Prolonged CPR Research Articles

Mortality Predictors and Neurological Outcomes Following Extracorporeal Cardiopulmonary Resuscitation (eCPR): A Single-Center Retrospective Study.

Extracorporeal cardiopulmonary resuscitation (eCPR) offers cardiorespiratory support to patients experiencing cardiac arrest. However, this technology is not yet considered a standard treatment, and the evidence on eCPR criteria and its association with survival and good neurological outcomes remains scarce. Therefore, we aimed to investigate the overall mortality and risk factors for mortality. Moreover, we provide a comparison of demographic, clinical, and laboratory characteristics of patients, including neurological outcomes and adverse events during support. This retrospective analysis included in-hospital and out-of-hospital cardiac arrest patients who received eCPR and were admitted between January 2008 and June 2022 at a tertiary and trauma one-level university hospital in Austria. In total, 90 patients fulfilled inclusion criteria, 41 (46%) patients survived until intensive care unit discharge, and 39 (43%) survived until hospital discharge. The most common cause of cardiac arrest was myocardial infarction (42, 47%), and non-shockable initial rhythm was reported in 50 patients (56%). Of 33 survivors with documented outcomes, 30 had a good recovery as measured with Cerebral Performance Category score, 2 suffered severe disability, and 1 remained in a persistent vegetative state. Finally, multivariate analysis identified asystole as initial rhythm (HR 2.88, p = 0.049), prolonged CPR (HR 1.02, p = 0.043), and CPR on the weekend (HR 2.57, p = 0.032) as factors with a higher risk of mortality. eCPR-related decision-making could be additionally supported by the comprehension of the reported risk factors for mortality and severe disability. Further studies are needed to elucidate the impact of peri-arrest variables on outcomes, aiming to improve patient selection.

2024 RECOVER Guidelines: Advanced Life Support. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR.

To systematically review the evidence and devise clinical recommendations on advanced life support (ALS) in dogs and cats and to identify critical knowledge gaps. Standardized, systematic evaluation of literature pertinent to ALS following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by Evidence Evaluators, and findings were reconciled by ALS Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk:benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4weeks prior to finalization. Transdisciplinary, international collaboration in university, specialty, and emergency practice. Seventeen questions pertaining to vascular access, vasopressors in shockable and nonshockable rhythms, anticholinergics, defibrillation, antiarrhythmics, and adjunct drug therapy as well as open-chest CPR were reviewed. Of the 33 treatment recommendations formulated, 6 recommendations addressed the management of patients with nonshockable arrest rhythms, 10 addressed shockable rhythms, and 6 provided guidance on open-chest CPR. We recommend against high-dose epinephrine even after prolonged CPR and suggest that atropine, when indicated, is used only once. In animals with a shockable rhythm in which initial defibrillation was unsuccessful, we recommend doubling the defibrillator dose once and suggest vasopressin (or epinephrine if vasopressin is not available), esmolol, lidocaine in dogs, and/or amiodarone in cats. These updated RECOVER ALS guidelines clarify the approach to refractory shockable rhythms and prolonged CPR. Very low quality of evidence due to absence of clinical data in dogs and cats continues to compromise the certainty with which recommendations can be made.

Associated Factors of Cardiopulmonary Resuscitation Outcomes; a Cohort Study on an Adult In-hospital Cardiac Arrest Registry.

In-hospital cardiac arrest (IHCA) remains a substantial cause of morbidity and mortality for hospitalized patients worldwide. This study aimed to identify associated factors of return of spontaneous circulation (ROSC) and survival with favorable neurological outcomes of IHCA patients. A two-year retrospective cohort study was conducted at a university-based tertiary care hospital in Bangkok, Thailand, studying adult patients aged ≥ 18 years with IHCA from January 2021 to December 2022. The primary endpoint was sustained ROSC, and the secondary endpoint was survival with favorable neurological outcomes defined as Cerebral Performance Categories (CPC) Scale of 1 or 2 at discharge. Pre-arrest and intra-arrest variables were collected and analyzed using multivariable logistic regression to identify independent factors associated with the outcomes. During the study period, 156 patients were included in the study. 105 (67.3%) patients achieved sustained ROSC after the CPR, 28 patients (18.0%) were discharged alive, and 15 patients (9.6%) survived with a favorable neurological outcome at hospital discharge. Overall, sustained ROSC was higher in patients who had IHCA during the day shift (odds ratio (OR): 4.11; 95% confidence interval (CI): 1.05-16.06) and electrocardiogram (ECG) monitoring prior to arrest (OR: 6.38; 95% CI: 1.18-34.54). In contrast, higher adrenaline doses administrated, and increased CPR duration reduced the odds of sustained ROSC (OR: 0.72; 95% CI: 0.54-0.94 and OR: 0.92; 95% CI: 0.85-0.98, respectively). Arrest due to cardiac etiology was associated with increased discharged survival with favorable neurological outcomes (OR: 13.43; 95% CI: 2.00-89.80), while a higher Good Outcome Following Attempted Resuscitation (GO-FAR) score reduced the odds of the secondary outcome (OR: 0.89; 95% CI: 0.81-0.98). The sustained ROSC was higher in IHCA during the daytime shift and under prior ECG monitoring. The administration of higher doses of adrenaline and prolonged CPR durations decreased the likelihood of achieving sustained ROSC. Furthermore, patients with cardiac-related causes of cardiac arrest exhibited a higher rate of survival to hospital discharge with favorable neurological outcomes.

ECPR for prolonged Pediatric Cardiac Arrest, an outcome without major neurological compromise

Pediatric in-hospital cardiac arrest (IHCA) has been reported in 1–3% of pediatric intensive care unit (ICU) admissions and up to 6% of children admissions to the cardiac ICU. In the last 25 years, the survival to hospital discharge after pediatric IHCA has improved from 9% to 13.7% up to 35%. The improvement in outcomes was attributed in part to the application of ECMO as a rescue strategy when prolonged conventional CPR cannot restore spontaneous circulation. We report a case of a 4-month-old patient with a history of ventricular and septal defects, with left to right shunt and enlargement of left heart chambers that underwent surgery for the closure of the atrial and septal defects, and experienced complications that led to the use of ECMO in response to a prolonged cardiac arrest.

The impact of BMI on arrest characteristics and survival of patients with out-of-hospital cardiac arrest treated with extracorporeal cardiopulmonary resuscitation

AimTo assess the impact of body mass index (BMI) on survival to hospital discharge of patients presenting with refractory ventricular fibrillation treated with extracorporeal cardiopulmonary resuscitation. We hypothesize that due to limitations in pre-hospital care delivery, people with high BMI have worse survival after prolonged resuscitation and ECPR. MethodsThis study is a retrospective single-centre study that included patients suffering refractory VT/VF OHCA from December 2015 to October 2021 and had a BMI calculated at hospital admission. We compared the baseline characteristics and survival between patients with obesity (>30 kg/m2) and those without (≤30 kg/m2). ResultsTwo-hundred eighty-three patients were included in this study, and two-hundred twenty-four required mechanical support with veno-arterial extracorporeal cardiopulmonary membrane oxygenation (VA ECMO). Patients with BMI > 30 (n = 133) had significantly prolonged CPR duration compared to their peers with BMI ≤ 30 kg/m2 (n = 150) and were significantly more likely to require support with VA ECMO (85.7% vs 73.3%, p = 0.015). Survival to hospital discharge was significantly higher in patients with BMI ≤ 30 kg/m2 (48% vs. 29.3%, p < 0.001). BMI was an independent predictor of mortality in a multivariable logistic regression analysis. The four-year mortality rate was low and not significantly different between the two groups (p = 0.32). ConclusionECPR yields clinically meaningful long-term survival in patients with BMI > 30 kg/m2. However, the resuscitation time is significantly prolonged, and the overall survival significantly lower compared to patients with BMI ≤ 30 kg/m2. ECPR should, therefore, not be withheld for this population, but faster transport to an ECMO capable centre is mandated to improve survival to hospital discharge.

Intraarrest transport, extracorporeal cardiopulmonary resuscitation, and early invasive management in refractory out-of-hospital cardiac arrest: an individual patient data pooled analysis of two randomised trials.

Refractory out-of-hospital cardiac arrest (OHCA) treated with standard advanced cardiac life support (ACLS) has poor outcomes. Transport to hospital followed by in-hospital extracorporeal cardiopulmonary resuscitation (ECPR) initiation may improve outcomes. We performed a pooled individual patient data analysis of two randomised controlled trials evaluating ECPR based approach in OHCA. The individual patient data from two published randomised controlled trials (RCTs) were pooled: ARREST (enrolled Aug 2019-June 2020; NCT03880565) and PRAGUE-OHCA (enrolled March 1, 2013-Oct 25, 2020; NCT01511666). Both trials enrolled patients with refractory OHCA and compared: intra-arrest transport with in-hospital ECPR initiation (invasive approach) versus continued standard ACLS. The primary outcome was 180-day survival with favourable neurological outcome (defined as Cerebral Performance Category 1-2). Secondary outcomes included: cumulative survival at 180 days, 30-day favourable neurological survival, and 30-day cardiac recovery. Risk of bias in each trial was assessed by two independent reviewers using the Cochrane risk-of-bias tool. Heterogeneity was assessed via Forest plots. The two RCTs included 286 patients. Of those randomised to the invasive (n=147) and standard (n=139) groups, respectively: the median age was 57 (IQR 47-65) and 58 years (IQR 48-66), and the median duration of resuscitation was 58 (IQR 43-69) and 49 (IQR 33-71) minutes (p=0.17). In a modified intention to treat analysis, 45 (32.4%) in the invasive and 29 (19.7%) patients in the standard arm survived to 180 days with a favourable neurological outcome [absolute difference (AD), 95% CI: 12.7%, 2.6-22.7%, p=0.015]. Forty-seven (33.8%) and 33 (22.4%) patients survived to 180 days [HR 0.59 (0.43-0.81); log rank test p=0.0009]. At 30 days, 44 (31.7%) and 24 (16.3%) patients had favourable neurological outcome (AD 15.4%, 5.6-25.1%, p=0.003), 60 (43.2%), and 46 (31.3%) patients had cardiac recovery (AD: 11.9%, 0.7-23%, p=0.05), in the invasive and standard arms, respectively. The effect was larger in patients presenting with shockable rhythms (AD 18.8%, 7.6-29.4; p=0.01; HR 2.26 [1.23-4.15]; p=0.009) and prolonged CPR (>45min; HR 3.99 (1.54-10.35); p=0.005). In patients with refractory OHCA, the invasive approach significantly improved 30- and 180-day neurologically favourable survival. None.

Supraglottic airway devices are associated with asphyxial physiology after prolonged CPR in patients with refractory Out-of-Hospital cardiac arrest presenting for extracorporeal cardiopulmonary resuscitation

BackgroundMultiple randomized clinical trials have compared specific airway management strategies during ACLS with conflicting results. However, patients with refractory cardiac arrest died in almost all cases without the availability of extracorporeal cardiopulmonary resuscitation (ECPR). Our aim was to determine if endotracheal intubation (ETI) was associated with improved outcomes compared to supraglottic airways (SGA) in patients with refractory cardiac arrest presenting for ECPR. MethodsWe retrospectively studied 420 consecutive adult patients with refractory out-of-hospital cardiac arrest due to shockable presenting rhythms presenting to the University of Minnesota ECPR program. We compared outcomes between patients receiving ETI (n = 179) and SGA (n = 204). The primary outcome was the pre-cannulation arterial PaO2 upon arrival to the ECMO cannulation center. Secondary outcomes included neurologically favorable survival to hospital discharge and eligibility for VA-ECMO based upon resuscitation continuation criteria applied upon arrival to the ECMO cannulation center. ResultsPatients receiving ETI had significantly higher median PaO2 (71 vs. 58 mmHg, p = 0.001), lower median PaCO2 (55 vs. 75 mmHg, p < 0.001), and higher median pH (7.03 vs. 6.93, p < 0.001) compared to those receiving SGA. Patients receiving ETI were also significantly more likely to meet VA-ECMO eligibility criteria (85% vs. 74%, p = 0.008). Of patients eligible for VA-ECMO, patients receiving ETI had significantly higher neurologically favorable survival compared to SGA (42% vs. 29%, p = 0.02). ConclusionsETI was associated with improved oxygenation and ventilation after prolonged CPR. This resulted in increased rate of candidacy for ECPR and increased neurologically favorable survival to discharge with ETI compared to SGA.

Acute lung injury and recovery in patients with refractory VT/VF cardiac arrest treated with prolonged CPR and veno-arterial extracorporeal membrane oxygenation

AimDescribe the lung injury patterns among patients presenting with refractory ventricular tachycardia/ventricular fibrillation out-of-hospital cardiac arrest (VT/VF OHCA) supported with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) facilitated resuscitation. MethodsIn this retrospective single-center cohort study including VT/VF OHCA patients supported with VA ECMO, we compared OHCA characteristics, post-arrest computed tomography (CT) scans, ventilator parameters, and other lung-related pathology between survivors, patients who developed brain death, and those with other causes of death. ResultsAmong 138 patients, 48/138 (34.8%) survived, 31/138 (22.4%) developed brain death, and 59/138 (42.7%) died of other causes. Successful extubation was achieved in 39/138 (28%) with a median time to extubation of 8.0 days (6.0, 11.0) in those who survived. Tracheostomy was required in 15/48 (31.3%) survivors. Chest CT obtained on all patients showed lung injury in at least one lung area in 124/135 (91.8%) patients, predominantly in the dependent posterior areas. There was no association between the number of affected areas and survival. Lung compliance was low on admission [26 (19,33) ml/cmH20], improved throughout hospitalization (p = 0.03), and recovered faster in survivors compared to those who died (p < 0.001). VA-ECMO allowed the use of lung-protective ventilation while maintaining normalized PaO2 and PaCO2. Patients treated with V-A ECMO and either IABP or Impella had lower pulmonary compliance and more affected areas on their CT compared to those treated with V-A ECMO alone. ConclusionsLung injury is common among patients with refractory VT/VF OHCA requiring V-A ECMO, but imaging severity is not associated with survival. Reductions in lung compliance accompany post-arrest lung injury while compliance recovery is associated with survival.

Abstract 11161: Thymic Hemorrhage – A Cause for Cardiac Arrest?

Introduction: Thymic hemorrhage is a rare cause of sudden cardiac death, particularly in adults. We present a 35- year- old with sudden “cardiac” death secondary to thymic hemorrhage. Case: A 35-year-old healthy man presented following witnessed cardiac arrest. CPR was initiated immediately. The initial rhythm was shockable, he was defibrillated, and ROSC was achieved. He was intubated on site and transferred to the hospital. Initial labs were negative for electrolyte derangements and drugs of abuse. His high-sensitivity troponin T was 238 ng/L (nl&lt;23 ng/L) and subsequently trended downward. His electrocardiogram showed non-specific ST-T abnormalities. His echocardiogram showed an ejection fraction of 25 to 29% with global hypokinesis. He was extubated on day 4 and scheduled for coronary angiography. On day 5, when he attempted to get out of bed, he lost consciousness and became pulseless. His initial rhythm was PEA, but with episodes of ventricular fibrillation during CPR, he was shocked accordingly. He had prolonged CPR, therefore, obviating advanced therapies. His autopsy showed only thymic hemorrhage. His coronary arteries were normal, with no signs of myocardial injury or myocarditis. Conclusion: Massive acute thymic hemorrhage is extremely rare in adults but is a rare but recognized cause of sudden death in utero and infants. There are only two reported cases of thymic hemorrhage in adults in the literature. Both the patients were nearly 40-year-old men who presented with chest pain. Initial imaging was consistent with mediastinal widening requiring thoracotomy that demonstrated hemorrhagic thymus. Similar to our patient, the reported cases were young men with no prior history of trauma. In contrast, our patient presented with cardiac arrest, and initial imaging was negative for mediastinal widening. The underlying etiology of cardiac arrest from thymic hemorrhage is poorly understood. Right atrial compression from acute hemorrhage of a benign thymic tumor was postulated as the cause of sudden death in a previously healthy 15-year-old boy. Our patient is a rare case since there are, to our knowledge, no reported cases in the literature of thymic hemorrhage as the cause of death in adults.

Abstract 187: Synergy Of Elevation Of The Head And Thorax And Resuscitative Endovascular Balloon Occlusion Of The Aorta In A Porcine Model Of Prolonged Cardiac Arrest: A Pilot Study

Background: Two new approaches to improve cardiac arrest outcomes, active compression-decompression (ACD) with an impedance threshold device (ITD) CPR with automated Head Up Positioning, (AHUP-CPR), and resuscitative endovascular balloon occlusion (REBOA) have been studied separately but never together. This was a pilot animal study exploring potential hemodynamic synergy of AHUP+ REBOA after prolonged CPR. Methods: Farm pigs (~40 kg) were sedated, intubated, and anesthetized. Central venous, and intracranial pressures were measured. Bilateral femoral arterial access was obtained for arterial pressure measurement and REBOA placement in the proximal thoracic aorta. Hemodynamics were measured with solid state pressure catheters. The arterial pressure catheter was placed in the thoracic aorta and confirmed via fluoroscopy. After 35 minutes of AHUP CPR, animals underwent two-minute epochs of AHUP-CPR, AHUP+REBOA CPR, ACD+ITD CPR flat + REBOA, and ACD+ITD CPR flat. Pressures are reported as mean (mmHg) ± standard deviation. Comparison testing was not performed in this pilot study. Results: In 4 pigs after 35 minutes, the AHUP CPR cerebral perfusion pressure (CerPP) was 21.1 ± 10.4, aortic compression (AOC) and decompression (AOD) pressures were 43.4 ± 9.1 and 14.1 ± 9.4, and intracranial compression (ICP) and decompression (DIP) pressures were 9.2 ± 2.7 and 6.5 ± 3.6, respectively. With AHUP+REBOA, CerPP was 39.0 ± 8.7, AOC and AOD pressures were 69.2 ± 10.7 and 21.0 ± 8.9, and ICP and DIP 9.7 ± 2.6 and 5.8 ± 2.9. The ACD+ITD CPR flat + REBOA CerPP was 21.7 ± 11.8, AOC and AOD pressures were 57.1 ± 9.5, and ICP and DIP were 20.5 ± 4.1 and 15.9 ± 3.2. The ACD+ITD CPR flat CerPP was 11.2 ± 7.5, AOC and AOD pressures were 38.8 ± 6.7 and 15.9 ± 6.6, and ICP and DIB were 17.4 ± 1.1 and 15.0 ± 1.6. A representative study tracing is shown. Conclusions: The combination of AHUP CPR with REBOA is feasible and may work synergistically after prolonged resuscitation in this ongoing animal study.

Abstract 280: Extracorporeal Cardiopulmonary Resuscitation Outcomes In Children Without Underlying Cardiac Disease

Introduction: Extracorporeal cardiopulmonary resuscitation (ECPR) has been associated with improved outcomes compared to conventional CPR (CCPR) in children with underlying cardiac disease. There are limited data on ECPR survival outcomes in the non-cardiac population. Hypothesis: ECPR will be associated with improved survival to discharge in children without underlying cardiac disease with prolonged CPR. Methods: Retrospective cohort study using the AHA Get With The Guidelines® - Resuscitation registry of children (&lt;18 years) without cardiac disease who received ≥30 minutes of CPR for in-hospital cardiac arrest between 2000-2020. Weighted propensity scores were used to balance ECPR and CCPR groups based on hospital and patient characteristics. Multivariable logistic regression incorporating these scores tested the association of ECPR with survival to discharge. A Bayesian logistic regression model was used to estimate the probability of a positive effect from ECPR. A secondary analysis explored temporal trends in ECPR relative to the index year of 2000. Results: Of 875 patients, 159 received ECPR and 716 received CCPR (median age 1 year, primary diagnosis respiratory insufficiency, median CPR duration 45 minutes for full cohort). Survival to discharge was similar between the ECPR group (21.4%) compared to the CCPR group (16.2%) in both the univariable analysis (p= 0.13) and the propensity-weighted multivariable logistic regression (aOR 1.44 [CI 0.85-2.44, p= 0.173]. The Bayesian model estimated an 85.1% probability of a positive effect of ECPR on survival to discharge. ECPR use increased over time (test for trend p&lt;0.001). Conclusion: In children without cardiac disease who required ≥30 minutes of CPR, ECPR usage significantly increased in the last 20 years. Compared to CCPR, ECPR was not associated with a statistically significant increase in survival to discharge. However, a Bayesian model estimated weak evidence of a positive survival effect of ECPR.

Characteristics of pediatric non-cardiac eCPR programs in United States and Canadian hospitals: A cross-sectional survey

ObjectiveTo characterize practices surrounding pediatric eCPR in the U.S. and Canada. MethodsCross-sectional survey of U.S. and Canadian hospitals with non-cardiac eCPR programs. Variables included hospital and surgical group demographics, eCPR inclusion/exclusion criteria, cannulation approaches, and outcomes (survival to decannulation and survival to discharge). ResultsSurveys were completed by 40 hospitals in the United States (37) and Canada (3) among an estimated 49 programs (82% response rate). Respondents tended to work in >200 bed free-standing children's hospitals (27, 68%). Pediatric general surgeons respond to activations in 32 (80%) cases, with a median group size of 7 (IQR 5,9.5); 8 (20%) responding institutions take in-house call and 63% have a formal back-up system for eCPR. Dedicated simulation programs were reported by 22 (55%) respondents. Annual eCPR activations average approximately 6/year; approximately 39% of patients survived to decannulation, with 35% surviving to discharge. Cannulations occurred in a variety of settings and were mostly done through the neck at the purview of cannulating surgeon/proceduralist. Exclusion criteria used by hospitals included pre-hospital arrest (21, 53%), COVID+ (5, 13%), prolonged CPR (18, 45%), lethal chromosomal anomalies (15, 38%) and terminal underlying disease (14, 35%). ConclusionsWhile there are some similarities regarding inclusion/exclusion criteria, cannulation location and modality and follow-up in pediatric eCPR, these are not standard across multiple institutions. Survival to discharge after eCPR is modest but data on cost and long-term neurologic sequela are lacking. Codification of indications and surgical approaches may help clarify the utility and success of eCPR. Level of evidence4

Cardiopulmonary resuscitation duration and favorable neurological outcome after out-of-hospital cardiac arrest: a nationwide multicenter observational study in Japan (the JAAM-OHCA registry)

ObjectiveWe aimed to assess the association between cardiopulmonary resuscitation (CPR duration) and outcomes after OHCA.MethodsThis secondary analysis of a prospective, multicenter, observational study included adult non-traumatic OHCA patients aged ≥ 18 years between June 2014 and December 2017. CPR duration was defined as the time from professional CPR initiation to the time of return of spontaneous circulation or termination of resuscitation. The primary outcome was 1-month survival, with favorable neurological outcomes defined by cerebral performance category 1 or 2. We performed multivariable logistic regression analysis to investigate the association between CPR duration and favorable neurological outcomes. We also investigated the association between CPR duration and favorable neurological outcomes stratified by case features, including the first documented cardiac rhythm, witnessed status, and presence of bystander CPR.ResultsA total of 23,803 patients were included in this analysis. Multivariable logistic regression analysis demonstrated that the probability of favorable neurological outcomes decreased with CPR duration (i.e., 20.8% [226/1084] in the ≤ 20 min group versus 0.0% [0/708] in the 91–120 min group, P for trend < 0.001). Furthermore, the impact of CPR duration differed depending on the presence of case features; those with shockable, witnessed arrest, and bystander CPR were more likely to achieve favorable neurological outcomes after prolonged CPR duration > 30 min.ConclusionThe probability of favorable neurological outcome rapidly decreased within a few minutes of CPR duration. But, the impact of CPR duration may be influenced by each patient’s clinical feature.

Abstract 13071: Supraglottic Airway Devices Are Associated With Asphyxial Physiology Upon Arrival for ECPR in Patients With Refractory OHCA Treated With Prolonged CPR

Introduction: Multiple clinical trials have failed to show significant differences in survival between use of endotracheal intubation (ETI) and supraglottic airway devices (SGA) in patients with out-of-hospital cardiac arrest (OHCA). However, treatment in these trials was limited to standard ACLS, which favors short duration of CPR. We sought to compare the physiological effect of ETI versus SGA use in patients treated with prolonged CPR and extracorporeal pulmonary resuscitation (ECPR) for refractory ventricular fibrillation/ventricular tachycardia (VT/VF) by the Minnesota Mobile Resuscitation Consortium (MMRC). Methods: Consecutive refractory VT/VF OHCA patients transported by the MMRC to the University of Minnesota for ECPR between 2015 and 2021 were included in this retrospective analysis. Patients were considered ineligible for ECPR if they failed specific arterial blood gas metabolic criteria (lactic acid &gt;18 mmol/L, PaO2 &lt;50 mmHg, and ETCO2 &lt;10 mmHg). Metabolic parameters at presentation and survival were compared between patients receiving ETI and SGA. Results: Among 260 patients (58.0±11.8 years), 46.5% received ETI and 53.5% received SGA. During the index hospitalization, 78/260 (30%) achieved neurologically favorable survival. Compared to those receiving ETI, patients receiving SGA had lower PaO2 (116.8±118.7 versus 135.8±128.3 mmHg, p=0.03), higher PaCO2 (69.7±28.9 versus 60.7±25.6 mmHg, p=0.01), and lower pH (7.00±0.19 versus 7.06±0.21, p=0.008). Significantly more patients who received SGA had PaO2 &lt;50mmHg (29.1% versus 16.9%, respectively; p=0.02) and ≥1 ECPR exclusion criteria (33.1% versus 20.7%, respectively; p=0.03). Among patients excluded for PaO2 &lt;50 mmHg, the presenting PaO2 was 35.5±11.0 mmHg and the presenting PaCO2 was 94.5±26.2 mmHg, suggestive of absence of effective ventilation (asphyxia) at presentation. Survival with CPC 1-2 was 34.7% versus 25.9% for ETI versus SGA, respectively (p=0.12). Conclusion: Use of SGA, during prolonged CPR in refractory VT/VF OHCA, was associated with a significant increase in the proportion of patients presenting with significant hypoxemia and asphyxial physiology, thus increasing ineligibility for ECPR.

Abstract 14075: Infective Endocarditis Associated With Irreversible Coronary Spasm and Cardiac Arrest

Introduction: Coronary artery spasm (CAS) can elicit ischemia with transient ST-segment deviation that usually responds to nitrates; however, CAS can precipitate arrhythmias leading to sudden cardiac arrest. Infective endocarditis (IE) is associated with the acute coronary syndrome (ACS) usually via coronary embolism and compression secondary to peri-annular complications. CAS in association with IE causing ACS is extremely rare. Case: A 54-year-old man had a recent ST-elevation (STE) myocardial infarction, which required stenting to obtuse marginal artery (OM2) artery. He presented with a fever for one week. A new diastolic murmur at the aortic area on examination. Echocardiography showed a bicuspid aortic valve with perforation and new-onset aortic regurgitation suggestive of vegetation. Diagnosis of infective endocarditis was established, and the patient was started on medical treatment and was being prepared for surgical repair. During the hospital stay, he had recurrent episodes of severe chest pain accompanied by transient STE on ECG but normal troponin level. It was always responding to sublingual nitrates. CT coronary Angiogram showed no significant coronary stenosis and patent stent in OM2. The patient had again an attack of severe chest pain with ECG showed extensive STE then he developed pulseless electrical activity. Result: Resuscitation was started and emergency coronary angiography was performed and showed severe spasms in both LAD and LCX with TIMI-1 flow. A repeated image during resuscitation showed patent arteries with TIMI-III flow. A prolonged CPR in Cath-lab failed and the patient died. Although there was no clear explanation of the mechanism, the simultaneous association between the CAS and IE raises the suspicion of a possible relationship between both pathologies. Conclusions: Severe coronary spasm should be considered as a possible cause of ACS in association with IE.

Prognostic factors for adults with cardiac arrest in the emergency department: a retrospective cohort study

Cardiac arrest in the emergency department is associated with the following three scenarios: out-of-hospital cardiac arrest, primary emergency department cardiac arrest (EDCA), and patients transferred from other hospitals after the return of spontaneous circulation from cardiac arrest. Among them, the primary cardiac arrest episode in the emergency department has been less studied. This aim of this study was to explore patient characteristics and the relationship between causes of EDCA and survival outcomes according to different patient management strategies. The main finding of this study was that EDCA with Cardiogenic etiology was associated with higher survival to discharge (OR: 2.31; 95% CI: 1.59–3.91) and discharged neurological outcome (OR: 2.84; 95% CI: 1.57–5.97). More favorable discharged neurological outcome were also found in EDCA patients with initial shockable rhythm (OR: 4.83; 95% CI: 2.33–10.01) and shorter resuscitation time (≤11.5 min, OR: 3.62; 95% CI: 1.57–8.32). EDCA patients under sedative medication (OR: 0.24; 95% CI: 0.10–0.59) and ventilator support by intubation before EDCA episode (OR: 0.26; 95% CI: 0.09–0.75) had poor neurological outcome. We conclude that EDCA patients with cardiogenic etiology have more favorable survival to discharge and discharged neurological outcomes. Prolonged CPR time during EDCA, post-intubation status and sedative medication use were prognostic factors of negative survival and neurological outcomes.

Abstract 299: Effect of Start Position and Compression Depth on Mechanical CPR Hemodynamics in Swine

Introduction: Mechanical devices offer the ability to provide consistent fixed-depth chest compressions during CPR. Although compression depth is considered a primary determinant of CPR quality, the influence of other device settings has received less attention. Accordingly, we evaluated the combined effect of compression depth and device start position on CPR hemodynamics in a porcine model of cardiac arrest (CA). Methods: Swine (n=119) were subjected to 7-10 min of CA following electrical induction of ventricular fibrillation. CPR was subsequently performed manually (target peak aortic pressure: 100 mmHg; n=73) or with a mechanical compression system (LUCAS 3.1, Stryker; n=46). Within the mechanical CPR group, animals received 102 compressions/min using either factory default settings (“QuickFit” automated suction cup start position; compression depth: 2.1”; n=13) or custom settings (manual suction cup start position; compression depth: 1.8”; n=33). Aortic pressure (Ao), coronary perfusion pressure (CPP), and regional cerebral oxygen saturation (rSO 2 ; via near infrared spectroscopy) were compared between groups after 1 min of CPR. Results: Mechanical CPR with automated suction cup start position and compression depth of 2.1” resulted in significantly higher peak Ao and CPP than mechanical CPR with manual start position and compression depth of 1.8” ( Table ). Compared with manual CPR, only mechanical CPR with automated start position and compression depth of 2.1” led to a higher CPP. However, cerebral rSO 2 values fell from 61±1 % at baseline to 49±1 % during CA (p&lt;0.01) and did not increase during CPR in any group. Conclusion: Compared with a manual start position and compression depth of 1.8”, use of the LUCAS “QuickFit” feature and compression depth of 2.1” led to a significantly higher CPP during mechanical CPR. Future studies are necessary to determine if differences persist during prolonged CPR with and without concomitant vasopressor administration.

Abstract 261: Acute Lung Injury and Recovery in Patients with Refractory Vf/vt Cardiac Arrest Treated with Prolonged Cpr and Veno Arterial Extracorporeal Membrane Oxygenation

Background: Post cardiac arrest syndrome includes significant pulmonary injury that is not clearly understood. Objectives: Describe the lung injury patterns among patients presenting with refractory ventricular tachycardia/ventricular fibrillation out-of-hospital cardiac arrest (VT/VF OHCA) patients who were treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Methods: OHCA characteristics, post-arrest computed tomography (CT) scans, ventilator parameters and complications were collected using a retrospective cohort design. Changes in lung compliance were compared over time between survivors, patients with acute brain death and those who had other modes of death with a two- way analysis of variance. Results: Among138 refractory VT/VF OHCA patients (81% were male with a median age of 59.0 years, mean CPR time of 64.3 ±16.1 min, a mean APACHE II score of 30.5 ± 4.6) 48/138 (34.8%) survived, acute brain death occurred in 48/138 (34.8%) and other modes of death in 56/138 (40.6%). The dependent posterior segments of the lung were the most commonly affected areas on the initial CT scan(Fig1A). There was no difference in the number of hyperattenuated areas between the survival groups.Compliance was borderline on day one (median 26.3(19.3,33.3)ml/cmH 2 0), but improved throughout the hospitalization (p=0.001) and was higher in survivors compared to those who died (p&lt;0.001, Fig1B). VA-ECMO allowed the use of lung-protective ventilation in patients with borderline compliances maintaining safe PaO2 and PaCO2. Patients additionally treated with IABP/Impella had lower pulmonary compliance and more hyperattenuated areas on their initial CT scan compared to those treated exclusively with VA-ECMO. Conclusions: Refractory VT/VF OHCA patients who are treated with VA-ECMO frequently have lung injury with borderline compliance soon after the index event. Lung compliance improves throughout hospitalization and is higher in survivors.

A Glimpse Into the Future.

The novel coronavirus will forever change the world in ways we have yet to realize What will our lives look like when the crisis abates? Will we still shake hands? Will my Italian relatives still kiss me on both cheeks (or just give air kisses)? When this is over there may be fewer elderly, more guns, less movie theaters and greater paranoia in America but perhaps more generosity and kindness as well Most of what will change after the pandemic is beyond my ability to guess However, I see more clearly the changes that will come to Emergency Medicine once the Hot Zone has cooled Let's pull back the curtain of time and glimpse into the future for our specialty after the Time of COVID

Abstract 265: Deterioration of Hemodynamic Support During Prolonged Mechanical CPR in a Porcine Model of Cardiac Arrest

Introduction: Although mechanical CPR devices provide automated delivery of fixed depth chest compressions, the consistency of hemodynamic support during prolonged resuscitation efforts is unclear, particularly in the absence of concomitant vasopressor treatment. In light of recent concerns regarding potentially harmful effects of epinephrine, we evaluated the hemodynamic support generated by 20 min of mechanical CPR without concurrent vasopressor administration in a porcine model of cardiac arrest (CA). Methods: Swine (n=10) were subjected to 7-8 min of CA following electrical induction of ventricular fibrillation. CPR was subsequently performed for 20 min using a mechanical compression system (LUCAS 3.1, Stryker) programmed to administer 102 compressions/min at a fixed depth of 2.1 inches. Aortic pressure (Ao), coronary perfusion pressure (CPP), and cerebral oxygen saturation (rSO 2 ; near-infrared spectroscopy) were continuously recorded. Results were compared to a separate group of swine (n=11) that received manual CPR with a compression rate of 100/min and depth necessary to achieve peak Ao of 100 mmHg. Results: Initially, mechanical CPR generated significantly higher peak Ao and CPP vs. manual CPR ( Figure ). However, by 4 min CPR, peak Ao and CPP were no longer different between groups. Both parameters continued to decline in the mechanical CPR group but remained stable in animals receiving manual CPR. Cerebral rSO 2 values fell from 57±2 % at baseline to 42±4 % during CA (p&lt;0.01) but were not significantly improved by mechanical or manual CPR. Conclusion: The superior hemodynamic support initially offered by mechanical CPR deteriorates during prolonged CPR when pharmacologic vasopressor support is absent. These results demonstrate that a fixed compression depth does not necessarily produce consistent hemodynamic support and suggest that concomitant vasopressor administration may be necessary to sustain Ao and CPP during prolonged mechanical CPR.