Large urban center improves out-of-hospital cardiac arrest survival.

Background: Large cities pose unique challenges that limit the effectiveness of system improvement interventions. Successful implementation of integrated cardiac resuscitation systems of care can serve as a model for other urban centers.

Methods: This was a retrospective analysis of prospectively collected data of adult cases of non-traumatic cardiac arrest who received treatment by Chicago Fire Department EMS from September 1, 2013 through December 31, 2016. We measured temporal OHCA outcomes during implementation of system-wide initiatives including telephone-assisted and community CPR training programs; high performance CPR and team based simulation training; new post resuscitation care and destination protocols; and case review for EMS providers. Outcomes measured included bystander CPR rates, return of spontaneous circulation (ROSC), hospital admission and survival, and favorable neurologic outcomes (CPC 1-2). Relative risk was determined by logistic regression model where observed group-specific outcomes are expressed as odds ratios (OR).

Results: We included 6103 adult OHCA cases occurring outside of health care facilities from September 1, 2013 through December 31, 2016. Significantly improved outcomes (p < 0.05) were observed between 2013 and 2016 for bystander CPR (11.6% vs 19.4%), ROSC (28.6% vs 36.9%), hospital admission (22.5% vs 29.4%), survival (7.3% vs 9.9%), and CPC 1-2 (4.3% vs 6.4%). Utstein survival increased from 16.3%-35.4% and CPC 1-2 survival from 11.6%-29.1% (p < 0.05). After adjustment for OHCA characteristics, survival with CPC 1-2 increased over time (OR 1.15, p = 0.0277).

Conclusions: Densely populated cities with low survival rates can overcome systematic challenges and improve OHCA survival.