Outcomes of patients with refractory out-of-hospital cardiac arrest transported to an ECMO centre compared with transport to non-ECMO 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.

A randomized trial of expedited intra-arrest transfer versus more extended on-scene resuscitation for refractory out of hospital cardiac arrest: Rationale and design of the EVIDENCE trial

BACKGROUND

Refractory Out of Hospital Cardiac Arrest (r-OHCA) is common and the benefit versus harm of intra-arrest transport of patients to hospital is not clear.

OBJECTIVE

To assess the rate of survival to hospital discharge in adult patients with r-OHCA, initial rhythm pulseless ventricular tachycardia (VT)/ventricular fibrillation (VF) or Pulseless Electrical Activity (PEA) treated with 1 of 2 locally accepted standards of care:1 expedited transport from scene; or2 ongoing advanced life support (ALS) resuscitation on-scene.

HYPOTHESIS

We hypothesize that expedited transport from scene in r-OHCA improves survival with favorable neurological status/outcome.

METHODS/DESIGN

Phase III, multi-center, partially blinded, prospective, intention-to-treat, safety and efficacy clinical trial with contemporaneous registry of patient ineligible for the clinical trial. Eligible patients for inclusion are adults with witnessed r-OHCA; estimated age 18 to 70, assumed medical cause with immediate bystander cardiopulmonary resuscitation (CPR); initial rhythm of VF/pulseless VT, or PEA; no return of spontaneous circulation following 3 shocks and/or 15 minutes of professional on-scene resuscitation; with mechanical CPR available. Two hundred patients will be randomized in a 1:1 ratio to either expedited transport from scene or ongoing ALS at the scene of cardiac arrest.

SETTING

Two urban regions in NSW Australia.

OUTCOMES

Primary: survival to hospital discharge with cerebral performance category (CPC) 1 or 2. Secondary: safety, survival, prognostic factors, use of ECMO supported CPR and functional assessment at hospital discharge and 4 weeks and 6 months, quality of life, healthcare use and cost-effectiveness.

CONCLUSIONS

The EVIDENCE trial will determine the potential risks and benefits of an expedited transport from scene of cardiac arrest.

Pre-hospital ECPR in an Australian metropolitan setting: a single-arm feasibility assessment-The CPR, pre-hospital ECPR and early reperfusion (CHEER3) study

INTRODUCTION

Survival from refractory out of hospital cardiac arrest (OHCA) without timely return of spontaneous circulation (ROSC) utilising conventional advanced cardiac life support (ACLS) therapies is dismal. CHEER3 was a safety and feasibility study of pre-hospital deployed extracorporeal membrane oxygenation (ECMO) during cardiopulmonary resuscitation (ECPR) for refractory OHCA in metropolitan Australia.

METHODS

This was a single jurisdiction, single-arm feasibility study. Physicians, with pre-existing ECMO expertise, responded to witnessed OHCA, age < 65 yrs, within 30 min driving-time, using an ECMO equipped rapid response vehicle. If pre-hospital ECPR was undertaken, patients were transported to hospital for investigations and therapies including emergent coronary catheterisation, and standard intensive care (ICU) therapy until either cardiac and neurological recovery or palliation occurred. Analyses were descriptive.

RESULTS

From February 2020 to May 2023, over 117 days, the team responded to 709 "potential cardiac arrest" emergency calls. 358 were confirmed OHCA. Time from emergency call to scene arrival was 27 min (15-37 min). 10 patients fulfilled the pre-defined inclusion criteria and all were successfully cannulated on scene. Time from emergency call to ECMO initiation was 50 min (35-62 min). Time from decision to ECMO support was 16 min (11-26 min). CPR duration was 46 min (32-62 min). All 10 patients were transferred to hospital for investigations and therapy. 4 patients (40%) survived to hospital discharge neurologically intact (CPC 1/2).

CONCLUSION

Pre-hospital ECPR was feasible, using an experienced ECMO team from a single-centre. Overall survival was promising in this highly selected group. Further prospective studies are now warranted.