Mechanical Cardiopulmonary Resuscitation Research Articles

The impact of specialized pediatric palliative care on advance care planning and healthcare utilization in children and young adults: a retrospective analysis of medical records of in-hospital deaths.

Pediatric palliative care supports children and young adults with life-limiting conditions and their families, seeking to minimize suffering and enhance quality of life. This study evaluates the impact of specialized palliative care (SPC) on advance care planning (ACP) and patterns of end-of-life care for patients who died in the hospital. This is a retrospective cohort study of medical records extracted from a clinical data warehouse, covering patients who died aged 0-24 in an academic tertiary children's hospital in South Korea. Participants were categorized into before (2011-2013; pre-period) and after (2017-2019; post-period) the introduction of an SPC service. Within the post-period, patients were further categorized into SPC recipients and non-recipients. We identified 274 and 205 patients in the pre-period and post-period, respectively. ACP was conducted more and earlier in the post-period than in the pre-period, and in patients who received palliative care than in those who did not. Patients who received SPC were likely to receive less mechanical ventilation or cardiopulmonary resuscitation and more opioids. A multivariable regression model showed that earlier ACP was associated with not being an infant, receiving SPC, and having a neurological or neuromuscular disease. SPC involvement was associated with more and earlier ACP and less intense end-of-life care for children and young adults who died in the hospital. Integrating palliative care into routine care can improve the quality of end-of-life care by reflecting patients' and their families' values and preferences.

Favourable outcome in survivors of CPR-related chest wall injuries

BackgroundThere is a lack of studies focusing on long-term chest function after chest wall injury due to cardiopulmonary resuscitation (CPR). The purpose of this cross-sectional study was to investigate long-term pain, lung function, physical function, and fracture healing after manual or mechanical CPR and in patients with and without flail chest. MethodsPatients experiencing out-of-hospital cardiac arrest between 2013 and 2020 and transported to Sahlgrenska University Hospital were identified. Survivors who had undergone a computed tomography (CT) showing chest wall injury were contacted. Thirty-five patients answered a questionnaire regarding pain, physical function, and quality of life and 25 also attended a clinical examination to measure the respiratory and physical functions 3.9 (SD 1.7, min 2-max 8) years after the CPR. In addition, 22 patients underwent an additional CT scan to evaluate fracture healing. ResultsThe initial CT showed bilateral rib fractures in all but one patient and sternum fracture in 69 %. At the time of the follow-up none of the patients had persistent pain, however, two patients were experiencing local discomfort in the chest wall. Lung function and thoracic expansion were significantly lower compared to reference values (FVC 14 %, FEV1 18 %, PEF 10 % and thoracic expansion 63 %) (p < 0.05). Three of the patients had remaining unhealed injuries. Patients who had received mechanical CPR in additional to manual CPR had a lower peak expiratory flow (80 vs 98 % of predicted values) (p=0.030) =0.030) and those having flail chest had less range of motion in the thoracic spine (84 vs 127 % of predicted) (p = 0.019) otherwise the results were similar between the groups. ConclusionNone of the survivors had long-term pain after CPR-related chest wall injuries. Despite decreased lower lung function and thoracic expansion, most patients had no limitations in physical mobility. Only minor differences were seen after manual vs. mechanical CPR or with and without flail chest.

Splenic Modulation of Early Post-Resuscitation Inflammation in a Porcine Model of Sudden Cardiac Arrest

Objective: The spleen has been implicated as a potential therapeutic target for acute anti-inflammatory intervention via modulation of splenic nerve activity, but the translational viability of this approach is unclear due to limited mechanistic understanding of splenic leukocyte mobilization in clinically relevant models. In contrast to prior rodent studies, we recently demonstrated that the spleen is not required for leukocyte mobilization after focal myocardial ischemia/reperfusion in swine. However, the spleen's role in the early inflammatory response to whole-body ischemia/reperfusion following resuscitation from sudden cardiac arrest (SCA) remains unexplored. Therefore, we used a surgical approach to investigate the spleen's contribution to early post-resuscitation inflammation in a porcine model of SCA. Methods: Eighteen swine were randomized to splenectomy (SPLX; n=9) or sham surgery (SHAM; n=9), and subsequently underwent 8 minutes of electrically-induced ventricular fibrillation SCA one week later. Mechanical CPR with defibrillation and intravenous epinephrine (EPI; 0.015 mg/kg) was performed to achieve return of spontaneous circulation (ROSC; defined as sustained MAP&gt;60mmHg). Hemodynamic parameters, cardiac function, circulating biomarkers of injury (cTnI) and inflammation (IL-6, TNF-⍺), and blood leukocyte levels were assessed for 4 hours post-ROSC, at which time the heart and brain were collected for post-mortem analysis of leukocyte infiltration via flow cytometry. Results: SPLX and SHAM animals were resuscitated at a similar rate (SHAM vs SPLX: 56% vs. 44%) and required a similar number of defibrillation attempts (4.3±0.8 vs. 5.2±1.3), but SPLX required more EPI boluses during CPR (3.3±1.3 vs. 1.4±0.2; p&lt;0.05) and took longer to achieve ROSC (779±196 vs. 455±37 sec; p&lt;0.05). After ROSC, SPLX animals required more EPI (43±10 vs. 13±10 μg/kg; p&lt;0.05) to maintain MAP &gt;60mmHg and tended to have higher circulating cTnI levels compared to SHAM (19.5±4.4 vs. 5.8±4.4 ng/mL; p=0.07). A significant elevation in circulating leukocytes was observed from pre-SCA to 4-hours post-ROSC in both SPLX (19.5±1.3 to 32.0±2.6 103/μl; p&lt;0.05) and SHAM (from 15.1±1.3 to 23.7±2.9 103/μl; p&lt;0.05), along with an increase in circulating IL-6 and TNF-α vs. pre-SCA values that tended to be higher in SPLX. Flow cytometry revealed post-ROSC leukocyte infiltration that was particularly evident in the brain, with an increased number of inflammatory granulocytes (CD172+CD163-) and dendritic cells (CD172+CD16+) in multiple brain regions of SPLX and SHAM animals compared with healthy controls. Conclusion: These results demonstrate that, in swine, the spleen is not required for the robust early inflammatory response to resuscitation from SCA. This observation provides further evidence that, in contrast to rodents, the spleen is not a primary contributor to sterile inflammation following ischemia/reperfusion injury in large animals. This translational study suggests that neuromodulation of splenic leukocyte mobilization may not be a viable therapeutic strategy for mitigating acute inflammation in clinical post-cardiac arrest syndrome. Supported by funding from the NIH and US Department of Veteran's Affairs. 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.

Mechanical Cardiopulmonary Resuscitation (CPR) Is Better Than Manual CPR? Literature Study

Introduction: Mechanical CPR mitigate rescuer fatigue and ensure adherence to guidelines, potentially enhancing overall survival rates. Contrarily, manual CPR relies on human skill, presenting challenges in maintaining uniformity and endurance. Unveiling the complexities within this juxtaposition becomes imperative in shaping future resuscitative paradigms. The purposeof studi is to determine the effectiveness of mechanical CPR in cardiac arrest management compared to manual CPRMethods: Database used were Pubmed and Proquest using the keywords "Mechanical CPR", "Automatic CPR Device" and "Cardiac Arrest". The inclusion criteria were last 5 years published, analyzing the effect of automatic CPR devices on cardiac arrest management, as well as full text articles. The inclusion criteria are literature review, systematic review or is not original research. The number of articles eligible for review is 10 journal articlesResults: The use of automatic CPR equipment is still inferior compared to manual CPR during cardiac arrest with the use value being 4-5% of all cardiac arrest patients. There are 4 journals that state that ROSC in cardiac arrest management using automatic CPR devices is higher than manual, but there are 2 journal articles that report the opposite. Automatic CPR device is very vulnerable to injury with fractures reaching 85.5% of total injuries compared to manual CPR which does not experience injury.Conclusion: The use of automatic CPR device does not produce better results than manual CPR overall for ROSC, but is very useful and meaningful in certain conditions such as during the transportation process, therefore, the automatic CPR device is more meaningful for pre-hospital useKeywords: Manual CPR; Mechanical CPR; CPR; OHCA

Critical care management of acute intoxications, dynamics and changes over time: a cohort study.

Acute intoxications and poisonings are a relevant cause for ICU admission of critically ill patients. This study aimed to determine the characteristics of intoxicated patients in a tertiary center medical ICU in Austria over time and to investigate parameters associated with ICU mortality. This study was a retrospective data analysis including adult ICU patients from the years 2007 to 2021. In addition to ICU documentation, pre-hospital, and emergency department documents as well as autopsy reports were utilized. In an exploratory subanalysis, we compared these findings to a historical dataset from our facility from 1992 to 1996. We identified 581 cases admitted to the medical ICU because of acute poisoning (2007-2021), of which 45% were female and 46.6% were mixed intoxications. Suicidal intent was the primary cause of intoxication (48.2%) and ICU length of stay was median 1.2days. The majority of deceased patients received pre-hospital mechanical CPR. Primary and secondary poison/toxin removal modalities were used in 29.9% and 11.7% of cases, whereas antidotes were administered in 54.4%. Comparing the data with a historical cohort (n = 168), we found a shift in primary detoxification away from gastric lavage and an increase in alternative secondary poison/toxin removal techniques. The ICU mortality was 4.1% and 4.2% in the present and historic cohort, respectively. Pre-existing psychiatric illnesses increased from 49% in the historic to 69% in the present cohort. Psychiatric illness predisposes patients to severe intoxications necessitating ICU care, thus increasing prevention measures seems warranted. Females did present with a different spectrum of intoxications compared to males. ICU mortality remained low over time and most deceased patients had a grim prognosis already on ICU arrival.

A remote-controlled automatic chest compression device capable of moving compression position during CPR: A pilot study in a mannequin and a swine model of cardiac arrest.

Recently, we developed a chest compression device that can move the chest compression position without interruption during CPR and be remotely controlled to minimize rescuer exposure to infectious diseases. The purpose of this study was to compare its performance with conventional mechanical CPR device in a mannequin and a swine model of cardiac arrest. A prototype of a remote-controlled automatic chest compression device (ROSCER) that can change the chest compression position without interruption during CPR was developed, and its performance was compared with LUCAS 3 in a mannequin and a swine model of cardiac arrest. In a swine model of cardiac arrest, 16 male pigs were randomly assigned into the two groups, ROSCER CPR (n = 8) and LUCAS 3 CPR (n = 8), respectively. During 5 minutes of CPR, hemodynamic parameters including aortic pressure, right atrial pressure, coronary perfusion pressure, common carotid blood flow, and end-tidal carbon dioxide partial pressure were measured. In the compression performance test using a mannequin, compression depth, compression time, decompression time, and plateau time were almost equal between ROSCER and LUCAS 3. In a swine model of cardiac arrest, coronary perfusion pressure showed no difference between the two groups (p = 0.409). Systolic aortic pressure and carotid blood flow were higher in the LUCAS 3 group than in the ROSCER group during 5 minutes of CPR (p < 0.001, p = 0.008, respectively). End-tidal CO2 level of the ROSCER group was initially lower than that of the LUCAS 3 group, but was higher over time (p = 0.022). A Kaplan-Meier survival analysis for ROSC also showed no difference between the two groups (p = 0.46). The prototype of a remote-controlled automated chest compression device can move the chest compression position without interruption during CPR. In a mannequin and a swine model of cardiac arrest, the device showed no inferior performance to a conventional mechanical CPR device.

Rib fractures and other injuries after cardiopulmonary resuscitation for non-traumatic cardiac arrest: a systematic review and meta-analysis.

This study aims to ascertain the prevalence of rib fractures and other injuries resulting from CPR and to compare manual with mechanically assisted CPR. An additional aim was to summarize the literature on surgical treatment for rib fractures following CPR. Systematic review and meta-analysis. Embase, Medline Ovid, Cochrane Central, Web of Science, and Google Scholar. The databases were searched to identify studies reporting on CPR-related injuries in patients who underwent chest compressions for a non-traumatic cardiopulmonary arrest. Subgroup analysis was conducted to compare the prevalence of CPR-related injuries in manual versus mechanically assisted chest compressions. Studies reporting on surgery for CPR-related rib fractures were also reviewed and summarized. Seventy-four studies reporting CPR-related injuries were included encompassing a total of 16,629 patients. Any CPR-related injury was documented in 60% (95% confidence interval [95% CI] 49-71) patients. Rib fractures emerged as the most common injury, with a pooled prevalence of 55% (95% CI 48-62). Mechanically assisted CPR, when compared to manual CPR, was associated with a higher risk ratio for CPR-related injuries of 1.36 (95% CI 1.17-1.59). Eight studies provided information on surgical stabilization of CPR-related rib fractures. The primary indication for surgery was the inability to wean from mechanical ventilation in the presence of multiple rib fractures. Rib fractures and other injuries frequently occur in patients who undergo CPR after a non-traumatic cardiopulmonary arrest, especially when mechanical CPR is administered. Surgical stabilization of CPR-related rib fractures remains relatively uncommon. Level III, systematic review and meta-analysis.

Prognostic influence of mechanical cardiopulmonary resuscitation on survival in patients with out-of-hospital cardiac arrest undergoing ECPR on VA-ECMO.

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in extracorporeal cardiopulmonary resuscitation (ECPR) in selected patients after out-of-hospital cardiac arrest (OHCA) is an established method if return of spontaneous circulation cannot be achieved. Automated chest compression devices (ACCD) facilitate transportation of patients under ongoing CPR and might improve outcome. We thus sought to evaluate prognostic influence of mechanical CPR using ACCD in patients presenting with OHCA treated with ECPR including VA-ECMO. We retrospectively analyzed data of 171 consecutive patients treated for OHCA using ECPR in our cardiac arrest center from the years 2016 to 2022. A Cox proportional hazards model was used to identify characteristics related with survival. Of the 171 analyzed patients (84% male, mean age 56 years), 12% survived the initial hospitalization with favorable neurological outcome. The primary reason for OHCA was an acute coronary event (72%) followed by primary arrhythmia (9%) and non-ischemic cardiogenic shock (6.7%). In most cases, the collapse was witnessed (83%) and bystander CPR was performed (83%). The median time from collapse to VA-ECMO was 81 min (Q1: 69 min, Q3: 98 min). No survival benefit was seen for patients resuscitated using ACCD. Patients in whom an ACCD was used presented with overall longer times from collapse to ECMO than those who were resuscitated manually [83 min (Q1: 70 min, Q3: 98 min) vs. 69 min (Q1: 57 min, Q3: 84 min), p = 0.004]. No overall survival benefit of the use of ACCD before ECPR is established was found, possibly due to longer overall CPR duration. This may arguably be because of the limited availability of ACCD in pre-clinical paramedic service at the time of observation. Increasing the availability of these devices might thus improve treatment of OHCA, presumably by providing efficient CPR during transportation and transfer.

Characteristics and outcomes of out-of-hospital cardiac arrest in a hilly area: Utstein Registry data from the Nagasaki Medical Region, Japan.

To analyze characteristics and investigate prognostic indicators of out-of-hospital cardiac arrest (OHCA) in a hilly area in Japan. A retrospective population-based study was conducted using the Utstein Registry for 4280 OHCA patients in the Nagasaki Medical Region (NMR) registered over the 10-year period from 2011 to 2020. The main outcome measure was a favorable cerebral performance category (CPC 1-2). Sites at which OHCA occurred were classified into "sloped places (SPs)" (not easily accessible by emergency medical services [EMS] personnel due to slopes) and "accessible places (APs)" (EMS personnel could park an ambulance close to the site). The characteristics and prognosis based on CPC were compared between SPs and APs, and multivariable analysis was performed. No significant improvement in prognosis occurred in the NMR from 2011 to 2020. Prognosis in SPs was significantly worse than that in APs. However, multivariable analysis did not identify SP as a prognostic indicator. The following factors were associated with survival and CPC 1-2: age group, witness status, first documented rhythm, bystander-initiated cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use, use of mechanical CPR (m-CPR) device or esophageal obturator airway (EOA), and year. Both m-CPR and EOA use were associated with a poor prognosis. In a hilly area, OHCA patients in SPs had a worse prognosis than those in APs, but SPs was not significantly associated with prognosis by multivariable analysis. Interventions to increase bystander-initiated CPR and AED use could potentially improve outcomes of OHCA in the NMR.

Real-world comparison between mechanical and manual cardiopulmonary resuscitation during the COVID-19 pandemic

BackgroundThe COVID-19 pandemic has posed significant challenges to healthcare systems worldwide, including an increase in out-of-hospital cardiac arrests (OHCA). Healthcare providers are now required to use personal protective equipment (PPE) during cardiopulmonary resuscitation (CPR). Additionally, mechanical CPR devices have been introduced to reduce the number of personnel required for resuscitation. This study aimed to compare the outcomes of CPR performed with a mechanical device and the outcomes of manual CPR performed by personnel wearing PPE. MethodsThis multicenter observational study utilized data from the Korean Cardiac Arrest Research Consortium registry. The study population consisted of OHCA patients who underwent CPR in emergency departments (EDs) between March 2020 and June 2021. Patients were divided into two equal propensity score matched groups: mechanical CPR group (n = 421) and PPE-equipped manual CPR group (n = 421). Primary outcomes included survival rates and favorable neurological outcomes at discharge. Total CPR duration in the ED was also assessed. ResultsThere were no significant between-group differences with respect to survival rate at discharge (mechanical CPR: 7.4% vs PPE-equipped manual CPR: 8.3%) or favorable neurological outcomes (3.3% vs. 3.8%, respectively). However, the mechanical CPR group had a longer duration of CPR in the ED compared to the manual CPR group. ConclusionThis study found no significant differences in survival rates and neurological outcomes between mechanical CPR and PPE-equipped manual CPR in the ED setting. However, a longer total CPR duration was observed in the mechanical CPR group. Further research is required to explore the impact of PPE on healthcare providers' performance and fatigue during CPR in the context of the pandemic and beyond.

End-tidal carbon dioxide after sodium bicarbonate infusion during mechanical ventilation or ongoing cardiopulmonary resuscitation

PurposeEnd-tidal CO2 is used to monitor the ventilation status or hemodynamic efficacy during mechanical ventilation or cardiopulmonary resuscitation (CPR), and it may be affected by various factors including sodium bicarbonate administration. This study investigated changes in end-tidal CO2 after sodium bicarbonate administration. Materials and methodsThis single-center, prospective observational study included adult patients who received sodium bicarbonate during mechanical ventilation or CPR. End-tidal CO2 elevation was defined as an increase of ≥20% from the baseline end-tidal CO2 value. The time to initial increase (lag time, Tlag), time to peak (Tpeak), and duration of the end-tidal CO2 rise (Tduration) were compared between the patients with spontaneous circulation (SC group) and those with ongoing resuscitation (CPR group). ResultsThirty-three patients, (SC group, n = 25; CPR group, n = 8), were included. Compared with the baseline value, the median values of peak end-tidal CO2 after sodium bicarbonate injection increased by 100% (from 21 to 41 mmHg) in all patients, 89.5% (from 21 to 39 mmHg) in the SC group, and 160.2% (from 15 to 41 mmHg) in the CPR group. The median Tlag was 17 s (IQR: 12–21) and the median Tpeak was 35 s (IQR: 27–52). The median Tduration was 420 s (IQR: 90–639). The median Tlag, Tpeak, and Tduration were not significantly different between the groups. Tduration was associated with the amount of sodium bicarbonate for SC group (correlation coefficient: 0.531, p = 0.006). ConclusionThe administration of sodium bicarbonate may lead to a substantial increase in end-tidal CO2 for several minutes in patients with spontaneous circulation and in patients with ongoing CPR. After intravenous administration of sodium bicarbonate, the use of end-tidal CO2 pressure as a physiological indicator may be limited.

Life-Sustaining Treatments Among Medicare Beneficiaries with and without Dementia at the End of Life.

Older adults with dementia including Alzheimer's disease may have difficulty communicating their treatment preferences and thus may receive intensive end-of-life (EOL) care that confers limited benefits. This study compared the use of life-sustaining interventions during the last 90 days of life among Medicare beneficiaries with and without dementia. This cohort study utilized population-based national survey data from the 2000-2016 Health and Retirement Study linked with Medicare and Medicaid claims. Our sample included Medicare fee-for-service beneficiaries aged 65 years or older deceased between 2000 and 2016. The main outcome was receipt of any life-sustaining interventions during the last 90 days of life, including mechanical ventilation, tracheostomy, tube feeding, and cardiopulmonary resuscitation. We used logistic regression, stratified by nursing home use, to examine dementia status (no dementia, non-advanced dementia, advanced dementia) and patient characteristics associated with receiving those interventions. Community dwellers with dementia were more likely than those without dementia to receive life-sustaining treatments in their last 90 days of life (advanced dementia: OR = 1.83 [1.42-2.35]; non-advanced dementia: OR = 1.16 [1.01-1.32]). Advance care planning was associated with lower odds of receiving life-sustaining treatments in the community (OR = 0.84 [0.74-0.96]) and in nursing homes (OR = 0.68 [0.53-0.86]). More beneficiaries with advanced dementia received interventions discordant with their EOL treatment preferences. Community dwellers with advanced dementia were more likely to receive life-sustaining treatments at the end of life and such treatments may be discordant with their EOL wishes. Enhancing advance care planning and patient-physician communication may improve EOL care quality for persons with dementia.

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.

AMplitude Spectral Area (AMSA) is associated with one-year survival with good neurological outcome in out-of-hospital cardiac arrest

Abstract Background Patients resuscitated from Out-of-Hospital Cardiac Arrest (OHCA) with shockable rhythms are reported to have better survival rates. Amplitude spectral area (AMSA) of ventricular fibrillation (VF), a surrogate for the metabolic status of the myocardium, can predict shock success and return of spontaneous circulation (ROSC). There is minimal evidence regarding its role in predicting survival from OHCA, and the evidence that exists is limited to survival at discharge. Purpose To test the hypothesis that the first, the maximum, the minimum and the average values of AMSA are associated with one-year survival with good neurological outcome in OHCA patients. Methods All the OHCAs with at least one shockable rhythm, that occurred from January 2015 to December 2020 and collected from an Utstein-style database, were considered. AMSA values were calculated by retrospectively analyzing the data collected by the monitors/defibrillators used and by using a 2-second pre-shock ECG interval. The first, the maximum, the minimum and the average AMSA values during resuscitation were computed. Data were analyzed by using Cox regression analysis. Results 250 patients (84% male, median age 67 [57-77] years) with at least one computable AMSA value were included; 12% achieved ROSC and 9.4% survived at one year with good neurological outcome, defined as Cerebral Performance Category (CPC) ≤ 2. The first, the maximum, the minimum and the average values of AMSA were higher in patients alive one year after OHCA with CPC≤2 (first: 11.6 [9.9-14.7] vs 7.8 [5.1-11.8]; max: 15.4 [12-20] vs 9.9 [6.2-14.4]; min: 9.9 [8.5-12.2] vs 6.1 [4.3-9.6]; avg: 12.5 [10.7-15.2] vs 8.3 [5.5-12]; all p &amp;lt;0.01). These values showed similar areas under the curve of the receiver operating characteristic (ROC) curve for one-year survival with good neurological outcome (first: 0.77; max: 0.76; min: 0.78; avg: 0.78, p=ns). In univariable model, the survival probability with good neurological outcome was significantly lower in the first tertile (T1) of AMSA compared to the third one (T3; p&amp;lt;0.05; figure). In multivariable analysis, after correction for sex, presence of bystander CPR, age, EMS arrival time, witnessed status, OHCA location, the use of mechanical CPR and the total amount of epinephrine administrated, AMSA was significantly associated with probability of death or poor neurologic outcome [HR 0.5 (95%CI 0.3-0.9), p=0.03]. Conclusions This is the first study to evaluate the association between AMSA values and one-year survival with good neurological outcome. We found that AMSA is independently associated with one-year survival with­ good neurological outcome in OHCA patients and that the first, the maximum, the minimum and the average of AMSA values all have similar prediction power in survival rate with CPC≤2.

Abstract 278: Injuries and Outcomes Associated With Manual vs Mechanical CPR Post Out of Hospital Cardiac Arrest

Objectives: Mechanical CPR is increasingly being used for field out of hospital cardiac arrest (OHCA) care. However, existing literature does not identify a survival benefit of mechanical versus manual CPR. We hypothesized that CPR related injury may impact patient outcomes. For that reason, our primary objective is to compare mechanical and manual CPR-related injury in resuscitated OHCA patients. Our secondary objective is to compare hospital outcomes including length of stay (LOS) and survival between these two CPR methods. Methods: We performed a retrospective study of adult OHCA patients admitted to three teaching hospitals in Southeastern Michigan from 2017-2021. Resuscitated patients were matched to hospital electronic medical records (EMRs), included if they had CT imaging of chest or abdomen/pelvis, and then dichotomized by CPR method. Patients were excluded if no EMR match or CPR method was unknown. Hospital EMRs were queried for CT imaging results, LOS variables and survival to hospital discharge. Injuries are identified using hospital ICD-10 codes. Univariate statistics are reported. Results: There were 808 patients admitted after OHCA, with 235 (103 mechanical CPR, 132 manual CPR) meeting the inclusion criteria. Demographics between groups were similar in age, gender, or body mass index (BMI). There were no abdominal/visceral injuries and few patients (4) had a pneumothorax. CPR associated injury was more common with manual CPR (28.8% vs 15.5%, p=0.02) and an increased rate of rib(s), sternum, or thoracic spine fracture (27.3% vs 14.6%, p=0.02). . We identified no differences in survival to hospital discharge (39 (29.5%) vs. 29 (28.2%), p=0.8), median hospital LOS, ICU LOS, and ventilator time between groups. Paradoxically amongst survivors, mechanical CPR was associated with longer LOS (15.7 vs 11.0 days, p=0.012) and a non-significant increased ventilator time (143 vs 99 hours, p=0.23). Conclusion: We identified a higher rate of injury with manual CPR compared to mechanical CPR in resuscitated OHCA patients We also did not identify any association between CPR method and ICU LOS, ventilator time, and survival. Further work is needed to assess the impact on outcome of CPR method and injuries typically associated with resuscitation.

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 308: Comparison of Cardiopulmonary Resuscitation Performance Between Integrated CPR Device Performing Chest Compression and External Defibrillation versus LUCAS3 With Automated External Defibrillator: A Animal and Manikin-Based Pilot Study

Background: Early chest compression and defibrillation are important components for successful resuscitation. The use of mechanical CPR has increased after the outbreak of COVID-19, and this trend continued in the post-pandemic period. We developed an automatic CPR performing chest compression and external defibrillation simultaneously following current CPR algorithm. Methods: This study was designed as a study to compare the performance of CPR and AED between automatic CPR apparatus (A-CPR) and commercially proven mechanical CPR device (LUCAS3) plus AED (C-CPR) during CPR in swine cardiac arrest model and the study to evaluate feasibility of A-CPR in simulated cardiac arrest model. Results: There were no significant differences in hemodynamic variables between the groups. Time to ECG analysis [38.0 sec in A-CPR, 48.0 sec in C-CPR, p =0.010], time to initial shock advice plus subsequent chest compression [46.0 sec in A-CPR, 57.0 sec in C-CPR, p =0.017], time to first defibrillation [48.5 sec in A-CPR, 65.0 sec in C-CPR, p =0.004], charge to shock interval [3.0 sec in A-CPR, 8.0 sec in C-CPR, p =0.001], and hands-off time [11.0 sec in A-CPR, 22.5 sec in C-CPR, p =0.001] were significantly shorter in A-CPR group than C-CPR group. In the simulation study, the pure chest compression time [101 sec in A-CPR, 110 sec in C-CPR, p&lt; 0.001], hands-off time [75 sec in A-CPR, 94 sec in C-CPR, p&lt; 0.001], time from power-on to first chest compression [55 sec in A-CPR, 82 sec in C-CPR, p&lt; 0.001], time to first shock delivery [40 sec in A-CPR, 51 sec in C-CPR, p= 0.001] were significantly shorter in A-CPR group than C-CPR group, respectively. Chest compression fraction showed a significant higher in A-CPR than C-CPR [57% in A-CPR, 54% in C-CPR, p &lt;0.001]. Conclusions: The A-CPR device demonstrated significant time savings effect than conventional mechanical CPR device and automated external defibrillation device. In addition, A-CPR and C-CPR showed similar hemodynamic effects and resuscitation outcomes in a swine model of cardiac arrest

Abstract 361: Effect of Percutaneous Ventricular Assisted Device on a Recovery of Myocardial Function in Swine Model With Prolonged Cardiac Arrest

Background: Percutaneous ventricular assist device (pLVAD) support and Transient aortic balloon occlusion (AO) can preserve cerebral and cardiac blood flow during cardiopulmonary resuscitation (CPR), but it remains unclear if pLVAD reduces post-cardiac arrest myocardial dysfunction. Hypothesis: pLVAD support immediately after the return of spontaneous circulation (ROSC) improves early recovery of myocardial function following prolonged cardiac arrest. Aims: Evaluate the association between early post-ROSC pLVAD support and recovery of myocardial function in a swine model of prolonged cardiac arrest. Methods: This is a secondary analysis of a subset of animals that achieved ROSC in a study comparing pLVAD, transient AO or both during CPR after prolonged cardiac arrest. pLVAD, aortic occlusion, or both were initiated after 24 minutes of ventricular fibrillation cardiac arrest (8 min no-flow and 16 min mechanical CPR). AO was discontinued post-ROSC, and pLVAD support or standard care were continued. Beginning 60 minutes post-ROSC, pLVAD support was weaned to &lt;1.0 L/min while maintaining a MAP &gt;70 mmHg, and subsequently removed at 4 hours when feasible. The primary outcome was the recovery of cardiac index (CI) and left ventricular ejection fraction (LVEF) at 4 hours post-ROSC. Data are shown as mean (standard error). Results: Seventeen animals achieved ROSC without complication and were included in this analysis (pLVAD group, n = 11 [8 were removed from pLVAD], and standard care group, n = 6). For the primary outcome, the pLVAD group had significantly higher CI of 4.2(0.3) vs. 3.1(0.4) L/min/m2 (p=0.043) and LVEF 60(3) vs. 49(4) % (p=0.029) at 4 hours after ROSC, respectively, when compared with the standard care group. Focusing on the early period within 60 minutes after ROSC when maximum pLVAD flow was maintained, the pLVAD group had significantly higher coronary perfusion pressure (62[4] vs. 47[5] mmHg, p=0.019), lower LV stroke work index (3.9[3.0] vs. 14.9[4.4] cJ/m2, p=0.043), and lower total pulmonary resistance index (13.2[4.8] vs. 21.5[14.4] Wood Unit, p=0.001). Conclusion: These results suggest that early pLVAD support after ROSC is associated with better recovery myocardial function compared to standard care after prolonged cardiac arrest.

Abstract 189: How Quickly Does Arterial Blood Pressure Recover After Pauses in Mechanical Chest Compressions in Humans With Out-of-Hospital Cardiac Arrest?

Introduction: Conventional wisdom says that arterial blood pressure (ABP) recovers slowly after interrupting CPR chest compressions (CCs). An oft-cited animal study with manual compressions and 15:2 compression:ventilation ratio showed that all 15 compressions were needed to restore pre-pause invasive pressure, implying that even short pauses substantially reduce CPR blood flow. Whether this holds true for humans receiving mechanical chest compressions is unknown. We measured recovery of ABP after pauses in mechanical compressions by LUCAS in patients treated for out-of-hospital cardiac arrest (OHCA). Methods: We analyzed data from a subset of patients enrolled in both groups of a prospective, randomized LUCAS 2 Active Decompression trial performed by an anesthesiologist-staffed rapid response car program in Oslo, Norway from 2016 to 2018. Only patients with an ABP signal and at least one CC pause longer than 2 sec were included. All CCs were mechanical. Arterial cannulation was verified, and CC pauses were identified by physician review of the patient care record and physiological signals. Pauses were excluded if ROSC or a LUCAS “soft start” occurred or epinephrine had been applied within 5 minutes of the pause. Peak compression (cAP), mean (mAP), and mean decompression arterial blood pressures (dAP) for 10 CCs before and after each pause were measured with custom MATLAB code. Results: We included 56 patients with a total of 148 pauses (mean pause duration: 10.63 ± 3.05 sec). Pre-pause mean cAP, mAP, and dAP were 95.6 ± 0.3, 49.9 ± 0.1 and 30.5 ± 0.1 mmHg. Post-pause dAP for each compression was not significantly different than pre-pause dAP (Fig. 1A,B). cAP and mAP recovered to &gt;90% of pre-pause pressure within 2 CCs. Pause duration was not predictive of post-pause pressures (Fig. 1C). Conclusions: ABP generated by mechanical CPR recovered quickly after pauses. Consequently, short pauses (such as pauses for 30:2 CPR) may pose less hemodynamic concern than previously thought.

Effect of no-flow period on the vasopressor effect of initial epinephrine administration in cardiac arrest

ObjectivesWhether a longer no-flow (NF) interval affects the magnitude of response to epinephrine in the resuscitation has not been well studied. Therefore, this study aimed to evaluate the effect of NF interval on the vasopressor effect of initial epinephrine administration in a porcine model. MethodsWe enrolled 20 pigs from two randomized porcine experimental studies using a ventricular fibrillation (VF) cardiac arrest model. The first experiment subjects were resuscitated after 4 min of NF (Short NF group), followed by three cycles (6 min) of chest compression using a mechanical cardiopulmonary resuscitation device before epinephrine administration. Second experiment subjects received 6 min of NF (Long NF group), two cycles (4 min) of chest compressions, and administration of epinephrine. Defibrillation for VF was delivered 8 and 10 min after VF induction in the Short NF and Long NF groups, respectively. The mean arterial pressure (MAP) and cerebral perfusion pressure (CePP) in the 2-min resuscitation period after epinephrine administration were compared between the study groups using the Wilcoxon rank-sum test. The mean differences in the parameters between phases were also compared. ResultsSeven pigs in the Short NF group and 13 pigs in the Long NF group were included in the analysis. All 2-min resuscitation phases from 6 to 16 min after VF induction were compared between the study groups. The Short NF group showed higher MAP and CePP in all phases (p < 0.01). Change of mean MAP after the epinephrine administration was significantly different between the study groups: mean difference (95% confidence interval) of 16.6 (15.8–17.4) mmHg in the Short NF group and 4.2 (3.9–4.5) mmHg in the Long NF group. ConclusionIn the porcine VF cardiac arrest model, 6 min of NF before resuscitation may affect the vasopressor effect of the initial epinephrine administered compared to 4 min of NF. A short NF may play a role in maximizing the effect of epinephrine in advanced cardiovascular life support.