[Epidemiological characteristics of out-of-hospital cardiorespiratory arrest recorded by the 061 emergencies system (SAMU) in the Balearic Islands (Spain), 2009-2012]

Objective: To describe the epidemiology of out-of-hospital cardiorespiratory arrest (OHCA) and identify factors associated with recovery of spontaneous circulation (ROSC).

Design: Observational study of OHCA registered on a continuous basis in the Emergency Medical Services (EMS) database during 2009-2012.

Setting: The islands of Mallorca, Ibiza, Menorca and Formentera (Balearic Islands, Spain).

Patients: OHCA in patients ≥ 18 years of age. The main variables were: Patient sex, age, probable cause, place of arrest, bystander, witnessed, basic life support (BLS), shockable rhythm, intervention time, semi-automatic defibrillator (AED), duration of cardiopulmonary arrest (CA), and ROSC. Independent variables were defined according to the Utstein protocol, and the dependent variable was defined as ROSC.

Results: The EMS treated 1170 OHCAs (28/100,000 persons-year). We included 1130 CA. The mean age was 61.4 years (73.4% males). Most CA (72.3%) were of cardiac etiology, and 84.7% were witnessed. A total of 840 (74.3%) received BLS and 400 (47.6%) did so before arrival of the EMS (45 by bystander relatives). AED was available in 330 cases CA (29.2%) (96 with shockable rhythm). The interval between emergency call and BLS and between emergency call and advanced life support was 8.4 and 15.8min, respectively. Shockable rhythm was monitored in 257 CAs (22.7%). ROSC occurred in 261 (23.1%). Factors associated with ROSC were age, shockable rhythm, BLS before EMS arrival, and CA duration less than 30min.

Conclusion: The incidence rate of the OHCA is low. The proportion of patients receiving BLS from relatives was low. Age, shockable rhythm and BSL before EMS arrival were associated with ROSC.