Comparing strategies for prehospital transport to specialty care after cardiac arrest.

Unlabelled: Outcomes are better when patients resuscitated from out-of-hospital cardiac arrest (OHCA) are treated at specialty centers. The best strategy to transport patients from the scene of resuscitation to specialty care is unknown.

Methods: We performed a retrospective cohort study. We identified patients treated at a single specialty center after OHCA from 2010 to 2021 and used OHCA geolocations to develop a catchment area using a convex hull. Within this area, we identified short term acute care hospitals, OHCA receiving centers, adult population by census block group, and helicopter landing zones. We determined population-level times to specialty care via: (1) direct ground transport; (2) transport to the nearest hospital followed by air interfacility transfer; and (3) ground transport to air ambulance. We used an instrumental variable (IV) adjusted probit regression to estimate the causal effect of transport strategy on functionally favorable survival to hospital discharge.

Results: Direct transport to specialty care by ground to air ambulance had the shortest population-level times from OHCA to specialty care (median 56 [IQR 47-66] minutes). There were 1,861 patients included in IV regression of whom 395 (21%) had functionally favorable survival. Most (n = 1,221, 66%) were transported to the nearest hospital by ground EMS then to specialty care by air. Patient outcomes did not differ across transport strategies in our IV analysis.

Discussion: We did not find strong evidence in favor of a particular strategy for transport to specialty care after OHCA. Population level time to specialty care was shortest with ground ambulance transport to the nearest helicopter landing zone.