Does Autopulse Mechanical chest compression improve outcomes after cardiac arrest? A systemic review and meta-analysis

Background: Cardiac arrest remains a critical global health challenge, necessitating effective interventions to improve outcomes. Autopulse Mechanical chest compression (CC) has emerged as a potential adjunct to conventional manual cardiopulmonary resuscitation (M-CPR). This study aimed to comprehensively investigate the association between Autopulse use and various outcomes following cardiac arrest. Methods: A thorough literature review was conducted using PubMed, Embase, Scopus, Google Scholar, CINAHL, and the Cochrane Library. Articles were evaluated for eligibility according to predefined criteria. The collected data was synthesized, and the findings were subsequently presented. Results: Sixteen studies were included in the study. A synthesis of diverse studies revealed nuanced perspectives on Autopulse Mechanical CC. Enhanced cardiopulmonary resuscitation success and improved survival rates in out-of-hospital cardiac arrest were demonstrated, while potential drawbacks were suggested, war-ranting scrutiny of device design and implementation strategies. Meta-analyses on the return of spontane-ous circulation favored Autopulse, indicating a statistically significant advantage over M-CPR (relative risk 1.43, 95% CI 1.07-1.92). Complication analyses showed no significant difference (relative risk 1.11, 95% CI 0.93-1.33), emphasizing comparable safety profiles. Patient survival rates exhibited variations, with Autopulse demonstrating higher rates in some studies, but nuances were observed in 30-day survival and hospital discharge rates. Conclusion: Autopulse Mechanical CC holds promise as a supplementary strategy in cardiac arrest resuscitation. However, complexities arose in longer-term outcomes, highlighting the need for contextual considerations


Introduction
Cardiac arrest stands as a critical medical emergency, necessitating prompt intervention to optimize patient outcomes [1].For more than five decades, cardiopulmonary resuscitation (CPR) has stood as a wellknown and acknowledged emergency intervention in instances of cardiac arrest [2,3].The cornerstone of CPR involves manual chest compressions (CCs), a procedure

REVIEW ARTICLE
Does Autopulse Mechanical chest compression improve outcomes after cardiac arrest?A systemic review and meta-analysis integral to restoring circulation [4].Annually, in the United Kingdom, around 35,000 individuals experience an in-hospital cardiac arrest, with a mere 18.4% surviving until discharge from the hospital [5].The caliber of CCs is a crucial factor that can be modified to influence survival rates after a cardiac arrest [6].However, challenges associated with the consistency and efficacy of manual compressions have prompted exploration into alternative methods to enhance resuscitative efforts.
Despite the crucial role of CPR in cardiac arrest management, conventional manual CCs present inherent limitations.Variability in compression depth, rate, and interruptions can compromise the effectiveness of resuscitation efforts, leading to suboptimal outcomes.Over the last few decades, researchers have persisted in investigating the ideal depth and rate of CCs.As a result, the American Heart Association has advocated that CCs be conducted at a depth ranging from 5 to 6 cm and at a frequency between 100 and 120 compressions per minute, as indicated in its CPR Guidelines [7].The quest for improved resuscitation strategies has given rise to innovative technologies, among which Autopulse Mechanical CC has garnered attention.
During the early 2000s, the US Food and Drug Administration approved two mechanical compression devices, namely AutoPulse and LUCAS, aiming to address the challenges associated with manual CCs.The AutoPulse device is characterized as a load-distributing band (LDB) mechanism featuring broadband that encircles the chest wall.This band is automated to alternate between shortening and lengthening, facilitating the provision of compressions.The Autopulse system introduces a mechanized approach to CCs, aiming to address the limitations associated with manual techniques.This automated system is designed to deliver consistent and high-quality CCs, potentially overcoming challenges encountered during manual CPR (M-CPR) [8].
While several studies have investigated the use of Autopulse in the context of cardiac arrest, the existing literature reveals a landscape marked by varying methodologies and, at times, conflicting findings.Recent randomized clinical trials (RCTs) did not show enhanced patient survival rates with mechanical CPR compared to M-CPR controls [9,10].This observation is consistent with recent systematic reviews and meta-analyses [11,12].Unfortunately, some studies even indicated that mechanical compressions might be linked to higher instances of injuries compared to M-CPR, potentially influencing survival outcomes [13,14].
In light of the inconsistencies in the current literature, the systematic review and meta-analysis will provide a comprehensive and evidence-based assessment of Autopulse's impact on post-cardiac arrest outcomes.By clearly understanding the existing evidence, this study endeavors to contribute valuable insights to clinical practitioners and researchers, informing future resuscitation strategies and fostering improved patient care.

Research objectives
The primary objectives are to synthesize the current state of evidence regarding the association between the utilization of Autopulse Mechanical CC and enhanced outcomes, including but not limited to survival rates, return of spontaneous circulation (ROSC), quality of CPR, complications and adverse events, duration of resuscitation, cost-effectiveness, and neurological outcomes.

Research question
Is the use of Autopulse Mechanical CC associated with improved outcomes, such as survival rates, ROSC, quality of CPR, complications and adverse events, duration of resuscitation, cost-effectiveness, and neurological outcomes, compared to conventional manual CCs in patients who have experienced cardiac arrest?

Search strategy
A pre-established protocol was employed, adhering to the guidelines outlined in the preferred reporting items for systematic reviews and metaanalyses (PRISMA) statement, ensuring transparency and replicability in our literature search and synthesis (Figure 1).The review protocol has been duly registered in Inplasy under the registration number INPLASY202410002.We conducted a comprehensive search across multiple databases, namely PubMed, Embase, Scopus, Google Scholar, CINAHL, and the Cochrane Library, encompassing articles published up to December 2023.Within all electronic databases, we implemented a meticulously designed search strategy, querying the following key terms (in the title/abstract, keywords, and their associated MeSH subheadings) with appropriate constraints: "CPR" AND "out-of-hospital cardiac arrests (OHCA)" AND "AutoPulse devices" AND "ROSC."To further ensure completeness, we meticulously examined the reference lists of the included studies and relevant reviews identified through our search.We also explored available gray literature, thus striving for comprehensive coverage and saturation in our investigation.

Data collection and analysis
Data selection and extraction were carried out collaboratively by pairs of autonomous reviewers, with the findings subsequently validated by a third reviewing author.Any disparities that arose were subject to thorough discussion and resolution through team consensus.In presenting the outcomes in this systematic review, the authors diligently adhered to the prescribed recommendations outlined in the quality of reporting of the meta-analysis statement.Information was collected from each study using a form and a database created explicitly for this study, utilizing a Microsoft Excel spreadsheet.Data extracted included article information (Author, year of publication, study design, study setting, country, sample size, and results/outcome).

Eligibility criteria
In our study, we considered specific criteria for inclusion: We focused on research involving adults, specifically those aged 18 years or older, who had experienced cardiac arrests outside of a hospital setting.
These studies compared the outcomes of utilizing AutoPulse devices versus manual CCs.
We did not limit our selection to any particular language or country; studies from any linguistic background and countries with advanced emergency medical services (EMSs) services were eligible for inclusion.
Excluded from consideration were case reports, narrative reviews, commentaries, letters, abstracts, studies that used mannequins or animals, and investigations involving mechanical devices other than AutoPulse for resuscitation.
Our interest centered on patients in nontraumatic situations who received CCs through mechanical devices, while the control group consisted of similar patients receiving manual CCs.This approach allowed us to comprehensively assess the effectiveness of AutoPulse compared to manual methods in OHCA scenarios.

Statistical analyses
We selected ROSC lasting 20 minutes or more following resuscitation in OHCA as the primary outcome.Our rationale was that this outcome most directly reflects the immediate effects of CPR.Long-term outcomes, such as survival until discharge and neurological results, were more likely influenced by post-resuscitation care.Cohen's d was chosen as the statistical measure of the effect size.To assess heterogeneity among studies, we computed I 2 , where values of 25%, 50%, and 75% denoted mild, moderate, and substantial heterogeneity, respectively.In this meta-analysis, log [odds ratio (OR)] and SE were considered the optimal approach.Review Manager 5.4 was employed for the meta-analysis, calculating the OR to measure the association between the intervention and control outcomes.A random-effect model was utilized, and a significance threshold of a p-value of 0.05 was adopted.

Risk of bias assessment
The included studies were thoroughly assessed using the Cochrane Quality Rating Scale and the Newcastle Ottawa Scale (NOS) adopted by Zhu et al. [11] RCTs were assessed using the Cochrane scale, which evaluates random sequence generation, randomized concealment, blinding procedures, and outcome description (Tables 1 and 2).The NOS scale was applied for observational studies, considering criteria such as cohort/case selection, comparability between groups, and outcome/exposure  [29] reporting, with a potential score of 9 stars (represented as points).A study could be awarded a maximum of 4 stars for the Selection category, three stars for the outcome/exposure category, and a maximum of 2 stars for comparability.

Results of the search
In the systematic review and meta-analysis process, an initial search yielded 732 records.Following the removal of 421 duplicates and another 30 records for various reasons, 287 citations were left for title and abstract screening.Two independent reviewers evaluated these citations, excluding 177 based on pre-established inclusion and exclusion criteria.Efforts to retrieve the full texts for the remaining 110 citations resulted in 21 needing to be attainable.The 89 articles that were accessed underwent a thorough eligibility assessment, which led to the exclusion of 74 for reasons such as lack of comparison groups (34 articles), irrelevance of outcomes (17), being systematic reviews or metaanalyses themselves (11), case reports or series (10), and animal studies (2).After this comprehensive screening process, 16 studies were deemed suitable for inclusion in the final systematic review and meta-analysis.

Study characteristics
This study included 16 studies (Table 3).These articles, published between 2006 and 2023, employed diverse study designs, including prospective RCTs prospective multicenter observational studies, phased prospective cohorts, retrospective case-control studies, and cohort studies.The research settings varied, covering both inhospital and out-of-hospital scenarios across different countries, such as China, Poland, the USA, Canada, Japan, Singapore, Australia, Korea, the Netherlands, Germany, Italy, the UK, and Austria.The sample sizes ranged from 18 to 12,901 participants.The observational studies were of moderate to high quality, while the risk of bias in the included studies was generally unclear (Tables 1 and 2).

Results of included studies
In a prospective randomized controlled trial conducted by Gao et al. [16], the impact of AutoPulse compared to manual CC for CPR in OHCA patients was assessed.The researchers concluded that using AutoPulse enhances the success of CPR and improves survival rates among individuals experiencing OHCA.However, they noted that further evaluation is needed to determine its effectiveness in strengthening cerebral performance.In a randomized controlled trial conducted by Hallstrom et al. [4], the study compared resuscitation outcomes in OHCA cases where an automated LDB cardiopulmonary resuscitation (LDB-CPR) device was incorporated into standard EMS care, as opposed to M-CPR.The findings led the authors to conclude that the utilization of an automated LDB-CPR device was linked to poorer neurological outcomes and indicated a tendency toward decreased survival compared to M-CPR.They further suggested that additional evaluation is necessary, mainly focusing on the design of the device and the strategies for its implementation.Research conducted by Hayashida et al. [22] aimed to establish a connection between mechanical cardiopulmonary resuscitation (mCPR) administered in the emergency department (ED) and subsequent clinical outcomes.The study's findings revealed that the application of mCPR in the ED correlated with reduced probabilities of achieving positive clinical outcomes following nontraumatic OHCA in adults.In a retrospective observational study conducted by Kim et al. [28], the research aimed to explore prognostic variations between AutoPulse and LUCAS for adult patients experiencing OHCA.The study's conclusion indicated no substantial improvement in the ROSC or survival rates with the use of LUCAS compared to AutoPulse in either subgroup.Furthermore, the study suggested that the in-hospital use of LUCAS might have an adverse impact on survival compared to AutoPulse.
In an observational study conducted by Gorący et al. [21], the efficacy of AutoPulse in patients with shockresistant ventricular fibrillation was investigated.The study revealed that shock-resistant ventricular fibrillation was indicative of a probable coronary component contributing to the cardiac arrest.Consequently, the authors concluded that AutoPulse proves to be beneficial in facilitating resuscitation efforts, contributing to a reduction in the time taken to reach the hospital.In a retrospective case-control study conducted by Jennings et al. [24], the rates of survival between conventional cardiopulmonary resuscitation (C-CPR) and automated CPR (A-CPR) using AutoPulse were compared in adults following OHCA.The findings indicated that the utilization of A-CPR led to a higher rate of survival in the hospital in comparison to C-CPR.However, there was a tendency for a lower survival rate to hospital discharge with A-CPR, although these associations did not achieve statistical significance.In a randomized controlled trial conducted by Koster et al. [15], the study focused on assessing the safety of mechanical CC and identifying potential excess damage when compared with manual CC.The researchers concluded that, in the case of LUCAS, there was no evidence to suggest a significant increase in severe or life-threatening visceral damage compared to manual CC.However, in the case of AutoPulse, the study indicated that a definitive conclusion regarding the occurrence of significantly more severe or lifethreatening visceral damage compared to manual CC could not be excluded.In a survey conducted by Krep et al. [19], the effectiveness, safety, and practicability of the new automated LDB resuscitation device, AutoPulse, in OHCA were evaluated.The authors concluded that the AutoPulse system proves to be an effective and safe mechanical CPR device that is beneficial in the context of OHCA CPR.Furthermore, the study suggested that A-CPR devices may assume a growing significance in CPR practices in the future, as they ensure the provision of continuous CCs of a consistent quality.
In a study conducted by Omori et al. [20], the efficacy of AutoPulse on cardiopulmonary arrest (CPA) patients during helicopter transport was investigated.The authors found that using AutoPulse in helicopters significantly improved the rate of ROSC in CPA patients.As a result, the utilization of automated CC devices, such as AutoPulse, may be recommended, especially for CPA patients being transported by helicopters.In a study by Ong et al. [26], a comparison of resuscitation outcomes was conducted before and after an urban EMS system transitioned from M-CPR to LDB CPR.The authors concluded that implementing a resuscitation strategy involving LDB-CPR on EMS ambulances is linked with enhanced survival to hospital discharge in adults experiencing out-of-hospital nontraumatic cardiac arrest.In another study conducted by Hock Ong et al. [27], the objective was to compare resuscitation outcomes before and after the transition from M-CPR to LDB CPR.The authors concluded that implementing a resuscitation strategy involving LDB-CPR in an ED setting was associated with improved neurologically intact survival upon discharge in adults experiencing prolonged, nontraumatic cardiac arrest.In a study conducted by Primi et al. [17], the investigation aimed to assess whether the choice of mechanical chest compressor could impact the likelihood of ROSC and 30-day survival in patients experiencing OHCA when compared to standard M-CPR.The authors concluded that mechanical chest compressors can potentially increase the ROSC rate, particularly in prolonged resuscitation cases.They also highlighted the distinctiveness of the devices, emphasizing that their varied performances could significantly influence patient outcomes.Notably, the load-distributing-band device was identified as the only mechanical chest compressor capable of positively affecting 30-day survival.
In a prospective cohort study conducted by Spiro et al. [18], the primary objectives were to evaluate the proficiency of healthcare staff in using A-CPR during a cardiac arrest scenario at baseline, after re-training, and over time through scenario-based training.In addition, the study aimed to investigate the clinical experience of A-CPR at their institution over 2 years, specifically focusing on details such as invasive cardiac procedures performed, encountered challenges, resuscitation rates, and in-hospital outcomes as recorded in the AutoPulse-CPR Registry.The authors reported that A-CPR demonstrated the potential to offer excellent hemodynamic support and enable concurrent invasive cardiac procedures.Furthermore, they noted the presence of a significant learning curve when integrating A-CPR into clinical practice.In a randomized controlled trial conducted by Steinmetz et al. [25], the findings indicated that introducing new resuscitation guidelines was linked to an enhancement in 30-day survival rates following OHCA.In a study conducted by Wik et al. [9], a comparison between integrated automated LDB CPR (iA-CPR) and high-quality M-CPR was undertaken to ascertain whether they were equivalent, superior, or inferior in terms of survival to hospital discharge.The authors concluded that iA-CPR led to statistically equivalent survival rates to hospital discharge compared to high-quality M-CPR.In a retrospective case-control study conducted by Zeiner et al. [23], the findings revealed that, despite providing high-quality CPR in both manual and mechanical CC groups, patients who received mechanical CCs experienced significantly worse outcomes.Based on the study results, the expected advantages of a higher compression ratio and a more consistent compression depth offered by mechanical CC devices were deemed uncertain.

Return of spontaneous circulation
The meta-analysis comparing the ROSC between Autopulse Mechanical CC and M-CPR reveals a significant pooled effect with a relative risk of 1.43 (95% CI 1.07-1.92).However, notable heterogeneity is observed (Tau 2 = 0.14, Chi 2 = 49.79,df = 7, p < 0.00001; I 2 =86%), indicating variability across the included studies.The forest plot demonstrates a significant overall effect with a Z value of 2.39 (p = 0.02), suggesting a favorable impact of Autopulse over M-CPR on achieving ROSC (Figure 2).It is essential to acknowledge the high heterogeneity, and further exploration of contributing factors may be warranted.Despite this, the findings underscore the potential benefit of Autopulse in enhancing the likelihood of achieving ROSC in the context of cardiac arrest.Meanwhile, the funnel plot indicated the publication bias of the review was acceptable (Figure 3).

Hospital discharge
Table 4 summarizes the percentage of hospital discharge across selected studies comparing Autopulse Mechanical CC to M-CPR.Notably, the studies included in the metaanalysis revealed varying outcomes.

Survival rates
Table 5 presents the 24-hour patient survival rates and 30-day survival rates from selected studies, comparing outcomes between Autopulse Mechanical CC and M-CPR.

Complications and adverse events
The meta-analysis comparing complications between Autopulse Mechanical CC and M-CPR reveals a relative risk of 1.11 (95% CI 0.93-1.33).The forest plot demonstrates no significant heterogeneity (Chi 2 = 0.77, df = 3, p = 0.86; I 2 = 0), indicating consistent findings across studies.The test for the overall effect yields a Z value of 1.17 (p = 0.24), suggesting no statistically significant difference in complications between Autopulse and M-CPR (Figure 4).These findings emphasize the comparable safety profiles of Autopulse and M-CPR in terms of rib breakage and chest complications.Meanwhile, the funnel plot indicated the publication bias of the review was acceptable (Figure 5).

Discussion
The primary aim of this systematic review and metaanalysis was to investigate the association between the use of Autopulse Mechanical CC and various outcomes following cardiac arrest.The comprehensive research question guiding this study was: "Is the use of Autopulse Mechanical CC associated with improved outcomes, such as survival rates, ROSC, quality of CPR, complications and adverse events, duration of resuscitation, costeffectiveness, and neurological outcomes, compared to conventional manual CCs in patients who have experienced cardiac arrest?Our investigation spanned diverse studies, and the critical findings shed light on the multifaceted impact of Autopulse Mechanical CC on post-cardiac arrest outcomes.
In a prospective randomized controlled trial by Gao et al. [16], Autopulse was associated with enhanced CPR success and improved survival rates in OHCA.However, a call for further evaluation, explicitly focusing on cerebral performance, was noted.Conversely, findings from Hallstrom et al. [4] suggested poorer neurological outcomes and a potential decrease in survival with an automated LDB CPR device, warranting additional scrutiny of device design and implementation strategies.Notably, studies by Kim et al. [28] and Gorący et al. [21] revealed nuanced perspectives, indicating no substantial improvement in outcomes with specific devices and highlighting the benefits of Autopulse in facilitating resuscitation efforts, especially in particular contexts.Furthermore, the synthesis of evidence, ranging from Koster et al. [15] to Spiro et al. [18], provided insights into safety, practicability, and proficiency, offering a comprehensive view of Autopulse Mechanical CC's role in the continuum of care.The meta-analysis of the ROSC between Autopulse Mechanical CC and M-CPR reveals a compelling narrative favoring Autopulse.
The pooled effect with a relative risk of 1.43 (95% CI 1.07-1.92)signifies a statistically significant advantage of Autopulse over M-CPR in facilitating ROSC.This finding aligns with the overarching goal of enhancing crucial resuscitation milestones.However, it is essential to acknowledge the observed heterogeneity (I 2 = 86%) across the studies, indicating potential variability in outcomes.
Turning our attention to the meta-analysis comparing complications between Autopulse Mechanical CC and M-CPR, a crucial facet of our findings emerges.The analysis, encapsulated by a relative risk of 1.11 (95% CI 0.93-1.33),signifies a nuanced aspect of the safety profile associated with these two resuscitation approaches.The forest plot provides reassuring insights, revealing no significant heterogeneity (I 2 = 0), indicating consistent findings across studies.The test for the overall effect, with a Z value of 1.17 (p = 0.24), suggests no statistically significant difference in complications between Autopulse and M-CPR.Delving into the critical aspect of patient survival rates, our synthesis of studies provides valuable insights into the comparative performance of Autopulse Mechanical CC and M-CPR.Noteworthy findings from Gao et al. [16] reveal a notable difference in the 24-hour patient survival rate, with Autopulse exhibiting a substantially higher rate of 39.1% compared to 21.9% for M-CPR.
Similarly, the study by Jennings et al. [24] underscores a survival advantage for Autopulse with a 26% rate compared to 20% for M-CPR.Contrasting results from Wik et al. [9] show Autopulse at 21.8% and M-CPR at 25.0%, indicating nuanced variations across studies.Regarding the 30-day survival rate, findings from Primi et al. [17] highlight a divergence in outcomes, with Autopulse demonstrating a 6% survival rate compared to 14% for M-CPR.Steinmetz et al. [25] also contribute to the discussion with a 16% survival rate, offering a comprehensive view of the temporal dimension in survival outcomes.
An integral aspect of our comparative analysis involves exploring hospital discharge rates between Autopulse Mechanical CC and M-CPR.Across various studies, distinct patterns emerge, shedding light on the complexities of patient outcomes.Examining Gao et al. [16], the study demonstrates a substantial disparity in hospital discharge rates, with Autopulse showing an 18.8% discharge rate compared to 6.3% for M-CPR.In contrast, Hayashida et al. [22] and Jennings et al. [24] reveal more nuanced differences, highlighting Autopulse rates of 2.5% and 3%, respectively, against M-CPR rates of 2.6% and 7%.Ong et al. [26] and Hock Ong et al. [27] contribute to the discourse with their findings, indicating higher hospital discharge rates for Autopulse at 9.71% and 3.3%, respectively, compared to M-CPR rates of 2.88% and 1.3%.Spiro et al. [18] further emphasize the potential impact of Autopulse with a substantial discharge rate of 28%, compared to 11% for M-CPR.Finally, Wik et al. [9] showcase a nuanced perspective, with Autopulse at 9.4% and M-CPR at 11%.
Our analysis aligns with prior studies, notably the findings of Gao et al. [16] and Jennings et al. [24], indicating higher 24-hour patient survival rates with Autopulse than with M-CPR.This consistency suggests a potential trend towards improved immediate survival outcomes when utilizing Autopulse.Conversely, Wik et al. [9] present a divergence, reporting a higher 24-hour survival rate with M-CPR.Such variations may be attributed to differences in study populations, resuscitation settings, or the quality of CPR provided.The 30-day survival rates, as highlighted by Primi et al. [17], exhibit a divergence, indicating lower rates with Autopulse than with M-CPR.This discrepancy prompts a closer examination of the specific patient populations, intervention protocols, and potentially nuanced   factors influencing longer-term survival.Hospital discharge rates demonstrate notable variability across studies.While Gao et al. [16] and Spiro et al. [18] align with our findings, emphasizing higher hospital discharge rates with Autopulse, other studies, such as Jennings et al. [24] and Ong et al. [27], report lower rates for Autopulse compared to M-CPR.These divergences may be rooted in differences in healthcare systems, pre-existing comorbidities, or varying resuscitation strategies employed.
Our meta-analytical results on ROSC and complications align with the existing literature, emphasizing the potential advantage of Autopulse in achieving ROSC without a significant increase in complications [11,30].Seven comprehensive analyses, including the most recent by Sheraton et al. [31], collectively suggest that mechanical CC should not replace M-CPR.However, it holds promise as a supplemental treatment within a broader strategy for treating CA patients.A nationwide population-based observational study in South Korea by Kim et al. [32] echoes these sentiments, reporting comparable survival to discharge between mechanical CPR devices and M-CPR in OHCA patients.However, a notable caveat emerges when considering in-hospital use of the AutoPulse device, which is associated with a significant reduction in survival compared to M-CPR.These findings underscore the importance of nuanced considerations, acknowledging that the impact of mechanical CPR may vary based on the specific clinical context.
The contradictory results from the most recent study inject an element of complexity into the existing body of evidence.It is crucial to note that while presenting fresh insights, this study has limitations that may impact the reliability of its findings.This realization emphasizes the ongoing evolution of research and guidelines in the field, necessitating a cautious interpretation of conflicting data.The observed outcome variations may be attributed to several factors, including differences in study designs, patient populations, and implementation strategies.
Variances in the quality of CPR provided by healthcare professionals, device familiarity, and regional disparities in EMS may contribute to the divergent findings.Our findings underscore the need to carefully consider Autopulse Mechanical CC's role within a broader resuscitation strategy.While immediate survival benefits are evident, the nuances in longer-term outcomes and hospital discharge rates warrant caution.Future research should focus on refining strategies, exploring contextspecific benefits, and addressing conflicting findings to guide more effective clinical decision-making.This meta-analysis contributes to the evolving knowledge on  mechanical CC, aligning with recent meta-analyses that position it as a supplementary, not replacement, strategy in treating cardiac arrest.

Conclusion
This study revealed diverse outcomes across various studies.Notably, Autopulse demonstrated enhanced CPR success and improved survival rates in OHCA, aligning with the overarching goal of enhancing resuscitation milestones.However, the nuanced perspectives from different studies, including contradictory findings and divergent survival rates, underscored the complexity of Autopulse's impact.The meta-analysis on ROSC favored Autopulse, highlighting its statistically significant advantage over M-CPR.However, the observed heterogeneity across studies emphasizes the need for a nuanced interpretation of these findings.Exploring complications, patient survival rates, and hospital discharge rates provided valuable insights, stressing the need for tailored approaches.Consistency with prior studies, such as higher 24-hour patient survival rates with Autopulse, suggests a potential trend in immediate survival benefits.However, 30-day survival and hospital discharge rate variations underscored the importance of contextual factors and intervention protocols.
In light of the findings, Autopulse Mechanical CC emerges as a valuable tool within a broader resuscitation strategy, offering immediate benefits but requiring careful consideration of contextual factors.Future research should focus on refining strategies, exploring contextspecific benefits, and addressing conflicting findings to guide more effective clinical decision-making.This meta-analysis contributes to the evolving knowledge of mechanical CC, emphasizing its role as a supplementary strategy in treating cardiac arrest.

Figure 1 .
Figure 1.PRISMA 2020 flow diagram for new systematic reviews, which included searches of databases and registers only[29]

Figure 5 .
Figure 5. Funnel plot complications and adverse events.

Table 1 .
Cochrane quality scale for randomized controlled studies.

Table 2 .
NOS quality scale for observational studies.
The rate of survival to hospital discharge tended to be higher in the LDB-CPR phase (LDB 3.3% vs. Manual 1.3%; AOR, 1.42; 95% CI, 0.47,4.29).There were more survivors in the LDB group with cerebral performance category (CPC) 1 (good) (Manual 1 vs. LDB 12, p = 0.01).Overall performance category 1 (good) was Manual 1 versus LDB 10, p = 0.06.8%) were discharged from ICU. End-tidal capnography showed significantly higher etCO 2 values in patients with ROSC than in patients without ROSC.No injuries were detected after the use of the AutoPulse-CPR.

Table 4 .
Hospital discharge rates for Autopulse versus M-CPR.