Impact of dual dispatch system implementation on response times and survival outcomes in out-of-hospital cardiac arrest in rural areas

Objectives: Dual dispatch early defibrillation in out-of-hospital cardiac arrest (OHCA) victims provided by firefighters in addition to Emergency medical services (EMS) has proven to increase rate of return of spontaneous circulation (ROSC) and thus survival in the metropolitan or suburban areas whereas the data in rural areas are scarce. Methods: This was a retrospective observational cohort study of EMS resuscitated OHCA victims in regions with dual dispatch of volunteer firefighters as first responders (intervention group). Historical group was based on all OHCAs occurring in these regions before the implementation of first responders (EMS response only). Multivariate logistic regression with following variables: intervention, age, gender, witnessed status, bystander cardiopulmonary resuscitation (CPR), first rhythm and etiology were used to control for confounding factors affecting ROSC. Results: A total of 312 OHCAs were included in the study (historical group, n = 115 and intervention group, n = 197). Median time to arrival of first help shortened significantly for all patients, patients with ROSC and patients with Cerebral Performance Category 1/2 (CPC 1/2) in intervention vs historical group (8 vs 12 min, p < 0.001; 7.5 vs 11 min, p = 0.002; 7 vs 10 min, p = 0.011; respectively). The proportion of patients with ROSC, 30-day survival and CPC 1/2 at hospital discharge remained unchanged in intervention vs historical group (21% vs 23%, p = 0.808; 7% vs 6%, p = 0.914; 6% vs 3%, p = 0.442; respectively). The logistic regression model of adjustment confirms the absence of improvement in the ROSC rate after the implementation of first responders. Conclusions: Introduction of a dual dispatch of local first responders in addition to EMS in cases of OHCA significantly shortened response times. However, reduced response times were not associated with better survival outcomes.