Out-of-Hospital Cardiac Arrest in the Eye of the Beholder and Emergency Medical Service.

Purpose:Out-of-hospital cardiac arrest (OHCA) remains a global healthcare problem, with low survival and bystander cardiopulmonary resuscitation (CPR) rates. This study aimed to identify event-related factors in OHCA and their impact on return of spontaneous circulation (ROSC) achievement and maintenance until hospital admission. Patients and Methods:All data were collected from Utstein Resuscitation Registry Template for OHCA from The Institute of Emergency Medicine of Zagreb from January 2012 to August 2022. This cross-sectional research analyzed 2839 Utstein reports, including 2001 male, 836 female, and 8 subjects of unknown gender. The average age was 65.4 ± 16.2 years. Results:The most frequent place of collapse was private residence, and 27% of collapses were unwitnessed. Dispatcher-provided CPR instructions were provided in 39.7% of cases until the arrival of the emergency service team, which showed a very strong effect on bystander-provided CPR, and were followed in 68.4% of cases, while non-instructed bystander CPR was provided in only 7.9% of cases. Bystander CPR is more likely to be provided in public places than in private residences, often with both compression and ventilation. Bystander CPR was also more likely to be provided to men. Cases with bystander CPR, and compressions with ventilation compared to compression only CPR, showed a significantly greater success in maintaining ROSC later in CPR, both with moderate effects. Conclusion:Bystander CPR has been shown to have a significant role in achieving and maintaining ROSC until hospital admission. However, our results showed a location-dependent nature of bystanders' willingness to perform CPR as well as sex disparities in patients receiving CPR. With deficient education in basic life support in Croatia, dispatchers need to insist on and instruct bystander CPR performance.