Predictive Factors of Emergency Department In-Hospital Cardiac Arrest Caused by Respiratory Diseases

Objective To analyze the clinical characteristics of emergency department in-hospital cardiac arrest (EDIHCA) patients caused by respiratory diseases, explore predictive factors for EDIHCA etiology potentially related to respiratory diseases, and provide reference for early prevention and effective treatment of such patients. Methods This retrospective study enrolled non-traumatic EDIHCA patients admitted to the emergency department of The Second Affiliated Hospital of Kunming Medical University between January 2021 and May 2025. Clinical data were extracted from electronic medical records. Descriptive statistics, Lasso regression, and multivariate binary logistic regression were used to determine independent predictive factors. Model performance was assessed using the Hosmer–Lemeshow (HL) test and the area under the receiver operating characteristic curve (AUC). Subgroup and interaction analyses were performed to evaluate model stability. Results Independent predictors of EDIHCA due to respiratory diseases included cough (OR 1.03, 95%CI 1.01–1.05, p  = 0.002), dyspnea (OR 7.87, 95%CI 3.26–18.96, p  < 0.001), fever (OR 6.55, 95%CI 2.32–18.49, p  < 0.001), history of lung tumor (OR 4.67, 95%CI 1.29–16.87, p  = 0.019), mechanical ventilation on admission (OR 2.24, 95%CI 1.23–4.09, p  = 0.008), age (OR 1.03, 95%CI 1.01–1.05, p  = 0.002), hs-CRP (OR 1.01, 95%CI 1.01–1.02, p <0.001), hemoglobin (OR 1.01, 95%CI 1.01–1.01, p  = 0.039). Abdominal pain was a negative predictor OR 0.15, 95%CI 0.04–0.59, p  = 0.006). The model achieved an AUC of 0.89 (95% CI 0.87–0.92), and the HL test showed χ ²=13.071, p  = 0.11, indicating good discrimination and calibration. Significant heterogeneity by sex was observed for hemoglobin (interaction P  = 0.033) and hs-CRP (interaction P  = 0.021). Conclusion Cough, dyspnea, fever, history of lung tumor, mechanical ventilation on admission, older age, elevated hs-CRP, and higher hemoglobin levels are independent positive predictors of respiratory-etiology EDIHCA, while abdominal pain is a negative predictor. Some predictors show sex-related heterogeneity. These findings require validation in larger multi-center studies. Trial registration ChiCTR2500110150, 09/10/2025. Retrospectively registered.