Sub30: Protocol for the Sub30 feasibility study of a pre-hospital Extracorporeal membrane oxygenation (ECMO) capable advanced resuscitation team at achieving blood flow within 30 ​min in patients with refractory out-of-hospital cardiac arrest

Sub30: Feasibility study of a pre-hospital extracorporeal membrane oxygenation (ECMO) in patients with refractory out-of-hospital cardiac arrest in London, United Kingdom

AIM

Sub30 study is an open-label, prospective, single-arm feasibility study with the primary objective of assessing the logistics, feasibility, and safety of ECPR delivery in a pre-hospital setting for refractory out-of-hospital cardiac arrest patients in London, United Kingdom.

RESULTS

Forty-three eligible patients were identified by London Ambulance Service over 27 trial recruitment days during a 13-month study period resulting in the despatch of the pre-hospital ECPR team to 18 patients. Five patients met full criteria and were cannulated for ECPR. All patients were male with a median age of 61 years and received ECPR full flows at a mean of 47 min (range 37-59 min) from initial collapse after a median travel time to scene of 14 min (range 3-20 min). No patient met the primary outcome measure of being established on pre-hospital ECPR within 30 min of the call to the emergency services. Out of 5 patients, 3 patients had treatment withdrawn and 2 survived to hospital discharge (both CPC score 3 and modified Rankin Score (mRS) score 4 and 5 respectively).

METHODS

Open-label, single-arm, feasibility, prospective study.

CONCLUSIONS

Whilst our study did not meet primary outcome of achieving full ECPR flow within 30-minute of collapse, it demonstrated safe, timely and effective delivery of ECPR with comparable survival rates by pre-hospital teams in a large metropolitan city and this has potential to improve outcomes in refractory out-of-hospital cardiac arrest patients.

Extracorporeal Cardiopulmonary Resuscitation-Where Do We Currently Stand?

Extracorporeal cardiopulmonary resuscitation (eCPR) is a method of acute resuscitation for patients who have suffered a cardiac arrest through the utilization of an extracorporeal membrane oxygenation (ECMO) pump. The use and efficacy of eCPR is an active area of investigation with ongoing clinical investigation across the world. Since its inception, ECMO has been utilized for several conditions, but more recently, its efficacy in maintaining cerebrovascular perfusion in eCPR has generated interest in more widespread utilization, particularly in cases of out-of-hospital cardiac arrest. However, successful implementation of eCPR can be technically challenging and resource intensive and has been countered with ethical challenges beyond the scope of conventional in-hospital ECMO care. The aim of this review is to summarize the status of eCPR in the current era.

Pre-assembled ECMO: Enhancing efficiency and reducing stress in refractory cardiac arrest care

Aim

Extracorporeal cardiopulmonary resuscitation (ECPR) by veno-arterial extracorporeal membrane oxygenation (VA-ECMO) during refractory cardiac arrest presents significant medical and psychological challenges for healthcare providers. Beyond managing cardiac arrest and preparing for potential coronary angiography, the ECMO circuit must be assembled and primed under strictly sterile conditions, contributing to additional psychological stress and potential delays in ECMO cannulation. This pragmatic study thought to evaluate whether pre-assembled and pre-primed ECMO circuits (pre-primed group) maintain sterility over a 21-day period, expedite ECMO initiation in ECPR patients and alleviate the psychological burden on the ECPR team, compared to newly assembled and primed ECMO circuits (on-demand group).

Methods

In a prospective manner, ECMO circuits were either pre-assembled and pre-primed under sterile conditions, maintained for 21 days with culture samples taken every seventh day, or newly assembled and primed during the acute emergency situation. The transition from on-demand assembly and priming of ECMO circuits to pre-primed ECMO circuits occurred on January 1st, 2021. The interval between patients' arrival in the cardiac catheterization laboratory and the initiation of ECMO was recorded and retrospectively compared between the two treatment groups. The ECPR team, comprising experienced cardiologists and nurses, was prospectively surveyed using the modified Perceived Stress Questionnaire (PSQ-20).

Results

All aseptically pre-assembled and pre-primed ECMO circuits demonstrated sterile cultures for aerobic and anaerobic microorganisms as well as fungal agents over the 21-day period: 0/120 positive cultures (0 %, 95 % CI for binomial probability 0-0.03). The time to ECMO initiation was significantly reduced in the pre-primed group compared to the on-demand group: 13 [IQR 9-17] versus 31 [IQR 27-44] minutes, P < 0.001. Responses from ECPR physicians and nurses on the PSQ-20 were similar across all items. With the use of pre-primed ECMO circuits, all ECPR professionals reported a greater sense of settled inner feeling, considerably less psychological tension, fewer worries and insecurities, as well as more effective ICU shifts with improved personal goal achievement. However, treating ECPR patients with pre-primed ECMO circuits did not lead to increased job satisfaction or higher physical energy levels.

Conclusion

Aseptically pre-assembled and pre-primed ECMO circuits maintain sterility for multiple weeks, significantly reducing ECMO initiation times and alleviating psychological strain on the ECPR team. Consequently, implementing these circuits in ECPR centers could enhance both patient outcomes and healthcare provider well-being.

Clinicians' experience of barriers and facilitators to care delivery of an extracorporeal cardiopulmonary resuscitation service for out-of-hospital cardiac arrest: a qualitative survey

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) survival in the UK remains overall poor with fewer than 10% of patients surviving to hospital discharge. Extracorporeal cardiopulmonary resuscitation (ECPR) is a developing therapy option that can improve survival in select patients if treatment begins within an hour. Clinicians' perspectives are a pivotal consideration to the development of effective systems for OHCA ECPR, but they have been infrequently explored. This study investigates clinicians' views on the barriers and facilitators to establishing effective systems to facilitate transport of OHCA patients for in-hospital ECPR.

METHODS

In January 2023, Thames Valley Air Ambulance (TVAA) and Harefield Hospital developed an ECPR partnership pathway for conveyance of OHCA patients for in-hospital ECPR. The authors of this study conducted a survey of clinicians across both services looking to identify clear barriers and positive contributors to the effective implementation of the programme. The survey included questions about technical and non-technical barriers and facilitators, with free-text responses analysed thematically.

RESULTS

Responses were received from 14 pre-hospital TVAA critical care and 9 in-hospital clinicians' representative of various roles and experiences. Data analysis revealed 10 key themes and 19 subthemes. The interconnected themes, identified by pre-hospital TVAA critical care clinicians as important barriers or facilitators in this ECPR system included educational programmes; collectiveness in effort and culture; teamwork; inter-service communication; concurrent activity; and clarity of procedures. Themes from in-hospital clinicians' responses were distilled into key considerations focusing on learning and marginal gains, standardising and simplifying protocols, training and simulation; and nurturing effective teams.

CONCLUSION

This study identified several clear themes and subthemes from clinical experience that should be considered when developing and modelling an ECPR system for OHCA. These insights may inform future development of ECPR programmes for OHCA in other centres. Key recommendations identified include prioritising education and training (including regular simulations), standardising a 'pitstop style' handover process, establishing clear roles during the cannulation process and developing standardised protocols and selection criteria. This study also provides insight into the feasibility of using pre-hospital critical care teams for intra-arrest patient retrieval in the pre-hospital arena.

Novel and innovative resuscitation systems in Japan

Aim

Out-of-hospital cardiac arrest (OHCA) is a life-threatening emergency that requires rapid and efficient intervention. Recently, several novel approaches have emerged and have been incorporated into resuscitation systems in some local areas of Japan. This review describes innovative resuscitation systems and highlights their strengths.

Main text

First, we discuss the deployment of a physician-staffed ambulance, in which emergency physicians offer advanced resuscitation to patients with OHCA on site. In addition, we describe the experimental practice of extracorporeal membrane oxygenation (ECPR) in a prehospital setting. Second, we describe a physician-staffed helicopter, wherein a medical team provides advanced resuscitation at the scene. We also explain their initiative to provide early ECPR, even in remote areas. Finally, we provide an overview of the "hybrid ER" system which is a "one-fits-all" resuscitation bay equipped with computed tomography and fluoroscopy equipment. This system is expected to help swiftly identify and rule out irreversible causes of cardiac arrest, such as massive subarachnoid hemorrhage, and implement ECPR without delay.

Conclusion

Although these revolutionary approaches may improve the outcomes of patients with OHCA, evidence of their effectiveness remains limited. In addition, it is crucial to ensure cost-effectiveness and sustainability. We will continue to work diligently to assess the effectiveness of these systems and focus on the development of cost-effective and sustainable systems.

A review of pre-hospital extracorporeal cardiopulmonary resuscitation and its potential application in the North East of England

Patients in the UK who suffer an out-of-hospital cardiac arrest are treated with cardiopulmonary resuscitation in the pre-hospital environment. Current survival outcomes are low in out-of-hospital cardiac arrest. Extracorporeal cardiopulmonary resuscitation is a technique which is offered to patients in specialised centres which provides better blood flow and oxygen delivery than conventional chest compressions. Shortening the interval between cardiac arrest and restoration of circulation is associated with improved outcomes in extracorporeal cardiopulmonary resuscitation. Delivering extracorporeal cardiopulmonary resuscitation in the pre-hospital environment can shorten this interval, improving outcomes in out-of-hospital cardiac arrest. This article will review recently published studies and summarise studies currently being undertaken in pre-hospital extracorporeal cardiopulmonary resuscitation. It will also discuss the potential application of a pre-hospital extracorporeal cardiopulmonary resuscitation programme in the North East of England.

Expert consensus on training and accreditation for extracorporeal cardiopulmonary resuscitation an international, multidisciplinary modified Delphi Study

BACKGROUND

A multidisciplinary group of stakeholders were used to identify: (1) the core competencies of a training program required to perform in-hospital ECPR initiation (2) additional competencies required to perform pre-hospital ECPR initiation and; (3) the optimal training method and maintenance protocol for delivering an ECPR program.

METHODS

A modified Delphi process was undertaken utilising two web based survey rounds and one virtual meeting. Experts rated the importance of different aspects of ECPR training, competency and governance on a 9-point Likert scale. A diverse, representative group was targeted. Consensus was achieved when greater than 70% respondents rated a domain as critical (> or = 7 on the 9 point Likert scale).

RESULTS

35 international ECPR experts from 9 countries formed the expert panel, with a median number of 14 years of ECMO practice (interquartile range 11-38). Participant response rates were 97% (survey round one), 63% (virtual meeting) and 100% (survey round two). After the second round of the survey, 47 consensus statements were formed outlining a core set of competencies required for ECPR provision. We identified key elements required to safely train and perform ECPR including skill pre-requisites, surrogate skill identification, the importance of competency-based assessment over volume of practice and competency requirements for successful ECPR practice and skill maintenance.

CONCLUSIONS

We present a series of core competencies, training requirements and ongoing governance protocols to guide safe ECPR implementation. These findings can be used to develop training syllabus and guide minimum standards for competency as the growth of ECPR practitioners continues.

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.

Prehospital Ultrasound: Nationwide Incidence from the NEMSIS Database

OBJECTIVE

We sought to describe prehospital ultrasound (PHUS) use and trends in PHUS utilization over time using a national database.

METHODS

Using the 2018 - 2021 National Emergency Medical Services Information System databases, we identified those EMS activations where PHUS was performed. We evaluated the association between year and number of PHUS exams performed using univariable and multivariable regression analysis. Analysis was performed on the overall group and various subgroups.

RESULTS

In total, there were 148,709,000 EMS activations by 13,899 agencies over the 4 years. Of these, 3,291 unique activations (0.002%) involved PHUS, performed by 71 EMS agencies (0.5%). The annual rate of ultrasound evaluations per 1 million EMS activations significantly increased over the study period: 5.2 in 2018, 14.8 in 2019, 18.6 in 2020, and 38.9 in 2021 (p < 0.01). The number of agencies performing PHUS each year increased over the study period from 11 in 2018 to 54 in 2021 (p < 0.05). Each year after 2018 had an increased odds of PHUS use demonstrated with logistic regression (p < 0.01). PHUS was used in each US census region, and paramedics performed most of the PHUS exams (75.5%). We identified 1,060 out-of-hospital cardiac arrest, 820 trauma, and 427 respiratory PHUS cases. These three cohorts accounted for 70.1% of all PHUS cases.

CONCLUSION

Prehospital ultrasound use in the United States increased significantly over the study period, but remains exceedingly rare. The performance of PHUS was recorded throughout the United States, with paramedics performing the majority of PHUS studies included in this database.

ECPR Survivor Estimates: A Simulation-Based Approach to Comparing ECPR Delivery Strategies

Objective: The number of out-of-hospital cardiac arrest (OHCA) patients who may benefit from prehospital extracorporeal cardiopulmonary resuscitation (ECPR) is yet to be elucidated. Patient eligibility is determined both by case characteristics and physical proximity to an ECPR service. We applied accessibility principles to historical cardiac arrest data, to identify the number of patients who would have been eligible for prehospital ECPR in Sydney, Australia, and the potential survival benefit had prehospital ECPR been available.Methods: The New South Wales cardiac arrest registry between January 2017 to June 2021 included 39,387 cardiac arrests. We retrospectively defined two groups: 1) possible ECPR eligible arrests that would have triggered activation of a team, and 2) ECPR eligible arrests, those arrests that met ECPR inclusion criteria and remained refractory. Transport accessibility modeling was used to ascertain the number of arrests that would have been served by a hypothetical prehospital service and the potential survival benefit.Results: There were 699 arrests screened as possibly ECPR eligible in the Sydney metropolitan area, 488 of whom were subsequently confirmed as ECPR eligible refractory OHCA. Of these, 38% (n = 185) received intra-arrest transfer to hospital, with 37% (n = 180) arriving within 60 min. Using spatial and transport modeling, a prehospital team located at an optimal location could establish 437 (90%) patients onto ECMO within 60 min, with an estimated survival of 48% (IQR 38-57). Based on existing survival curves, compared to conventional CPR, an optimally located prehospital ECPR service has the potential to save one additional life for every 3.0 patients.Conclusions: A significant number of historical OHCA patients could have benefited from prehospital ECPR, with a potential survival benefit above conventional CPR.

What is the potential benefit of pre-hospital extracorporeal cardiopulmonary resuscitation for patients with an out-of-hospital cardiac arrest? A predictive modelling study

AIM

In this predictive modelling study we aimed to investigate how many patients with an out-of-hospital cardiac arrest (OHCA) would benefit from pre-hospital as opposed to in-hospital initiation of extracorporeal cardiopulmonary resuscitation (ECPR).

METHODS

A temporal spatial analysis of Utstein data was performed for all adult patients with a non-traumatic OHCA attended by three emergency medical services (EMS) covering the north of the Netherlands during a one-year period. Patients were considered potentially eligible for ECPR if they had a witnessed arrest with immediate bystander CPR, an initial shockable rhythm (or signs of life during resuscitation) and could be presented in an ECPR-centre within 45 minutes of the arrest. Endpoint of interest was defined as the hypothetical number of ECPR eligible patients after 10, 15 and 20 minutes of conventional CPR and upon (hypothetical) arrival in an ECPR-centre as a fraction of the total number of OHCA patients attended by EMS.

RESULTS

During the study period 622 OHCA patients were attended, of which 200 (32%) met ECPR eligibility criteria upon EMS arrival. The optimal transition point between conventional CPR and ECPR was found to be after 15 minutes. Hypothetical intra-arrest transport of all patients in whom no return of spontaneous circulation (ROSC) was obtained after that point (n=84) would have yielded 16/622 (2.5%) patients being potentially ECPR eligible upon hospital arrival (average low-flow time 52 minutes), whereas on-scene initiation of ECPR would have resulted in 84/622 (13.5%) potential candidates (average estimated low-flow time 24 minutes before cannulation).

CONCLUSION

Even in healthcare systems with relatively short transport distances to hospital, consideration should be given to pre-hospital initiation of ECPR for OHCA as it shortens low-flow time and increases the number of potentially eligible patients.

Left-ventricular unloading in extracorporeal cardiopulmonary resuscitation due to acute myocardial infarction - A multicenter study

BACKGROUND

Guidelines advocate the use of extracorporeal cardio-pulmonary resuscitation with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in selected patients with cardiac arrest. Effects of concomitant left-ventricular (LV) unloading with Impella® (ECMELLA) remain unclear. This is the first study to investigate whether treatment with ECMELLA was associated with improved outcomes in patients with refractory cardiac arrest caused by acute myocardial infarction (AMI).

METHODS

This study was approved by the local ethical committee. Patients treated with ECMELLA at three centers between 2016 and 2021 were propensity score (PS)-matched to patients receiving VA-ECMO based on age, electrocardiogram rhythm, cardiac arrest location and Survival After Veno-Arterial ECMO (SAVE) score. Cox proportional-hazard and Poisson regression models were used to analyse 30-day mortality rate (primary outcome), hospital and intensive care unit (ICU) length of stay (LOS) (secondary outcomes). Sensitivity analyses on patient demographics and cardiac arrest parameters were performed.

RESULTS

95 adult patients were included in this study, out of whom 34 pairs of patients were PS-matched. ECMELLA treatment was associated with decreased 30-day mortality risk (Hazard Ratio [HR] 0.53 [95% Confidence Interval (CI) 0.31-0.91], P = 0.021), prolonged hospital (Incidence Rate Ratio (IRR) 1.71 [95% CI 1.50-1.95], P < 0.001) and ICU LOS (IRR 1.81 [95% CI 1.57-2.08], P < 0.001). LV ejection fraction significantly improved until ICU discharge in the ECMELLA group. Especially patients with prolonged low-flow time and high initial lactate benefited from additional LV unloading.

CONCLUSIONS

LV unloading with Impella® concomitant to VA-ECMO therapy in patients with therapy-refractory cardiac arrest due to AMI was associated with improved patient outcomes.

Extracorporeal cardiopulmonary resuscitation for adult out-of-hospital cardiac arrest patients: time-dependent propensity score-sequential matching analysis from a nationwide population-based registry

BACKGROUND

There is inconclusive evidence regarding the effectiveness of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) patients. We aimed to evaluate the association between ECPR and neurologic recovery in OHCA patients using time-dependent propensity score matching analysis.

METHODS

Using a nationwide OHCA registry, adult medical OHCA patients who underwent CPR at the emergency department between 2013 and 2020 were included. The primary outcome was a good neurological recovery at discharge. Time-dependent propensity score matching was used to match patients who received ECPR to those at risk for ECPR within the same time interval. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated, and stratified analysis by the timing of ECPR was also performed.

RESULTS

Among 118,391 eligible patients, 484 received ECPR. After 1:4 time-dependent propensity score matching, 458 patients in the ECPR group and 1832 patients in the no ECPR group were included in the matched cohort. In the matched cohort, ECPR was not associated with good neurological recovery (10.3% in ECPR and 6.9% in no ECPR; RR [95% CI] 1.28 [0.85-1.93]). In the stratified analyses according to the timing of matching, ECPR with a pump-on within 45 min after emergency department arrival was associated with favourable neurological outcomes (RR [95% CI] 2.51 [1.33-4.75] in 1-30 min, 1.81 [1.11-2.93] in 31-45 min, 1.07 (0.56-2.04) in 46-60 min, and 0.45 (0.11-1.91) in over 60 min).

CONCLUSIONS

ECPR itself was not associated with good neurological recovery, but early ECPR was positively associated with good neurological recovery. Research on how to perform ECPR at an early stage and clinical trials to evaluate the effect of ECPR is warranted.

Improving access to extracorporeal membrane oxygenation for out of hospital cardiac arrest: pre-hospital ECPR and alternate delivery strategies

BACKGROUND

The use of extracorporeal membrane oxygenation (ECPR) in refractory out-of-hospital cardiac arrest (OHCA) patients is usually implemented in-hospital. As survival in ECPR patients is critically time-dependent, alternative models in ECPR delivery could improve equity of access.

OBJECTIVES

To identify the best strategy of ECPR delivery to provide optimal patient access, to examine the time-sensitivity of ECPR on predicted survival and to model potential survival benefits from different delivery strategies of ECPR.

METHODS

We used transport accessibility frameworks supported by comprehensive travel time data, population density data and empirical cardiac arrest time points to quantify the patient catchment areas of the existing in-hospital ECPR service and two alternative ECPR strategies: rendezvous strategy and pre-hospital ECPR in Sydney, Australia. Published survival rates at different time points to ECMO flow were applied to predict the potential survival benefit.

RESULTS

With an in-hospital ECPR strategy for refractory OHCA, five hospitals in Sydney (Australia) had an effective catchment of 811,091 potential patients. This increases to 2,175,096 under a rendezvous strategy and 3,851,727 under the optimal pre-hospital strategy. Assuming earlier provision of ECMO flow, expected survival for eligible arrests will increase by nearly 6% with the rendezvous strategy and approximately 26% with pre-hospital ECPR when compared to the existing in-hospital strategy.

CONCLUSION

In-hospital ECPR provides the least equitable access to ECPR. Rendezvous and pre-hospital ECPR models substantially increased the catchment of eligible OHCA patients. Traffic and spatial modelling may provide a mechanism to design appropriate ECPR service delivery strategies and should be tested through clinical trials.

British Cardiovascular Interventional Society Consensus Position Statement on Out-of-Hospital Cardiac Arrest 1: Pathway of Care

Out-of-hospital cardiac arrest (OHCA) affects 80,000 patients per year in the UK; despite improvements in care, survival to discharge remains lower than 10%. NHS England and several societies recommend all resuscitated OHCA patients be directly transferred to a cardiac arrest centre (CAC). However, evidence is limited that all patients benefit from transfer to a CAC, and there are significant organisational, logistic and financial implications associated with such change in policies. Furthermore, there is significant variability in interventional cardiovascular practices for OHCA. Accordingly, the British Cardiovascular Interventional Society established a multidisciplinary group to address variability in practice and provide recommendations for the development of cardiac networks. In this position statement, we recommend: the formal establishment of dedicated CACs; a pathway of conveyance to CACs; and interventional practice to standardise our approach. Further research is needed to understand the role of CACs and which interventions benefit patients with OHCA to support wide-scale changes in networks of care across the UK.

Case report: Refractory cardiac arrest supported with veno-arterial-venous extracorporeal membrane oxygenation and left-ventricular Impella CP®-Physiological insights and pitfalls of ECMELLA

INTRODUCTION

To the best of our knowledge, this is the first case report which provides insights into patient-specific hemodynamics during veno-arterio-venous-extracorporeal membrane oxygenation (VAV ECMO) combined with a left-ventricular (LV) Impella® micro-axial pump for therapy-refractory cardiac arrest due to acute myocardial infarction, complicated by acute lung injury (ALI).

PATIENT PRESENTATION

A 54-year-old male patient presented with ST-segment elevation acute coronary syndrome complicated by out-of-hospital cardiac arrest with ventricular fibrillation upon arrival of the emergency medical service. As cardiac arrest was refractory to advanced cardiac life support, the patient was transferred to the Cardiac Arrest Center for immediate initiation of extracorporeal cardiopulmonary resuscitation (ECPR) with peripheral VA ECMO and emergency percutaneous coronary intervention using drug eluting stents in the right coronary artery. Due to LV distension and persistent asystole after coronary revascularization, an Impella® pump was inserted for LV unloading and additional hemodynamic support (i.e., "ECMELLA"). Despite successful unloading by ECMELLA, post-cardiac arrest treatment was further complicated by sudden differential hypoxemia of the upper body. This so called "Harlequin phenomenon" was explained by a new onset of ALI, necessitating escalation of VA ECMO to VAV ECMO, while maintaining Impella® support. Comprehensive monitoring as derived from the Impella® console allowed to illustrate patient-specific hemodynamics of cardiac unloading. Ultimately, the patient recovered and was discharged from the hospital 28 days after admission. 12 months after the index event the patient was enrolled in the ECPR Outpatient Care Program which revealed good recovery of neurologic functions while physical exercise capacities were impaired.

CONCLUSION

A combined mechanical circulatory support strategy may successfully be deployed in complex cases of severe cardio-circulatory and respiratory failure as occasionally encountered in clinical practice. While appreciating potential clinical benefits, it seems of utmost importance to closely monitor the physiological effects and related complications of such a multimodal approach to reach the most favorable outcome as illustrated in this case.