Purpose of the study: The aim of the study was to estimate the incidence and the outcome of out-of-hospital cardiac arrest (OHCA) in Ljubljana after the implementation of 2015 European Resuscitation Council guidelines and to identify the factors influencing the OHCA outcome.
Materials and methods: Data of all patients with OHCA in Ljubljana in the period 2016-2018 were retrospectively recorded according to the Utstein style. Regarding statistical methods, descriptive statistics and multivariate logistic regression were used.
Results: Between 1 January 2016 and 31 December 2018 cardiac arrest was confirmed in 958 patients. Cardiopulmonary resuscitation was attempted in 557 patients. Of those, in 430 (77.2%) cases the OHCA were witnessed, and in 344 (61.8%) cases basic life support was performed. Defibrillation with an automated external defibrillator was performed in 53 (9.5%) patients before the emergency medical service (EMS) arrived. Later, 77 (13.8%) patients survived to discharge from hospital. At the time of discharge 61 (10.9%) patients had cerebral performance category 1 or 2. 
321 cases of OHCA were adults with primary cardiac arrest.  In this group, 56 (17.4%) patients survived to discharge from hospital. At the time of discharge 50 (15.6%) of these patients had cerebral performance category 1 or 2. 
Factors influencing the survival after OHCA were: arrival time (p˂0.001), witnessed arrest (p=0.002), defibrillation before the arrival of the EMS (p=0.033) and the onset of cooling in the field (p=0.027).
Conclusion: In the studied population, 77 (13.8%) patients having suffered OHCA survived to discharge from hospital and 61 (10.9%) had favourable functional outcome. Arrival time of EMS, witnessed arrest, defibrillation before the arrival of EMS and onset of cooling in the field had influence on survival after OHCA.

7 - Out-of-hospital cardiac arrest in Ljubljana: Utstein style and factors influencing the outcome after implementation of the ERC Resuscitation Guidelines 2015