Is initial rhythm in OHCA a predictor of preceding no flow time? Implications for bystander response and ECPR candidacy evaluation

The association between prehospital post-return of spontaneous circulation core temperature and survival after out-of-hospital cardiac arrest

BACKGROUND AND IMPORTANCE

Following the return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA), a low body temperature on arrival at the hospital and on admission to the ICU is reportedly associated with increased mortality. Whether this association exists in the prehospital setting, however, is unknown.

OBJECTIVE

The objective of this study was to investigate whether the initial, prehospital core temperature measured post-ROSC is independently associated with survival to hospital discharge in adult patients following OHCA.

DESIGN, SETTING AND PARTICIPANTS

This retrospective observational study was conducted at East Anglian Air Ambulance, a physician-paramedic staffed Helicopter Emergency Medical Service in the East of England, UK. Adult OHCA patients attended by East Anglian Air Ambulance from 1 February 2015 to 30 June 2023, who had post-ROSC oesophageal temperature measurements were included.

OUTCOME MEASURE AND ANALYSIS

The primary outcome measure was survival to hospital discharge. Core temperature was defined as the first oesophageal temperature recorded following ROSC. Multivariable logistic regression evaluated the adjusted association between core temperature and survival to hospital discharge.

MAIN RESULTS

Resuscitation was attempted in 3990 OHCA patients during the study period, of which 552 patients were included in the final analysis. The mean age was 61 years, and 402 (72.8%) patients were male. Among them, 194 (35.1%) survived to hospital discharge. The mean core temperature was lower in nonsurvivors compared with those who survived hospital discharge; 34.6 and 35.2 °C, respectively (mean difference, -0.66; 95% CI, -0.87 to -0.44; P  < 0.001). The adjusted odds ratio for survival was 1.41 (95% CI, 1.09-1.83; P  = 0.01) for every 1.0 °C increase in core temperature between 32.5 and 36.9 °C.

CONCLUSION

In adult patients with ROSC following OHCA, early prehospital core temperature is independently associated with survival to hospital discharge.

Prognostic Impact of Heart Rhythm Shockability Trajectory in Out-of-Hospital Cardiac Arrest: A Multicenter Retrospective Study

BACKGROUND

This study aimed to investigate the association between the temporal transitions in heart rhythms during cardiopulmonary resuscitation (CPR) and outcomes after out-of-hospital cardiac arrest.

METHODS

This was an analysis of the prospectively collected databases in 3 academic hospitals in northern and central Taiwan. Adult patients with out-of-hospital cardiac arrest transported by emergency medical service between 2015 and 2022 were included. Favorable neurological recovery and survival to hospital discharge were the primary and secondary outcomes, respectively. Time-specific heart rhythm shockability was defined as the probability of shockable rhythms at a particular time point during CPR. The temporal changes in the time-specific heart rhythm shockability were calculated by group-based trajectory modeling. Multivariable logistic regression analyses were performed to examine the association between the trajectory group and outcomes. Subgroup analyses examined the effects of extracorporeal CPR in different trajectories.

RESULTS

The study comprised 2118 patients. The median patient age was 69.1 years, and 1376 (65.0%) patients were male. Three distinct trajectories were identified: high-shockability (52 patients; 2.5%), intermediate-shockability (262 patients; 12.4%), and low-shockability (1804 patients; 85.2%) trajectories. The median proportion of shockable rhythms over the course of CPR for the 3 trajectories was 81.7% (interquartile range, 73.2%-100.0%), 26.7% (interquartile range, 16.7%-37.5%), and 0% (interquartile range, 0%-0%), respectively. The multivariable analysis indicated both intermediate- and high-shockability trajectories were associated with favorable neurological recovery (intermediate-shockability: adjusted odds ratio [aOR], 4.98 [95% CI, 2.34-10.59]; high-shockability: aOR, 5.40 [95% CI, 2.03-14.32]) and survival (intermediate-shockability: aOR, 2.46 [95% CI, 1.44-4.18]; high-shockability: aOR, 2.76 [95% CI, 1.20-6.38]). The subgroup analysis further indicated extracorporeal CPR was significantly associated with favorable neurological outcomes (aOR, 4.06 [95% CI, 1.11-14.81]) only in the intermediate-shockability trajectory.

CONCLUSIONS

Heart rhythm shockability trajectories were associated with out-of-hospital cardiac arrest outcomes, which may be a supplementary factor in guiding the allocation of medical resources, such as extracorporeal CPR.

Mediators of the Association Between Socioeconomic Status and Survival After Out-of-Hospital Cardiac Arrest: A Systematic Review

Low socioeconomic status (SES) is associated with poor outcomes after out-of-hospital cardiac arrest (OHCA). Patient characteristics, care processes, and other contextual factors may mediate the association between SES and survival after OHCA. Interventions that target these mediating factors may reduce disparities in OHCA outcomes across the socioeconomic spectrum. This systematic review identified and quantified mediators of the SES-survival after OHCA association. Electronic databases (MEDLINE, Embase, PubMed, Web of Science) and grey literature sources were searched from inception to July or August 2023. Observational studies of OHCA patients that conducted mediation analyses to evaluate potential mediators of the association between SES (defined by income, education, occupation, or a composite index) and survival outcomes were included. A total of 10 studies were included in this review. Income (n = 9), education (n = 4), occupation (n = 1), and composite indices (n = 1) were used to define SES. The proportion of OHCA cases that had bystander involvement, presented with an initial shockable rhythm, and survived to hospital discharge or 30 days increased with higher SES. Common mediators of the SES-survival association that were evaluated included initial rhythm (n = 6), emergency medical services response time (n = 5), and bystander cardiopulmonary resuscitation (n = 4). Initial rhythm was the most important mediator of this association, with a median percent excess risk explained of 37.4% (range 28.6%-40.0%; n = 5; 1 study reported no mediation) and mediation proportion of 41.8% (n = 1). To mitigate socioeconomic disparities in outcomes after OHCA, interventions should target potentially modifiable mediators, such as initial rhythm, which may involve improving bystander awareness of OHCA and the need for prompt resuscitation.

What factors are effective on the CPR duration of patients under extracorporeal cardiopulmonary resuscitation: a single-center retrospective study

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) is an alternative method for patients with reversible causes of cardiac arrest (CA) after conventional cardiopulmonary resuscitation (CCPR). However, cardiopulmonary resuscitation (CPR) duration during ECPR can vary due to multiple factors. Healthcare providers need to understand these factors to optimize the resuscitation process and improve outcomes. The aim of this study was to examine the different variables impacting the duration of CPR in patients undergoing ECPR.

METHODS

This retrospective, single-center, observational study was conducted on adult patients who underwent ECPR due to in-hospital CA (IHCA) or out-of-hospital CA (OHCA) at Hamad General Hospital (HGH), the tertiary governmental hospital of Qatar, between February 2016 and March 2020. Univariate and multivariate binary logistic regression analyses were performed to identify the prognostic factors associated with CPR duration, including demographic and clinical variables, as well as laboratory tests.

RESULTS

The mean ± standard division age of the 48 participants who underwent ECPR was 41.50 ± 13.15 years, and 75% being male. OHCA and IHCA were reported in 77.1% and 22.9% of the cases, respectively. The multivariate analysis revealed that several factors were significantly associated with an increased CPR duration: higher age (OR: 1.981, 95%CI: 1.021-3.364, P = 0.025), SOFA score (OR: 3.389, 95%CI: 1.289-4.911, P = 0.013), presence of comorbidities (OR: 3.715, 95%CI: 1.907-5.219, P = 0.026), OHCA (OR: 3.715, 95%CI: 1.907-5.219, P = 0.026), and prolonged collapse-to-CPR time (OR: 1.446, 95%CI:1.092-3.014, P = 0.001). Additionally, the study found that the initial shockable rhythm was inversely associated with the duration of CPR (OR: 0.271, 95%CI: 0.161-0.922, P = 0.045). However, no significant associations were found between laboratory tests and CPR duration.

CONCLUSION

These findings suggest that age, SOFA score, comorbidities, OHCA, collapse-to-CPR time, and initial shockable rhythm are important factors influencing the duration of CPR in patients undergoing ECPR. Understanding these factors can help healthcare providers better predict and manage CPR duration, potentially improving patient outcomes. Further research is warranted to validate these findings and explore additional factors that may impact CPR duration in this population.

Out-of-hospital cardiac arrest outcomes when law enforcement arrives before emergency medical services

BACKGROUND

Law enforcement (LE) professionals are often dispatched to out-of-hospital cardiac arrests (OHCA) to provide early cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) application with mixed evidence of a survival benefit. Our objective was to comprehensively evaluate LE care in OHCA.

METHODS

This is a secondary analysis of adults with non-traumatic OHCA not witnessed by EMS and without bystander AED use from 2018-2021. Our primary outcome was survival with Cerebral Perfusion Category score ≤ 2 (functional survival). Our exposures included: LE On-scene Only (without providing care); LE CPR Only (without applying an AED); LE Ideal Care (ensuring CPR and AED application). Our control group had no LE arrival before EMS. We performed multivariable logistic regression analyses adjusting for confounders and stratified our analyses by patients with and without bystander CPR.

RESULTS

There were 2569 adult, non-traumatic OHCAs from 2018-2021 meeting inclusion criteria. There were no differences in the odds of functional survival for LE On-scene Only (adjusted odds ratio [95% CI]: 1.28 [0.47-3.45]), LE CPR Only (1.26 [0.80-1.99]), or LE Ideal Care (1.36 [0.79-2.33]). In patients without bystander CPR, LE Ideal Care had significantly higher odds of functional survival (2.01 [1.06-3.81]) compared to no LE on-scene, with no significant associations for LE On-scene Only or LE CPR Only. There were no significant differences by LE care in patients already receiving bystander CPR.

CONCLUSIONS

LE arrival before EMS and ensuring both CPR and AED application is associated with significantly improved functional survival in OHCA patients not already receiving bystander CPR.

Impact of the COVID-19 pandemic on Canadian emergency medical system management of out-of-hospital cardiac arrest: A retrospective cohort study

AIM

We sought to describe the impact of the COVID-19 pandemic on the care provided by Canadian emergency medical system (EMS) clinicians to patients suffering out of hospital cardiac arrest (OHCA), and whether any observed changes persisted beyond the initial phase of the pandemic.

METHODS

We analysed cases of adult, non-traumatic, OHCA from the Canadian Resuscitation Outcome Consortium (CanROC) registry who were treated between January 27th, 2018, and December 31st, 2021. We used adjusted regression models and interrupted time series analysis to examine the impact of the COVID-19 pandemic (January 27th, 2020 - December 31st, 2021)on the care provided to patients with OHCA by EMS clinicians.

RESULTS

There were 12,947 cases of OHCA recorded in the CanROC registry in the pre-COVID-19 period and 17,488 during the COVID-19 period. We observed a reduction in the cumulative number of defibrillations provided by EMS (aRR 0.91, 95% CI 0.89 - 0.93, p < 0.01), a reduction in the odds of attempts at intubation (aOR 0.33, 95% CI 0.31 - 0.34, p < 0.01), higher rates of supraglottic airway use (aOR 1.23, 95% CI 1.16-1.30, p < 0.01), a reduction in vascular access (aOR for intravenous access 0.84, 95% CI 0.79 - 0.89, p < 0.01; aOR for intraosseous access 0.89, 95% CI 0.82 - 0.96, p < 0.01), a reduction in the odds of epinephrine administration (aOR 0.89, 95% CI 0.85 - 0.94, p < 0.01), and higher odds of resuscitation termination on scene (aOR 1.38, 95% CI 1.31 - 1.46, p < 0.01). Delays to initiation of chest compressions (2 min. vs. 3 min., p < 0.01), intubation (16 min. vs. 19 min., p = 0.01), and epinephrine administration (11 min. vs. 13 min., p < 0.01) were observed, whilst supraglottic airways were inserted earlier (11 min. vs. 10 min., p < 0.01).

CONCLUSION

The COVID-19 pandemic was associated with substantial changes in EMS management of OHCA. EMS leaders should consider these findings to optimise current OHCA management and prepare for future pandemics.

Extracorporeal cardiopulmonary resuscitation for refractory OHCA: lessons from three randomized controlled trials-the trialists' view

Extracorporeal cardiopulmonary resuscitation is a promising treatment for refractory out-of-hospital cardiac arrest. Three recent randomized trials (ARREST trial, Prague OHCA study, and INCEPTION trial) that addressed the clinical benefit of extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest yielded seemingly diverging results. The evidence for extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest, derived from three recent randomized controlled trials, is not contradictory but rather complementary. Excellent results can be achieved with a very high level of dedication, provided that strict selection criteria are applied. However, pragmatic implementation of extracorporeal cardiopulmonary resuscitation does not necessarily lead to improved outcome of refractory out-of-hospital cardiac arrest. Centres that are performing extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest or aspire to do so should critically evaluate whether they are able to meet the pre-requisites that are needed to conduct an effective extracorporeal cardiopulmonary resuscitation programme.

Effectiveness of Lay Bystander Hands-Only Cardiopulmonary Resuscitation on a Mattress versus the Floor: A Randomized Cross-Over Trial

STUDY OBJECTIVE

Bystander cardiopulmonary resuscitation increases the likelihood of out-of-hospital cardiac arrest survival by more than two-fold. A common barrier to the prompt initiation of compressions is moving victims to the floor, but compression quality on a "floor" versus a "mattress" has not been tested among lay bystanders.

METHODS

We conducted a prospective, randomized, cross-over trial comparing lay bystander compression quality using a manikin on a bed versus the floor. Participants included adults without professional health care training. We randomized participants to the order of manikin placement, either on a mattress or on the floor. For both, participants were instructed to perform 2 minutes of chest compressions on a cardiopulmonary resuscitation Simon manikin Gaumard (Gaumard Scientific, Miami, FL). The primary outcome was mean compression depth (cm) over 2 minutes. We fit a linear regression model adjusted for scenario order, age, sex, and body mass index with robust standard errors to account for repeated measures and reported mean differences with 95% confidence intervals (CIs).

RESULTS

Our sample of 80 adults was 66% female with a mean age of 50.5 years (SD 18.2). The mean compression depth on the mattress was 2.9 cm (SD 2.3) and 3.5 cm (SD 2.2) on the floor, a mean difference of 0.58 cm (95% CI 0.18, 0.98). Compression depth fell below the 5 to 6 cm depth recommended by the American Heart Association on both surfaces. In the adjusted model, the mean depth was greater when the manikin was on the floor than the mattress (adjusted mean difference 0.62 cm; 95% CI 0.23 to 1.01), and mean depth was less for females than males (adjusted mean difference -1.42 cm, 95% CI -2.59, -0.25). In addition, the difference in compression depth was larger for female participants (mean difference 0.94 cm; 95% CI 0.54, 1.34) than for male participants (mean difference -0.01 cm; 95% CI -0.80, 0.78), and the interaction was statistically significant (P = .04).

CONCLUSION

The mean compression depth was significantly smaller on the mattress and with female bystanders. Further research is needed to understand the benefit of moving out-of-hospital cardiac arrest victims to the floor relative to the detrimental effect of delaying chest compressions.

Public access defibrillation: challenges and new solutions

PURPOSE OF REVIEW

The purpose of this article is to review the current status of public access defibrillation and the various utility modalities of early defibrillation.

RECENT FINDINGS

Defibrillation with on-site automated external defibrillators (AEDs) has been the conventional approach for public access defibrillation. This strategy is highly effective in cardiac arrests occurring in close proximity to on-site AEDs; however, only a few cardiac arrests will be covered by this strategy. During the last decades, additional strategies for public access defibrillation have developed, including volunteer responder programmes and drone assisted AED-delivery. These programs have increased chances of early defibrillation within a greater radius, which remains an important factor for survival after out-of-hospital cardiac arrest.

SUMMARY

Recent advances in the use of public access defibrillation show great potential for optimizing early defibrillation. With new technological solutions, AEDs can be transported to the cardiac arrest location reaching OHCAs in both public and private locations. Furthermore, new technological innovations could potentially identify and automatically alert the emergency medical services in nonwitnessed OHCA previously left untreated.

Selection of patients for mechanical circulatory support for refractory out-of-hospital cardiac arrest

OBJECTIVE

To describe characteristics of patients admitted with refractory cardiac arrest for possible extracorporeal cardiopulmonary resuscitation (ECPR) and gain insight into the reasons for refraining from treatment in some.

METHODS

Nationwide retrospective cohort study involving all tertiary centres providing ECPR in Denmark. Consecutive patients admitted with ongoing chest compression for evaluation for ECPR treatment were enrolled. Presenting characteristics, duration of no-flow and low-flow time, end-tidal carbon dioxide (ETCO₂), lactate and pH, and recording of reasons for refraining from ECPR documented by the treating team were recorded. Outcomes were survival to intensive care unit admission and survival to hospital discharge.

RESULTS

Of 579 patients admitted with refractory cardiac arrest for possible ECPR, 221 patients (38%) proceeded to ECPR and 358 patients (62%) were not considered candidates. Median prehospital low-flow time was 70 min (IQR 56 to 85) in ECPR patients and 62 min (48 to 81) in no-ECPR patients, p<0.001. Intra-arrest transport was more than 50 km in 92 (42%) ECPR patients and 135 in no-ECPR patients (38%), p=0.25. The leading causes for not initiating ECPR stated by the treating team were duration of low-flow time in 39%, severe metabolic derangement in 35%, and in 31% low ETCO₂. The prevailing combination of contributing factors were non-shockable rhythm, low ETCO₂, and metabolic derangement or prehospital low-flow time combined with low ETCO₂. Survival to discharge was only achieved in six patients (1.7%) in the no-ECPR group.

CONCLUSIONS

In this large nationwide study of patients admitted for possible ECPR, two-thirds of patients were not treated with ECPR. The most frequent reasons to abstain from ECPR were long duration of prehospital low-flow time, metabolic derangement and low ETCO₂.

Association of ultra-early diffusion-weighted magnetic resonance imaging with neurological outcomes after out-of-hospital cardiac arrest

BACKGROUND

This study aimed to investigate the association between ultra-early (within 6 h after return of spontaneous circulation [ROSC]) brain diffusion-weighted magnetic resonance imaging (DW-MRI) and neurological outcomes in comatose survivors after out-of-hospital cardiac arrest.

METHODS

We conducted a registry-based observational study from May 2018 to February 2022 at a Chungnam national university hospital in Daejeon, Korea. Presence of high-signal intensity (HSI) (P_HSI) was defined as a HSI on DW-MRI with corresponding hypoattenuation on the apparent diffusion coefficient map irrespective of volume after hypoxic ischemic brain injury; absence of HSI was defined as A_HSI. The primary outcome was the dichotomized cerebral performance category (CPC) at 6 months, defined as good (CPC 1-2) or poor (CPC 3-5).

RESULTS

Of the 110 patients (30 women [27.3%]; median (interquartile range [IQR]) age, 58 [38-69] years), 48 (43.6%) had a good neurological outcome, time from ROSC to MRI scan was 2.8 h (IQR 2.0-4.0 h), and the P_HSI on DW-MRI was observed in 46 (41.8%) patients. No patients in the P_HSI group had a good neurological outcome compared with 48 (75%) patients in the A_HSI group. In the A_HSI group, cerebrospinal fluid (CSF) neuron-specific enolase (NSE) levels were significantly lower in the group with good neurological outcome compared to the group with poor neurological outcome (20.1 [14.4-30.7] ng/mL vs. 84.3 [32.4-167.0] ng/mL, P < 0.001). The area under the curve for P_HSI on DW-MRI was 0.87 (95% confidence interval [CI] 0.80-0.93), and the specificity and sensitivity for predicting a poor neurological outcome were 100% (95% CI 91.2%-100%) and 74.2% (95% CI 62.0-83.5%), respectively. A higher sensitivity was observed when CSF NSE levels were combined (88.7% [95% CI 77.1-95.1%]; 100% specificity).

CONCLUSIONS

In this cohort study, P_HSI findings on ultra-early DW-MRI were associated with poor neurological outcomes 6 months following the cardiac arrest. The combined CSF NSE levels showed higher sensitivity at 100% specificity than on DW-MRI alone. Prospective multicenter studies are required to confirm these results.

Accuracy of the Initial Rhythm to Predict a Short No-Flow Time in Out-of-Hospital Cardiac Arrest

OBJECTIVES

The no-flow time (NFT) can help establish prognosis in out-of-hospital cardiac arrest (OHCA) patients. It is often used as a selection criterion for extracorporeal resuscitation. In patients with an unwitnessed OHCA for whom the NFT is unknown, the initial rhythm has been proposed to identify those more likely to have had a short NFT. Our objective was to determine the predictive accuracy of an initial shockable rhythm for an NFT of 5 minutes or less (NFT ≤ 5).

DESIGN

Retrospective analysis of prospectively collected data.

SETTING

Prehospital OHCA in eight U.S. and three Canadian sites.

PATIENTS

A total of 28,139 adult patients with a witnessed nontraumatic OHCA were included, of whom 11,228 (39.9%) experienced an emergency medical service-witnessed OHCA (NFT = 0), 695 (2.7%) had a bystander-witnessed OHCA, and an NFT less than or equal to 5, and 16,216 (57.6%) with a bystander-witnessed OHCA and an NFT greater than 5.

INTERVENTIONS

Sensitivity, specificity, and likelihood ratios of an initial shockable rhythm to identify patients with an NFT less than or equal to 5 minutes.

MEASUREMENTS AND MAIN RESULTS

The sensitivity of an initial shockable rhythm to identify patients with an NFT less than or equal to 5 was poor (25% [95% CI, 25-26]), but specificity was moderate (70% [95% CI, 69-71]). The positive and likelihood ratios were inverted (negative accuracy) (positive likelihood ratio, 0.76 [95% CI, 0.74-0.79]; negative likelihood ratio, 1.12 [95% CI, 1.10-1.12]). Including only patients with a bystander-witnessed OHCA improved the sensitivity to 48% (95% CI, 45-52), the positive likelihood ratio to 1.45 (95% CI, 1.33-1.58), and the negative likelihood ratio to 0.77 (95% CI, 0.72-0.83), while slightly lowering the specificity to 67% (95% CI, 66-67).

CONCLUSIONS

Our analysis demonstrated that the presence of a shockable rhythm at the time of initial assessment was poorly sensitive and only moderately specific for OHCA patients with a short NFT. The initial rhythm, therefore, should not be used as a surrogate for NFT in clinical decision-making.

Characteristics, prognostic factors, and chronological trends of out-of-hospital cardiac arrests with shockable rhythms in Taiwan - A 7-year observational study

BACKGROUND

The study aimed to explore the characteristics, predictors, and chronological trends of outcomes for adult out-of-hospital cardiac arrests (OHCAs) with shockable rhythms.

METHODS

A 7-year, community-wide observational study using an Utstein-style registry was conducted. Patients who were not transported, those who experienced trauma and those who lacked electronic electrocardiography data were excluded; those with initial shockable rhythms of ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) were included. Outcomes were survival of discharge (SOD) and favorable neurological status (CPC 1-2). The outcome predictors, chronological trends, and their relationship with system interventions were analyzed.

RESULTS

Of the 1544 shockable OHCAs (incidence 12.6%) included, 97.6% had VF and 2.4% had pVT. VF showed better outcomes than pVT. Predictors for both outcomes (SOD; CPC 1-2) were chronological change (adjusted odds ratio [aOR]: 1.133; 1.176), younger age (aOR: 0.973; 0.967), shorter response time (aOR: 0.998; 0.999), shorter scene time (aOR: 0.999; 0.999), witnessed collapse (aOR: 1.668; 1.670), and bystander cardiopulmonary resuscitation (BCPR) (aOR: 1.448; 1.576). Predictors for only SOD were public location (aOR: 1.450) and successful prehospital defibrillation (aOR: 3.374). The use of the supraglottic airway was associated with adverse outcomes. Chronologically with system interventions, BCPR rate, the proportion of shockable OHCA, and improved neurological outcomes increased over time.

CONCLUSIONS

The incidence of shockable OHCA remained low in Asian community. VF showed better outcomes than pVT. Over time, the incidence of shockable rhythm, BCPR rate and patient outcomes did improve with health system interventions. The number of prehospital defibrillations did not predict outcomes.

Evaluation of initial shockable rhythm as an indicator of short no-flow time in cardiac arrest: a national registry study

BACKGROUND

The duration from collapse to initiation of cardiopulmonary resuscitation (no-flow time) is one of the most important determinants of outcomes after out-of-hospital cardiac arrest (OHCA). Initial shockable cardiac rhythm (ventricular fibrillation or ventricular tachycardia) is reported to be a marker of short no-flow time; however, there is conflicting evidence regarding the impact of initial shockable cardiac rhythm on treatment decisions. We investigated the association between initial shockable cardiac rhythm and the no-flow time and evaluated whether initial shockable cardiac rhythm can be a marker of short no-flow time in patients with OHCA.

METHODS

Patients aged 18 years and older experiencing OHCA between 2010 and 2016 were selected from a nationwide population-based Japanese database. The association between the no-flow time duration and initial shockable cardiac rhythm was evaluated. Diagnostic accuracy was evaluated using the sensitivity, specificity and positive predictive value.

RESULTS

A total of 177 634 patients were eligible for the analysis. The median age was 77 years (58.3%, men). Initial shockable cardiac rhythm was recorded in 11.8% of the patients. No-flow time duration was significantly associated with lower probability of initial shockable cardiac rhythm, with an adjusted OR of 0.97 (95% CI 0.96 to 0.97) per additional minute. The sensitivity, specificity and positive predictive value of initial shockable cardiac rhythm to identify a no-flow time of <5 min were 0.12 (95% CI 0.12 to 0.12), 0.88 (95% CI 0.88 to 0.89) and 0.35 (95% CI 0.34 to 0.35), respectively. The positive predictive values were 0.90, 0.95 and 0.99 with no-flow times of 15, 18 and 28 min, respectively.

CONCLUSIONS

Although there was a significant association between initial shockable cardiac rhythm and no-flow time duration, initial shockable cardiac rhythm was not reliable when solely used as a surrogate of a short no-flow time duration after OHCA.

Utilization and cost-effectiveness of school and community center AED deployment models in Canadian cities

BACKGROUND

The optimal locations and cost-effectiveness of placing automated external defibrillators(AEDs) for out-of-hospital cardiac arrest(OHCAs) in urban residential neighbourhoods are unclear.

METHODS

We used prospectively collected data from 2016 to 2018 from the British Columbia OHCA Registry to examine the utilization and cost-effectiveness of hypothetical AED deployment in municipalities with a population of over 100 000. We geo-plotted OHCA events using seven hypothetical deployment models where AEDs were placed at the exteriors of public schools and community centers and fetched by bystanders. We calculated the "radius of effectiveness" around each AED within which it could be retrieved and applied to an individual prior to EMS arrival, comparing automobile and pedestrian-based retrieval modes. For each deployment model, we estimated the number of OHCAs within the "radius of effectiveness".

RESULTS

We included 4017 OHCAs from ten urban municipalities. The estimated radius of effectiveness around each AED was 625 m for automobile and 240m for pedestrian retrieval. With AEDs placed outside each school and community center, 2567(64%) and 605(15%) of OHCAs fell within the radii of effectiveness for automobile and pedestrian retrieval, respectively. For each AED, there was an average of 1.20-2.66 and 0.25-0.61 in-range OHCAs per year for automobile retrieval and pedestrian retrieval, respectively, depending on the deployment model. All of our proposed surpassed the cost-effectiveness threshold of 0.125 OHCA/AED/year provided >5.3-11.6% in-range AEDs were brought-to-scene.

CONCLUSIONS

The systematic deployment of AEDs at schools and community centers in urban neighbourhoods may result in increased application and be a cost-effective public health intervention.

Trend in survival after out-of-hospital cardiac arrest and its relationship with bystander cardiopulmonary resuscitation: a six-year prospective observational study in Beijing

Background

Out-of-hospital cardiac arrest (OHCA), a global health problem with a survival rate ranging from 2 to 22% across different countries, has been a leading cause of premature death for decades. The aim of this study was to evaluate the trends of survival after OHCA over time and its relationship with bystander cardiopulmonary resuscitation (CPR), initial shockable rhythm, return of spontaneous circulation (ROSC), and survived event.

Methods

In this prospective observational study, data of OHCA patients were collected following the “Utstein style” by the Beijing, China, Emergency Medical Service (EMS) from January 2011 (data from February to June in 2011 was not collected) to October 2016. Patients who had a cardiac arrest and for whom an ambulance was dispatched were included in this study. All cases were followed up to determine hospital discharge or death. The trend of OHCA survival was analyzed using the Chi-square test. The relationship among bystander CPR, initial shockable rhythm, ROSC, survived event, and OHCA survival rate was analyzed using multivariate path analyses with maximum standard likelihood estimation.

Results

A total of 25,421 cases were transferred by the Beijing EMS; among them, 5042 (19.8%) were OHCA (median age: 78 years, interquartile range: 63–85, 60.1% male), and 484 (9.6%) received bystander CPR. The survival rate was 0.6%, which did not improve from 2012 to 2015 (P = 0.569). Overall, bystander CPR was indirectly associated with an 8.0% (β = 0.080, 95% confidence interval [CI] = 0.064–0.095, P = 0.002) increase in survival rate. The indirect effect of bystander CPR on survival rate through survived event was 6.6% (β = 0.066, 95% CI = 0.051–0.081, P = 0.002), which accounted for 82.5% (0.066 of 0.080) of the total indirect effect. With every 1 increase in survived event, the possibility of survival rate will directly increase by 53.5% (β = 0.535, 95% CI = 0.512–0.554, P = 0.003).

Conclusions

The survival rate after OHCA was low in Beijing which has not improved between 2012 and 2015. The effect of bystander CPR on survival rate was mainly mediated by survived event.

Trial registration

Chinese Clinical Trial Registry: ChiCTR-TRC-12002149 (2 May, 2012, retrospectively registered). http://www.chictr.org.cn/showproj.aspx?proj=7400

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02446-z.

Circulatory trajectories after out-of-hospital cardiac arrest: a prospective cohort study

BACKGROUND

Circulatory failure frequently occurs after out-of-hospital cardiac arrest (OHCA) and is part of post-cardiac arrest syndrome (PCAS). The aim of this study was to investigate circulatory disturbances in PCAS by assessing the circulatory trajectory during treatment in the intensive care unit (ICU).

METHODS

This was a prospective single-center observational cohort study of patients after OHCA. Circulation was continuously and invasively monitored from the time of admission through the following five days. Every hour, patients were classified into one of three predefined circulatory states, yielding a longitudinal sequence of states for each patient. We used sequence analysis to describe the overall circulatory development and to identify clusters of patients with similar circulatory trajectories. We used ordered logistic regression to identify predictors for cluster membership.

RESULTS

Among 71 patients admitted to the ICU after OHCA during the study period, 50 were included in the study. The overall circulatory development after OHCA was two-phased. Low cardiac output (CO) and high systemic vascular resistance (SVR) characterized the initial phase, whereas high CO and low SVR characterized the later phase. Most patients were stabilized with respect to circulatory state within 72 h after cardiac arrest. We identified four clusters of circulatory trajectories. Initial shockable cardiac rhythm was associated with a favorable circulatory trajectory, whereas low base excess at admission was associated with an unfavorable circulatory trajectory.

CONCLUSION

Circulatory failure after OHCA exhibits time-dependent characteristics. We identified four distinct circulatory trajectories and their characteristics. These findings may guide clinical support for circulatory failure after OHCA.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02648061.

Electrical rhythm degeneration in adults with out-of-hospital cardiac arrest according to the no-flow and bystander low-flow time

AIMS

For out-of-hospital cardiac arrest (OHCA) patients, the influence of the delay before the initiation of resuscitation, termed the no-flow time (NFT), and duration of bystander-only resuscitation low-flow time (BLFT) on the type of electrical rhythm observed has not been well described. The objective of this study is to determine the relationship between NFT, BLFT and the likelihood of a shockable rhythm over time.

METHODS

Using a North American prospective registry (2005-2015; mostly urban settings), we selected adult (18 years and over) patients who experienced a witnessed OHCA from a suspected cardiac etiology. Patients with an emergency medical services witnessed OHCA were only included in sensitivity analyses. The association between the NFT, BLFT and the presence of a shockable rhythm was evaluated using a multivariable logistic regression adjusting for the registry version, age, sex, and public location.

RESULTS

A total of 229,632 patients were logged in the registry, 50,957 of whom were included. Of these, 17,704 (34.7%) had an initial shockable rhythm. After the first minute, a significant decrease over time in the occurrence of shockable rhythm is observed but is slower when bystander cardiopulmonary resuscitation (CPR) is provided (each supplemental minute of BLFT: adjusted odds ratio = 0.95, 95 %CI = 0.94-0.95; each supplemental minute of NFT: adjusted odds ratio = 0.91, 95 %CI = 0.90-0.91]).

CONCLUSIONS

In this large observational study, we were able to demonstrate that longer NFT were associated with lower odds of shockable presenting rhythms. Bystander CPR significantly mitigates the degradation of shockable rhythms over time, strengthening the need to improve bystander CPR rates around the world.

Premenopausal-aged females have no neurological outcome advantage after out-of-hospital cardiac arrest: A multilevel analysis of North American populations

AIM

We investigated the impact of premenopausal age on neurological function at hospital discharge in patients with out-of-hospital cardiac arrest (OHCA). We hypothesized that premenopausal-aged females (18-47 years of age) with OHCA would have a higher probability of survival with favourable neurological function at hospital discharge compared with males of the same age group, older males, and older females (>53 years of age).

METHODS

Retrospective analyses of data from the Resuscitation Outcomes Consortium multi-center randomized controlled trial (June 2011-May 2015). We included adults with non-traumatic OHCA treated by emergency medical service. We stratified the cohort into four groups by age and sex: premenopausal-aged females (18-47 years of age), older females (≥53 years old), younger males (18-47 years of age), and older male. We used multilevel logistic regression to examine the association between age-sex and favourable neurological outcomes (modified Rankin Scale ≤ 3).

RESULTS

In total, 23,725 patients were included: 1050 (4.5%) premenopausal females; 1930 (8.1%) younger males; 7569 (31.9%) older females; and 13,176 (55.5%) older males. The multilevel analysis showed no difference in neurological outcome between younger males and younger females (OR 0.95, 95% CI 0.69-1.32, p = 0.75). Both older females (OR 0.36, 95% CI 0. 0.26-0.48, p < 0.001) and older males (OR 0.52, 95% CI 0.39-0.69, p < 0.001) had a significantly lower odds of favourable neurological outcome than younger females. Among all groups, older females had the worst outcomes.

CONCLUSIONS

We did not detect an association between premenopausal age and survival with good neurological outcome, suggesting females sex hormones do not impact OHCA outcomes. Our findings are not in line with results from other studies. Studies that rigorously evaluate menopausal status are required to definitively assess the impact of female sex hormones on outcomes.

Association between length of stay in the emergency department and outcomes in out-of-hospital cardiac arrest

OBJECTIVE

Several studies have previously reported that a prolonged emergency department length of stay (EDLOS) is associated with poor outcomes in critically ill patients. This study was performed to investigate the relationship between the EDLOS and the neurologic outcome at 28 days in out-of-hospital cardiac arrest (OHCA) patients.

METHODS

We conducted a retrospective analysis of prospectively collected data from OHCA patients who achieved the return of spontaneous circulation (ROSC) in the EDs of three urban tertiary teaching hospitals from December 2013 to October 2020. Patients were divided into four groups according to the EDLOS, according to the quartile distribution: EDLOS <107 min, EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min. Comparisons of outcomes among the groups and multivariable logistic regression analysis were performed.

RESULTS

A total of 807 patients were included in the analysis. The proportions of patients with a good neurologic outcome at 28 days in the groups with EDLOS <107 min, EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min were 37.0%, 29.8%, 26.9, and 20.4%, respectively (p < 0.001). In the multivariable analysis, the odds ratios for a poor neurologic outcome at 28 days in the groups with EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min compared with the group with EDLOS <107 min were 1.19 (95% CI, 0.67-2.13), 1.73 (95% CI, 0.95-3.21), and 1.91 (95% CI, 1.03-3.57), respectively.

CONCLUSIONS

An EDLOS longer than 275 min after the ROSC was independently associated with a poor neurologic outcome at 28 days.

Goal-Directed Care Using Invasive Neuromonitoring Versus Standard of Care After Cardiac Arrest: A Matched Cohort Study

PURPOSE

Following return of spontaneous circulation after cardiac arrest, hypoxic ischemic brain injury is the primary cause of mortality and disability. Goal-directed care using invasive multimodal neuromonitoring has emerged as a possible resuscitation strategy. We evaluated whether goal-directed care was associated with improved neurologic outcome in hypoxic ischemic brain injury patients after cardiac arrest.

DESIGN

Retrospective, single-center, matched observational cohort study.

SETTING

Quaternary academic medical center.

PATIENTS

Adult patients admitted to the ICU following return of spontaneous circulation postcardiac arrest with clinical evidence of hypoxic ischemic brain injury defined as greater than or equal to 10 minutes of cardiac arrest with an unconfounded postresuscitation Glasgow Coma Scale of less than or equal to 8.

INTERVENTIONS

We compared patients who underwent goal-directed care using invasive neuromonitoring with those treated with standard of care (using both total and matched groups).

MEASUREMENTS AND MAIN RESULTS

Goal-directed care patients were matched 1:1 to standard of care patients using propensity scores and exact matching. The primary outcome was a 6-month favorable neurologic outcome (Cerebral Performance Category of 1 or 2). We included 65 patients, of whom 21 received goal-directed care and 44 patients received standard of care. The median age was 50 (interquartile range, 35-61), 48 (74%) were male, and seven (11%) had shockable rhythms. Favorable neurologic outcome at 6 months was significantly greater in the goal-directed care group (n = 9/21 [43%]) compared with the matched (n = 2/21 [10%], p = 0.016) and total (n = 8/44 [18%], p = 0.034) standard of care groups. Goal-directed care group patients had higher mean arterial pressure (p < 0.001 vs total; p = 0.0060 vs matched) and lower temperature (p = 0.007 vs total; p = 0.041 vs matched).

CONCLUSIONS

In this preliminary study of patients with hypoxic ischemic brain injury postcardiac arrest, goal-directed care guided by invasive neuromonitoring was associated with a 6-month favorable neurologic outcome (Cerebral Performance Category 1 or 2) versus standard of care. Significant work is required to confirm this finding in a prospectively designed study.

The effect of sex and age on return of spontaneous circulation and survival to hospital discharge in patients with out of hospital cardiac arrest: A retrospective analysis of a Canadian population

OBJECTIVES

We evaluated the effect of sex and age on out-of-hospital cardiac arrest (OHCA) outcomes in a Canadian population.

METHODS

This study was a retrospective analysis of the British Columbia (BC) Cardiac Arrest Registry (2011-16). We included adult, non-traumatic, EMS-treated OHCA. We stratified the cohort into four groups by age and sex: younger females (18-47 years of age), younger males (18-47 years of age), older females, and older males (>53 years old). We used logistic regression to examine the effect of sex and interaction effect of sex and age on ROSC and survival to hospital discharge.

RESULTS

We included 8115 patients; 31.4% were females. Females had a lower proportion of OHCA in public locations, bystander witnessed arrests, and with initial shockable rhythms. Overall, females had greater adjusted odds of ROSC (OR 1.29, 95% CI 1.15-1.42, p < 0.001). The ROSC advantage was significant in females with non-shockable rhythms (OR 1.48, 95% CI 1.24-1.78, p < 0.001) and females of premenopausal age. However, there was no significant difference in survival to hospital discharge between females and males overall or by sex-age groups. Both younger females and younger males have higher odds of survival to hospital discharge compared to older females and males. Older females had the lowest survival rate among all other sex-age groups.

CONCLUSIONS

Female sex was associated with ROSC but not survival to hospital discharge. In the post-arrest phase, females, specifically those in the older age group, had a higher death rate, demonstrating the need for sex- and age-specific research in pre-and-post-OHCA care.

ECMO in Cardiac Arrest: A Narrative Review of the Literature

Cardiac arrest (CA) is a frequent cause of death and a major public health issue. To date, conventional cardiopulmonary resuscitation (CPR) is the only efficient method of resuscitation available that positively impacts prognosis. Extracorporeal membrane oxygenation (ECMO) is a complex and costly technique that requires technical expertise. It is not considered standard of care in all hospitals and should be applied only in high-volume facilities. ECMO combined with CPR is known as ECPR (extracorporeal cardiopulmonary resuscitation) and permits hemodynamic and respiratory stabilization of patients with CA refractory to conventional CPR. This technique allows the parallel treatment of the underlying etiology of CA while maintaining organ perfusion. However, current evidence does not support the routine use of ECPR in all patients with refractory CA. Therefore, an appropriate selection of patients who may benefit from this procedure is key. Reducing the duration of low blood flow by means of performing high-quality CPR and promoting access to ECPR, may improve the survival rate of the patients presenting with refractory CA. Indeed, patients who benefit from ECPR seem to carry better neurological outcomes. The aim of this present narrative review is to present the most recent literature available on ECPR and to clarify its potential therapeutic role, as well as to provide an in-depth explanation of equipment and its set up, the patient selection process, and the patient management post-ECPR.

Early outcome prediction for out-of-hospital cardiac arrest with initial shockable rhythm using machine learning models

AIM

Early outcome prediction for out-of-hospital cardiac arrest with initial shockable rhythm is useful in selecting the choice of resuscitative treatment by clinicians. This study aimed to develop and validate a machine learning-based outcome prediction model for out-of-hospital cardiac arrest with initial shockable rhythm, which can be used on patient's arrival at the hospital.

METHODS

Data were obtained from a nationwide out-of-hospital cardiac arrest registry in Japan. Of 43,350 out-of-hospital cardiac arrest patients with initial shockable rhythm registered between 2013 and 2017, patients aged <18 years and those with cardiac arrest caused by external factors were excluded. Subjects were classified into training (n = 23,668, 2013-2016 data) and test (n = 6381, data from 2017) sets for validation. Only 19 prehospital variables were used for the outcome prediction. The primary outcome was death at 1 month or survival with poor neurological function (cerebral performance category 3-5; "poor" outcome). Several machine learning models, including those based on logistic regression, support vector machine, random forest, and multilayer perceptron classifiers were compared.

RESULTS

In validation analyses, all machine learning models performed satisfactorily with area under the receiver operating characteristic curve values of 0.882 [95% confidence interval [CI]: 0.869-0.894] for logistic regression, 0.866 [95% CI: 0.853-0.879] for support vector machine, 0.877 [95% CI: 0.865-0.890] for random forest, and 0.888 [95% CI: 0.876-0.900] for multilayer perceptron classifiers.

CONCLUSIONS

A favourable machine learning-based prognostic model available to use on patient arrival at the hospital was developed for out-of-hospital cardiac arrest with initial shockable rhythm.

Can a Shockable Initial Rhythm Identify Out-of-Hospital Cardiac Arrest Patients with a Short No-flow Time?

AIMS

Initial shockable rhythms may be a marker of shorter duration between collapse and initiation of cardiopulmonary resuscitation, known as no-flow time (NFT), for patients suffering an out-of-hospital cardiac arrest (OHCA). Eligibility for extracorporeal resuscitation is conditional on a short NFT. Patients with an unwitnessed OHCA could be candidate for extracorporeal resuscitation despite uncertain NFT if an initial shockable rhythm is a reliable stand-in. Herein, we sought to describe the sensitivity and specificity of an initial shockable rhythm for predicting a NFT of five minutes or less.

METHODS

Using a registry of OHCA in Montreal, Canada, adult patients who experienced a witnessed non-traumatic OHCA, but who did not receive bystander cardiopulmonary resuscitation, were included. The sensitivity and specificity of an initial shockable rhythm for predicting a NFT of five minute or less were calculated. The association between the NFT and the presence of a shockable rhythm was evaluated using a multivariable logistic regression.

RESULTS

A total of 2450 patients were included, of whom 863 (35%) had an initial shockable rhythm and 1085 (44%) a NFT of five minutes or less. The sensitivity of an initial shockable rhythm to predict a NFT of five minutes or less was 36% (95% confidence interval [95%CI] 33-39), specificity was 66% (95%CI 63-68), the positive likelihood ratio was 1.05 (95%CI 0.94-1.17) and the negative likelihood ratio of 0.97 (95%CI 0.92-1.03). The probabilities of observing a shockable rhythm stayed stable up to 15 minutes, while the probabilities of observing a PEA lowered rapidly initially. Longer NFT were associated with lower odds of observing an initial shockable rhythm (adjusted odds ratio = 0.97 [95%CI 0.94-0.99], p = 0.012).

CONCLUSIONS

An initial shockable rhythm is a poor predictor of a short NFT, despite there being an association between the NFT and the presence of a shockable rhythm.

Prognostic Impact of No-Flow Time on 30-Day Neurological Outcomes in Patients With Out-of-Hospital Cardiac Arrest Who Received Extracorporeal Cardiopulmonary Resuscitation

BACKGROUND

How the time sequence of cardiopulmonary resuscitation (CPR) procedures is related to clinical outcomes in patients with out-of-hospital cardiac arrest (OHCA) remains unclear. This study examined the impact of the time interval from collapse to start of CPR (no-flow time, NF time) and the time interval from start of CPR to implementation of extracorporeal CPR (ECPR) (low-flow time, LF time) on neurological outcomes.

METHODS AND RESULTS

During the period from 2010 to 2015, we enrolled 85 patients who received ECPR. Fourteen patients (16.5%) showed favorable 30-day neurological recovery. NF time was shorter in the favorable neurological recovery group than in the unfavorable recovery group (1.4±3.0 vs. 5.2±5.8 min, P<0.05), though combined NF+LF times were similar in the 2 groups (50.1±13.2 vs. 55.1±14.8 min, P=0.25). Multivariate logistic regression analysis indicated that pupil diameter at arrival and NF time were independently associated with favorable neurological recovery. The optimal cut-off value of NF time to predict favorable neurological recovery was 5 min (area under curve: 0.70, P<0.05; sensitivity, 85.7%; specificity, 52.1%).

CONCLUSIONS

The results suggest that NF time is a better predictor than NF+LF time for neurological outcomes in OHCA patients who received ECPR, and that start of CPR within 5 min after collapse is crucial for improving neurological outcomes followed by use of ECPR.

Pre-arrest and intra-arrest prognostic factors associated with survival following traumatic out-of-hospital cardiac arrest - A systematic review and meta-analysis

AIM

To summarize the prognostic associations of pre- and intra-arrest factors with return of spontaneous circulation (ROSC) and survival (in-hospital or 30 days) after traumatic out-of-hospital cardiac arrest.

METHODS

We conducted this review in accordance with the PRISMA and CHARMS guidelines. We searched Medline, Pubmed, Embase, Scopus, Web of Science and the Cochrane Database of Systematic Reviews from inception through December 1st, 2019. We included English language studies evaluating pre- and intra-arrest prognostic factors following penetrating or blunt traumatic OHCA. Risk of bias was assessed using the QUIPS tool. We pooled unadjusted odds ratios using random-effects models and presented adjusted odds ratios with 95% confidence intervals. We used the GRADE method to describe certainty.

RESULTS

We included 53 studies involving 37,528 patients. The most important predictors of survival were presence of cardiac motion on ultrasound (odds ratio 33.91, 1.87-613.42, low certainty) or a shockable initial cardiac rhythm (odds ratio 7.29, 5.09-10.44, moderate certainty), based on pooled unadjusted analyses. Importantly, mechanism of injury was not associated with either ROSC (odds ratio 0.97, 0.51-1.85, very low certainty) or survival (odds ratio 1.40, 0.79-2.48, very low certainty).

CONCLUSION

This review provides very low to moderate certainty evidence that pre- and intra-arrest prognostic factors following penetrating or blunt traumatic OHCA predict ROSC and survival. This evidence is primarily based on unadjusted data. Further well-designed studies with larger cohorts are warranted to test the adjusted prognostic ability of pre- and intra-arrest factors and guide therapeutic decision-making.

Turn-to-Shockable Rhythm Has Comparable Neurologic Outcomes to Initial Shockable Rhythm in Out-of-Hospital Cardiac Arrest Patients Who Underwent Targeted Temperature Management

Shockable rhythm in out-of-hospital cardiac arrest (OHCA) implies better outcome and underlying coronary stenosis. We investigated the neurologic outcome and coronary lesions between initial shockable rhythm and turn-to-shockable rhythm. This multicenter, retrospective observational study included adult nontraumatic OHCA survivors with any shockable rhythm during cardiopulmonary resuscitation (CPR) who underwent targeted temperature management between January 2010 and December 2016. Patients were divided into two groups according to the first monitored rhythm: initial shockable rhythm or turn-to-shockable rhythm. The primary outcome was good neurologic outcome at discharge based on cerebral performance categories, and the secondary outcomes were survival discharge, recurrent arrest, and coronary lesions. The two groups were matched in a 1:1 ratio using propensity score (PS). Of 426 patients, 137 and 289 patients were divided into the turn-to-shockable and initial shockable rhythm groups, respectively. Overall, 224 (52.6%) patients had good neurologic outcomes. The turn-to-shockable rhythm group had less patients with good neurologic outcome (57/137 vs. 167/289; p = 0.002) and less culprit lesions in the left anterior descending and left circumflex arteries. However, survival discharge and recurrent arrest were not different between the two groups, and the turn-to-shockable rhythm had no independent association with neurologic outcome (odds ratio, 1.874; 95% confidence interval, 0.909-3.863). In the PS-matched cohort, the turn-to-shockable rhythm group had similar good neurologic outcome (47/100 vs. 35/100, p = 0.083). Survival discharge, recurrent arrest, and coronary culprit lesions were not different between the two groups. In this PS-matched study, OHCA with any shockable rhythm during CPR had similar neurologic outcome and coronary culprit lesions, irrespective of the first monitored rhythm.

Optimal extracorporeal cardiopulmonary resuscitation inclusion criteria for favorable neurological outcomes: a single-center retrospective analysis

Aim

Although age ≤75 years, witnessed arrest, shockable initial cardiac rhythm, and short cardiac arrest duration are commonly cited inclusion criteria for extracorporeal cardiopulmonary resuscitation (ECPR), these criteria are not well‐established, and ECPR outcomes remain poor. We aimed to evaluate whether the aforementioned inclusion criteria are appropriate for ECPR, and estimate the improvements in prognoses associated with their fulfillment.

Methods

Between October 2009 and December 2017, we retrospectively examined consecutive out‐of‐hospital cardiac arrest patients who were admitted to our hospital and received ECPR. We established four ECPR inclusion criteria: age ≤75 years, witnessed arrest, shockable initial cardiac rhythm, and call‐to‐hospital arrival time ≤45 min, and also evaluated the relationship between these criteria and patient outcomes.

Results

During the study period, 1,677 out‐of‐hospital cardiac arrest patients were admitted to our hospital, and 156 (9%) with ECPR were examined. The proportion of favorable neurological outcomes was 15% (24/156). However, when the study population was limited to individuals who fulfilled all four criteria, 27% (15/55) had favorable neurological outcomes; only one patient had favorable outcomes when two or more criteria were fulfilled. There was a significant positive linear correlation between the proportion of cases with favorable neurological outcomes and fulfillment of the four criteria (P = 0.005, r = 0.975).

Conclusion

Fulfillment of at least three of the aforementioned criteria could yield improved ECPR outcomes.