Late-Breaking Clinical Trial Abstracts.

Abstract

Background: Cities around the world have underground or above-ground enclosed networks for pedestrian travel, representing unique environments for studying out-of-hospital cardiac arrest (OHCA) and resuscitation. The characteristics of OHCAs that occur in such networks are unknown. Objective: To determine whether cardiac arrests occurring in enclosed pedestrian networks are different from those in the encompassing city, using the PATH network in Toronto, the largest underground shopping complex in the world, as a model site. Methods: We identified all atraumatic, public-location OHCAs in Toronto from Apr. 2006 – Mar. 2015, and classified them according to location: Toronto, downtown, and PATH-accessible. PATH-accessible OHCAs are those that occur within the PATH network between the first underground and second above-ground floor. We collected demographic, prehospital intervention, and survival data for each OHCA. Statistical analysis was performed using t-tests and chi-squared tests. Results: We identified 2621 atraumatic public OHCAs, of which 521 were in downtown and 50 were PATH-accessible. Compared to Toronto overall, PATH-accessible OHCAs had significantly higher proportions of bystander witnessed interventions, initial shockable rhythm, and overall survival, with all differences being statistically significant. Similar significant differences were observed when comparing PATH-accessible to downtown OHCAs. There were no significant differences in demographics and survival among patients with initial shockable rhythm. Conclusion: This study suggests that OHCAs in enclosed pedestrian networks are uniquely different from other public settings. Bystander resuscitation efforts are significantly more frequent and survival rates are higher. Urban planners in similar networks worldwide should consider these findings when deciding on AED placement and how to cue bystander response.