Mechanical Chest Compression Devices Research Articles

Complication frequency of mechanical chest compression devices: A single-center, blinded study using retrospective data

AimUse of mechanical chest compression devices for patients with cardiac arrest is increasing. As cardiopulmonary resuscitation (CPR) guidelines and LUCAS are updated, the evidence requires updating. MethodsThis single-center, retrospective study observed adult patients with out-of-hospital cardiac arrest receiving CPR from emergency services. Patients were assigned to LUCAS or manual CPR groups, matched by propensity score, and evaluated through computed tomography images by a radiologist blinded to their data. The primary outcome was complications from chest compressions, and logistic regression was used to analyze their risk factors. ResultsOverall, 261 patients were selected and divided into manual and LUCAS groups (n = 69 each). The manual CPR group exhibited higher witnessed cardiac arrest percentages (p = 0.023) and shorter times from scene to emergency department (p = 0.001) and total CPR duration (p = 0.002), versus the LUCAS group. Complication rates showed no significant intergroup differences in overall CPR complications (p = 0.462); however, the LUCAS group reported more hemothorax incidents (p = 0.028), versus the manual group. Logistic regression indicated that female sex (odds ratio [OR] 3.743, 95 % confidence interval [CI] 1.333–10.506), older age (OR 1.089, 95 % CI 1.048–1.132), and longer CPR durations (OR 1.045, 95 % CI 1.006–1.085) significantly correlated with compression complications, whereas LUCAS use did not (OR 0.713, 95 % CI 0.304–1.673). ConclusionNo association was observed between LUCAS use and the overall incidence of chest compression complications in adults with OHCA. LUCAS is associated with more hemothorax cases and longer transport time, versus manual CPR. Evaluating LUCAS’s benefits necessitates multiple perspectives and further research.

A Scientometric Analysis of Mechanical Cardiopulmonary Resuscitiation Device Publications

Aim: Today, the use of automatic chest compression devices is increasing. The aim of this study is to identify popular publications about chest compression devices, save time for researchers, and summarize the important points of chest compression devices using the scientometric analysis method. Material and Methods: All data were collected using the Web of Science Core Collection between July 1-8, 2023. Articles related to the topic were selected using the keywords "automated chest compression device" or "mechanical chest compression device". All articles in the database were manually scanned and analyzed. The distribution of relevant articles in the database was analysed according to scientific journals. Global research productivity, international collaborations, and research themes were analyzed using the scientometric method. Results: A total of 589 articles were identified in the WoS. Out of these, 439 (74.407%) were original articles, followed by 63 (10.678%) review articles and 30 (5.085%) editorial materials. When examining the distribution of research articles by country, the United States (US) topped the list with 171 articles, followed by Germany (n=77). Although the UK ranked third in terms of the number of publications with 53 articles, it ranked first in terms of the number of citations. (n=3465). An assessment of the top 20 publishing journals revealed that the Resuscitation Journal led in terms of publication count (n=133), citation count (n=5906), and average citations per publication (n=44.41). Conclusion: Our bibliometric study analyzed 589 articles on mechanical cardiopulmonary resuscitation. This can help researchers identify trending topics and areas of interest more quickly. More research is needed to fully understand the effectiveness and best tools for saving lives in emergency situations.

Manual mastery vs. mechanized magic: current opinions on manual vs. mechanical chest compressions.

Mechanical chest compression devices are increasingly deployed during cardiopulmonary resuscitation. We discuss the data supporting the use of mechanical chest compression devices during cardiac arrest and provide an opinion about the future of the technology. Multiple randomized trials investigating the use of mechanical chest compression devices for out-of-hospital cardiac arrest have not demonstrated improved outcomes. There is little prospective evidence to support the use of mechanical chest compression devices in other settings. Data from observational studies do not support the routine use of mechanical chest compression devices for in-hospital cardiac arrest, but there may be a role for mechanical chest compressions for cardiac arrest in procedural areas and cardiac arrest prior to cannulation for extracorporeal membrane oxygenation. Mechanical chest compression devices offer a solution to some of the human limiting factors of resuscitation, but have failed to demonstrate meaningful improvement in outcomes from cardiac arrest. Routine use of mechanical chest compression devices during cardiac arrest is not supported by evidence.

Ventilation during cardiopulmonary resuscitation with mechanical chest compressions: How often are two insufflations being given during the 3-second ventilation pauses?

BackgroundMechanical chest compression devices in 30:2 mode provide 3-second pauses to allow for two insufflations. We aimed to determine how often two insufflations are provided in these ventilation pauses, in order to assess if prehospital providers are able to ventilate out-of-hospital cardiac arrest (OHCA) patients successfully during mechanical chest compressions. MethodsData from OHCA cases of the regional ambulance service of Utrecht, The Netherlands, were prospectively collected in the UTrecht studygroup for OPtimal registry of cardIAc arrest database (UTOPIA). Compression pauses and insufflations were visualized on thoracic impedance and waveform capnography signals recorded by manual defibrillators. Ventilation pauses were analyzed for number of insufflations, duration of the subintervals of the ventilation cycles, and ratio of successfully providing two insufflations over the course of the resuscitation. Generalized linear mixed effects models were used to accurately estimate proportions and means. ResultsIn 250 cases, 8473 ventilation pauses were identified, of which 4305 (51%) included two insufflations. When corrected for non-independence of the data across repeated measures within the same subjects with a mixed effects analysis, two insufflations were successfully provided in 45% of ventilation pauses (95% CI: 40–50%). In 19% (95% CI: 16–22%) none were given. ConclusionProviding two insufflations during pauses in mechanical chest compressions is mostly unsuccessful. We recommend developing strategies to improve giving insufflations when using mechanical chest compression devices. Increasing the pause duration might help to improve insufflation success.

A retrospective comparison of mechanical cardio-pulmonary ventilation and manual bag valve ventilation in non-traumatic out-of-hospital cardiac arrests: A study from the Belgian cardiac arrest registry

BackgroundThe optimal ventilation modalities to manage out-of-hospital cardiac arrest (OHCA) remain debated. A specific pressure mode called cardio-pulmonary ventilation (CPV) may be used instead of manual bag ventilation (MBV). We sought to analyse the association between mechanical CPV and return of spontaneous circulation (ROSC) in non-traumatic OHCA. MethodsMBV and CPV were retrospectively identified in patients with non-traumatic OHCA from the Belgian Cardiac Arrest Registry. We used a two-level mixed-effects multivariable logistic regression analysis to determine the association between the ventilation modalities and outcomes. The primary and secondary study criteria were ROSC and survival with a Cerebral Performance Category (CPC) score of 1 or 2 at 30 days. Age, sex, initial rhythm, no-flow duration, low-flow duration, OHCA location, use of a mechanical chest compression device and Rankin status before arrest were used as covariables. ResultsBetween January 2017 and December 2021, 2566 patients with OHCA who fulfilled the inclusion criteria were included. 298 (11.6%) patients were mechanically ventilated with CPV whereas 2268 were manually ventilated. The use of CPV was associated with greater probability of ROSC both in the unadjusted (odds ratio: 1.28, 95% confidence interval [CI]: 1.01–1.63; p = 0.043) and adjusted analyses (adjusted odds ratio [aOR]: 2.16, 95%CI 1.37–3.41; p = 0.001) but not with a lower CPC score (aOR: 1.44, 95%CI 0.72–2.89; p = 0.31). ConclusionsCompared with MBV, CPV was associated with an increased risk of ROSC but not with improved an CPC score in patients with OHCA. Prospective randomised trials are needed to challenge these results.

Abstract 383: Effect of Audiovisual Feedback Device Type on Prehospital Chest Compression Quality During Prehospital Resuscitation

Background: Real-time audiovisual feedback devices have been implemented to optimize cardiopulmonary resuscitation (CPR) performance during out-of-hospital cardiac arrest (OHCA). Emergency medical service (EMS) personnel perceive different levels of usability regarding feedback device type. The study aimed to evaluate the effect of type of audiovisual feedback device used during prehospital CPR on chest compression quality during prehospital resuscitation. Method: Adult OHCA patients who received CPR by EMS personnel utilizing feedback device in Seoul between April 2020 and December 2021 were included. Cases that utilized mechanical chest compression devices were excluded. Feedback devices were classified into two types: sticker-type (S-type) and puck-type (P-type). The quality of chest compressions during prehospital resuscitation was compared based on the feedback device type. The primary outcome assessed was chest compression depth. Subgroup analysis was conducted for cases in which EMS personnel had experience using both types of devices. Results: In total, 2,896 OHCA cases were included. 1,596 cases utilized S-type devices and 1,300 cases utilized P-type devices. The median chest compression depth was significantly higher in cases that utilized the S-type device (Median: 5.2, interquartile range (IQR): 4.5-5.8) compared to those that used the P-type device (Median: 4.3, IQR: 3.7-5.0) (P<0.001). In addition, proportion of chest compressions with adequate depth (5-6 cm) was significantly higher in the S-type group, while average chest compression rate and chest compression fraction were higher in the P-type group. Similar findings were observed in the subgroup analysis. Conclusion: Difference in chest compression quality parameters were observed during prehospital resuscitation according to type of audiovisual feedback device utilized. Chest compression quality regarding chest compression depth was superior when S-type feedback device was used.

Prehospital factors associated with out-of-hospital cardiac arrest outcomes in a metropolitan city: a 4-year multicenter study

BackgroundPrehospital factors play a vital role in out-of-hospital cardiac arrest (OHCA) survivability, and they vary between countries and regions. We investigated the prehospital factors associated with OHCA outcomes in a single metropolitan city in the Republic of Korea.MethodsThis study included adult medical OHCA patients enrolled prospectively, using data from the citywide OHCA registry for patients registered between 2018 and 2021. The primary outcome was survival to hospital discharge. Multivariable logistic regression analysis was conducted to determine the factors associated with the study population’s clinical outcomes, adjusting for covariates. We performed a sensitivity analysis for clinical outcomes only for patients without prehospital return of spontaneous circulation prior to emergency medical service departure from the scene.ResultsIn multivariable logistic regression analysis, older age (odds ratio [OR] 0.96; 95% confidence interval [CI] 0.95–0.97), endotracheal intubation (adjusted odds ratio [aOR] 0.29; 95% [CIs] 0.17–0.51), supraglottic airway (aOR 0.29; 95% CI 0.17–0.51), prehospital mechanical chest compression device use (OR 0.13; 95% CI 0.08–0.18), and longer scene time interval (OR 0.96; 95% CI 0.93–1.00) were negatively associated with survival. Shockable rhythm (OR 24.54; 95% CI 12.99–42.00), pulseless electrical activity (OR 3.11; 95% CI 1.74–5.67), and witnessed cardiac arrest (OR 1.59; 95% CI 1.07–2.38) were positively associated with survival. In the sensitivity analysis, endotracheal intubation, supraglottic airway, prehospital mechanical chest compression device use, and longer scene time intervals were associated with significantly lower survival to hospital discharge.ConclusionsRegional resuscitation protocol should be revised based on the results of this study, and modifiable prehospital factors associated with lower survival of OHCA should be improved.

Comparison of hemodynamic effects of chest compression delivered via machine or human in asphyxiated piglets

BackgroundHigh-quality chest compressions (CC) are an important factor of neonatal resuscitation. Mechanical CC devices may provide superior CC delivery and improve resuscitation outcomes. We aimed to compare the hemodynamic effects of CC delivered by machine and human using a neonatal piglet model.MethodsTwelve asphyxiated piglets were randomized to receive CC during resuscitation using an automated mechanical CC device (“machine”) or the two-thumb encircling technique (“human”). CC was superimposed with sustained inflations.ResultsTwelve newborn piglets (age 0–3 days, weight 2.12 ± 0.17 kg) were included in the study. Machine-delivered CC resulted in an increase in stroke volume, and minimum and maximum rate of left ventricle pressure change (dp/dtmin and dp/dtmax) compared to human-delivered CC.ConclusionsDuring machine-delivered CC, stroke volume and left ventricular contractility were significantly improved. Mechanical CC devices may provide improved cardiopulmonary resuscitation outcomes in neonatal cardiac arrest induced by asphyxia.ImpactMachine chest compression leads to changes in hemodynamic parameters during resuscitation of asphyxiated neonatal piglets, namely greater stroke volume and left ventricular contractility, compared with standard two-thumb compression technique. Mechanical chest compression devices may provide improved cardiopulmonary resuscitation outcomes in neonatal and pediatric asphyxia-induced cardiac arrest.

Efficacy of Cardiopulmonary Resuscitation Using Automatic Compression-Defibrillation Apparatus: An Animal Study and A Manikin-Based Simulation Study.

Chest compression and defibrillation are essential components of cardiac arrest treatment. Mechanical chest compression devices (MCCD) and automated external defibrillators (AED) are used separately in clinical practice. We developed an automated compression-defibrillation apparatus (ACDA) that performs mechanical chest compression and automated defibrillation. We investigated the performance of cardiopulmonary resuscitation (CPR) with automatic CPR (A-CPR) compared to that with MCCD and AED (conventional CPR: C-CPR). Pigs were randomized into A-CPR or C-CPR groups: The A-CPR group received CPR+ACDA, and the C-CPR group received CPR+MCCD+AED. Hemodynamic parameters, outcomes, and time variables were measured. During a simulation study, healthcare providers performed a basic life support scenario for manikins with an ACDA, MCCD, and AED, and time variables and chest compression parameters were measured. The animals showed no significant in hemodynamic effects, including aortic pressures, coronary perfusion pressure, carotid blood flow, and end-tidal CO2, and resuscitation outcomes between the two groups. In both animal and simulation studies, the time to defibrillation, time to chest compression, and hands-off time were significantly shorter in the A-CPR group than those in the C-CPR group. CPR using ACDA showed similar hemodynamic effects and resuscitation outcomes as CPR using AED and MCCD separately, with the advantages of a reduction in the time to compression, time to defibrillation, and hands-off time.

Evaluating the Efficacy and Safety of the Thumper Device for Cardiac Arrest: A Systematic Literature Review and Meta-Analysis.

Cardiopulmonary resuscitation (CPR) is a major rescue measure for cardiac arrest (CA) patients, and chest compression is the key to CPR. The Thumper device was designed to facilitate manual compression during CPR. However, current randomized controlled trials (RCTs) provide controversial findings on the efficacy of the Thumper device. This meta-analysis aimed to compare the clinical benefits of using the Thumper device with manual chest compressions during the provision of CPR for patients in CA. Relevant studies were retrieved from various databases, including Ovid, PubMed, Web of Science, EMBASE, Cochrane, and CNKI, and by manually searching the reference lists of research and review articles. All RCTs published in either English or Chinese until June 31, 2020, were included in the meta-analysis. The odds ratios (ORs) and their 95% confidence intervals (95% CIs) for the return of spontaneous circulation (ROSC), survival rate (SR), and the incidence of rib fractures (RFs) were compared between the manual and Thumper chest compressions. A total of 2164 records were identified, of which 16 were RCTs with an overall risk of bias ranging from low to medium classification. Following CPR, the odds ratios for ROSC, SR, and RF were significantly better for the Thumper chest compression with ORs of 2.56 (95% CI 2.11-3.11, = 0%), 4.06 (95% CI 2.77-5.93, = 0%), and 0.24 (95% CI 0.14-0.41, = 0%), respectively. The Thumper compression devices may improve patient outcome, when used at inhospital cardiac arrest. This review suggests a potential role for mechanical chest compression devices for in-hospital cardiac arrest, but there is an urgent need for high-quality research, particularly adequately powered randomised trials, to further examine this role.

Surviving the storm: manual vs. mechanical chest compressions onboard a lifeboat during bad weather conditions

ObjectiveIt is challenging for rescuers to perform cardiopulmonary resuscitation (CPR) onboard lifeboats, particularly during rough weather. A mechanical chest compression device (MCD) may provide better quality chest compressions. The aim of this study was to compare the quality of chest compressions performed by lifeboat-crewmembers with those of a MCD during rough-sea conditions.MethodsLifeboat-crewmembers were scheduled to provide compression-only CPR on a resuscitation-mannequin during two sets of five 6-min epochs on a lifeboat at sea in two different weather-conditions. Simultaneously a MCD was used for compression-only CPR on another mannequin onboard the lifeboat. On a third occasion compressions by MCD only were measured due to COVID-19 restrictions. The primary outcome variable was the quality of chest compression, evaluated using published variables and standards (mean compression depth and compression frequency, percentage correct compression depth, percentage of not leaning on the thorax, percentage of correct hand placement on the thorax, hands-off-time).ResultsSix male lifeboat-crewmembers (mean age 35 years) performed CPR during two different weather conditions. In weather-conditions one (wind ~6–7 Beaufort/wave-height: 100–150 cm) quality of manual compressions was significantly worse than mechanical compressions for mean compression depth (p < 0.05) and compression frequency (p < 0.05), percentage correct compression depth (p < 0.05), percentage of not leaning on the thorax (p < 0.05), and hands off time (p < 0.05). Crewmembers could only perform CPR for a limited time-period (sea-conditions/seasickness) and after one set of five epochs measurements were halted. In weather-condition two (wind ~9 Beaufort/wave-height ~200 cm) similar results were found during two epochs, after which measurements were halted (sea-conditions/seasickness). In weather-condition three (wind ~7 Beaufort/wave-height ~300–400 cm) MCD compressions were according to resuscitation-guidelines except for three epochs during which the MCD was displaced.ConclusionCrewmembers were only able to perform chest-compressions for a limited time because of the weather-conditions. The MCD was able to provide good quality chest compressions during all but three epochs during the study period. More research is needed to determine whether MCD-use in real-life circumstances improves outcome. Inclusion of data on use of a MCD on lifeboats should be considered in future revisions of the USFD and resuscitation guidelines.

Effects of mechanical cardiopulmonary resuscitation during vertical spatial pre-hospital transport in patients with cardiac arrest: a historical cohort study

To analyze the effect of mechanical cardiopulmonary resuscitation (CPR) on patients with cardiac arrest with the vertical spatial pre-hospital emergency transport. A retrospective cohort study was conducted. The clinical data of 102 patients with out-of-hospital cardiac arrest (OHCA) who were transferred to the emergency medicine department of Huzhou Central Hospital from the Huzhou Emergency Center from July 2019 to June 2021 were collected. Among them, the patients who performed artificial chest compression during the pre-hospital transfer from July 2019 to June 2020 served as the control group, and the patients who performed artificial-mechanical chest compression (implemented artificial chest compression first, and implemented mechanical chest compression immediately after the mechanical chest compression device was ready) during pre-hospital transfer from July 2020 to June 2021 served as the observation group. The clinical data of patients of the two groups were collected, including basic data (gender, age, etc.), pre-hospital emergency process evaluation indicators [chest compression fraction (CCF), total CPR pause time, pre-hospital transfer time, vertical spatial transfer time], and in-hospital advanced resuscitation effect evaluation indicators [initial end-expiratory partial pressure of carbon dioxide (PETCO2), rate of restoration of spontaneous circulation (ROSC), time of ROSC]. Finally, a total of 84 patients were enrolled, including 46 patients in the control group and 38 in the observation group. There was no significant difference in gender, age, whether to accept bystander resuscitation or not, initial cardiac rhythm, time-consuming pre-hospital emergency response, floor location at the time of onset, estimated vertical height, and whether there was any vertical transfer elevator/escalator, etc. between the two groups. In the evaluation of the pre-hospital emergency process, the CCF during the pre-hospital emergency treatment of patients in the observation group was significantly higher than that in the control group [69.05% (67.35%, 71.73%) vs. 61.88% (58.18%, 65.04%), P < 0.01], the total pause time of CPR was significantly shorter than that in the control group [s: 266 (214, 307) vs. 332 (257, 374), P < 0.05]. However, there was no significant difference in the pre-hospital transfer time and vertical spatial transfer time between the observation group and the control group [pre-hospital transfer time (minutes): 14.50 (12.00, 16.75) vs. 14.00 (11.00, 16.00), vertical spatial transfer time (s): 32.15±17.43 vs. 27.96±18.67, both P > 0.05]. It indicated that mechanical CPR could improve the CPR quality in the process of pre-hospital first aid, and did not affect the transfer of patients by pre-hospital emergency medical personnel. In the evaluation of the in-hospital advanced resuscitation effect, the initial PETCO2 of the patients in the observation group was significantly higher than that of the patients in the control group [mmHg (1 mmHg ≈ 0.133 kPa): 15.00 (13.25, 16.00) vs. 12.00 (11.00, 13.00), P < 0.01], the time of ROSC was significantly shorter than that in the control group (minutes: 11.00±3.25 vs. 16.64±2.54, P < 0.01), and the rate of ROSC was slightly higher than that in the control group (31.58% vs. 23.91%, P > 0.05). It indicated that continuous mechanical compression during pre-hospital transfer helped to ensure continuous high-quality CPR. Mechanical chest compression can improve the quality of continuous CPR during the pre-hospital transfer of patients with OHCA, and improve the initial resuscitation outcome of patients.

Ventilation during continuous compressions or at 30:2 compression-to-ventilation ratio results in similar arterial oxygen and carbon dioxide levels in an experimental model of prolonged cardiac arrest

BackgroundIn refractory out-of-hospital cardiac arrest, transportation to hospital with continuous chest compressions (CCC) from a chest compression device and ventilation with 100% oxygen through an advanced airway is common practice. Despite this, many patients are hypoxic and hypercapnic on arrival, possibly related to suboptimal ventilation due to the counterpressure caused by the CCC. We hypothesized that a compression/ventilation ratio of 30:2 would provide better ventilation and gas exchange compared to asynchronous CCC during prolonged experimental cardiopulmonary resuscitation (CPR).MethodsWe randomized 30 anaesthetized domestic swine (weight approximately 50 kg) with electrically induced ventricular fibrillation to the CCC or 30:2 group and bag-valve ventilation with a fraction of inspired oxygen (FiO2) of 100%. We started CPR after a 5-min no-flow period and continued until 40 min from the induction of ventricular fibrillation. Chest compressions were performed with a Stryker Medical LUCAS® 2 mechanical chest compression device. We collected arterial blood gas samples every 5 min during the CPR, measured ventilation distribution during the CPR using electrical impedance tomography (EIT) and analysed post-mortem computed tomography (CT) scans for differences in lung aeration status.ResultsThe median (interquartile range [IQR]) partial pressure of oxygen (PaO2) at 30 min was 110 (52–117) mmHg for the 30:2 group and 70 (40–171) mmHg for the CCC group. The median (IQR) partial pressure of carbon dioxide (PaCO2) at 30 min was 70 (45–85) mmHg for the 30:2 group and 68 (42–84) mmHg for the CCC group. No statistically significant differences between the groups in PaO2 (p = 0.40), PaCO2 (p = 0.79), lactate (p = 0.37), mean arterial pressure (MAP) (p = 0.47) or EtCO2 (p = 0.19) analysed with a linear mixed model were found. We found a deteriorating trend in PaO2, EtCO2 and MAP and rising PaCO2 and lactate levels through the intervention. There were no differences between the groups in the distribution of ventilation in the EIT data or the post-mortem CT findings.ConclusionsThe 30:2 and CCC protocols resulted in similar gas exchange and lung pathology in an experimental prolonged mechanical CPR model.

Introduction to ecological innovations in resuscitation training. Does made of cardboard has to mean single-use?

Aim: To assess the initial usefulness of an innovative, ecological manikin made of cardboard and coconut fiber, which is intended for resuscitation training. Material and methods: The study was conducted with the use of a mechanical chest compression device and assistance of human subjects. The first phase quantified the initial durability of the manikin. Phases two and three initially assessed manikins’ mechanical properties, its resistance to repetitive chest com¬pression training, and the quality of chest compressions performed on the tested manikin. Results: 268 and 49 participants took part in the first and the second phase of the study, respectively. The total number of chest compressions performed on the manikin was 30.736 and 4.928, respectively. The number of mechanical chest compressions reached 75.000 in phase three. The mean compression depth ranged between 47.1 ± 1.4 and 52.7 ± 0.6 mm, and the compression force ranged from 577 ± 10.0 to 686 ± 187 N. The rate of compressions ranged from 99.5 to 133/min, and the percentage of complete chest recoil ranged from 62.1 ± 20.3% to 100%. Conclusions: The tested ecological manikin invented for the purpose of resuscitation training provides the parameters necessary for students to master the ability to deliver high-quality chest compressions in terms of depth, rate, full recoil and force needed to perform chest compressions in a large adult. Durability tests showed that a manikin made of ecological materials can also be used multiple times, for many training groups.

Abstract 136: The Effect Of Mechanical Chest Compression Device On Survival After Out-of-hospital Cardiac Arrest According To Patient Transport Interval: A Multicenter Observational Study

Objectives: This study aimed to investigate the effect of mechanical chest compression device (MCPRD) on patients with OHCA according to patient transport interval (PTI). We hypothesized that MCPRD is effective on survival with prolonged PTI compared with manual chest compression (non-MCPRD). Methods: This cross-sectional multicenter observational study used the Korean Cardiac Arrest Research Consortium registry data from 2015 to 2019. Emergency medical service (EMS) treated OHCAs presumed of cardiac etiology without return of spontaneous circulation (ROSC) at scene were included. Exposure was prehospital MCPRD use and PTI. The main outcome was survival to admission. PTI was categorized into three groups; short PTI for 0-5 minutes, intermediate for 6-10 minutes and long PTI for over 10 minutes, respectively. Multivariable logistic regression was performed to estimate the adjusted odds ratios (AORs) and its’ corresponding 95% confidence intervals (95% CI) for the effect of MCPRD compared with manual compression on outcome. Interaction of PTI on the effect of MCPRD on outcome were tested. To control for selection bias and confounding factors, propensity score (PS) matched cohort was extracted. PS score for each patient to receive MCPRD was estimated using a multivariable logistic regression model. To reduce the standard error of MCPRD on outcomes, a two-to-one propensity score matched cohort was extracted. Results: For unmatched cohort, a total of 3,530 patients were eligible and after PS matching, a total of 2,049 patients were eligible for the analysis. The MCPRD was applied at 19.3% of all unmatched cohort. After adjusting for potential confounders, the AOR of MCPRD for survival to admission was 1.36 (95% CI 1.07-1.72) for unmatched cohort and 1.37 (95% CI 1.06-1.78) for PS matched cohort. Interaction according to PTI on the effect of MCPRD was significant at prolonged PTI on both cohorts; AOR 1.60 (95% CI 1.06-2.42) for unmatched cohort and AOR 1.60 (95% CI 1.06-2.42) for PS matched cohort, respectively. Conclusion : For patients with OHCA with PTI longer than 10 minutes, MCPRD use showed a significant survival benefit compared with manual chest compressions. Further studies are needed to evaluate the appropriate use of MCPRD in special situations.

Abstract 197: Location, Location, Location! Association Of Success In Transthoracic Echocardiography Image Acquisition With Location During Cardiopulmonary Resuscitation.

Introduction: Currently, no consensus exists regarding the ideal location for obtaining a transthoracic echocardiography (TTE) image during cardiopulmonary resuscitation (CPR). Of the three common locations, sub-xiphoid (SX), parasternal (PS) and apical (AP), the SX is most frequently used in cardiac arrest (CA) to avoid interfering with CPR. The recent adoption of mechanical chest compression devices may have led to increased use of alternate locations. We aim to assess the association between successful TTE image acquisition and the locations, also to compare the duration of CPR interruptions at each location. Hypothesis: We hypothesized that PS location will have a higher success rate compared to SX, but not a longer CPR interruption time. Methods: This is a retrospective study of all video-recorded non-traumatic, CA patients ≥18 years old in a quaternary care Emergency Department (ED) from 08/07/2019 to 05/18/2022 where an intra-arrest TTE was performed. Video recordings of cardiac arrest patients were reviewed by 2 physicians with years of experience and a well-established process. Successful image acquisition was defined as 1) visualization of the heart on the ultrasound machine or 2) clinicians verbalizing visualization in the video recording. Chi-square and Kruskal-Wallis tests were performed to compare the success rates and duration of CPR interruptions based on TTE locations. Our health system’s Institutional Review Board approved the conduct of this study. Results: A total of 59 patients yielded a combined 154 video recorded TTE attempts 90 (58.4%) SX, 56 (36.4%) PS, and 8 (5.2%) AP. Median age was 81 years, 50.8% female, 81.4% non-shockable initial rhythm, and 89.8% were receiving mechanical CPR. Because there were only 8 AP attempts, PS and SX were the only locations analyzed. PS was successful in 89.3% (68 of 90) compared to 75.6% (50 of 56) for the SX (p=0.04). The median duration of interruptions for PS was 17.5 seconds (IQR: 12.0, 22.0) compared to 15 seconds (IQR: 11.0, 24.0) for SX (p=0.5). Conclusion: During CPR, PS location for TTE image acquisition is associated with higher success when compared to SX. However, the median CPR interruption times are not significantly different.

National Comparison of Mechanical Chest Compression Devices and Manual Cardiopulmonary Resuscitation in Trauma and Nontrauma Patients

INTRODUCTION: Most trials comparing mechanical chest compression devices and manual CPR exclude trauma patients. The purpose of this study was to perform a retrospective comparison of mechanical chest compression devices and manual CPR in trauma and nontrauma patients. METHODS: The National Emergency Medical Services Information System (NEMSIS) database was queried for all patients undergoing CPR in 2020. The primary outcome was the return of spontaneous circulation (ROSC). Chi-square tests and multivariable logistic regression were performed. RESULTS: There were 160,838 patients undergoing CPR during the study period. The rate of ROSC was 24.8% (n = 39,813). A mechanical compression device was used in 15.0% (n = 24,170), and trauma patients composed 6.3% (p = 10,072). The rate of ROSC with device use was 20.0% (n = 4,838, p < 0.001). Multivariable logistic regression found a decreased likelihood of ROSC with device use (odds ratio 0.73 [0.70 to 0.75], p < 0.001) and in trauma patients (odds ratio 0.39 [0.37 to 0.42], p < 0.001). Subgroup analysis of only trauma patients found that the rate of ROSC was 13.0% (n = 1,312). The rate of ROSC with device use in trauma patients was 11.7% (n = 146, p = 0.14). CONCLUSION: The likelihood of achieving ROSC was decreased in patients when a mechanical chest compression device was used. When evaluating only trauma patients, the rate of ROSC was decreased and was further decreased when a device was used. However, this decreased rate was not statistically significant compared with manual CPR. Further randomized controlled trials comparing mechanical vs manual chest compressions in trauma patients are warranted.

46 The Effect of Mechanical Chest Compression Device on Survival After Out-of-Hospital Cardiac Arrest According to Patient Transport Interval: A Multi-center Observational Study

46 The Effect of Mechanical Chest Compression Device on Survival After Out-of-Hospital Cardiac Arrest According to Patient Transport Interval: A Multi-center Observational Study

Manual chest compression pause duration for ventilations during prehospital advanced life support – An observational study to explore optimal ventilation pause duration for mechanical chest compression devices

AimMechanical chest compression devices in the 30:2 mode generally provide a pause of three seconds to give two insufflations without evidence supporting this pause duration. We aimed to explore the optimal pause duration by measuring the time needed for two insufflations, during advanced life support with manual compressions. MethodsProspectively collected data in the AmsteRdam REsuscitation STudies (ARREST) registry were analysed, including thoracic impedance signal and waveform capnography from manual defibrillators of the Amsterdam ambulance service. Compression pauses were analysed for number of insufflations, time interval from start of the compression pause to the end of the second insufflation, chest compression pause duration and ventilation subintervals. ResultsDuring 132 out-of-hospital cardiac arrests, 1619 manual chest compression pauses to ventilate were identified. In 1364 (84%) pauses, two insufflations were given. In 28% of these pauses, giving two insufflations took more than three seconds. The second insufflation is completed within 3.8 seconds in 90% and within 5 seconds in 97.5% of these pauses. An increasing likelihood of achieving two insufflations is seen with increasing compression pause duration up to five seconds. ConclusionThe optimal chest compression pause duration for mechanical chest compression devices in the 30:2 mode to provide two insufflations, appears to be five seconds, warranting further studies in the context of mechanical chest compression. A 5-second pause will allow providers to give two insufflations with a very high success rate. In addition, a 5-second pause can also be used for other interventions like rhythm checks and endotracheal intubation.

What are ambulance crews' experiences of using a mechanical chest compression device for out-of-hospital resuscitation? A constructivist qualitative study utilising online focus groups.

Mechanical chest compression devices (MCCDs) provide chest compressions mechanically to a person in cardiac arrest. Those chest compressions would usually be provided manually. Previous studies into the use of MCCDs have focused on the quantitative outcomes, with little emphasis on the qualitative experiences of those using MCCDs. To collect and report ambulance crews' experiences of using MCCDs for out-of-hospital resuscitation attempts. The philosophical approach was constructivist, the methodology qualitative and the data collection method online focus groups. Convenience sampling was used to recruit participants who met the inclusion criteria, which broadly were to have experience of using MCCDs for out-of-hospital resuscitation. There have been two types of MCCD used locally. Participants were included regardless of which type of device they had experience of. Similarly, participants were included whether they had active or passive experience of the devices. The focus groups were recorded, fully transcribed and then analysed using constant comparison. Four selective codes emerged. These were factors directly affecting ambulance crew members; practicalities of a resuscitation attempt; ambulance crew members' perceptions, experiences and thoughts; negatives of MCCDs. The main perceptions arising from the participants' discussion in this work were that MCCD use could potentially provide psychological protection to ambulance crew members when reflecting on resuscitation attempts, and participants felt there is an overall reduction of cognitive load for ambulance crew members when using MCCDs for resuscitation attempts. There were particularly timely benefits expressed of MCCDs easing the physical fatigue of a resuscitation attempt when responding wearing personal protective equipment, as has been required during the COVID-19 pandemic. MCCDs were felt to be of benefit when transporting a patient in cardiac arrest but differences were expressed as to whether the LUCAS-2 in particular helps or hinders extrication of a patient.