Abstract
BACKGROUND: Emergency department cardiac arrest is increasingly recognized as a distinct entity, but little is known about its epidemiology in Asia. We compared patient characteristics, arrest etiologies, resuscitation processes, and outcomes between two tertiary university hospitals in Thailand. METHODS: We conducted a retrospective cohort study of adults (≥18 years) with emergency department cardiac arrest at Chiang Mai University Hospital (January 2020-December 2024) and Khon Kaen University Hospital (November 2021-December 2024). Cases were identified using institutional electronic cardiac arrest registries. Data included demographics, comorbidities, presumed etiology (5H/5T framework), initial rhythm, resuscitation processes, and outcomes. Primary outcomes were return of spontaneous circulation, survival to hospital admission, and survival to discharge. RESULTS: A total of 261 cases were analyzed (192 from Chiang Mai University Hospital and 69 from Khon Kaen University Hospital). The median age was 65 years (interquartile range 53-75), and 56.7% were male. Most arrests were non-traumatic (72.8%), and pulseless electrical activity predominated (76.6%). Hypoxia (43.3%), acidosis (33.7%), and hypovolemia (31.0%) were the leading presumed causes. Institutional variation was observed in comorbidity profiles, presumed etiologies, ventilation strategies, and resuscitation durations. Median cardiopulmonary resuscitation duration was longer at Khon Kaen University Hospital (9 vs. 6 min). No statistically significant differences in survival outcomes were detected between hospitals. CONCLUSION: Emergency department cardiac arrest in Thailand mirrors global patterns, with a predominance of non-shockable rhythms and low discharge survival rates. Observed institutional variation in patient characteristics and resuscitation processes highlights the need for standardized protocols, training, and the development of national emergency department cardiac arrest registries to support quality improvement in low- and middle-income country settings.