSED) may depend on the interval between the two shocks, or “DSED interval”. No human studies have examined this concept. ObjectivesTo determine the relationship between DSED interval and termination of ventricular fibrillation (VFT), return of spontaneous circulation (ROSC), survival to hospital discharge, and favourable neurological status (MRS < 2) for patients in refractory VF. MethodsWe performed a retrospective review of adult (≥18 years) out-of-hospital cardiac arrest between January 2015 and May 2022 with refractory VF who received ≥1 DSED shock. DSED interval was divided into four pre-defined categories. We examined the association between DSED interval and patient outcomes using general estimated equation logistic regression or Fisher's exact test. ResultsAmong 106 included patients, 303 DSED shocks were delivered (median 2, IQR 1-3). DSED intervals of 75-125 msec (OR 0.39, 95% CI 0.16-0.98), 125-500 msec (OR 0.36, 95% CI 0.16-0.82), and >500 msec (OR 0.27, 95% CI 0.11-0.63) were associated with lower probability of VF termination compared to <75 msec interval. DSED interval of >75 msec was associated with lower probability of ROSC compared to <75 msec interval (OR 0.37, 95% CI 0.14-0.98). No association was noted between DSED interval and survival to hospital discharge or neurologic outcome. ConclusionsAmong patients in refractory VF a DSED interval of less than 75 msec was associated with improved rates of VF termination and ROSC. No association was noted between DSED interval and survival to hospital discharge or neurologic outcome.

Assessing the influence of abdominal compression on time to return of circulation during resuscitation of asphyxiated newborn lambs: a randomised preclinical study.

During neonatal resuscitation, the return of spontaneous circulation (ROSC) can be achieved using epinephrine which optimises coronary perfusion by increasing diastolic pressure. Abdominal compression (AC) applied during resuscitation could potentially increase diastolic pressure and therefore help achieve ROSC. We assessed the use of AC during resuscitation of asystolic newborn lambs, with and without epinephrine. Near-term fetal lambs were instrumented for physiological monitoring and after delivery, asphyxiated until asystole. Resuscitation was commenced with ventilation followed by chest compressions. Lambs were randomly allocated to: intravenous epinephrine (20 µg/kg, n=9), intravenous epinephrine+continuous AC (n=8), intravenous saline placebo (5 mL/kg, n=6) and intravenous saline+AC (n=9). After three allocated treatment doses, rescue intravenous epinephrine was administered if ROSC had not occurred. Time to achieve ROSC was the primary outcome. Lambs achieving ROSC were ventilated and monitored for 60 min before euthanasia. Brain histology was assessed for micro-haemorrhage. Use of AC did not influence mean time to achieve ROSC (epinephrine lambs 177 s vs epinephrine+AC lambs 179 s, saline lambs 602 s vs saline+AC lambs 585 s) or rate of ROSC (nine of nine lambs, eight of eight lambs, one of six lambs and two of eight lambs, respectively). Application of AC was associated with higher diastolic blood pressure (mean value >10 mm Hg), mean and systolic blood pressure and carotid blood flow during resuscitation. Cortex and deep grey matter micro-haemorrhage was more frequent in AC lambs. Use of AC during resuscitation increased diastolic blood pressure, but did not impact time to ROSC.

Chest compressions for pediatric organized rhythms: A hemodynamic and outcomes analysis

AimPediatric cardiopulmonary resuscitation (CPR) guidelines recommend starting CPR for heart rates (HRs) less than 60 beats per minute (bpm) with poor perfusion. Objectives were to (1) compare HRs and arterial blood pressures (BPs) prior to CPR among patients with clinician-reported bradycardia with poor perfusion (“BRADY”) vs. pulseless electrical activity (PEA); and (2) determine if hemodynamics prior to CPR are associated with outcomes. Methods and ResultsProspective observational cohort study performed as a secondary analysis of the ICU-RESUScitation trial (NCT028374497). Comparisons occurred (1) during the 15 seconds “immediately” prior to CPR and (2) over the two minutes prior to CPR, stratified by age (≤1 year, >1 year). Poisson regression models assessed associations between hemodynamics and outcomes. Primary outcome was return of spontaneous circulation (ROSC). Pre-CPR HRs were lower in BRADY vs. PEA (≤1 year: 63.8 [46.5, 87.0] min−1 vs. 120 [93.2, 150.0], p < 0.001; >1 year: 67.4 [54.5, 87.0] min−1 vs. 100 [66.7, 120], p < 0.014). Pre-CPR pulse pressure was higher among BRADY vs. PEA (≤1 year (12.9 [9.0, 28.5] mmHg vs. 10.4 [6.1, 13.4] mmHg, p > 0.001). Pre-CPR pulse pressure ≥ 20 mmHg was associated with higher rates of ROSC among PEA (aRR 1.58 [CI95 1.07, 2.35], p = 0.022) and survival to hospital discharge with favorable neurologic outcome in both groups (BRADY: aRR 1.28 [CI95 1.01, 1.62], p = 0.040; PEA: aRR 1.94 [CI95 1.19, 3.16], p = 0.008). Pre-CPR HR ≥ 60 bpm was not associated with outcomes. ConclusionsPulse pressure and HR are used clinically to differentiate BRADY from PEA. A pre-CPR pulse pressure >20 mmHg was associated with improved patient outcomes.

Thrombolytics in Cardiac Arrest from Pulmonary Embolism: A Systematic Review and Meta Analysis.

During cardiopulmonary resuscitation, intravenous thrombolytics are commonly used for patients whose underlying etiology of cardiac arrest is presumed to be related to pulmonary embolism (PE). We performed a systematic review and meta-analysis of the existing literature that focused on the use of thrombolytics for cardiac arrest due to presumed or confirmed PE. Outcomes of interest were return of spontaneous circulation (ROSC), survival to hospital discharge, neurologically-intact survival, and bleeding complications. Thirteen studies with a total of 803 patients were included in this review. Most studies included were single-armed and retrospective. Thrombolytic agent and dose were heterogeneous between studies. Among those with control groups, intravenous thrombolysis was associated with higher rates of ROSC (OR 2.55, 95% CI = 1.50-4.34), but without a significant difference in survival to hospital discharge (OR 1.41, 95% CI = 0.79-2.41) or bleeding complications (OR 2.21, 0.95-5.17). Use of intravenous thrombolytics in cardiac arrest due to confirmed or presumed PE is associated with increased ROSC but not survival to hospital discharge or change in bleeding complications. Larger randomized studies are needed. Currently, we recommend continuing to follow existing consensus guidelines which support use of thrombolytics for this indication.

Does the type of mechanical chest compressor affect resuscitation outcome of out of hospital cardiac arrest patients? A propensity-score based comparison of three devices

Abstract Background Mechanical cardiopulmonary resuscitation (CPR) devices are currently recommended when high-quality CPR could not be provided and only if used by trained rescuers. Guidelines are against their routinely use since clinical trials results are controversial, and solid evidence of improved survival are missing. Moreover, many studies compared these devices to very high-quality manual CPR, hardly replicable in a pre-hospital emergency setting. Nowadays, different machines are available but literature is poor in direct comparison studies. Purpose To assess whether the type of mechanical chest compressor could affect the probability of return of spontaneous circulation (ROSC) and of 30-days mortality after an out-of-hospital cardiac arrest (OHCA) as compared to manual standard CPR. Methods Data were prospectively collected from our Utstein-based cardiac arrest registry. We considered all OHCAs from January 1, 2015 to December 31, 2022 from 7 provinces covered by the same regional emergency system (population covered 4.2mln. inhabitants) but equipped with three different types of mechanical compressor: Autopulse®; LUCAS® and Easy Pulse®. Patients treated with mechanical CPR and manual CPR were randomly matched via a multivariable logistic regression propensity score considering age, gender, witnessed OHCA, presence of bystander CPR, first rhythm recorded, EMS arrival time and lay defibrillation before EMS arrival. Logistic regression and COX regression models were performed and adjusted for resuscitation duration to investigate the association between the type of CPR and the probability of ROSC and of 30-day mortality. Results Among 13,203 OHCAs with attempted CPR, 10,497 (79.5%) received manual CPR and in 2,405 (18.2%) mechanical CPR [Easy Pulse® in 1,102(45.8%), Autopulse® in 776 (32.3%) and LUCAS® in 521 (21.7%)]. ROSC before hospital admission was obtained in 1,712 patients (13.0%) and 762 (5.8%) were alive after 30 days. After propensity score matching two homogeneous groups of 1,946 patients each (manual and mechanical CRP) were identified. The rate of ROSC and of 30-day survival were lower in the mechanical CPR group (ROSC: 14.7% vs 24.1%; p&amp;lt;0.001; 30-day survival 6% vs 14%; p&amp;lt;0.001). The three devices showed an independent association with the probability of ROSC as compared to manual CPR [Autopulse®: OR 1.76, 95% CI (1.36-2.28) p&amp;lt;0.001; LUCAS®:OR 1.55, 95% CI (1.13-2.13), p=0.006 and Easy Pulse®:OR 0.49; 95% CI (0.37-0.65), p&amp;lt;0.001] (Figure 1A). Only Autopulse® was independently associated with 30-day mortality [AutoPulse HR 0.87, 95%CI (0.79-0.97), p=0.01; LUCAS®: HR 1.00, 95%CI (0.88-1.14), p=0.97) and Easy Pulse®: HR: 1.06, 95%CI (0.97-1.16), p=0.19] (Figure 1B). Conclusions This is the first study comparing the performance of three devices for mechanical chest compressions revealing that they differently affect the probability of ROSC and of 30-day survival.

Abstract 315: Endovascular Aortic Occlusion Preferentially Improves Hemodynamics and Return of Spontaneous Circulation After Longer Periods of Cardiopulmonary Resuscitation: A Translational Study in Swine

Introduction: Non-traumatic cardiac arrest (NTCA) is associated with low survival and substantial societal cost. Standard-of-care treatments, such as cardiopulmonary resuscitation (CPR) and advanced cardiac life support (ACLS), have limitations in restoring cardiac function and improving outcomes. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has emerged as an adjunct to CPR for NTCA. However, the optimal patient population that will benefit most from REBOA remains uncertain. Goals: This translational study investigated the impact of varying low-flow duration (15- vs 30-mins) on REBOA's hemodynamic performance and ability to achieve return of spontaneous circulation (ROSC) in a swine model of NTCA. Methods: Thirty-two swine were anesthetized and placed into ventricular fibrillation. All animals received a 4-min “no-flow” period before mechanical CPR was initiated. Animals were randomized into four groups to receive: 1) 15- vs 30-minutes of CPR; 2) REBOA vs. no-REBOA (control). After completion of the 15- or 30-minute low-flow period, ACLS was initiated and REBOA was fully-inflated in experimental animals. Results: There were no differences in demographics or hemodynamics at baseline (T = -10-mins) or at randomization (T = +10-mins). In the 15-mins groups, there were no differences in the rates of ROSC between REBOA (4 / 8, 50%) and control (4 / 8, 50%; p = 0.99). However, in the 30-min group the REBOA animals had a significantly higher rate of ROSC (6 / 8, 75%) compared to control (1 / 8, 12.5%; p = 0.04). In the 7-mins (T = 34 - 41 mins) after REBOA deployment in the 30-min animals there was a statistically significant difference in diastolic blood pressure (repeated measures ANOVA; p = 0.027). Importantly, 5 / 6 (83%) animals that received ROSC in the 30-min group with REBOA re-arrested at least once with 3 / 6 (50%) maintaining ROSC until study completion. Conclusion: In our swine model of NTCA, REBOA preferentially improved hemodynamics and ROSC after a 30-mins period of low-flow CPR, compared to 15-mins of low-flow CPR. REBOA may be a viable strategy to improve ROSC after prolonged downtime. More hemodynamic support will be required to maintain ROSC. This has implications for patient selection in upcoming human trials of REBOA in NTCA.

Abstract 220: Association Between Initial Defibrillator Pad Position And Outcomes For Out-of-hospital Cardiac Arrest Patients Presenting With Shockable Rhythms

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&lt;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 196: Splenic Red Blood Cell Mobilization During Cardiac Arrest in Swine

Objective: The spleen can rapidly mobilize red blood cells (RBCs) to increase blood O 2 carrying capacity in response to a variety of stressors. However, the contribution of splenic RBC mobilization to blood oxygenation during cardiac arrest (CA) and its impact on resuscitation efforts have not been directly studied. Accordingly, we subjected splenectomized swine to CA to test the hypothesis that splenic RBC mobilization meaningfully affects blood O 2 content during CPR. Methods: Swine (n=18) were randomized to splenectomy (SPLX; n=9) or sham surgery (SHAM; n=9) 1-week before undergoing 8-minutes of electrically-induced VF CA followed by CPR with defibrillation and epinephrine (EPI; 0.015 mg/kg iv). Serial blood sampling was performed to assess hemoglobin, hematocrit, and blood O 2 content before CA, during CPR, and following return of spontaneous circulation (ROSC). Results: Compared to baseline, SHAM animals exhibited a significant 41±5% increase in hemoglobin and hematocrit and 30±4% rise in O 2 carrying capacity during CA that was absent after SPLX ( Figure ). Although this did not significantly affect the rate of ROSC between SPLX (44%) and SHAM (56%) groups, time to ROSC (779±196 vs. 455±37 sec; p=0.02) and EPI needed to achieve ROSC (3.3±1.3 vs. 1.4±0.2 boluses, p=0.04) were significantly higher after SPLX. Among animals that achieved ROSC (n=4/group), between-group differences in hemoglobin, hematocrit, and O 2 carrying capacity persisted for up to 90 min post-ROSC alongside a significant reduction in RBC count in SPLX (6.4±0.1 x 10 6 /μL) vs. SHAM (7.3±0.2 x 10 6 /μL) animals (p=0.01). Conclusion: Splenic RBC mobilization during CA contributes to a significant rise in blood O 2 carrying capacity that is evident during CPR and throughout the early post-ROSC period. The absence of this response is associated with a prolonged time to ROSC and additional hemodynamic support, suggesting that impaired splenic RBC mobilization may adversely affect outcomes after CA.

Outcomes of prehospital traumatic cardiac arrest managed by helicopter emergency medical service personnel in Japan: a registry data analysis

BackgroundTraumatic cardiac arrest (TCA) is associated with poor outcomes. Helicopter emergency medical services (HEMSs) are often used to transport critically ill patients to hospitals. However, the role of HEMS in the treatment of TCA remains unclear. Therefore, in this study, we aimed to determine the current status of patients with prehospital TCA managed by HEMS personnel in Japan and compare the outcomes of patients who experienced TCA before and after the arrival of HEMS.MethodsThe Japanese Society for Aeromedical Services registry data of patients managed by HEMS personnel from April 2015 to March 2020 were analyzed in this retrospective cohort study. HEMS arrival and physicians’ interventions at the scene were the variables of interest. The survival rate and neurological outcomes at 28 days after injury were analyzed.ResultsOf the 55 299 registered patients, 722 who experienced prehospital TCA were included in the analysis. The distribution of first-witnessed TCA was as follows: pre-emergency medical service (EMS) arrival (n = 426/722, 60.3%), after EMS arrival (n = 113/722, 16.0%), and after HEMS arrival (n = 168/722, 23.8%). The 28-day survival rate was 6.2% (n = 44/706), with a cerebral performance category of 1 or 2 in 18 patients. However, patients who experienced TCA after receiving interventions provided by physicians before HEMS arrival had the worst outcomes, with only 0.6% of them surviving with favorable neurological outcomes. Multivariable analysis revealed that securing the intravenous route by the EMS team (adjusted odds ratio: 2.43, 95% confidence interval [CI]: 1.11–5.30) and tranexamic acid infusion by the HEMS team (adjusted odds ratio: 2.78, 95% CI: 1.16–6.64) may have increased the return of spontaneous circulation (ROSC) rate.ConclusionsThe results of our study were similar to those reported in previous studies with regards to the use of HEMS in Japan for transporting patients with TCA. Our findings suggest that in patients with severe trauma, cardiac arrest after initiation of HEMS, the highest level of prehospital medical intervention, may be associated with an inferior prognosis. Tracheal intubation and administration of tranexamic acid by the EMS team may increase the rate of ROSC in TCA.