Tehran University of Medical Sciences Frontiers in Emergency Medicine 2717-3593 7 3 2023 09 25 e27 e27 Ersin Kırış Department of Emergency Medicine, Ankara Etlik City Hospital, Ankara, Turkey Gülşah Çıkrıkçı Işık Department of Emergency Medicine, Ankara Atatürk Sanatoryum Training and Research Hospital, University of Health Sciences, Ankara, Turkey Fatma Karaarslan Department of Emergency Medicine, Ankara Atatürk Sanatoryum Training and Research Hospital, University of Health Sciences, Ankara, Turkey Şeref Çorbacıoğlu Department of Emergency Medicine, Ankara Atatürk Sanatoryum Training and Research Hospital, University of Health Sciences, Ankara, Turkey Emine Emektar Department of Emergency Medicine, Ankara Atatürk Sanatoryum Training and Research Hospital, University of Health Sciences, Ankara, Turkey Yunsur Çevik Department of Emergency Medicine, Ankara Atatürk Sanatoryum Training and Research Hospital, University of Health Sciences, Ankara, Turkey 2023 05 24 2023 08 26 Objective: Aim of this study was to examine immature granulocyte/total granulocyte (IG/TG) ratio for prediction of return of spontaneous circulation (ROSC) and early mortality in post cardiac arrest survivors. Methods: The study was carried out prospectively between January 2021 and January 2022. Non-traumatic out-of-hospital cardiac arrest (OHCA), over the age of 18 and non-pregnant were included. Patients’ whose IG levels were not studied, with hematological disease and who receiving immunosuppressive therapy were excluded. A palpable pulsation of the main arteries for at least 15 minutes was considered ROSC. Data were compared between the<4 hour and ≥4 hour survival groups and patients with and without ROSC. Results: Total of 254 OHCA patients were included in the study. ROSC was achieved in 84 (33.1%) of these patients and 170 (66.9%) patients were died. There were 28 patients (33.3%) with survival of <4 hours and 56 patients (66.7%) with survival of ≥4 hours in patients    with ROSC. The IG count and IG/TG ratio did not differ significantly between the ROSC groups and  between the groups separated by survival time (P>0.05). Conclusion: We found  no significant differences between subgroups defined according to survival duration. Similarly, no differences found between OHCA patients with and without sustained ROSC. https://fem.tums.ac.ir/index.php/fem/article/view/1223 https://fem.tums.ac.ir/index.php/fem/article/download/1223/451