Burden of In-Hospital Cardiac Arrest in Emergency Care Units in Brazil: Epidemiology and Outcomes from Bauru

Background: Cardiac arrest is a time-critical emergency with high mortality, and Brazilian data from emergency care units are still scarce and heterogeneous. National guidelines recommend standardized Utstein-style registries to support quality improvement and system planning, but implementation in routine services remains limited. Objective: To describe the incidence, clinical profile, resuscitation practices and immediate outcomes of adult in-hospital cardiac arrest cases treated in urgent and emergency care units (UPAs and municipal emergency department) in Bauru, São Paulo, Brazil. Methods: We conducted a retrospective observational cohort study based on a registry including all adult patients (≥18 years) with documented cardiac arrest managed in four Emergency Care Units and the Central Emergency Department of Bauru from 1 January to 31 December 2024. Cases were identified through ICD-10 codes for cardiac arrest. Data were extracted from medical records using a structured form adapted from the Utstein template, and entered into an electronic spreadsheet. We performed descriptive analyses of demographics, comorbidities, pre-arrest characteristics, initial rhythm, resuscitation measures and immediate outcomes (return of spontaneous circulation [ROSC] vs death). Results: We identified 137 cardiac arrest events in 121 patients. Median age was 66 (range 19–101), and 57.9% were male. The most frequent comorbidities were hypertension (36.5%), structural cardiopathy (23.4%) and diabetes (19.0%). Overall, 23.4% of events involved activation of the Mobile Emergency Medical Service (SAMU 192) prior to arrival. Initial rhythm was not documented in 54.7% of cases; among documented rhythms, asystole accounted for 21.2%, pulseless electrical activity for 13.9%, ventricular tachycardia for 4.4%, ventricular fibrillation for 3.6%, and other rhythms for 2.1%. Endotracheal intubation was recorded in 66.4% of arrests. Duration of cardiopulmonary resuscitation (CPR) was available for 79 events, with a median of 15 minutes (interquartile range [IQR] 7–21). Immediate outcome was known in 131 events: ROSC occurred in 58 (44.3%). ROSC rates varied across units, from 31.6–37.5% in UPAs to 65.9% in the Central Emergency Department. Patients transported by SAMU had markedly higher ROSC (83.9%) than those arriving by other means (32.3%). Median CPR duration among patients with ROSC was 10 minutes (IQR 4.5–18) versus 19 minutes (IQR 10–26.3) among those who died. Conclusion: In this municipal network of emergency care units, in-hospital cardiac arrest affected predominantly older adults with a high burden of cardiovascular comorbidities and was associated with substantial immediate mortality. Profound incompleteness of core variables highlights the urgent need to strengthen Utstein-based registries and documentation routines in Brazilian emergency services. Differences in ROSC between units and among patients transported by SAMU suggest potential opportunities for system-level quality improvement and regional benchmarking.