Time to Return of Spontaneous Circulation and Survival: When to Transport in out-of-Hospital Cardiac Arrest?

Rare Complication of Cardiopulmonary Resuscitation-Liver Injury

Background and Objectives: Liver injury is a rare complication of cardiopulmonary resuscitation. Correct and early diagnosis and treatment are essential. The clinical signs of injury may be masked by the cardiac arrest. We present a single-centre retrospective observational study of traumatic liver injury after cardiopulmonary resuscitation. Materials and Methods: A retrospective analysis of the patients treated for liver injury after cardiopulmonary resuscitation was conducted. Demographic data, the cause of resuscitation, the duration of restoration of spontaneous circulation (ROSC), and the surgical approach were analysed. Results: We have treated nine patients with severe liver injury after cardiopulmonary resuscitation. The diagnosis was made on the basis of cardiopulmonary instability, a fall in the erythrocyte count in eight cases, and was confirmed by CT or ultrasound examination. The last one was diagnosed accidentally on MR. Surgery, in cases of unstable patients, was followed immediately after a diagnosis. We combined liver sutures and intra-abdominal packing with a planned second-look surgery. Five of the nine patients survived. Conclusions: Liver injury after cardiopulmonary resuscitation is rare and is associated with high mortality. The recurrence of cardiopulmonary instability and/or a low or falling red blood cell count are the main signs of this injury. Bedside ultrasound and CT scans are the most important methods to confirm the diagnosis. The rule of surgical repair is the same as in all liver injuries, regardless of aetiology. The key factors for survival include early diagnosis, together with the length of restoration of spontaneous circulation (ROSC).

Machine Learning Identifies Higher Survival Profile In Extracorporeal Cardiopulmonary Resuscitation

OBJECTIVES

Extracorporeal cardiopulmonary resuscitation (ECPR) has been shown to improve neurologically favorable survival in patients with refractory out-of-hospital cardiac arrest (OHCA) caused by shockable rhythms. Further refinement of patient selection is needed to focus this resource-intensive therapy on those patients likely to benefit. This study sought to create a selection model using machine learning (ML) tools for refractory cardiac arrest patients undergoing ECPR.

DESIGN

Retrospective cohort study.

SETTING

Cardiac ICU in a Quaternary Care Center.

PATIENTS

Adults 18-75 years old with refractory OHCA caused by a shockable rhythm.

METHODS

Three hundred seventy-six consecutive patients with refractory OHCA and a shockable presenting rhythm were analyzed, of which 301 underwent ECPR and cannulation for venoarterial extracorporeal membrane oxygenation. Clinical variables that were widely available at the time of cannulation were analyzed and ranked on their ability to predict neurologically favorable survival.

INTERVENTIONS

ML was used to train supervised models and predict favorable neurologic outcomes of ECPR. The best-performing models were internally validated using a holdout test set.

MEASUREMENTS AND MAIN RESULTS

Neurologically favorable survival occurred in 119 of 301 patients (40%) receiving ECPR. Rhythm at the time of cannulation, intermittent or sustained return of spontaneous circulation, arrest to extracorporeal membrane oxygenation perfusion time, and lactic acid levels were the most predictive of the 11 variables analyzed. All variables were integrated into a training model that yielded an in-sample area under the receiver-operating characteristic curve (AUC) of 0.89 and a misclassification rate of 0.19. Out-of-sample validation of the model yielded an AUC of 0.80 and a misclassification rate of 0.23, demonstrating acceptable prediction ability.

CONCLUSIONS

ML can develop a tiered risk model to guide ECPR patient selection with tailored arrest profiles.

Emergence of Artificial Intelligence and Machine Learning Models in Sudden Cardiac Arrest: A Comprehensive Review of Predictive Performance and Clinical Decision Support

Sudden cardiac death/sudden cardiac arrest (SCD/SCA) is an increasingly prevalent cause of mortality globally, particularly in individuals with preexisting cardiac conditions. The ambiguous premortem warnings and the restricted interventional window related to SCD account for the complexity of the condition. Current reports suggest SCD to be accountable for 20% of all deaths hence accurately predicting SCD risk is an imminent concern. Traditional approaches for predicting SCA, particularly "track-and-trigger" warning systems have demonstrated considerable inadequacies, including low sensitivity, false alarms, decreased diagnostic liability, reliance on clinician involvement, and human errors. Artificial intelligence (AI) and machine learning (ML) models have demonstrated near-perfect accuracy in predicting SCA risk, allowing clinicians to intervene timely. Given the constraints of current diagnostics, exploring the benefits of AI and ML models in enhancing outcomes for SCA/SCD is imperative. This review article aims to investigate the efficacy of AI and ML models in predicting and managing SCD, particularly targeting accuracy in prediction.

Development of a Predictive Model for Survival Over Time in Patients With Out-of-Hospital Cardiac Arrest Using Ensemble-Based Machine Learning

As of now, a model for predicting the survival of patients with out-of-hospital cardiac arrest has not been established. This study aimed to develop a model for identifying predictors of survival over time in patients with out-of-hospital cardiac arrest during their stay in the emergency department, using ensemble-based machine learning. A total of 26 013 patients from the Korean nationwide out-of-hospital cardiac arrest registry were enrolled between January 1 and December 31, 2019. Our model, comprising 38 variables, was developed using the Survival Quilts model to improve predictive performance. We found that changes in important variables of patients with out-of-hospital cardiac arrest were observed 10 minutes after arrival at the emergency department. The important score of the predictors showed that the influence of patient age decreased, moving from the highest rank to the fifth. In contrast, the significance of reperfusion attempts increased, moving from the fourth to the highest rank. Our research suggests that the ensemble-based machine learning model, particularly the Survival Quilts, offers a promising approach for predicting survival in patients with out-of-hospital cardiac arrest. The Survival Quilts model may potentially assist emergency department staff in making informed decisions quickly, reducing preventable deaths.

A national multi centre pre-hospital ECPR stepped wedge study; design and rationale of the ON-SCENE study

BACKGROUND

The likelihood of return of spontaneous circulation with conventional advanced life support is known to have an exponential decline and therefore neurological outcome after 20 min in patients with a cardiac arrest is poor. Initiation of venoarterial ExtraCorporeal Membrane Oxygenation (ECMO) during resuscitation might improve outcomes if used in time and in a selected patient category. However, previous studies have failed to significantly reduce the time from cardiac arrest to ECMO flow to less than 60 min. We hypothesize that the initiation of Extracorporeal Cardiopulmonary Resuscitation (ECPR) by a Helicopter Emergency Medical Services System (HEMS) will reduce the low flow time and improve outcomes in refractory Out of Hospital Cardiac Arrest (OHCA) patients.

METHODS

The ON-SCENE study will use a non-randomised stepped wedge design to implement ECPR in patients with witnessed OHCA between the ages of 18-50 years old, with an initial presentation of shockable rhythm or pulseless electrical activity with a high suspicion of pulmonary embolism, lasting more than 20, but less than 45 min. Patients will be treated by the ambulance crew and HEMS with prehospital ECPR capabilities and will be compared with treatment by ambulance crew and HEMS without prehospital ECPR capabilities. The primary outcome measure will be survival at hospital discharge. The secondary outcome measure will be good neurological outcome defined as a cerebral performance categories scale score of 1 or 2 at 6 and 12 months.

DISCUSSION

The ON-SCENE study focuses on initiating ECPR at the scene of OHCA using HEMS. The current in-hospital ECPR for OHCA obstacles encompassing low survival rates in refractory arrests, extended low-flow durations during transportation, and the critical time sensitivity of initiating ECPR, which could potentially be addressed through the implementation of the HEMS system. When successful, implementing on-scene ECPR could significantly enhance survival rates and minimize neurological impairment.

TRIAL REGISTRATION

Clinicaltyrials.gov under NCT04620070, registration date 3 November 2020.

Time Is Life: Golden Ten Minutes on Scene-EuReCa_Serbia 2014-2023

Background and Objectives: This study analyzed the frequency of factors influencing the course and outcomes of out-of-hospital cardiac arrest (OHCA) in Serbia and the prediction of pre-hospital outcomes and survival. Materials and Methods: Data were collected during the period from 1 October 2014, to 31 September 2023, according to the protocol of the EuReCa_One study (clinical trial ID number NCT02236819). Results: Overall 9303 OHCA events were registered with a median age of 71 (IQR 61-81) years and 59.7% of them being males. The annual OHCA incidence was 85.60 ± 20.73/100,000. Within all bystander-witnessed cases, bystander-initiated cardiopulmonary resuscitation in 15.3%. Within the resuscitation-initiated group, return-of-spontaneous circulation (ROSC) on scene (any ROSC) was present in 1037/4053 cases (25.6%) and ROSC on admission to the nearest hospital in 792/4053 cases (19.5%), while 201/4053 patients survived to hospital discharge (5.0%). Predictive potential on pre-hospital outcomes was shown by several factors. Also, of all patients having any ROSC, 89.2% were admitted to the hospital alive. The probability of any ROSC dropped below 50% after 17 min passed after the emergency call and 10 min after the EMS scene arrival. These time intervals were significantly associated with survival to hospital discharge (p < 0.001). Five-minute time intervals between both emergency calls and any ROSC and EMS scene arrival and any ROSC also had a significant predictive potential for survival to hospital discharge (p < 0.001, HR 1.573, 95% CI 1.303-1.899 and p = 0.017, HR 1.184, 95% CI 1.030-1.361, respectively). Conclusions: A 10-min time on scene to any ROSC is a crucial time-related factor for achieving any ROSC, and indirectly admission ROSC and survival to hospital discharge, and represents a golden time interval spent on scene in the management of OHCA patients. A similar effect has a time interval of 17 min from an emergency call. Further investigations should be focused on factors influencing these time intervals, especially time spent on scene.

Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest: an overview of current practice and evidence

Cardiac arrest (CA) is a common and potentially avoidable cause of death, while constituting a substantial public health burden. Although survival rates for out-of-hospital cardiac arrest (OHCA) have improved in recent decades, the prognosis for refractory OHCA remains poor. The use of veno-arterial extracorporeal membrane oxygenation during cardiopulmonary resuscitation (ECPR) is increasingly being considered to support rescue measures when conventional cardiopulmonary resuscitation (CPR) fails. ECPR enables immediate haemodynamic and respiratory stabilisation of patients with CA who are refractory to conventional CPR and thereby reduces the low-flow time, promoting favourable neurological outcomes. In the case of refractory OHCA, multiple studies have shown beneficial effects in specific patient categories. However, ECPR might be more effective if it is implemented in the pre-hospital setting to reduce the low-flow time, thereby limiting permanent brain damage. The ongoing ON-SCENE trial might provide a definitive answer regarding the effectiveness of ECPR. The aim of this narrative review is to present the most recent literature available on ECPR and its current developments.

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

BACKGROUND

Prehospital 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.

METHODS

This 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.

RESULTS

In 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.

CONCLUSIONS

Regional 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.

The Impact of Body Mass Index on In-Hospital Mortality in Post-Cardiac-Arrest Patients-Does Sex Matter?

BACKGROUND

A number of factors influence mortality in post-cardiac-arrest (CA) patients, nutritional status being one of them. The aim of this study was to assess whether there are sex differences in the prognostic impact of BMI, as calculated on admission to an intensive care unit, on in-hospital mortality in sudden cardiac arrest (SCA) survivors.

METHODS

We carried out a retrospective analysis of data of 129 post-cardiac-arrest patients with return of spontaneous circulation (ROSC) admitted to the Intensive Care Unit (ICU) of the University Teaching Hospital in Wrocław between 2017 and 2022.

RESULTS

Female patients were significantly older than male patients (68.62 ± 14.77 vs. 62.7 ± 13.95). The results of univariable logistic regression analysis showed that BMI was not associated with the odds of in-hospital death in either male or female patients. In an age-adjusted model, age was an independent predictor of the odds of in-hospital death only in male patients (OR = 1.034). In our final multiple logistic regression model, adjusted for the remaining variables, none of the traits analysed were a significant independent predictor of the odds of in-hospital death in female patients, whereas an initial rhythm of ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) was an independent predictor of the odds of in-hospital death in male patients (OR = 0.247).

CONCLUSIONS

BMI on admission to ICU is not a predictor of the odds of in-hospital death in either male or female SCA survivors.

Impact of emergency medical service with advanced life support training for adults with out-of-hospital cardiac arrest in the Republic of Korea: A retrospective multicenter study

Prehospital advanced life support (ALS) has been offered in many countries for patients experiencing out-of-hospital cardiac arrest (OHCA); however, its effectiveness remains unclear. This study aimed to determine the impact of emergency medical service (EMS) with ALS training as a nationwide pilot project for adults with OHCA in the Republic of Korea. This retrospective multicenter observational study was conducted between July 2019 and December 2020 using the Korean Cardiac Arrest Research Consortium registry. The patients were categorized into an intervention group that received EMS with ALS training and a control group that did not receive EMS with ALS training. Conditional logistic regression analysis was performed using matched data to compare clinical outcomes between the two groups. Compared with the control group, the intervention group had a lower rate of supraglottic airway usage (60.5% vs. 75.6%) and a higher rate of undergoing endotracheal intubation (21.7% vs. 6.1%, P < 0.001). In addition, the intervention group was administered more intravenous epinephrine (59.8% vs. 14.2%, P < 0.001) and used mechanical chest compression devices more frequently in prehospital settings than the control group (59.0% vs. 23.8%, P < 0.001). Based on the results of multivariable conditional logistic regression analysis, survival to hospital discharge (odds ratio: 0.48, 95% confidence interval: 0.27-0.87) of the intervention group was significantly lower than that of the control group; however, good neurological outcome was not significantly different between the two groups. In this study, survival to hospital discharge was worse in patients with OHCA who received EMS with ALS training than in those who did not.

The association of the post-resuscitation on-scene interval and patient outcomes after out-of-hospital cardiac arrest

BACKGROUND

After resuscitation from out-of-hospital cardiac arrest (OHCA) by Emergency Medical Services (EMS), the amount of time that should be dedicated to pre-transport stabilization is unclear. We examined whether the time spent on-scene after return of spontaneous circulation (ROSC) was associated with patient outcomes.

METHODS

We examined consecutive adult EMS-treated OHCAs from the British Columbia Cardiac Arrest registry (January 1/2019-June 1/2021) that had on-scene ROSC (sustained to scene departure). The primary outcome was favourable neurological outcome (Cerebral Performance Category ≤ 2) at hospital discharge; secondary outcomes were re-arrest during transport and hospital-discharge survival. Using adjusted logistic regression models, we estimated the association between the post-resuscitation on-scene interval (divided into quartiles) and outcomes.

RESULTS

Of 1653 cases, 611 (37%) survived to hospital discharge, and 523 (32%) had favourable neurological outcomes. The median post-resuscitation on-scene interval was 18.8 minutes (IQR:13.0-25.5). Compared to the first post-resuscitation on-scene interval quartile, neither the second (adjusted odds ratio [AOR] 1.19; 95% CI 0.72-1.98), third (AOR 1.10; 95% CI 0.67-1.81), nor fourth (AOR 1.54; 95% CI 0.93-2.56) quartiles were associated with favourable neurological outcomes; however, the fourth quartile was associated with a greater odds of hospital-discharge survival (AOR 1.73; 95% CI 1.05-2.85), and both the third (AOR 0.40; 95% CI 0.22-0.72) and fourth (AOR 0.44;95% CI 0.24-0.81) quartiles were associated with a lower odds of intra-transport re-arrest.

CONCLUSION

Among resuscitated OHCAs, increased post-resuscitation on-scene time was not associated with improved neurological outcomes, but was associated with improved survival to hospital discharge and decreased intra-transport re-arrest.

Epidemiology and Outcome of Out-of-Hospital Cardiac Arrests during the COVID-19 Pandemic in South Korea: A Systematic Review and Meta-Analyses

PURPOSE

To evaluate the effect of coronavirus disease 2019 (COVID-19) on out-of-hospital cardiac arrest (OHCA) outcomes in South Korea, we conducted systematic review and meta-analysis.

MATERIALS AND METHODS

MEDLINE, Embase, KoreaMed, and Korean Information Service System databases were searched up to June 2022. We included observational studies and letters on OHCA during the COVID-19 pandemic and compared them to those before the pandemic. Epidemiologic characteristics, including at-home OHCA, bystander cardiopulmonary resuscitation, unwitnessed arrest, use of an automated external defibrillator (AED), shockable cardiac rhythm, and airway management, were evaluated. Survival and favorable neurological outcomes were extracted. We conducted a meta-analysis of each characteristic and outcome.

RESULTS

Six studies including 4628 OHCA patients were included in this study. The incidence of at-home OHCA significantly increased and the AED use decreased during the COVID-19 pandemic compared to before the pandemic [odds ratio (OR), 1.29; 95% confidence interval (CI), 1.08-1.55; I²=0% and OR, 0.74; 95% CI, 0.57-0.97; I²=0%, respectively]. Return of spontaneous circulation after OHCA, survival, and favorable neurological outcomes during and before the pandemic did not differ significantly (OR, 0.90; 95% CI, 0.71-1.13; I²=37%; OR, 0.74; 95% CI, 0.43-1.26; I²=72%; OR, 0.77; 95% CI, 0.43-1.37; I²=70%, respectively).

CONCLUSION

During the COVID-19 pandemic in South Korea, the incidence of at-home OHCA increased and AED use decreased among OHCA patients. However, survival and favorable neurological outcomes did not significantly differ from before the pandemic. This insignificant effect of the pandemic on OHCA in South Korea could be attributed to the slow increase in patient count in the early days of the pandemic. OSF Registry (DOI: 10.17605/OSF.IO/UGE9D).

Eligibility of out-of-hospital cardiac arrest patients for extracorporeal cardiopulmonary resuscitation in the United States: A geographic information system model

BACKGROUND

Recent evidence suggest that extracorporeal cardiopulmonary resuscitation (ECPR) may improve survival rates for nontraumatic out-of-hospital cardiac arrest (OHCA). Eligibility criteria for ECPR are often based on patient age, clinical variables, and facility capabilities. Expanding access to ECPR across the U.S. requires a better understanding of how these factors interact with transport time to ECPR centers.

METHODS

We constructed a Geographic Information System (GIS) model to estimate the number of ECPR candidates in the U.S. We utilized a Resuscitation Outcome Consortium (ROC) database to model time-dependent rates of ECPR eligibility and the Cardiac Arrest Registry to Enhance Survival (CARES) registry to determine the total number of OHCA patients who meet pre-specified ECPR criteria within designated transportation times. The combined model was used to estimate the total number of ECPR candidates.

RESULTS

There were 588,203 OHCA patients in the CARES registry from 2013 to 2020. After applying clinical eligibility criteria, 22,104 (3.76%) OHCA patients were deemed eligible for ECPR. The rate of ROSC increased with longer resuscitation time, which resulted in fewer ECPR candidates. The proportion of OHCA patients eligible for ECPR increased with older age cutoffs. Only 1.68% (9,889/588,203) of OHCA patients in the U.S. were eligible for ECPR based on a 45-minute transportation time to an ECMO-ready center model.

CONCLUSIONS

Less than 2% of OHCA patients are eligible for ECPR in the U.S. GIS models can identify the impact of clinical criteria, transportation time, and hospital capabilities on ECPR eligibility to inform future implementation strategies.

Time point for transport initiation in out-of-hospital cardiac arrest cases with ongoing cardiopulmonary resuscitation: a nationwide cohort study in Japan

Aim

This study aimed to investigate the time point of the decision to initiate transport with ongoing cardiopulmonary resuscitation (CPR) in Japan.

Methods

We analyzed adult out-of-hospital cardiac arrest (OHCA) cases that achieved return of spontaneous circulation (ROSC) before hospital arrival from the All-Japan Utstein Registry during 2015-2017. We constructed receiver operating characteristics (ROC) curves to illustrate the ability of achieving ROSC as a predictor of neurologically favorable outcomes as a function of increasing time points of resuscitation before ROSC. Furthermore, a multivariable logistic regression analysis was carried out to identify factors associated with outcomes.

Results

Of 373,993 OHCA patients with attempted resuscitation during 2015-2017, 22,067 patients with prehospital ROSC were included in our study. Patients were divided into the shockable initial rhythm (n = 5,580) and nonshockable initial rhythm (n = 16,487) cohorts. The ROC curves showed 10 min was the best test performance time point for a neurologically favorable outcome for shockable initial rhythm patients (sensitivity, 0.78; specificity, 0.53; area under the ROC curve [AUC], 0.70) and 8 min for nonshockable initial rhythm patients (sensitivity, 0.74; specificity, 0.77; AUC, 0.83). Multivariable logistic regression analyses revealed that CPR durations using the cut-off value were independently associated with better outcomes for both shockable initial rhythm patients (odds ratio, 2.09; 95% confidence interval, 1.81-2.42) and nonshockable initial rhythm patients (odds ratio, 3.34; 95% confidence interval, 2.92-3.82).

Conclusion

When Japanese emergency medical service (EMS) providers attend OHCA cases, the decision to initiate transport with ongoing CPR should be made at approximately 10 min after EMS providers initiate CPR for shockable initial rhythm patients and at approximately 8 min for nonshockable initial rhythm patients.

Long-term prognosis and clinical course of choking-induced cardiac arrest in patients without the return of spontaneous circulation at hospital arrival: a population-based community study from the Shizuoka Kokuho Database

Background

The risk of choking increases with aging, and the number of cases of choking-induced cardiac arrest is increasing. However, few studies have examined the prognosis of choking-induced cardiac arrest. The aim of this study was to reveal the rates of survival and dependence on devices in the long term after choking-induced cardiac arrest.

Methods

We analyzed data from the Shizuoka Kokuho Database, which consists of claims data of approximately 2.2 million people, from April 2012 to September 2018. We selected patients with choking-induced cardiac arrest who received cardiopulmonary resuscitation in the hospital. Patients were excluded if they were less than 20 years old, had an upper airway tumor, received ventilation assistance, or received enteral nutrition in the month prior to cardiac arrest. The primary outcome was death, and the secondary outcomes were the rates of survival at 3-months and independence on devices. Descriptive statistics are presented and compared among age groups (20–64 years, 65–74 years, 75–84 years, 85 years and older), and survival time analysis (Kaplan-Meier method) was performed.

Results

In total, 268 patients were analyzed, including 26 patients in the 20–64 age group, 33 patients in the 65–74 age group, 70 patients in the 75–84 age group, and 139 patients in the ≥85 age group. The overall 3-month survival rate was 5.6% (15/268). The 3-month survival rates were 3.8% (1/26) in the 20–64 age group, 15.2% (5/33) in the 65–74 age group, 8.6% (6/70) in the 75–84 age group, and 2.2% (3/139) in the ≥85 age group. The overall 12-month survival rate was 2.6% (7/268). Of the 7 patients who survived for 12 months, 3 received ventilation management and 5 received tube or intravenous feedings at 3 months. These survivors were still receiving ventilation assistance and tube feedings in the hospital and had not been discharged at 12 months.

Conclusions

The prognosis of choking-induced cardiac arrest was extremely poor when patients were not resuscitated before hospital arrival. Those who survived were mostly dependent on assistive devices. Additionally, none of the survivors dependent on assistive devices had discontinued the use of the devices at the long-term follow-up.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00676-8.

Targeted plasma metabolomics in resuscitated comatose out-of-hospital cardiac arrest patients

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a leading cause of death. Even if successfully resuscitated, mortality remains high due to ischemic and reperfusion injury (I/R). The oxygen deprivation leads to a metabolic derangement amplified upon reperfusion resulting in an uncontrolled generation of reactive oxygen species in the mitochondria triggering cell death mechanisms. The understanding of I/R injury in humans following OHCA remains sparse, with no existing treatment to attenuate the reperfusion injury.

AIM

To describe metabolic derangement in patients following resuscitated OHCA.

METHODS

Plasma from consecutive resuscitated unconscious OHCA patients drawn at hospital admission were analyzed using ultra-performance-liquid-mass-spectrometry. Sixty-one metabolites were prespecified for quantification and studied.

RESULTS

In total, 163 patients were included, of which 143 (88%) were men, and the median age was 62 years (53-68). All measured metabolites from the tricarboxylic acid (TCA) cycle were significantly higher in non-survivors vs. survivors (180-days survival). Hierarchical clustering identified four clusters (A-D) of patients with distinct metabolic profiles. Cluster A and B had higher levels of TCA metabolites, amino acids and acylcarnitine species compared to C and D. The mortality was significantly higher in cluster A and B (A:62% and B:59% vs. C:21 % and D:24%, p < 0.001). Cluster A and B had longer time to return of spontaneous circulation (A:33 min (21-43), B:27 min (24-35), C:18 min (13-28), and D:18 min (12-25), p < 0.001).

CONCLUSION

Circulating levels of metabolites from the TCA cycle best described the variance between survivors and non-survivors. Four different metabolic phenotypes with significantly different mortality were identified.

Cardiac arrest centres: what, who, when, and where?

PURPOSE OF REVIEW

Cardiac arrest centres (CACs) may play a key role in providing postresuscitation care, thereby improving outcomes in out-of-hospital cardiac arrest (OHCA). There is no consensus on CAC definitions or the optimal CAC transport strategy despite advances in research. This review provides an updated overview of CACs, highlighting evidence gaps and future research directions.

RECENT FINDINGS

CAC definitions vary worldwide but often feature 24/7 percutaneous coronary intervention capability, targeted temperature management, neuroprognostication, intensive care, education, and research within a centralized, high-volume hospital. Significant evidence exists for benefits of CACs related to regionalization. A recent meta-analysis demonstrated clearly improved survival with favourable neurological outcome and survival among patients transported to CACs with conclusions robust to sensitivity analyses. However, scarce data exists regarding 'who', 'when', and 'where' for CAC transport strategies. Evidence for OHCA patients without ST elevation postresuscitation to be transported to CACs remains unclear. Preliminary evidence demonstrated greater benefit from CACs among patients with shockable rhythms. Randomized controlled trials should evaluate specific strategies, such as bypassing nearest hospitals and interhospital transfer.

SUMMARY

Real-world study designs evaluating CAC transport strategies are needed. OHCA patients with underlying culprit lesions, such as those with ST-elevation myocardial infarction (STEMI) or initial shockable rhythms, will likely benefit the most from CACs.

Continuous versus routine EEG in patients after cardiac arrest-Analysis of a randomized controlled trial (CERTA) - RESUS-D-22-00369

BACKGROUND

Electroencephalography (EEG) is essential to assess prognosis in patients after cardiac arrest (CA). Use of continuous EEG (cEEG) is increasing in critically-ill patients, but it is more resource-consuming than routine EEG (rEEG). Observational studies did not show a major impact of cEEG versus rEEG on outcome, but randomized studies are lacking.

METHODS

We analyzed data of the CERTA trial (NCT03129438), including comatose adults after CA undergoing cEEG (30-48 hours) or two rEEG (20-30 minutes each). We explored correlations between recording EEG type and mortality (primary outcome), or Cerebral Performance Categories (CPC, secondary outcome), assessed blindly at 6 months, using uni- and multivariable analyses (adjusting for other prognostic variables showing some imbalance across groups).

RESULTS

We analyzed 112 adults (52 underwent rEEG, 60 cEEG,); 31 (27.7%) were women; 68 (60.7%) patients died. In univariate analysis, mortality (rEEG 59%, cEEG 65%, p=0.318) and good outcome (CPC 1-2; rEEG 33%, cEEG 27%, p=0.247) were comparable across EEG groups. This did not change after multiple logistic regressions, adjusting for shockable rhythm, time to return of spontaneous circulation, serum neuron-specific enolase, EEG background reactivity, regarding mortality (rEEG vs cEEG: OR 1.60, 95% CI 0.43 - 5.83, p=0.477), and good outcome (OR 0.51, 95% CI 0.14 - 1.90, p=0.318).

CONCLUSION

This analysis suggests that cEEG or repeated rEEG are related to comparable outcomes of comatose patients after CA. Pending a prospective, large randomized trial, this finding does not support the routine use of cEEG for prognostication in this setting. Trial registration Continuous EEG Randomized Trial in Adults (CERTA); NCT03129438; July 25, 2019.

Best Practices in Managing Cardiac Arrest in the Emergency Department During the COVID-19 Pandemic

Infection by severe acute respiratory syndrome coronavirus 2 has led to cardiac complications including an increasing incidence of cardiac arrest. The resuscitation of these patients requires a conscious effort to minimize the spread of the virus. We present a best-practice model based in four guiding principles: (1) reduce the risk of exposure to the entire health care team; (2) decrease the number of aerosol generating procedures; (3) use a small resuscitation team to limit potential exposure; and (4) consider early termination of resuscitative efforts.

Metrics of mechanical chest compression device use in out-of-hospital cardiac arrest

OBJECTIVE

The quality of cardiopulmonary resuscitation (CPR) affects outcomes from cardiac arrest, yet manual CPR is difficult to administer. Although mechanical CPR (mCPR) devices offer high quality CPR, only limited data describe their deployment, their interaction with standard manual CPR (sCPR), and the consequent effects on chest compression continuity and patient outcomes. We sought to describe the interaction between sCPR and mCPR and the impact of the sCPR-mCPR transition upon outcomes in adult out-of-hospital cardiac arrest (OHCA).

METHODS

We analyzed all adult ventricular fibrillation OHCA treated by the Anchorage Fire Department (AFD) during calendar year 2016. AFD protocols include the immediate initiation of sCPR upon rescuer arrival and transition to mCPR, guided by patient status. We compared CPR timing, performance, and outcomes between those receiving sCPR only and those receiving sCPR transitioning to mCPR (sCPR + mCPR).

RESULTS

All 19 sCPR-only patients achieved return of spontaneous circulation (ROSC) after a median of 3.3 (interquartile range 2.2-5.1) minutes. Among 30 patients remaining pulseless after sCPR (median 6.9 [5.3-11.0] minutes), transition to mCPR occurred with a median chest compression interruption of 7 (5-13) seconds. Twenty-one of 30 sCPR + mCPR patients achieved ROSC after a median of 11.2 (5.7-23.8) additional minutes of mCPR. Survival differed between groups: sCPR only 14/19 (74%) versus sCPR + mCPR 13/30 (43%), P = 0.045.

CONCLUSION

In this series, transition to mCPR occurred in patients unresponsive to initial sCPR with only brief interruptions in chest compressions. Assessment of mCPR must consider the interactions with sCPR.