Determining Access for a City-Wide Extracorporeal Cardiopulmonary Resuscitation (ECPR) Initiative Using Geospatial Analysis.

backgroundIn select situations, patients experiencing out-of-hospital cardiac arrest (OHCA) may be candidates for extracorporeal cardiopulmonary resuscitation (ECPR). Eligibility criteria for ECPR typically include a maximum time (usually 30 min) from arrest to arrival at an ECPR-capable center, which may exclude populations based on geographic factors.

methodsUsing geospatial modeling, we calculated drive times to ECPR-capable hospitals in Boston utilizing census block group centroid coordinates as proxy sites for OHCA locations. We used a fixed dispatch-to-scene arrival time of 7.4 min, extrapolated from Boston EMS median transport time data. We set conditions at the 50th (24 min), 25th (18 min), and 10th (13 min) percentiles for EMS on-scene time and, for each condition, determined access to ECPR with an arrest to arrival criterion of less than 30 min. We analyzed the effect of high- versus low-traffic conditions and then derived the arrest to arrival time necessary to achieve access for 90% of the city.

resultsThe entire City of Boston was excluded from ECPR with median times and current eligibility criteria. Decreasing time-on-scene to the 25th percentile led to increased access: 16% of block groups with low traffic and 6% of block groups with high traffic. At the 10th percentile for time-on-scene, 55% of block groups had access with low traffic and 28% had access with high traffic. To achieve access for 90% of the city under high-traffic conditions at the 50th percentile for time-on-scene, the criterion for arrest to arrival would need to be extended to 55.8 min.

conclusionsThe current arrest to arrival criterion for ECPR excludes the entire City of Boston using median transportation and on-scene times. Increasing access to ECPR should include efforts to decrease prehospital duration, such as minimizing time-on-scene for potential OHCA cases. Future study should examine potential levers to improve access, such as novel prehospital ECPR delivery models, air-based transport, and liberalized arrest to arrival criteria.