Prognostic factors for mortality in out-of-hospital cardiorespiratory arrest

BACKGROUND AND OBJECTIVE: Our purpose was to determine the prognostic factors of mortality among patients with cardiorespiratory arrest (CRA) assisted by 061 emergency teams in Andalusia. PATIENTS AND METHOD: Retrospective observational study from January 1998 to December 1999 of 1950 cases of out-of-hospital CRA (OH-CRA) assisted by Andalusian 061 emergency teams (ETs). Independent (predictor) variables considered in the study were those defined in the Utstein style, after categorization. The dependent (outcome) variable was out-of-hospital mortality. A multivariate model was constructed using logistic regression to define the factors that, when considered together, predict mortality. The model was calibrated using the Hosmer-Lemeshow test. For the discrimination of the model, we calculated the area under the ROC curve. RESULTS: The incidence of OH-CRA was 27/100,000. Among our population of 1950 patients, 24.95% (483) were admitted alive to hospital and 75.05% (1444) died in the out-of hospital setting; 1393 patients were male and 552 were female. The mean age was 61.3 +/- 28.4 years. The model revealed the following mortality prognostic factors: personnel performing cadio-pulmonary resuscitation before ET arrival (healthcare/non-healthcare), presence of defibrillation, number of defibrillations, CRA site, general function categories before CRA, and cardiac massage within the first minute by ET. CONCLUSIONS: In order to reduce the CRA-induced mortality in our setting, defibrillation and cardiac massage by ETs must be done without delay. It is fundamental to achieve greater health awareness and education among both the general population and the healthcare workers involved in the survival chain.