Association between total prehospital time and early mortality in patients with severe torso trauma: a retrospective study at an urban Emergency and Critical Care Center

Abstract Background In urban emergency and critical care centers (ECCCs), transport distances are relatively short, and severely injured trauma patients may reach the hospital before cardiac arrest occurs. Severe torso trauma is relevant as it may involve time-sensitive hemorrhage in the chest, abdomen, or pelvis. However, the association between total prehospital time (TPT) and early mortality has not been well examined in urban settings in Japan. We aimed to investigate this relationship in patients with severe torso trauma treated at an urban ECCC. Methods This single-center retrospective study was conducted at an urban ECCC in Tokyo from March 2016 to December 2024. We reviewed data from 342 patients with an Abbreviated Injury Scale score ≥ 3 for the neck, chest, abdomen, or pelvis. Associations between TPT and death within 24 h, Injury Severity Score (ISS), Revised Trauma Score (RTS), and probability of survival (P s ) were assessed. Geographic Information System was used to evaluate spatial patterns, and Delta Shock Index (DSI) was used to assess hemodynamic changes during transport. Patients meeting predefined exclusion criteria were excluded. Results Of the 342 patients, 20 patients died within 24 h of arrival, and no deaths were observed in patients with a TPT ≥ 61 min. Linear regression analysis revealed significant associations between shorter TPT and severity indicators (ISS, RTS, and P s ). Logistic regression analysis showed a significant association between ISS and early mortality. TPT was not significantly associated with early mortality after adjusting for ISS. Of the early deaths, 75% occurred within 5 km of the ECCC. Although no significant difference in DSI was observed between survivors and non-survivors, patients with an ISS of 25–49 and a DSI ≥ 0.1 had shorter TPT. Conclusion In this urban trauma system, shorter TPT was associated with higher early mortality. This may reflect rapid transport of critically injured patients rather than a harmful effect of shorter TPT itself. In settings with relatively short prehospital times, this association should be interpreted in the context of trauma severity and trauma system structure, and optimizing early in-hospital trauma response may be more important than further reducing transport time.