Modelling eCPR eligibility after out-of-hospital cardiac arrest: a 10-year retrospective temporospatial analysis from a mixed urban-rural region in Germany

Abstract

Abstract Background Survival with good neurological function after out-of-hospital cardiac arrest (OHCA) remains low. Extracorporeal cardiopulmonary resuscitation (eCPR) may benefit selected patients, but it is unclear how many patients in a mixed urban-rural European region would be eligible, whether regional case volumes justify dedicated eCPR programmes, and whether an in-hospital strategy after intra-arrest transport can meet a 60-minute low-flow target. Methods We conducted a retrospective cohort study of OHCA cases in the city and county of Göttingen, Germany (January 2015–February 2025). eCPR eligibility was assessed using a local protocol and a stricter modified ELSO definition. Eligibility was first determined at emergency medical services (EMS) arrival and then re-evaluated for three hypothetical intra-arrest transport strategies in which transport was initiated after 10, 15, or 20 minutes of on-scene conventional cardiopulmonary resuscitation (cCPR). Scene-to-hospital travel times were modelled and patients were classified according to whether they would be eligible for eCPR upon hospital arrival. A complementary analysis estimated time from collapse to hypothetical eCPR initiation under an on-scene scenario, split into simultaneous dispatch of a dedicated eCPR team (S1a) and delayed dispatch after 10 minutes of on-scene evaluation by the primary EMS team (S1b), and an in-hospital scenario following intra-arrest transport (S2), incorporating documented timing of sustained return of spontaneous circulation (ROSC). Results Of 2,218 OHCA cases, 1,696 registry-documented patients were analysed (median age 71.5 years; 67.5% male; shockable rhythm 20.5%). At EMS arrival, 348 patients (20.5%) met local and 149 (8.8%) modified ELSO criteria. With transport initiated after 10/15/20 minutes of on-scene cCPR, 11.1%/9.8%/8.8% (local) and 3.8%/3.1%/2.8% (modified ELSO) would have been eligible at hospital arrival. Extrapolated regional case volume was approximately 46 (local) and 20 (modified ELSO) eligible patients per year at EMS arrival. In patients who met local eCPR criteria the number of patients with sustained ROSC exceeded those without at 13.4 minutes after EMS arrival. Median estimated time from collapse to eCPR was 37 minutes under S1a (94.8% within 60 minutes) and 54 minutes under S1b (71.6% within 60 minutes) versus 75 minutes under S2 (<1% within 60 minutes). After excluding patients with ROSC before hypothetical eCPR initiation, 47.4% (S1a) and 31.6% (S1b) in the local cohort and 36.9% (S1a) and 24.8% (S1b) in the modified ELSO cohort would both still have required and could have received on-scene eCPR within 60 minutes. Conclusions A substantial number of OHCA patients in our region met eCPR eligibility criteria, but hospital arrival did not equate to eCPR initiation. Given realistic procedural time intervals, in-hospital eCPR following intra-arrest transport rarely met the 60-minute target, whereas on-scene eCPR might have remained feasible for most eligible patients.