Extracorporeal cardiopulmonary resuscitation (E-CPR) is the establishment of veno-arterial extracorporeal membrane oxygenation (ECMO) during ongoing cardiopulmonary resuscitation (CPR). E-CPR is the last rescue therapy when, despite high-quality conventional CPR, it is not possible to achieve the return of spontaneous circulation (ROSC) in patients with out-of-hospital cardiac arrest (OHCA). The probability of achieving ROSC and survival declines rapidly after ten minutes of resuscitation [1,2] and less than 1% of patients survive with a favorable neurological outcome after 35 minutes of conventional CPR [2]. In such situations, OHCA is considered refractory, and E-CPR recently demonstrated to improve outcomes among patients with favorable prognostic factors (e.g., young age, witnessed cardiac arrest, early bystander CPR and short no-flow time, signs of life, shockable rhythm).

In this issue of the Journal of Cardiothoracic and Vascular Anesthesia, Kruit and colleagues [6] report the results of a systematic review and meta-analysis investigating the effect of pre-hospital initiation of E-CPR on low-flow time (interval from CPR to ECMO initiation) and survival. A 2018 review identified that most evidence for pre-hospital E-CPR came from a small case series [7]. In their systematic review, Kruit and colleagues [6] included three new observational studies for a total of four studies and 222 patients treated with pre-hospital E-CPR [6]. Most patients come from a study conducted in a single EMS system in Paris [8], the first EMS system applying pre-hospital E-CPR since 2011.