This study examines the impact of emergency department (ED) management on short-term outcomes of nontraumatic adult out-of-hospital cardiac arrest (OHCA) patients. Conducted by a research team at National Taiwan University Hospital and its affiliated hospitals, including branches in Hsinchu and Yunlin, the study spans from January 2016 to August 2023. It focuses on a sequential population of patients, analyzing data like age, gender, medical history, prehospital care details (e.g., witnessed collapse, bystander CPR), and specifics of ED management. OHCA, with an incidence rate of 50-100 per 100,000 people, presents high mortality and severe complications, leading to significant healthcare expenditures. After resuscitation in the ED, only about one-fifth of patients achieve return of spontaneous circulation (ROSC). The prognosis for these patients remains grim, with a mere 5% experiencing favorable neurological outcomes. Understanding the mechanisms of OHCA, identifying risk factors, effective interventions, and the timing of ED treatments like vasopressors and electrocardiography are crucial. Patients post-OHCA often undergo a postcardiac arrest syndrome (PCAS), marked by cellular hypoxia and a consequential inflammatory response. Stability of vital signs and rapid ED interventions, including identifying OHCA causes and coordinating with specialists, are vital for short-term recovery. This study aims to determine if ED management and time-related factors from ROSC to various interventions (e.g., ECG, CT scans) affect short-term survival rates, including survival to hospital admission and survival after 1, 3, and 7 days. By retrospectively analyzing patient data, including Utstein Style prehospital cardiac arrest registry variables and emergency department management details, the study seeks to shed light on the crucial phase of post-resuscitation care. The ultimate goal is to improve survival rates and neurological outcomes in OHCA patients, emphasizing the need for more comprehensive research in this area