Factors predicting survival of out-of-hospital cardiac arrest managed with semiautomatic external defibrillators in Galicia

Objectives. To determine prognostic factors in out-of-hospital cardiac arrests managed with semiautomatic external defibrillators (SAEDs) by emergency health service responders in Galicia, Spain. Method. Retrospective descriptive study of out-of-hospital cardiac arrests treated with SAEDs over a period of 5 years. We collected Utstein outcome data from the database and analyzed the following variables: sex, age, date and time of cardiac event, rural vs urban setting, type of location, witnessed or not, bystander resuscitation attempts or not, time first heart rhythm was detected, use of orotracheal intubation or not, time of call for help, and time to arrival of emergency responders. Results. We analyzed 2005 cases (0.14/1000 person-years; 68.2% male, 70.8% in rural locations, 61% at home). Return of spontaneous circulation (ROSC) was achieved in situ in 10.9% (in 29.9% of patients with shockable rhythms and in 3.3% of those in asystole). Intubation was necessary in 15.7%; ROSC was achieved in 24.8% of the intubated patients. ROSC was achieved in significantly more patients when responders arrived soon after the call for help (mean: 12 minutes, 26 seconds) than when arrival was delayed (mean: 16 minutes, 16 seconds when ROSC was not achieved; P<.001). The presence of a shockable rhythm was also significantly more frequent when response time was faster (P<.001). Asystole, on the other hand, reduced the likelihood of survival (P<.005). Conclusion. Prognostic factors related to survival of SAED-managed out-of-hospital cardiac arrest in Galicia were the presence of a shockable rhythm, shorter response time, continuation of basic life support measures including advanced airway management, bystander life-support maneuvers, an urban location, and night timing of the arrest.