Analysis of the Relationship Between the Characteristics of the Blood Internal Environment and Early Prognosis in Patients with Cardiac Arrest

Background： Cardiac arrest is a highly time-dependent condition, and there is limited evidence regarding the relationship between changes in the blood internal environment before and after arrest and resuscitation and the return of spontaneous circulation (ROSC) in patients. This study aims to understand the dynamic changes in the internal environment of blood at different time points and to identify blood biomarkers for patients who achieve ROSC. Methods ：A retrospective analysis was conducted on patients with CA in a tertiary hospital in China from January 2021 to December 2023. The study described and compared laboratory blood indicators at different time points: prior to cardiac arrest, during resuscitation, and after ROSC. Multivariate logistic regression analysis was employed to identify independent influencing factors for ROSC, and receiver operating characteristic (ROC) curves were plotted to evaluate their predictive value. Result Among the 270 patients included in the final analysis, 122 achieved ROSC. Compared to pre-arrest and post-ROSC levels, WBC count, neutrophils, pH, and PO ₂ were lower during resuscitation, while lymphocytes, potassium, and PCO ₂ were higher (P < 0.05). In further comparison to the non-ROSC group, the ROSC group had higher WBC count, neutrophils, lymphocytes, platelets, and PO ₂ during resuscitation, but lower INR, D-dimer, and BE. WBC, D-dimer, and PO ₂ were identified as independent influencing factors for ROSC in cardiac arrest patients, with AUC of 0.686, 0.374, and 0.775. The combined detection of these three factors yielded an AUC of 0.826, with a sensitivity of 71.2% and specificity of 85.2%. Conclusion ：The different stages of CA and resuscitation exhibit distinct characteristics in the internal environment of blood. Factors such as WBC, neutrophils, and PO2 are significant influencing factors for ROSC in CA patients.