Cardiac Arrest Patients Research Articles

Abstract 188: Association Between Mean Arterial Pressure and Neurological Outcomes in Comatose Cardiac Arrest Patients: A Multicenter Observational Study

Aim: The target blood pressure has not been determined in comatose cardiac arrest patients. Therefore, we aimed to investigate the association between mean arterial pressure (MAP) and six-month neurological outcomes in out-of-hospital cardiac arrest (OHCA) survivors who underwent targeted temperature management (TTM). Methods: We analyzed the prospective registry of comatose OHCA survivors who underwent TTM. The arterial blood pressure measured every 1 hr in a 48-hour period after return of spontaneous circulation (ROSC) was recorded between January 2019 and May 2021 in the registry. We calculated the MAP during 48 hr and at every 6 hr. Patients with an MAP < 65 mmHg or missing MAP data for more than 6 hr were excluded. We conducted a multivariable logistic regression analysis to determine the association between MAP and neurological outcomes and conducted a linear mixed models analysis to reveal the interaction between MAP over time and neurological outcomes. The primary outcome was six-month neurological outcomes with Cerebral Performance Category (CPC), which was dichotomized into good (CPC 1 or 2) and poor (CPC 3-5) neurological outcomes. Results: Of the 394 included patients, 255 patients (64.7%) had poor neurological outcomes. MAP did not differ between the neurological outcome groups (poor [89 mmHg, 82-97 mmHg] vs. good [89 mmHg, 84-95 mmHg]; p = 0.498). MAP was not independently associated with poor neurological outcomes (odds ratio, 1.010 [95% confidence intervals, 0.978-1.042]) adjusted with age, sex, body mass index, pre-existing illness (coronary artery disease, diabetes, pulmonary disease, renal impairment), witnessed collapse, first-monitored rhythm, cardiac etiology, downtime, lactate level after ROSC, and sequential organ failure assessment score. Repeated MAP measurements every 6 hr did not differ between the neurological outcome groups (p = 0.403), and the interaction between MAP every 6hr and neurological outcomes was not significant (p = 0.136). Conclusions: MAP during 48 hr after ROSC was not associated with the six-month neurological outcomes. MAP measurements every 6 hr during 48 hr after ROSC did not differ between neurological outcome groups, and the changes in MAP over time were not associated with neurological outcomes.

Abstract 18865: Cardiac Arrest on Weekends Are More Fatal Than Weekdays - A Study From National Database

Introduction: The overall survival of cardiac arrest patients is very poor. There is a higher incidence of cardiac arrest on weekends especially on Saturdays as per national statistics. Also, hospitals experience reduced staffing on the weekends. We examined the outcomes of cardiac arrests on weekends compared to weekdays. Hypothesis: There is no difference in mortality in cardiac arrests which happen over the weekday compared to over the weekend. Methods: This retrospective cohort study used a national inpatient sample database to identify patients from 2016 to 2019 presenting with cardiac arrest on weekdays vs on weekends. SAS 9.3 was used for data analysis. The data were weighted to generate national estimates of the entire US hospitalized population. Results: Out of 57,300 patients who presented with cardiac arrest during the study period, 41,410 were on weekdays (72.2%; mean age 65.9; 56.2% males) and 15,890 were on weekends (27.8%, mean age 65.2; 56.7% males). Inhospital mortality was less on weekdays than on weekends (72.4% vs 76.2%). The younger age group (18-40 years) had a higher share of of cardiac arrest on weekends when compared to weekdays (8.2% vs 7.1%). Weekday admissions had a higher rate of prior MI (8.9% vs 7.6%) and a higher rate of comorbities including DM (39.4% vs 36%), CHF (32.2% vs 28.9%), Renal Failure (29.5% vs 26.6%), CAD (34.8% vs 31.7%). Weekend admissions had a higher rate of smoking history (16.9% vs 15.1%). All p values <0.001. Conclusions: Cardiac arrest on weekends has a higher mortality rate compared to weekdays. We found a higher burden of comorbidities on patients with weekday cardiac arrest.

Abstract 149: The Effect of Lumbar Cerebrospinal Fluid Drainage on Mortality Reduction and Neuro-Prognostic Improvement in Out of Hospital Cardiac Arrest Patients Underwent Targeted Temperature Management

Cerebral edema and increased ICP in post OHCA patients can be harmful due to the brain’s rigid encasement, although the increase is small. Lumbar CSF drainage (LD) may be a valuable treatment for refractory increased ICP in patients with discernible basal cisterns. Furthermore, much of the CSF volume is located in the subarachnoid spaces, which are not accessible for drainage by ventriculostomies. However, there has been no study on the effect of LD in OHCA patients. Therefore, we investigaed whether LD reduces mortality and improves neurological prognosis in OHCA patients who underwent TTM. This was a prospective single-center study conducted from July 2021 to April 2020 (CNUH IRB201907033003, NCT04328974). The target temperature of 33°C was maintained for 24 h, and LD was initiated when ICP exceeded 15 mmHg at the rate of 10 ml per hour via a LD catheter until ICP was less than 15 mmHg. We performed propensity score matching with the CAHP score variables between the group with and without LD. We used the binary logistic regression and the Cox proportional hazard regression with the NULL PLEASE score variables. After propensity score matching, 50 patients were selected in each group (Fig.1, Table 1). Serum levels of NSE and the percentage of brain tissue with ADC value < 650 X 10 -6 mm 2 /s (PV 650 ) obtained 72 h after ROSC were lower in the group with LD (Table 2). The analysis revealed that LD was associated with good neurological prognosis and increased the probability of survival (Table 3, Fig. 2). The subgroup analysis, focusing on OHCA patients with moderate severity based on the rCAST score, yieded consistent results (Table 4, Fig. 2).This study demonstrated that LD significantly improved neurological prognosis and reduced mortality in OHCA patients with moderate severity.

Abstract 185: Regional Oxygen Saturation and Capnography Monitoring During Resuscitation After Cardiac Arrest in a Swine Pediatric ARDS Model

Introduction: Survival and outcomes after cardiac arrest (CA) depend largely on the effectiveness of cardiopulmonary resuscitation (CPR). Traditional invasive methods of monitoring CPR can be challenging out-of-hospital and are lacking in more than 50% of in-hospital pediatric CA. Regional oxygen saturation (rSO 2 ) monitoring with Near Infrared Spectroscopy (NIRS) and volumetric capnography offers a noninvasive approach that could potentially overcome these challenges. Aim: To determine the feasibility and effectiveness of NIRS and volumetric capnography monitoring in a swine model of pediatric hypoxia induced CA. Approach: Juvenile pigs were sedated and mechanically ventilated. Mild to moderate Acute Respiratory Distress Syndrome (ARDS) was induced by continuous oleic acid infusion. Respiratory and hemodynamic variables were monitored using invasive and noninvasive (NIRS and capnography) monitoring to assess efficacy of CPR. Animals were randomized into one of the two groups: High-quality CPR (hqCPR) to achieve coronary perfusion pressure of 25-30 mmHg and low-quality CPR (lqCPR) to achieve coronary perfusion pressure of 10-15 mmHg. Trajectories over time were analyzed using regression analyses. The discriminatory ability to distinguish between groups based on trajectories were analyzed using receiver operating characteristics curve (ROC) analysis. Results: 39 animals (23±3 kg) were included in our study. In the hqCPR group, there are generally higher values for cerebral and renal rSO 2 , ETCO 2 , volume of CO 2 elimination (VCO 2 ), and carotid blood flow, compared to the lqCPR group (p<0.0001). Cerebral and renal rSO 2 values increase over time, while ETCO 2 , VCO 2 , and carotid flow values decrease in the hqCPR group. Cerebral rSO2 had a ROC AUC of 0.76 (95% CI: 0.58-0.94), whereas renal rSO2 had a ROC AUC of 0.54 (95% CI: 0.22-0.87) representing nearly no discrimination ability. ETCO 2 had a ROC AUC of 0.66 (95% CI: 0.49-0.84), whereas VCO 2 had a ROC AUC of 0.62 (95% CI: 0.38-0.85). Conclusions: Higher mean cerebral rSO2 values during CPR might be used to assess quality of CPR effectiveness and provide real-time adjustments as needed. This could guide healthcare providers in optimizing CPR quality and improving outcomes for cardiac arrest patients.

Abstract 157: Differences in Mid-Term Neurological Changes From 30 to 90 Days According to Age; is Plasticity Following Brain Injury After Cardiac Arrest Observed in Children or Young Adults?

Introduction: In clinical practice, younger patients following cardiac arrest (CA) are usually expected to recover, even though they are at high risk for poor neurological outcome. The aim of this study was to evaluate the differences of mid-term neurological improvements from 30 to 90 days after CA according to age. Methods: A retrospective observational study was conducted using data from the Japanese Association for Acute Medicine (JAAM) out-of-hospital cardiac arrest (OHCA) registry; a nationwide, prospective database including information on OHCA patients. All CA patients of any age except <1years who had recovered spontaneous circulation and survived after 30 days were analyzed. Patients who already showed cerebral performance category (CPC) (or pediatric CPC [PCPC]) of 1 at 30 days were excluded. We evaluated the proportion of patients in each age category (aged 1-17 [children and adolescents], 18-39 [young adults], 40-64 [middle-aged adults], 65-79 [older adults], ≥80 [elderly] years) who improved in either CPC or PCPC between the 30 and 90 days after CA by using a multivariate logistic regression analysis. Results: Of the 68,111 patients in the registry, 1,449 patients for whom 30- and 90-day CPC (or PCPC) data were available were analyzed. Among them, a total of 186 patients (13%) showed improvement in their 90-day CPC (or PCPC). Multivariate logistic regression analysis showed that patients aged 18-39, 40-64 and 65-79 years were more likely to have improved 90-day CPC compared with those aged ≥ 80 years (Odds ratios: 2.67 [1.19-5.96], 2.33[1.37-3.95] and 1.87 [1.13-3.11], respectively). Adjusted spline curve showed that patients ranging from children to middle-aged adults had an expectation of improved neurological changes (Figure). Conclusions: The expectation of improved neurological changes following an OHCA was higher in patient aged 18-39, 40-64 and 65-79 years compared to those aged >80 years, while it was not in patients aged 1-17 years.

Abstract 349: Deep Learning Detection of Chest Compression Location Using Transesophageal Echocardiography

Background: Recent work evaluating intra-arrest transesophageal echocardiography (TEE) in cardiac arrest (CA) has demonstrated that chest compression (CC) location is a strong predictor of return of spontaneous circulation. However, advanced skills to interpret images during resuscitation represent an important barrier to implementation of this modality. Deep Learning (DL) models have been increasingly used to perform the automated interpretation of TEE images. Given the unique challenges during the interpretation of images, DL-based automation represents an attractive adjunct to facilitate the use of intra-arrest TEE. We sought to evaluate the feasibility of a DL model to identify CC location in TEE images obtained during CA resuscitation. Methods: We analyzed videos from out-of-hospital and in-hospital CA patients evaluated with TEE collected through the Resuscitative TEE Collaborative Registry (NCT04972526). We reviewed and selected images for the DL algorithm, using midesophageal long axis clips. Videos were selected based on the visualization of anatomical structures necessary to identify the CC location. Images were annotated by an expert classifying them in CC over the LV (CC-LV) vs CC over the left ventricular outflow tract (CC-LVOT). We used TEENet, an end-to-end DL approach with input of TEE clips containing single compression cycles, to classify clips in CC-LV and CC-LVOT. The TEENet architecture includes two 3D convolution layers, followed by a global average pooling layer, and then appends a fully connected layer with a sigmoid layer. We used the F1-score as the evaluation metric for the model's performance. Results: Ten videos containing a total of 47 single CC cycle clips were selected for inclusion in the model, each clip with an average of 25 frames. The model was trained using 80% of the data (37 clips) and tested using the remaining 20% (10 clips). The model achieved an F1-score of 0.7273 in classifying CC-LV from CC-LVOT. Conclusion: We report the creation of a novel DL-model with acceptable precision and recall performance in the detection of CC location using intra-arrest TEE videos. This work is a proof-of-concept for future research aimed to evaluate the potential of DL-assisted TEE-guided CA resuscitation.

Abstract 166: Novel Mechanism of Docosahexaenoic Acid Reducing Tissue Injury by Targeting Immune Cells and HMGB1 Release

Introduction: Dysregulated immune blood cell response has been implicated in contributing to brain injury following cardiac arrest (CA). Specifically, increased plasma HMGB1 has emerged as a critical mediator of brain damage. However, the underlying mechanisms of the dysregulated immune response and increased HMGB1 after CA remains unclear. Moreover, limited efforts have been made to develop therapeutic interventions targeting this dysregulated immune response. Objective: To elucidate the pathologic immune response during early phase of post-resuscitation and explore this as a targeted therapeutic potential using LPC(22:6), a previously shown neuroprotective compound. Methods and Results: We examined changes in lymphocytes, neutrophils, and monocytes in blood samples obtained from human CA patients. Subsequently, we conducted a time course study in rat CA model to examine changes in these cell populations and investigate the mechanisms underlying the increased HMGB1 levels in post-CA blood with/without plasma supplementation of LPC(22:6). We observed an increase in lymphocytes and neutrophils within one-hour post-resuscitation in human patients and rats. In rats, the increased levels of lymphocytes and neutrophils were followed by an increase in plasma HMGB1 level and monocytes. We further, identified that HMGB1 was significantly upregulated in CD4-positive cells, indicating that T cell-released HMGB1 is the primary source for its elevation. Intriguingly, supplementation of LPC(22:6) prevented the overexpression of HMGB1 in CD4-positive cells, the increase in plasma HMGB1 levels, and the number of monocytes. These findings support the sequential events of dysregulated blood immune response initiated by lymphocyte activation, leading to increased HMGB1 levels and subsequent monocyte activation during early phase of resuscitation after CA. Thus, our results demonstrate the efficacy of LPC(22:6) in inhibiting the expression of HMGB1 in CD4-positive T cells, thereby mitigating this inflammatory cascade. Conclusion: These findings provide novel insights into the mechanisms underlying the dysregulated immune response after CA and highlight the therapeutic potential of targeting this immune response to improve brain function.

Abstract 13530: Life Quality, Work and Functional Recovery of Cardiac Arrest Survivors After Hospital Discharge

Background: Along with the improvement in resuscitation science and post-cardiac arrest care, an increasing number of cardiac arrest (CA) victims survived to hospital discharge. Research Questions: Do cardiac arrest survivors return to their life and work after hospital discharge? Aims: To investigate whether the life quality, work ability, and neurological recovery of cardiac arrest survivors improves continuously within 1 year after hospital discharge. Methods: The retrospective single center study enrolled 169 non-traumatic adult CA patients who survived to hospital discharge between 2017 and 2020. The following were excluded: patients who expired within 1 year following hospital discharge, patients who unable to be contact after hospital discharge, and patients who refused to join the study. A total of 71 patients were included in this study. The use of medical service including outpatient and ER visit, and hospital admission were collected from medical record. The work status, life quality and neurological function were evaluated by questionnaires including the World Health Organisation Quality of Life Brief Form and EuroQol 5-Dimension, 5-Level Health Scale (EQ-5D-5L). Results: There were 67 patients (94.4%) discharged with cerebral performance category (CPC) of 1, and the 2 patients (2.8%) with CPC of 2. Most patients (64, 90.1%) returned home. Sixty-seven patients (94.4%) returned to outpatient visit at a median time of 6 days, 22 patients (31%) visited ER at a median time of 70 days, and 21 patients (29.6%) were hospitalised again at a median time of 44 days. The neurological function evaluated by CPC at 3 months and 1 year post-discharge did not show significant improvement. Patients demonstrated improved ability to work as well as improved scores for overall life quality, general health, physical, psychological, social relations, and environmental status. With regard to mobility, self-care, usual activities, pain/discomfort, and health state assessed by EQ-5D-5L, the patients with more than moderate impaired also decreased significantly. Conclusions: Life quality and work ability of CA survivors improved continuously within 1 year after hospital discharge.

Abstract 184: Blood Pressure Matters After Cardiac Arrest: Is Our Target Too Low?

Introduction: Blood pressure is an important therapeutic target after cardiac arrest (CA), crucial for maintaining cerebral blood flow and preventing secondary brain injury. However, the optimal blood pressure during the post-resuscitation period remains unknown. Hypothesis: Proportion of time with mean arterial pressure (MAP) below a specific threshold will be associated with worse clinical outcomes. Methods: We assessed a retrospective cohort of CA patients admitted to an academic center between January 2014 - August 2022. Patients without a documented initial MAP, those who progressed to brain death, or who died within 96 hours were excluded. Multivariable logistic regression was used to test associations between proportion of time with MAP < 65mmHg or < 80mmHg and outcomes [survival and good neurologic outcome (Cerebral Performance Category 1-2) at hospital discharge]. We adjusted for age, sex, Charlson Comorbidity Score, CA location, initial rhythm, Pittsburgh Cardiac Arrest Category, and peak 24h norepinephrine equivalent. We evaluated the initial 96 hours from CA and the following sub-periods: 1) 0-24h, 2) 25-72h, and 3) 73-96h. Results: Of 817 patients with CA, 411 were included. Over the initial 96 hours, the proportion of time with MAP < 80 was inversely associated with survival and good neurologic outcome (adjusted OR [95% CI] per 10% time 0.83 [0.75 - 0.93] and 0.78 [0.69 - 0.89], respectively); no such association was found for MAP < 65. This inverse association held in period 2 (0.85 [0.78-0.93] and 0.79 [0.71-9.88], respectively) and period 3 (0.87 [0.80-0.94] and 0.85 [0.78-0.93], respectively), but not in period 1 (Figure 1). Conclusion: The proportion of time spent with MAP < 80mmHg was associated with worse outcomes, independent of disease severity. The neuroprotective effect of higher MAP appears to occur between 25-96h from CA. Future prospective studies are needed to further characterize the differential clinical impact of MAP across time.

Higher Risk of Reoperation after Total Knee Arthroplasty in Young and Elderly Patients

As outcomes and survivorship improve, total knee arthroplasty (TKA) has expanded into broader age groups. The purpose of this study is to analyze the impact of age on TKA outcomes using the National Surgical Quality Improvement Program (NSQIP) database from 2015 to 2020. Patients were categorized into young (40–49 years), middle (50–79 years), and elderly (80–89 years) groups. Findings reveal notable differences across age groups. The young cohort had the highest BMI, smoking incidence, and steroid use, while the elderly group exhibited a higher prevalence of comorbidities. Young patients experienced shorter hospital stays (p < 0.001) but longer operative times (p < 0.001), and outpatient surgery was most common in the middle age group. Multivariable regression demonstrated that the elderly group faced increased risks of pneumonia (p < 0.001), acute renal failure (p < 0.001), stroke (p < 0.001), cardiac arrest (p < 0.001), and transfusions (p < 0.001), while both young and elderly patients had higher 30-day reoperation risks (youngest cohort, 1.4% and elderly cohort 1.3% (p < 0.001)). In summary, elderly patients undergoing TKA are at the highest risk for medical complications, while young patients are more likely to undergo inpatient surgery, experience reoperations, and have longer operative times. This study underscores the importance of age-specific counseling for TKA patients and contributes valuable insights into the evolving landscape of knee replacement surgery.

Emergency Resuscitation Techniques:Airway, Breathing, and Circulation

Cardiac arrest causes cerebral anoxia, resulting in loss of consciousness within seconds and irreversible brain damage within 3-5 min. Emergency resuscitation is generally performed on patients in cardiopulmonary or near-cardiopulmonary arrest, i.e., life-threatening conditions, and requires rapid stabilization of the airway, breathing, and circulation(or "ABC")to maintain cerebral perfusion. Generally, the ABC approach represents the order of medical treatment for critically ill patients. It provides supportive care(resuscitation)after ensuring the flow of oxygen supply necessary to sustain life. The most important goal in emergency resuscitation is to ensure a secure airway, without which, resuscitation is hopeless. Clinicians should be prepared daily to avoid missing any opportunity to ensure a secure airway. Even in cardiac arrest, high-quality cardiopulmonary resuscitation is necessary to reduce the duration of cerebral anoxia. An algorithm for this high-quality cardiopulmonary resuscitation is described in this article.

The Identification of Subsequent Events Following Out-of-Hospital Cardiac Arrests with Targeted Temperature Management.

Out-of-hospital cardiac arrest (OHCA) is a critical issue due to poor neurological outcomes and high mortality rate. Severe ischemia and reperfusion injury often occur after cardiopulmonary resuscitation (CPR) and return of spontaneous circulation (ROSC). Targeted temperature management (TTM) has been shown to reduce neurological complications among OHCA survivors. However, it is unclear how "time-to-cool" influences clinical outcomes. In this study, we investigated the optimal timing to reach target temperature after cardiac arrest and ROSC. A total of 568 adults with OHCA and ROSC were admitted for targeted hypothermia assessment. Several events were predicted, including pneumonia, septic shock, gastrointestinal (GI) bleeding, and death. One hundred and eighteen patients [70 men (59.32%); 48 women (40.68%)] were analyzed for clinical outcomes. The duration of CPR after ROSC was significantly associated with pneumonia, septic shock, GI bleeding, and mortality after TTM (all p < 0.001). The duration of CPR was also positively correlated with poor outcomes on the Elixhauser score (p = 0.001), APACHE II score (p = 0.008), Cerebral Performance Categories (CPC) scale (p < 0.001), and Glasgow Coma Scale (GCS) score (p < 0.001). There was a significant association between the duration of CPR and time-to-cool of TTM after ROSC (Pearson value = 0.447, p = 0.001). Pneumonia, septic shock, GI bleeding, and death were significantly higher in the patients who underwent TTM with a time-to-cool exceeding 360 minutes (all p < 0.001). For cardiac arrest patients, early cooling has clear benefits in reducing clinical sequelae. Clinical outcomes could be improved by improving the time to reach target temperature and feasibility for critically ill patients.

269 Association Between Initial pH Levels and Neurological Outcomes in Out-of-Hospital Cardiac Arrest Patients with Shockable Rhythm: A Multi-Center Registry-Based Study

269 Association Between Initial pH Levels and Neurological Outcomes in Out-of-Hospital Cardiac Arrest Patients with Shockable Rhythm: A Multi-Center Registry-Based Study

437 Comparative Outcomes of Hypothermic and Normothermic Targeted Temperature Management in Out-of-Hospital Cardiac Arrest Patients with Acute Myocardial Infarction: A Secondary Analysis from a Nationwide Registry in Japan

437 Comparative Outcomes of Hypothermic and Normothermic Targeted Temperature Management in Out-of-Hospital Cardiac Arrest Patients with Acute Myocardial Infarction: A Secondary Analysis from a Nationwide Registry in Japan

357 A qualitative study of the work practices of UK paramedics while treating out-of-hospital cardiac arrest patients during the COVID-19 pandemic

357 A qualitative study of the work practices of UK paramedics while treating out-of-hospital cardiac arrest patients during the COVID-19 pandemic

38 Development and validation of the prediction model of diabetic out-of-hospital cardiac arrest patients: an eight-year populationbased cohort study in Taiwan

38 Development and validation of the prediction model of diabetic out-of-hospital cardiac arrest patients: an eight-year populationbased cohort study in Taiwan

44 Post-resuscitation outcomes among out-of-hospital cardiac arrest patients in Singapore and Japan with initial shockable rhythm using the population-based databases

44 Post-resuscitation outcomes among out-of-hospital cardiac arrest patients in Singapore and Japan with initial shockable rhythm using the population-based databases

421 Comparing of selective Out–of-Hospital Cardiac Arrest (OHCA) patients and no selective Cardiac Arrest Center (CAC) protocol OHCA patients in 10 years prospective registry, single CAC experiences

421 Comparing of selective Out–of-Hospital Cardiac Arrest (OHCA) patients and no selective Cardiac Arrest Center (CAC) protocol OHCA patients in 10 years prospective registry, single CAC experiences

256 Mechanical chest compressor for resuscitation of Out of Hospital Cardiac Arrest patients: can the device affect the outcome? A propensity-score based comparison of three devices

256 Mechanical chest compressor for resuscitation of Out of Hospital Cardiac Arrest patients: can the device affect the outcome? A propensity-score based comparison of three devices

25 Interaction effects between survival outcomes of out-of-hospital cardiac arrest patients receiving intravenous fluid resuscitation and emergency medical service time interval

25 Interaction effects between survival outcomes of out-of-hospital cardiac arrest patients receiving intravenous fluid resuscitation and emergency medical service time interval