摘要Background:Electrolyte imbalance is closely related to the occurrence and prognosis of cardiac arrest.However,current research mainly focuses on the three ions-sodium,potassium,and calcium-while lacking attention to magnesium ions,chloride ions,bicarbonate ions,and phosphate ions.Therefore,we plan to explore the effects of electrolytes on the 30-day in-hospital mortality rate of patients with cardiac arrest based on the Medical Information Mart for Intensive Care Ⅳ(MIMIC-Ⅳ)database.Method:Data were collected from the MIMIC Ⅳ database version 3.0(v3.0)on electrolyte levels and 30-day in-hospital mortality rates of hospitalized patients with"cardiac arrest"from 2008 to 2022.Cox regression analysis was used to identify variables that affect the 30-day mortality rate of patients.Finally,the Kaplan-Meier curve was used in this study to further explore the effects of electrolytes on the 30-day mortality rate of patients.Result:A total of 1491 patients who experienced cardiac arrest were included in this study.Cox regression analysis showed a correlation between age,calcium ions,bicarbonate ions,chloride ions,phosphate,and the 30-day in-hospital mortality rate in patients.The Kaplan-Meier curve further revealed that patients with advanced age,low calcium ion concentration,low chloride ion concentration,low bicarbonate concentration,and high phosphate concentration had poor prognoses.Conclusion:Levels of bicarbonate ions,chloride ions,and inorganic phosphate at admission were associated with mortality on day 30 of admission.