LAUSR

BACKGROUND We aimed to investigate the association between prehospital times and outcomes of patients who had hypotension at the scene after trauma incidents. METHODS We retrospectively analysed records from a nationwide database (2004-2017) of adults (aged ≥15 years) who were hypotensive (systolic blood pressure <90 mmHg) at the scene after trauma. The endpoint was in-hospital mortality. We used multivariable logistic regression analysis to adjust for confounding factors and to estimate the odds ratio (OR) of prehospital times for in-hospital mortality. Stratified analyses were performed based on patient age and type and severity of the trauma. RESULTS Among 5,499 patients included, 906 (16.5%) died in the hospital. The median Injury Severity Score (ISS) was 17 (interquartile range, 9-29). There was a significant trend towards patients having higher in-hospital mortality and ISS when their prehospital times were shorter (P < 0.001). However, the association between prehospital times and in-hospital mortality was not significant after adjusting for confounding factors, with an adjusted odds ratio of 1.00 (95% confidence interval: 0.98-1.01) per 10 min increments in prehospital time. The association remained insignificant when patients were stratified according to age and type and severity of the trauma. CONCLUSIONS Our analysis revealed that prehospital time was not significantly associated with in-hospital mortality among patients who had hypotension at the scene after trauma in the current emergency medical service system in Japan. Further studies are needed to validate our findings.