Signs of Life and Clinical Outcomes in Patients With Traumatic Out-of-Hospital Cardiac Arrest: A Nationwide Multicenter Observational Study

BACKGROUND: The prognostic value of individual signs of life (SOLs) remains unclear in patients experiencing traumatic out-of-hospital cardiac arrest (t-OHCA). OBJECTIVES: To describe clinical outcomes among patients with t-OHCA by the presence of each SOL at the scene. METHODS: Data from the SOS-KANTO 2017 study, a multicenter prospective registry of OHCA cases treated between 2019 and 2021, were retrospectively analyzed. Adult patients diagnosed with t-OHCA were included, excluding those with a palpable pulse upon emergency medical service (EMS) arrival. Patients were categorized into eight subgroups based on the presence of three SOLs at the scene-the pupillary light reflex, spontaneous respiration, and cardiac electrical activity - and descriptive analyses were performed. The primary outcome was survival beyond the emergency department (ED). RESULTS: Of the 462 patients included in the analysis, two (0.4%) exhibited all three SOLs, and 18 (3.9%) exhibited two SOLs; in the latter group, two demonstrated cardiac activity and a pupillary reflex, and 16 had cardiac activity and spontaneous respiration. Among the 124 patients (26.8%) with only one SOL, 117 had cardiac activity, three showed a pupillary reflex, and four exhibited spontaneous respiration. No SOLs were observed in 318 patients (68.8%). Overall, 22 patients (4.8%) survived beyond the ED. The highest survival rate was observed in the subgroup with both cardiac activity and spontaneous respiration (4/16; 25%), followed by the subgroup with cardiac activity alone (10/117; 8.5%). CONCLUSIONS: Among the t-OHCA patients, survival beyond the ED was observed more frequently in those with cardiac electrical activity at the scene.