Factors associated with mortality in out-of-hospital cardiac arrests attended in basic life support units in the Basque Country (Spain).

INTRODUCTION AND OBJECTIVES To describe the epidemiological characteristics of cardiac arrests attended in basic life support units in the Basque Country (Spain) and look for factors associated with failure of cardiopulmonary resuscitation. METHODS We conducted an observational study during 18 months, including all out-of-hospital cardiopulmonary resuscitation provided by basic life support units. The variables defined in the Utstein-style were considered as independent and mortality as the dependent variable. We applied descriptive and analytical statistics and evaluated the magnitude of the association using a logistic regression model, which included variables with P<.05 in the bivariate analysis. RESULTS Of 1050 cardiac arrests attended, 15.7% of patients were revived in situ. The presumed etiology was cardiac in 55.3% of cases and 71.4% occurred at home. Cardiopulmonary resuscitation was started before the arrival of the ambulance in 22.9% of cases and in 18.2% the rhythm of presentation was shockable. Variables associated with lower mortality were: shockable rhythms (relative risk=0.44; P=.003), patient aged<65 years (relative risk=0.44; P=.002), time to cardiopulmonary resuscitation<8 min (relative risk=0.56; P=.039), and out-of-home events (relative risk=0.55; P=.031). CONCLUSIONS Cardiac arrest survival was low. Cardiopulmonary resuscitation before the arrival of the ambulance was rare. A shockable rhythm, age younger than 65 years, early cardiopulmonary resuscitation efforts, and a location away from home were associated with longer survival. It is necessary to develop strategies designed to reduce ambulance response time and educate the public in basic resuscitation.