Fig. 1

Low-flow in ECPR. Time under resuscitation (low-flow) observed in randomized controlled trials (RCTs) are given. Three RCTs examined the role of extracorporeal cardiopulmonary resuscitation (ECPR) in patients following out-of-hospital cardiac arrest (OHCA). Time plays a crucial role in ECPR, as prognosis strongly correlates negatively with low-flow duration. The three primary intervals in refractory OHCA—time spent on the scene, during transportation, and for cannulation for ECMO—are presented. Delays not attributed to one of these three main aspects of ECPR (time on scene, transportation, and cannulation) are not shown. It is worth noting that the 'Arrest' [30] and 'Prague OHCA' [29] trials both were single-center trials, while the 'Inception' [12] trial was multi-centered