Outcome of Cardiac Arrest and Non-Cardiac Arrest Patients with Severe Acidosis in the Emergency Department: A Retrospective Cohort Study

Aim:We aimed to evaluate the outcome of cardiac arrest and non-cardiac arrest patients with severe acidosis admitted to the emergency department (ED) and to analyze the relationship between in-hospital mortality and clinical factors. Materials and Methods:Patients with severe acidosis (pH <7.1) presenting to the ED were included in the study.Patients were divided according to arrest status and outcomes and analyzed accordingly. Results:The study included 540 patients with severe acidosis.The 30-day mortality rate was 74.8% in all patients.In the non-cardiac arrest subgroup, the 30-day mortality rate was 21.4%.Non-arrest and non-survivors were more likely to be older, male, and have a higher prevalence of hypertension and coronary artery disease.Mortality was significantly higher among patients with sepsis, metabolic causes, and isolated respiratory arrest, while it was lower, in those with neurological etiologies, diabetic ketoacidosis, and seizures (p<0.05).Although no significant differences were observed in blood gas parameters, non-survivors had significantly higher lactate and creatinine levels lower hemoglobin levels (p<0.05).Univariate analysis identified advanced age, male sex, sepsis, metabolic causes, isolated respiratory arrest, hypertension, coronary artery disease, elevated partial carbon dioxide pressure (pCO 2 ) and creatinine, and reduced hemoglobin as significant predictors of 30-day mortality (p<0.05 for all). Conclusion:Severe acidosis is associated with high 30-day mortality, particularly in cardiac arrest patients.However, non-arrest patients also exhibit considerable mortality.Advanced age, male sex, cardiovascular comorbidities, sepsis, and elevated lactate, pCO 2 , and creatinine levels were identified as key predictors.Early recognition and management of these factors may improve outcomes.