Systematic review and meta-analysis comparing low-flow duration of extracorporeal and conventional cardiopulmonary resuscitation

Current trends in the management of out of hospital cardiac arrest (OHCA)

Sudden cardiac arrest remains a relevant problem with a significant number of deaths worldwide. Although survival rates have more than tripled over the last 20 years (4% in 2001 vs. 14% in 2020), survival rates with good neurological outcomes remain persistently low, representing a major socioeconomic problem. Every minute of delay from patient collapse to start cardiopulmonary resuscitation (CPR) and early defibrillation reduces the chance of survival by approximately 10-12%. Therefore, the time to treatment is a crucial factor in the prognosis of patients with out-of-hospital cardiac arrest (OHCA). Research teams working in the pre-hospital setting are therefore looking for ways to improve the transmission of information from the site of an emergency event and to make it easier for emergency medical dispatch centres (EMDC) to recognise life-threatening conditions with minimal deviation. For emergency unit procedures already at the scene of the event, methods are being sought to efficiently and temporarily replace a non-functioning cardiopulmonary system. In the case of traumatic cardiac arrest (TCA), the focus is mainly on effective affecting non-compressible haemorrhage.

Favorable resuscitation characteristics in patients undergoing extracorporeal cardiopulmonary resuscitation: A secondary analysis of the INCEPTION-trial

Introduction

Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used as a supportive treatment for refractory out-of-hospital cardiac arrest (OHCA). Still, there is a paucity of data evaluating favorable and unfavorable prognostic characteristics in patients considered for ECPR.

Methods

We performed a previously unplanned post-hoc analysis of the multicenter randomized controlled INCEPTION-trial. The study group consisted of patients receiving ECPR, irrespective of initial group randomization. The patients were divided into favorable survivors (cerebral performance category [CPC] 1-2) and unfavorable or non-survivors (CPC 3-5).

Results

In the initial INCEPTION-trial, 134 patients were randomized. ECPR treatment was started in 46 (66%) of 70 patients in the ECPR treatment arm and 3 (4%) of 74 patients in the conventional treatment arm. No statistically significant differences in baseline characteristics, medical history, or causes of arrest were observed between survivors (n = 5) and non-survivors (n = 44). More patients in the surviving group had a shockable rhythm at the time of cannulation (60% vs. 14%, p = 0.037), underwent more defibrillation attempts (13 vs. 6, p = 0.002), and received higher dosages of amiodarone (450 mg vs 375 mg, p = 0.047) despite similar durations of resuscitation maneuvers. Furthermore, non-survivors more frequently had post-ECPR implantation adverse events.

Conclusion

The persistence of ventricular arrhythmia is a favorable prognostic factor in patients with refractory OHCA undergoing an ECPR-based treatment. Future studies are warranted to confirm this finding and to establish additional prognostic factors.Clinical trial Registration:clinicaltrials.gov registration number NCT03101787.

Differences in Treatment Outcomes According to the Insertion Method Used in Extracorporeal Cardiopulmonary Resuscitation: A Single-Center Experience

Background

Venoarterial extracorporeal membrane oxygenation (ECMO) is a key treatment method used with patients in cardiac arrest who do not respond to medical treatment. A critical step in initiating therapy is the insertion of ECMO cannulas. Peripheral ECMO cannulation methods have been preferred for extracorporeal cardiopulmonary resuscitation (ECPR).

Methods

Patients who underwent ECPR at Daegu Catholic University Medical Center between January 2017 and May 2023 were included in this study. We analyzed the impact of 2 different peripheral cannulation strategies (surgical cutdown vs. percutaneous cannulation) on various factors, including survival rate.

Results

Among the 99 patients included in this study, 66 underwent surgical cutdown, and 33 underwent percutaneous insertion. The survival to discharge rates were 36.4% for the surgical cutdown group and 30.3% for the percutaneous group (p=0.708). The ECMO insertion times were 21.3 minutes for the surgical cutdown group and 10.3 minutes for the percutaneous group (p<0.001). The factors associated with overall mortality included a shorter low-flow time (hazard ratio [HR], 1.045; 95% confidence interval [CI], 1.019-1.071; p=0.001) and whether return of spontaneous circulation was achieved (HR, 0.317; 95% CI, 0.127-0.787; p=0.013). Low-flow time was defined as the time from the start of cardiopulmonary resuscitation to the completion of ECMO cannula insertion.

Conclusion

No statistically significant difference in in-hospital mortality was observed between the surgical and percutaneous groups. However, regardless of the chosen cannulation strategy, reducing ECMO cannulation time was beneficial, as a shorter low-flow time was associated with significant benefits in terms of survival.

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.

The approach to extracorporeal cardiopulmonary resuscitation (ECPR) in children. A narrative review by the paediatric ECPR working group of EuroELSO

Extracorporeal Cardiopulmonary Resuscitation (ECPR) has potential benefits compared to conventional Cardiopulmonary Resuscitation (CCPR) in children. Although no randomised trials for paediatric ECPR have been conducted, there is extensive literature on survival, neurological outcome and risk factors for survival. Based on current literature and guidelines, we suggest recommendations for deployment of paediatric ECPR emphasising the requirement for protocols, training, and timely intervention to enhance patient outcomes. Factors related to outcomes of paediatric ECPR include initial underlying rhythm, CCPR duration, quality of CCPR, medications during CCPR, cannulation site, acidosis and renal dysfunction. Based on current evidence and experience, we provide an approach to patient selection, ECMO initiation and management in ECPR regarding blood and sweep flow settings, unloading of the left ventricle, diagnostics whilst on ECMO, temperature targets, neuromonitoring as well as suggested weaning and decannulation strategies.

Eligibility of cardiac arrest patients for extracorporeal cardiopulmonary resuscitation and their clinical characteristics: a retrospective two-centre study

BACKGROUND AND IMPORTANCE

Sudden cardiac arrest has a high incidence and often leads to death. A treatment option that might improve the outcomes in refractory cardiac arrest is Extracorporeal Cardiopulmonary Resuscitation (ECPR).

OBJECTIVES

This study investigates the number of in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) patients eligible to ECPR and identifies clinical characteristics that may help to identify which patients benefit the most from ECPR.

DESIGN, SETTINGS AND PARTICIPANTS

A retrospective two-centre study was conducted in Rotterdam, the Netherlands. All IHCA and OHCA patients between 1 January 2017 and 1 January 2020 were screened for eligibility to ECPR. The primary outcome was the percentage of patients eligible to ECPR and patients treated with ECPR. The secondary outcome was the comparison of the clinical characteristics and outcomes of patients eligible to ECPR treated with conventional Cardiopulmonary Resuscitation (CCPR) vs. those of patients treated with ECPR.

MAIN RESULTS

Out of 1246 included patients, 412 were IHCA patients and 834 were OHCA patients. Of the IHCA patients, 41 (10.0%) were eligible to ECPR, of whom 20 (48.8%) patients were actually treated with ECPR. Of the OHCA patients, 83 (9.6%) were eligible to ECPR, of whom 23 (27.7%) were actually treated with ECPR. In the group IHCA patients eligible to ECPR, no statistically significant difference in survival was found between patients treated with CCPR and patients treated with ECPR (hospital survival 19.0% vs. 15.0% respectively, 4.0% survival difference 95% confidence interval -21.3 to 28.7%). In the group OHCA patients eligible to ECPR, no statistically significant difference in-hospital survival was found between patients treated with CCPR and patients treated with ECPR (13.3% vs. 21.7% respectively, 8.4% survival difference 95% confidence interval -30.3 to 10.2%).

CONCLUSION

This retrospective study shows that around 10% of cardiac arrest patients are eligible to ECPR. Less than half of these patients eligible to ECPR were actually treated with ECPR in both IHCA and OHCA.

Extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: 10-year experience in a metropolitan cardiac arrest centre in Milan, Italy

Introduction

Growing evidence supports extracorporeal cardiopulmonary resuscitation (ECPR) for refractory out-of-hospital cardiac arrest (OHCA) patients, especially in experienced centres. We present characteristics, treatments, and outcomes of patients treated with ECPR in a high-volume cardiac arrest centre in the metropolitan area of Milan, Italy and determine prognostic factors.

Methods

Refractory OHCA patients treated with ECPR between 2013 and 2022 at IRCCS San Raffaele Scientific Institute in Milan had survival and neurological outcome assessed at hospital discharge.

Results

Out of 307 consecutive OHCA patients treated with ECPR (95% witnessed, 66% shockable, low-flow 70 [IQR 58-81] minutes), 17% survived and 9.4% had favourable neurological outcome. Survival and favourable neurological outcome increased to 51% (OR = 8.7; 95% CI, 4.3-18) and 28% (OR = 6.3; 95% CI, 2.8-14) when initial rhythm was shockable and low-flow (time between CPR initiation and ROSC or ECMO flow) ≤60 minutes and decreased to 9.5% and 6.3% when low-flow exceeded 60 minutes (72% of patients). At multivariable analysis, shockable rhythm (aOR for survival = 2.39; 95% CI, 1.04-5.48), shorter low-flow (aOR = 0.95; 95% CI, 0.94-0.97), intermittent ROSC (aOR = 2.5; 95% CI, 1.2-5.6), and signs of life (aOR = 3.7; 95% CI, 1.5-8.7) were associated with better outcomes. Survival reached 10% after treating 104 patients (p for trend <0.001).

Conclusions

Patients with initial shockable rhythm, intermittent ROSC, signs of life, and low-flow ≤60 minutes had higher success of ECPR for refractory OHCA. Favourable outcomes were possible beyond 60 minutes of low-flow, especially with concomitant favourable prognostic factors. Outcomes improved as the case-volume increased, supporting treatment in high-volume cardiac arrest centres.

Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest in Australia: a narrative review

Extracorporeal cardiopulmonary resuscitation (ECPR) in patients with prolonged or refractory out-of-hospital cardiac arrest (OHCA) is likely to be beneficial when used as part of a well developed emergency service system. ECPR is technically challenging to initiate and resource-intensive, but it has been found to be cost-effective in hospital-based ECPR programs. ECPR expansion within Australia has thus far been reactive and does not provide broad coverage or equity of access for patients. Newer delivery strategies that improve access to ECPR for patients with OHCA are being trialled, including networked hospital-based ECPR and pre-hospital ECPR programs. The efficacy, scalability, sustainability and cost-effectiveness of these programs need to be assessed. There is a need for national collaboration to determine the most cost-effective delivery strategies for ECPR provision along with its place in the OHCA survival chain.

Extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest - current status

PURPOSE OF REVIEW

Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging treatment for refractory cardiac arrest. In recent years, several randomized controlled trials have been published that aimed to address the efficacy and effectiveness of ECPR for out-of-hospital cardiac arrest (OHCA). Despite the lack of high-quality evidence concerning clinical effectiveness and cost-effectiveness, ECPR is increasingly implemented throughout the world. In this review, we aim to provide an overview of the current status of ECPR for OHCA.

RECENT FINDINGS

Randomized controlled trials showed diverging results, largely due to differences in selection criteria and study design. Single-center studies, performed in centers with extraordinary expertise and dedication consistently achieve a low-flow time of around 60 min, but such achievements are rarely reproduced outside these centers. Strict patient selection can improve outcome but simultaneously limits the caseload. Preliminary data suggest that outcome may also be improved by avoiding hyperoxia postresuscitation.

SUMMARY

The potential of ECPR to increase survival in selected patients in highly dedicated systems seems to be proven, the question remains whether ECPR for OHCA can be widely implemented successfully and can develop into a sustainable, commonplace resource-effective treatment.

Epinephrine Dosing Use During Extracorporeal Cardiopulmonary Resuscitation: Single-Center Retrospective Cohort

OBJECTIVES

During pediatric cardiac arrest, contemporary guidelines recommend dosing epinephrine at regular intervals, including in patients requiring extracorporeal membrane oxygenation (ECMO). The impact of epinephrine-induced vasoconstriction on systemic afterload and venoarterial ECMO support is not well-defined.

DESIGN

Nested retrospective observational study within a single center. The primary exposure was time from last dose of epinephrine to initiation of ECMO flow; secondary exposures included cumulative epinephrine dose and arrest time. Systemic afterload was assessed by mean arterial pressure and use of systemic vasodilator therapy; ECMO pump flow and Vasoactive-Inotrope Score (VIS) were used as measures of ECMO support. Clearance of lactate was followed post-cannulation as a marker of systemic perfusion.

SETTING

PICU and cardiac ICU in a quaternary-care center.

PATIENTS

Patients 0-18 years old who required ECMO cannulation during resuscitation over the 6 years, 2014-2020. Patients were excluded if ECMO was initiated before cardiac arrest or if the resuscitation record was incomplete.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 92 events in 87 patients, with 69 events having complete data for analysis. The median (interquartile range) of total epinephrine dosing was 65 mcg/kg (37-101 mcg/kg), with the last dose given 6 minutes (2-16 min) before the initiation of ECMO flows. Shorter interval between last epinephrine dose and ECMO initiation was associated with increased use of vasodilators within 6 hours of ECMO ( p = 0.05), but not with mean arterial pressure after 1 hour of support (estimate, -0.34; p = 0.06). No other associations were identified between epinephrine delivery and mean arterial blood pressure, vasodilator use, pump speed, VIS, or lactate clearance.

CONCLUSIONS

There is limited evidence to support the idea that regular dosing of epinephrine during cardiac arrest is associated with increased in afterload after ECMO cannulation. Additional studies are needed to validate findings against ECMO flows and clinically relevant outcomes.

Feasibility of HEMS performed prehospital extracorporeal-cardiopulmonary resuscitation in paediatric cardiac arrests; two case reports

INTRODUCTION

A broad range of pathophysiologic conditions can lead to cardiopulmonary arrest in children. Some of these children suffer from refractory cardiac arrest, not responding to basic and advanced life support. Extracorporeal-Cardiopulmonary Resuscitation (E-CPR) might be a life-saving option for this group. Currently this therapy is only performed in-hospital, often necessitating long transport times, thereby negatively impacting eligibility and chances of survival. We present the first two cases of prehospital E-CPR in children performed by regular Helicopter Emergency Medical Services (HEMS).

CASE PRESENTATIONS

The first patient was a previously healthy 7 year old boy who was feeling unwell for a couple of days due to influenza. His course deteriorated into a witnessed collapse. Direct bystander CPR and subsequent ambulance advanced life support was unsuccessful in establishing a perfusing rhythm. While doing chest compressions, the patient was seen moving both his arms and making spontaneous breathing efforts. Echocardiography however revealed a severe left ventricular impairment (near standstill). The second patient was a 15 year old girl, known with bronchial asthma and poor medication compliance. She suffered yet another asthmatic attack, so severe that she progressed into cardiac arrest in front of the attending ambulance and HEMS crews. Despite maximum bronchodilator therapy, intubation and the exclusion of tension pneumothoraxes and dynamic hyperinflation, no cardiac output was achieved.

INTERVENTION

After consultation with the nearest paediatric E-CPR facilities, both patients were on-scene cannulated by regular HEMS. The femoral artery and vein were cannulated (15-17Fr and 21Fr respectively) under direct ultrasound guidance using an out-of-plane Seldinger approach. Extracorporeal Life Support flow of 2.1 and 3.8 l/min was established in 20 and 16 min respectively (including preparation and cannulation). Both patients were transported uneventfully to the nearest paediatric intensive care with spontaneous breathing efforts and reactive pupils during transport.

CONCLUSION

This case-series shows that a properly trained regular HEMS crew of only two health care professionals (doctor and flight nurse) can establish E-CPR on-scene in (older) children. Ambulance transport with ongoing CPR is challenging, even more so in children since transportation times tend to be longer compared to adults and automatic chest compression devices are often unsuitable and/or unapproved for children. Prehospital cannulation of susceptible E-CPR candidates has the potential to reduce low-flow time and offer E-CPR therapy to a wider group of children suffering refractory cardiac arrest.

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.

Extracorporeal CPR after the INCEPTION trial: No one steps twice into the same river

The use of veno-arterial extracorporeal membrane oxygenation as extracorporeal cardiopulmonary resuscitation in patients suffering out-of-hospital cardiac arrest, largely increased in the last decade despite evidence supporting this practice being limited to non-randomized studies. However, between 2020 and 2023, four randomized studies were published comparing extracorporeal cardiopulmonary resuscitation to conventional cardiopulmonary resuscitation with controversial findings that triggered great debates. In this controversy, we discuss merits and pitfalls, and provide a critical interpretation of the available evidence from randomized trials on the use of extracorporeal cardiopulmonary resuscitation, with a particular focus on the recent multi-center INCEPTION trial.

Refractory out-of-hospital cardiac arrest and extracorporeal cardiopulmonary resuscitation: A meta-analysis of randomized trials

BACKGROUND

In adults with refractory out-of-hospital cardiac arrest, when conventional cardiopulmonary resuscitation (CPR) alone does not achieve return of spontaneous circulation, extracorporeal CPR is attempted to restore perfusion and improve outcomes. Considering the contrasting findings of recent studies, we conducted a meta-analysis of randomized controlled trials to ascertain the effect of extracorporeal CPR on survival and neurological outcome.

METHODS

Pubmed via MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched up to February 3, 2023, for randomized controlled trials comparing extracorporeal CPR versus conventional CPR in adults with refractory out-of-hospital cardiac arrest. Survival with a favorable neurological outcome at the longest follow-up available was the primary outcome.

RESULTS

Among four randomized controlled trials included, extracorporeal CPR compared with conventional CPR increased survival with favorable neurological outcome at the longest follow-up available for all rhythms (59/220 [27%] vs. 39/213 [18%]; OR = 1.72; 95% CI, 1.09-2.70; p = 0.02; I²  = 26%; number needed to treat of 9), for initial shockable rhythms only (55/164 [34%] vs. 38/165 [23%]; OR = 1.90; 95% CI, 1.16-3.13; p = 0.01; I²  = 23%; number needed to treat of 7), and at hospital discharge or 30 days (55/220 [25%] vs. 34/212 [16%]; OR = 1.82; 95% CI, 1.13-2.92; p = 0.01; I²  = 0.0%). Overall survival at the longest follow-up available was similar (61/220 [25%] vs. 34/212 [16%]; OR = 1.82; 95% CI, 1.13-2.92; p = 0.59; I²  = 58%).

CONCLUSIONS

Extracorporeal CPR compared with conventional CPR increased survival with favorable neurological outcome in adults with refractory out-of-hospital cardiac arrest, especially when the initial rhythm was shockable.

REVIEW REGISTRATION

PROSPERO CRD42023396482.

Prehospital Extracorporeal Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis

OBJECTIVES

To evaluate the available published evidence of the effects of extracorporeal cardiopulmonary resuscitation (ECPR) in the prehospital setting on clinical outcomes in patients with out-of-hospital cardiac arrest.

DESIGN

A systematic review and meta-analysis designed according to the Preferred Reporting Items for Systematic Reviews an Meta-Analyses guidelines.

SETTING

In the prehospital setting.

PARTICIPANTS

All randomized control trials (RCTs) and observational trials using pre-hospital ECPR in adult patients (>17 years).

INTERVENTIONS

Prehospital ECPR.

MEASUREMENTS AND MAIN RESULTS

The study authors searched Medline, Embase, and PUBMED for all RCTs and observational trials. The studies were assessed for clinical, methodologic, and statistical heterogeneity. The primary outcome was survival at hospital discharge. The study outcomes were aggregated using random-effects meta-analysis of means or proportions as appropriate. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the quality of evidence. Four studies were included, with a total of 222 patients receiving prehospital ECPR (mean age = 51 years [95% CI 44-57], 81% of patients were male (CI 74-87), and 60% patients had a cardiac cause for their arrest (95% CI 43-76). Overall survival at discharge was 23.4% (95% CI 15.5-33.7; I² = 62%). The pooled low-flow time was 61.1 minutes (95% CI 45.2-77.0; I² = 97%). The quality of evidence was assessed to be low, and the overall risk of bias was assessed to be serious, with confounding being the primary source of bias.

CONCLUSION

No definitive conclusions can be made as to the efficacy of prehospital ECPR in refractory cardiac arrest. Higher quality evidence is required.