The association of prehospital rearrest with outcome following out-of-hospital cardiac arrest: a systematic review and meta-analysis of observational studies.

OBJECTIVES: Exposure to prehospital rearrest has previously been associated with mortality following out-of-hospital cardiac arrest (OHCA). Our objective was to conduct a systematic review and meta-analysis examining the association between prehospital rearrest and survival in adults following OHCA resuscitation. METHODS: We searched the PubMed, Scopus, and Web of Science bibliographic databases for observational studies that included adult OHCA patients who achieved return of spontaneous circulation in the prehospital setting following OHCA and reported survival to hospital discharge data stratified by rearrest status. The primary exposure was prehospital rearrest. The primary outcome for this study was survival to hospital discharge. Secondary outcomes included survival with a favorable neurological outcome and rearrest prevalence. We pooled data using inverse heterogeneity modeling and presented effect sizes for the survival outcomes as odds ratios with 95% confidence intervals. We quantified heterogeneity using Cochran's Q and the I2 statistic and examined small study effects using Doi plots and the LFK index. RESULTS: Of the 84 publications screened, we included 7 observational studies containing 27,045 patients with survival to hospital discharge data. Rearrest was common (30% [18-43%]; n = 7 studies; Q = 1086.1, p < 0.001; I2=99%; LFK index = 1.21) and associated with both decreased odds of survival to discharge (pooled aOR: 0.27 [0.22, 0.33]; n = 7 studies; Q = 32.2, p < 0.01, I2=81%, LFK index=-0.08) and decreased odds of survival to discharge with a favorable neurological outcome (pooled aOR: 0.25, [0.22, 0.28]; n = 4 studies; Q = 3.5, p = 0.3; I2=13%, LFK index = 1.30). CONCLUSIONS: Rearrest is common and associated with decreased survival following OHCA. The pooled result of this meta-analysis suggests that preventing rearrest in five patients would be necessary to save one life. PROSPERO REGISTRATION NUMBER: CRD42024525048.

Does extracorporeal cardiopulmonary resuscitation improve survival with favorable neurological outcome in out-of-hospital cardiac arrest? A systematic review and meta-analysis.

PURPOSE: Extracorporeal cardiopulmonary resuscitation (E-CPR) may improve survival with favorable neurological outcome in patients with refractory out-of-hospital cardiac arrest (OHCA). Unfortunately, recent results from randomized controlled trials were inconclusive. We performed a meta-analysis to investigate the impact of E-CPR on neurological outcome compared to conventional cardiopulmonary resuscitation (C-CPR). METHODS: A systematic research for articles assessing outcomes of adult patients with OHCA either treated with E-CPR or C-CPR up to April 27, 2023 was performed. Primary outcome was survival with favorable neurological outcome at discharge or 30 days. Overall survival was also assessed. RESULTS: Eighteen studies were included. E-CPR was associated with better survival with favorable neurological status at discharge or 30 days (14% vs 7%, OR 2.35, 95% CI 1.61-3.43, I2 = 80%, p < 0.001, NNT = 17) than C-CPR. Results were consistent if the analysis was restricted to RCTs. Overall survival to discharge or 30 days was also positively affected by treatment with E-CPR (OR = 1.71, 95% CI = 1.18-2.46, I2 = 81%, p = 0.004, NNT = 11). CONCLUSIONS: In this meta-analysis, E-CPR had a positive effect on survival with favorable neurological outcome and, to a smaller extent, on overall mortality in patients with refractory OHCA.

Association of hyperfibrinolysis with poor prognosis in refractory circulatory arrest: implications for extracorporeal cardiopulmonary resuscitation.

BACKGROUND: Identifying candidates for extracorporeal cardiopulmonary resuscitation (eCPR) is challenging, and novel predictive markers are urgently needed. Hyperfibrinolysis is linked to tissue hypoxia and is associated with poor outcomes in out-of-hospital cardiac arrest (OHCA). Rotational thromboelastometry (ROTEM) can detect or rule out hyperfibrinolysis, and could, therefore, provide decision support for initiation of eCPR. We explored early detection of hyperfibrinolysis in patients with refractory OHCA referred for eCPR. METHODS: We analysed ROTEM results and resuscitation parameters of 57 adult patients with ongoing OHCA who presented to our ICU for eCPR evaluation. RESULTS: Hyperfibrinolysis, defined as maximum lysis ≥15%, was present in 36 patients (63%) and was associated with higher serum lactate, lower arterial blood pH, and increased low-flow intervals. Of 42 patients who achieved return of circulation, 28 had a poor 30-day outcome. The incidence of hyperfibrinolysis was higher in the poor outcome group compared with patients with good outcomes (75% [21 of 28] vs 7.1% [1 of 14]; P<0.001). The ratio of EXTEM A5 to lactate concentration showed good predictive value in detecting hyperfibrinolysis (AUC of 0.89 [95% confidence interval 0.8-1]). CONCLUSIONS: Hyperfibrinolysis was common in patients with refractory cardiac arrest, and was associated with poor prognosis. The combination of high lactate with early clot firmness values, such as EXTEM A5, appears promising for early detection of hyperfibrinolysis. This finding could facilitate decisions to perform eCPR, particularly for patients with prolonged low-flow duration but lacking hyperfibrinolysis.

Mortality risk factors in patients receiving ECPR after cardiac arrest: Development and validation of a clinical prognostic prediction model.

BACKGROUND: Previous studies have shown an increasing trend of extracorporeal cardiopulmonary resuscitation (ECPR) use in patients with cardiac arrest (CA). Although ECPR have been found to reduce mortality in patients with CA compared with conventional cardiopulmonary resuscitation (CCPR), the mortality remains high. This study was designed to identify the potential mortality risk factors for ECPR patients for further optimization of patient management and treatment selection. METHODS: We conducted a prospective, multicentre study collecting 990 CA patients undergoing ECPR in 61 hospitals in China from January 2017 to May 2022 in CSECLS registry database. A clinical prediction model was developed using cox regression and validated with external data. RESULTS: The data of 351 patients meeting the inclusion criteria before October 2021 was used to develop a prediction model and that of 68 patients after October 2021 for validation. Of the 351 patients with CA treated with ECPR, 227 (64.8%) patients died before hospital discharge. Multivariate analysis suggested that a medical history of cerebrovascular diseases, pulseless electrical activity (PEA)/asystole and higher Lactate (Lac) were risk factors for mortality while aged 45-60, higher pH and intra-aortic balloon pump (IABP) during ECPR have protective effects. Internal validation by bootstrap resampling was subsequently used to evaluate the stability of the model, showing moderate discrimination, especially in the early stage following ECPR, with a C statistic of 0.70 and adequate calibration with GOF chi-square = 10.4 (p = 0.50) for the entire cohort. Fair discrimination with c statistic of 0.65 and good calibration (GOF chi-square = 6.1, p = 0.809) in the external validation cohort demonstrating the model's ability to predict in-hospital death across a wide range of probabilities. CONCLUSION: Risk factors have been identified among ECPR patients including a history of cerebrovascular diseases, higher Lac and presence of PEA or asystole. While factor such as age 45-60, higher pH and use of IABP have been found protective against in-hospital mortality. These factors can be used for risk prediction, thereby improving the management and treatment selection of patients for this resource-intensive therapy.

The impact of time to amiodarone administration on survival from out-of-hospital cardiac arrest.

Aim: To examine the impact of time to amiodarone administration on survival from shock-refractory Ventricular Fibrillation/pulseless Ventricular Tachycardia (VF/pVT) following out-of-hospital cardiac arrest (OHCA). Methods: A retrospective cohort study of adult (≥16 years) OHCA patients in shock-refractory VF/pVT (after 3 consecutive defibrillation attempts) of medical aetiology who arrested between January 2010 and December 2019. Time-dependent propensity score matching was used to sequentially match patients who received amiodarone at any given minute of resuscitation with patients eligible to receive amiodarone during the same minute. Log-binomial regression models were used to assess the association between time of amiodarone administration (by quartiles of time-to-matching) and survival outcomes. Results: A total of 2,026 patients were included, 1,393 (68.8%) of whom received amiodarone with a median (interquartile range) time to administration of 22.0 (18.0-27.0) minutes. Propensity score matching yielded 1,360 matched pairs. Amiodarone administration within 28 minutes of the emergency call was associated with a higher likelihood of return of spontaneous circulation (ROSC) (≤18minutes: RR = 1.03 (95%CI 1.02, 1.04); 19-22minutes: RR = 1.02 (95%CI 1.01, 1.03); 23-27minutes: RR = 1.01 (95%CI 1.00, 1.02)) and event survival (pulse on hospital arrival) (≤18 minutes: RR = 1.05 (95%CI 1.03, 1.07); 19-22 minutes: RR = 1.03 (95%CI 1.01, 1.05); 23-27 minutes: RR = 1.02 (95%CI 1.00, 1.03). Amiodarone administration within 23 minutes of the emergency call was associated with a higher likelihood of survival to hospital discharge (≤18minutes: RR = 1.17 (95%CI 1.09, 1.24; 19-22 minutes: RR = 1.10 (95%CI 1.04, 1.17). Conclusion: Amiodarone administered within 23 minutes of the emergency call is associated with improved survival outcomes in shock-refractory VF/pVT, although prospective trials are required to confirm these findings.

Resuscitation Strategies for Maximizing Survival.

There is no single resuscitation strategy that will uniformly improve cardiac arrest outcomes. Traditional vital signs cannot be relied on in cardiac arrest, and the use of continuous capnography, regional cerebral tissue oxygenation, and continuous arterial monitoring are options for use early defibrillation are critical elements of resuscitation. Cardio-cerebral perfusion may be improved with the use of active compression-decompression CPR, an impedance threshold device, and head-up CPR. In refractory shockable arrest, if ECPR is not an option, consider changing defibrillator pad placement and/or double defibrillation, additional medication options, and possibly stellate ganglion block.

Supraglottic airway devices are associated with asphyxial physiology after prolonged CPR in patients with refractory Out-of-Hospital cardiac arrest presenting for extracorporeal cardiopulmonary resuscitation.

BACKGROUND: Multiple randomized clinical trials have compared specific airway management strategies during ACLS with conflicting results. However, patients with refractory cardiac arrest died in almost all cases without the availability of extracorporeal cardiopulmonary resuscitation (ECPR). Our aim was to determine if endotracheal intubation (ETI) was associated with improved outcomes compared to supraglottic airways (SGA) in patients with refractory cardiac arrest presenting for ECPR. METHODS: We retrospectively studied 420 consecutive adult patients with refractory out-of-hospital cardiac arrest due to shockable presenting rhythms presenting to the University of Minnesota ECPR program. We compared outcomes between patients receiving ETI (n = 179) and SGA (n = 204). The primary outcome was the pre-cannulation arterial PaO2 upon arrival to the ECMO cannulation center. Secondary outcomes included neurologically favorable survival to hospital discharge and eligibility for VA-ECMO based upon resuscitation continuation criteria applied upon arrival to the ECMO cannulation center. RESULTS: Patients receiving ETI had significantly higher median PaO2 (71 vs. 58 mmHg, p = 0.001), lower median PaCO2 (55 vs. 75 mmHg, p < 0.001), and higher median pH (7.03 vs. 6.93, p < 0.001) compared to those receiving SGA. Patients receiving ETI were also significantly more likely to meet VA-ECMO eligibility criteria (85% vs. 74%, p = 0.008). Of patients eligible for VA-ECMO, patients receiving ETI had significantly higher neurologically favorable survival compared to SGA (42% vs. 29%, p = 0.02). CONCLUSIONS: ETI was associated with improved oxygenation and ventilation after prolonged CPR. This resulted in increased rate of candidacy for ECPR and increased neurologically favorable survival to discharge with ETI compared to SGA.

Coronary disease in refractory cardiac arrest undergoing resuscitation with extracorporeal membrane oxygenation.

AIMS: Because re-establishment of spontaneous circulation (ROSC) in patients with cardiac arrest is frequently not achieved by conventional cardiopulmonary resuscitation (C-CPR), selected patients may undergo resuscitation with extracorporeal membrane oxygenation (E-CPR). We compared angiographic features and percutaneous coronary intervention (PCI) between patients undergoing E-CPR and those with ROSC after C-CPR. METHODS AND RESULTS: Forty-nine consecutive E-CPR patients undergoing immediate coronary angiography admitted between August 2013 and August 2022 were matched to 49 patients with ROSC after C-CPR. Multivessel disease (69.4% vs. 34.7%; P = 0.001), ≥ 50% unprotected left main (ULM) stenosis (18.4% vs. 4.1%; P = 0.025), and ≥1 chronic total occlusion (CTO) (28.6% vs. 10.2%; P = 0.021) were more often documented in E-CPR group. There was no significant differences in the incidence, features, and distribution of acute culprit lesion which was present in >90%. Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) (27.6 vs. 13.4; P = 0.002) and GENSINI (86.2 vs. 46.0; P = 0.001) scores were increased in E-CPR group. Optimal cut-off predicting E-CPR was 19.75 for SYNTAX (sensitivity 74%, specificity 87%) and 60.50 (sensitivity 69%, specificity 75%) for GENSINI score. More lesions were treated (1.3 vs. 1.1 lesions/patient; P = 0.002) and stents implanted (2.0 vs. 1.3/patient; P < 0.001) in E-CPR group. Final TIMI three flow was comparable (88.6% vs. 95.7%; P = 0.196) but residual SYNTAX (13.6 vs. 3.1; P < 0.001) and GENSINI (36.7 vs. 10.9; P < 0.001) scores remained increased in E-CPR group. CONCLUSION: Extracorporeal membrane oxygenation patients have more multivessel disease, ULM stenosis, and CTO but similar incidence, features, and distribution of acute culprit lesion. Despite more complex PCI, revascularization is less complete.

Development of a clinical decision rule for the early prediction of Shock-Refractory Out-of-Hospital cardiac arrest.

BACKGROUND: Nearly half of ventricular fibrillation or ventricular tachycardia (VF/VT) out-of-hospital cardiac arrest (OHCA) patients receive three or more shocks, often referred to as refractory VF/VT. Our objective was to derive a clinical decision rule (CDR) for the early stratification of patients into risk categories for refractory VF/VT. METHODS: We included adults with non-traumatic OHCA in the Resuscitation Outcomes Consortium Epistry (2011-2015) with ≥ 1 EMS shock. We used Classification and Regression Tree analysis for CDR building using variables known at initial EMS rhythm analysis including age, sex, witness, location, bystander interventions, initial EMS rhythm, obvious non-cardiac etiology, and dispatch to arrival times. The outcome was refractory VF/VT (≥3 shocks). We calculated sensitivity, specificity, area under the receiver operating curve (AUROC), and odds ratios (OR). The rule was validated using the Portland Cardiac Arrest Epidemiologic Registry (2018-2020). RESULTS: There were 17,140 eligible patients and 8,146 (47.5%) had refractory VF/VT. The optimal CDR (AUROC = 0.671) defined three groups: high-risk were any patients requiring an EMS shock after a bystander AED shock; moderate-risk were any non-EMS witnessed arrests with shockable initial EMS rhythms; and the remainder were low-risk. Refractory VF/VT increased across the low (30.7%), moderate (58.5%) and high-risk (84.8%) groups. Compared to low-risk, being moderate-risk or higher (OR [95% CI]:3.37 [3.16-3.59]; sensitivity 72.7%; specificity 55.9%) or high-risk (OR:12.63 [9.89-16.13]; sensitivity 5.4%; specificity 99.1%) had higher odds of refractory VF/VT. Results was similar in the validation cohort (n = 765, AUROC = 0.672). CONCLUSIONS: Patients at higher risk for refractory VF/VT can be identified early in EMS care.

Cases of prolonged cardiac arrest with preserved gasping successfully resuscitated with ECPR.

Longer cardiopulmonary resuscitation (CPR) time is associated with worsened neurological outcomes in out-of-hospital cardiac arrest (OHCA). Gasping during CPR is a favorable neurological predictor for OHCA. Recently, the efficacy of extracorporeal cardiopulmonary resuscitation (ECPR) in refractory cardiac arrest has been reported. However, the significance of gasping in refractory cardiac arrest patients with long CPR durations treated with ECPR is still unclear. We report two cases of cardiac arrest with gasping that were successfully resuscitated by ECPR, despite extremely long low-flow times. In case 1, a 58-year-old man presented with cardiac arrest and ventricular fibrillation (VF). Gasping was observed when the patient arrived at the hospital. ECPR was initiated 82 min after cardiac arrest. The patient was diagnosed with hypertrophic cardiomyopathy. ECMO was withdrawn on day 4, and the patient was discharged without neurological impairment. In case 2, a 49-year-old man experienced cardiac arrest with VF, and his gasping was preserved during transportation. On arrival, VF persisted, and gasping was observed; therefore, ECMO was initiated 93 min after cardiac arrest. He was diagnosed with acute myocardial infarction. ECMO was withdrawn on day 4 and he was discharged from the hospital without any neurological impairment. Resuscitation and ECPR should not be abandoned in case of preserved gasping, even when the low-flow time is extremely long.

A novel strategy sequentially linking mechanical cardiopulmonary resuscitation with extracorporeal cardiopulmonary resuscitation optimizes prognosis of refractory cardiac arrest: an illustrative case series.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) to support cardiopulmonary resuscitation (CPR), also known as extracorporeal cardiopulmonary resuscitation (ECPR), has shown encouraging results in refractory cardiac arrest (RCA) resuscitation. However, its therapeutic benefits are linked to instant and uninterrupted chest compression (CC), besides early implementation. Mechanical CC can overcome the shortcomings of conventional manual CC, including fatigue and labor consumption, and ensure adequate blood perfusion. A strategy sequentially linking mechanical CPR with ECPR may earn extra favorable outcomes. CASE SERIES: We present a four-case series with ages ranging from 8 to 94 years who presented with prolonged absences of return of spontaneous circulation (ROSC) after CA associated with acute fulminant myocarditis (AFM) and myocardial infarction (MI). All the cases received VA-ECMO (ROTAFLOW, Maquet) assisted ECPR, with intra-aortic balloon pump (IABP) or continuous renal replacement treatment (CRRT) appended if persistently low mean blood pressure (MAP) or ischemic kidney injury occurred. All patients have successfully weaned off ECMO and the assistant life support devices with complete neurological recovery. Three patients were discharged, except the 94-year-old patient who died of irreversible sepsis 20 days after ECMO weaning-off. These encouraging results will hopefully lead to more consideration of this lifesaving therapy model that sequentially integrates mechanical CPR with ECPR to rescue RCA related to reversible cardiac causes. CONCLUSIONS: This successful case series should lead to more consideration of an integrated lifesaving strategy sequentially linking mechanical cardiopulmonary resuscitation with ECPR, as an extra favorable prognosis of refractory cardiac arrest related to this approach can be achieved.

Ethics of ECPR research.

The design of emergency medicine trials can raise several ethical concerns - risks may be greater, and randomisation may have to occur before consent. Research in emergency medicine is thus an illuminating context to explore the interplay between risk and randomisation, and the consequences for consent. Using a currently running trial, we describe possible concerns, considerations, and solutions to reconcile the conflicting interests of scientific inquiry, ethical principles, and clinical reality in emergency medicine research.

Outcome in refractory out-of-hospital cardiac arrest before and after implementation of an ECPR protocol.

AIM: To compare the outcomes in patients with refractory out-of-hospital cardiac arrest (OHCA) fulfilling the criteria for extracorporeal cardiopulmonary resuscitation (ECPR) before and after implementation of an ECPR protocol, whether the patient received ECPR or not. METHODS: We compared cardiac arrest registry data before (2014-2015) and after (2016-2019) implementation of the ECPR protocol. The ECPR criteria were presumed cardiac origin, witnessed arrest with ventricular fibrillation, bystander CPR, age 18-65, advanced life support (ALS) within 15 min and ALS > 10 min without return of spontaneous circulation (ROSC). The primary outcome was 30-day survival; the secondary outcomes were sustained ROSC, neurological outcome and the proportion of patients transported with ongoing ALS. RESULTS: There were 1086 and 3135 patients in the pre- and post-implementation sample; 48 (4%) and 100 (3%) met the ECPR criteria, respectively. Of these, 21 (44%) vs. 37 (37%) were alive after 30 days, p = 0.4, and 30 (63%) vs. 50 (50%) achieved sustained ROSC, p = 0.2. All survivors in the pre-implementation sample had cerebral performance category 1-2 vs. 30 (81%) in the post-implementation sample, p = 0.03. Of the patients fulfilling the ECPR criteria, 7 (15%) and 26 (26%), p = 0.1, were transported with ongoing ALS in the pre- and post-implementation sample, respectively. CONCLUSIONS: There were no differences in 30-day survival or prehospital ROSC in patients with refractory OHCA before and after initiation of an ECPR protocol.

Impella CP Implantation during Cardiopulmonary Resuscitation for Cardiac Arrest: A Multicenter Experience.

BACKGROUND: Impella CP is a left ventricular pump which may serve as a circulatory support during cardiopulmonary resuscitation (CPR) for cardiac arrest (CA). Nevertheless, the survival rate and factors associated with survival in patients undergoing Impella insertion during CPR for CA are unknown. METHODS: We performed a retrospective multicenter international registry of patients undergoing Impella insertion during on-going CPR for in- or out-of-hospital CA. We recorded immediate and 30-day survival with and without neurologic impairment using the cerebral performance category score and evaluated the factors associated with survival. RESULTS: Thirty-five patients had an Impella CP implanted during CPR for CA. Refractory ventricular arrhythmias were the most frequent initial rhythm (65.7%). In total, 65.7% of patients immediately survived. At 30 days, 45.7% of patients were still alive. The 30-day survival rate without neurological impairment was 37.1%. In univariate analysis, survival was associated with both an age < 75 years and a time from arrest to CPR ≤ 5 min (p = 0.035 and p = 0.008, respectively). CONCLUSIONS: In our multicenter registry, Impella CP insertion during ongoing CPR for CA was associated with a 37.1% rate of 30-day survival without neurological impairment. The factors associated with survival were a young age and a time from arrest to CPR ≤ 5 min.

First Description of a Helicopter-Borne ECPR Team for Remote Refractory Out-of-Hospital Cardiac Arrest.

Introduction: Access time to extracorporeal cardiopulmonary resuscitation (ECPR) refractory out of hospital cardiac arrest (OHCA) is a crucial factor. In our region, some patients are not eligible to this treatment due to the impossibility to reach the hospital with reasonable delay (ideally 60 min). In order to increase accessibility for patients far from ECPR centers, we developed a helicopter-borne ECPR-team which is sent out to the patient for ECPR implementation on the scene of the OHCA.Methods: We conducted a retrospective monocentric study to evaluate this strategy. The team is triggered by the local emergency medical service and heliborne on the site of the OHCA. All consecutive patients implemented with ECPR by our heliborne ECPR team from January 2014 to December 2017 were included. We analyzed usual CA characteristics, different times (no-flow, low-flow, time between OHCA and dispatch…), and patient outcome.Results: During this 4-year study period, 33 patients were included. Mean age was 43.9 years. Mean distance from the ECPR-team base to OHCA location was 41 km. Mean low-flow time was 110 minutes. Five patients survived with good neurological outcome; 6 patients developed brain death and became organ donors.Conclusion: These results show the possibility to make ECPR accessible for patients far from ECPR centers. Survival rate is non negligible, especially in the absence of therapeutic alternative. An earlier trigger of the ECPR-team could reduce the low-flow time and probably increase survival. This strategy improves equity of access to ECPR and needs to be confirmed by further studies.

Establishment of an extracorporeal cardio-pulmonary resuscitation program in Berlin - outcomes of 254 patients with refractory circulatory arrest.

OBJECTIVE: Optimal management of out of hospital circulatory arrest (OHCA) remains challenging, in particular in patients who do not develop rapid return of spontaneous circulation (ROSC). Extracorporeal cardiopulmonary resuscitation (eCPR) can be a life-saving bridging procedure. However its requirements and feasibility of implementation in patients with OHCA, appropriate inclusion criteria and achievable outcomes remain poorly defined. DESIGN: Prospective cohort study. SETTING: Tertiary referral university hospital center. PATIENTS: Here we report on characteristics, course and outcomes on the first consecutive 254 patients admitted between August 2014 and December 2017. INTERVENTION: eCPR program for OHCA. MESUREMENTS AND MAIN RESULTS: A structured clinical pathway was designed and implemented as 24/7 eCPR service at the Charité in Berlin. In total, 254 patients were transferred with ongoing CPR, including automated chest compression, of which 30 showed or developed ROSC after admission. Following hospital admission predefined in- and exclusion criteria for eCPR were checked; in the remaining 224, 126 were considered as eligible for eCPR. State of the art postresuscitation therapy was applied and prognostication of neurological outcome was performed according to a standardized protocol. Eighteen patients survived, with a good neurological outcome (cerebral performance category (CPC) 1 or 2) in 15 patients. Compared to non-survivors survivors had significantly shorter time between collaps and start of eCPR (58 min (IQR 12-85) vs. 90 min (IQR 74-114), p = 0.01), lower lactate levels on admission (95 mg/dL (IQR 44-130) vs. 143 mg/dL (IQR 111-178), p <  0.05), and less severe acidosis on admission (pH 7.2 (IQR 7.15-7.4) vs. 7.0 (IQR6.9-7.2), p <  0.05). Binary logistic regression analysis identified latency to eCPR and low pH as independent predictors for mortality. CONCLUSION: An eCPR program can be life-saving for a subset of individuals with refractory circulatory arrest, with time to initiation of eCPR being a main determinant of survival.

Can we predict patient outcome before extracorporeal membrane oxygenation for refractory cardiac arrest?

BACKGROUND: Refractory cardiac arrest resistant to conventional cardiopulmonary resuscitation (C-CPR) has a poor outcome. Although previous reports showed that extracorporeal cardiopulmonary resuscitation (E-CPR) can improve the clinical outcome, there are no clinically applicable predictors of patient outcome that can be used prior to the implementation of E-CPR. We aimed to evaluate the use of clinical factors in patients with refractory cardiac arrest undergoing E-CPR to predict patient outcome in our institution. METHODS: This is a single-center retrospective study. We report 112 patients presenting with refractory cardiac arrest resistant to C-CPR between January 2012 and November 2017. All patients received E-CPR for continued life support when a cardiogenic etiology was presumed. Clinical factors associated with patient outcome were analyzed. Significant pre-ECMO clinical factors were extracted to build a patient outcome risk prediction model. RESULTS: The overall survival rate at discharge was 40.2, and 30.4% of patients were discharged with good neurologic function. The six-month survival rate after hospital discharge was 36.6, and 25.9% of patients had good neurologic function 6 months after discharge. We stratified the patients into low-risk (n = 38), medium-risk (n = 47), and high-risk groups (n = 27) according to the TLR score (low-flow Time, cardiac arrest Location, and initial cardiac arrest Rhythm) that we derived from pre-ECMO clinical parameters. Compared with the medium-risk and high-risk groups, the low-risk group had better survival at discharge (65.8% vs. 42.6% vs. 0%, p < 0.0001) and at 6 months (60.5% vs. 38.3% vs. 0%, p = 0.0001). The low-risk group also had a better neurologic outcome at discharge (50% vs. 31.9% vs. 0%, p = 0.0001) and 6 months after discharge (44.7% vs. 25.5% vs. 0%, p = 0.0003) than the medium-risk and high-risk groups. CONCLUSIONS: Patients with refractory cardiac arrest receiving E-CPR can be stratified by pre-ECMO clinical factors to predict the clinical outcome. Larger-scale studies are required to validate our observations.

How long is long enough? Good neurologic outcome in out-of-hospital cardiac arrest survivors despite prolonged resuscitation: a retrospective cohort study.

BACKGROUND: Despite all efforts, mortality of out of hospital cardiac arrest (OHCA) remains high. Patients with OHCA due to a primary shockable rhythm typically have a better prognosis. However, outcome worsens if return of spontaneous circulation (ROSC) cannot be achieved quickly. There is insufficient evidence for maximum duration of resuscitation in these patients and it is unclear, which patients profit from transport under ongoing CPR. OBJECTIVE: Investigate predictors for favourable neurologic outcome in OHCA patients with presumed cardiac cause due to refractory shockable rhythm (rSR). METHODS: Retrospective analysis of OHCA patients that presented to a tertiary hospital due to a rSR. RESULTS: One hundred seventy-five OHCA patients with presumed cardiac cause due to rSR were included. Overall hospital mortality was 50% and 83% of initial survivors were discharged with a good neurologic outcome [cerebral performance category (CPC) 1-2]. In patients with a time from cardiac arrest to ROSC of > 45 min, 18% survived to CPC 1-2. Independent predictors for good neurologic outcome were age, lower no-flow time and lower serum lactate levels at hospital arrival. CONCLUSION: In an urban setting, a significant proportion of OHCA patients with rSR can survive to a good neurologic outcome, despite very long time to ROSC.