The Minnesota Mobile Resuscitation Consortium ECMO truck: a feasibility study for ECPR in refractory out-of-hospital cardiac arrest

Abstract

Background: Refractory ventricular fibrillation/ventricular tachycardia (VF/VT) out-of-hospital cardiac arrest (OHCA) carries poor survival with conventional resuscitation. Extracorporeal cardiopulmonary resuscitation (ECPR) improves outcomes in selected patients; however, time to reperfusion is the dominant determinant of neurologically intact survival, and geographic distance excludes many otherwise eligible patients.

Research question/hypothesis: We hypothesized that a purpose-built, fluoroscopy-enabled mobile ECMO truck delivering scene-based ECPR would be feasible and achieve neurologically favorable survival comparable to a mature in-hospital ECPR system when matched on low-flow time.

Goals/aims: To evaluate the feasibility, procedural performance, and clinical outcomes of a sustained prehospital ECPR program integrated within a regional cardiac arrest system of care.

Methods: We performed a single-center retrospective analysis of a prospectively collected registry within the Minnesota Mobile Resuscitation Consortium. Adults (18-75 years) with refractory VF/VT OHCA treated under the ECMO truck protocol were compared with a matched cohort treated under the standard in-hospital ECPR pathway, matched on low-flow time. Baseline characteristics, laboratory values, time intervals, cannulation metrics, and outcomes were compared. The primary outcome was survival to hospital discharge with a favorable neurological status.

Results: A total of eight patients underwent ECMO truck activation and were matched to eight in-hospital controls. Baseline characteristics were similar between groups. Total low-flow time was 74.8 [standard deviation (SD) 19.8] min in the ECMO truck group and 73.0 (SD 22.9) min in controls (p = 0.87). Needle-stick-to-ECMO flow times were 7.5 (SD 3.1) min versus 12.0 (SD 10.8) min, respectively (p = 0.71). Neurologically favorable survival was 25% in the ECMO truck cohort versus 25% in matched controls (p ≥ 0.99).

Conclusions: A sustained, protocolized prehospital ECPR program using a purpose-built ECMO truck is feasible and achieves outcomes comparable to an established in-hospital ECPR system when matched on low-flow time. This single-center feasibility study demonstrates that a mobile ECPR program using a purpose-built Mobile ECMO Truck can be implemented safely and with acceptable procedural performance.

Keywords: Extracorporeal cardiopulmonary resuscitation; Mobile ECMO truck; Out-of-hospital cardiac arrest; Prehospital ECPR.