Abstract
Objective: Cardiac arrest, which is characterized by sudden cessation of circulation and cardiac activity, leads to irreversible fatal outcomes without resuscitative interventions. Although various biomarkers have been studied for the prognostic evaluation of cardiac arrest, data on the utility of eosinophil counts remain limited. The current study aimed to investigate the association between eosinophil count and emergency department (ED) mortality among patients experiencing cardiac arrest.
Methods: This retrospective study included patients with cardiac arrest who presented to the ED between 2022 and 2024. In total, 274 patients were analyzed. Data were retrospectively obtained from the hospital information system, including demographic characteristics (age, gender) and biochemical parameters (e.g., white blood cell count, eosinophil count). Outcomes such as ED mortality and hospital admission were also examined.
Results: The study was completed in 274 patients after applying the inclusion and exclusion criteria. The mean age of the patients was 68 years, and 65.3% of them experienced mortality in the ED. Among the blood parameters, eosinophil, lymphocyte, platelet, and albumin levels were significantly higher in patients who survived compared with those who did not (p<0.001, p=0.001, p=0.006, and p=0.008, respectively), while no significant differences were observed in other parameters (p>0.05). Multivariate logistic regression analysis revealed that a 0.1-unit decrease in eosinophil count increased the mortality rate by 1.482 times (p=0.006). The ROC analysis assessing the relationship between eosinophil count and mortality yielded an area under the curve of 0.629, with a cut-off value of 0.055 (p<0.001).
Conclusion: Our findings demonstrate that eosinophil levels are a significant biomarker of ED mortality in patients with cardiac arrest. The distinct response of eosinophils to post-cardiac arrest perfusion disturbances suggests their potential role as prognostic indicators in critical illness. Future large-scale, multicenter prospective studies are needed to further clarify the prognostic value of eosinophil levels and their broader clinical applications.
