Analysis of the Positivity Rate of Sector-based Whole-body CT Scans in Grade C Trauma Patients in Essonne - NCT07929168

Sponsor: Centre Hospitalier Sud Francilien Conditions: Multiple Trauma/Injuries, Wounds and Injuries Background: Grade C trauma patients show no obvious severe injury at first assessment, but the mechanism or circumstances of the accident make serious lesions possible. Guidelines recommend a whole-body CT scan as first-line imaging1. The organization of the French trauma system varies between regions2. Île-de-France distinguishes level 1 trauma centers, which are authorized to manage the most severe patients, from level 2 hospitals, which can perform a full injury assessment3. Essonne has no level 1 trauma center, and most are located in Paris. Emergency dispatch physicians must therefore choose between performing the scan at the local hospital or transporting the patient directly to a trauma center. When a local scan is abnormal, specialist consultation, image transfer and secondary transport take time (median of about 6 hours4) and may worsen the prognosis. Objective: To assess whether the proportion of abnormal whole-body CT scans in grade C trauma patients justifies systematic transport to a trauma center rather than local imaging. Methods: Retrospective, multicenter cohort study of about 100 adult grade C trauma patients managed by an Essonne mobile emergency team (SMUR) in 2025 who underwent a whole-body CT scan. We will determine the proportion of abnormal scans, whether the lesions could be managed locally or required a level 1 or 2 trauma center, the secondary transfer rate, and the time to final destination. Hypothesis: The proportion of abnormal scans, particularly those requiring specific medical care, is high enough to support performing the first whole-body CT scan at a trauma center. Grade C trauma patients are a diagnostic and logistical challenge: their initial presentation is reassuring, yet the mechanism of injury may conceal severe lesions, which is why whole-body CT is recommended as first-line imaging6. The destination chosen at the pre-hospital stage therefore determines both the speed of diagnosis and the speed of access to specialized care. In Essonne, where no level 1 trauma center exists, this choice is made by the SAMU dispatch physician, case by case, without local data on how often a scan performed at the sector hospital reveals lesions requiring specialized management. The delays reported after an abnormal local scan are the main argument for direct transfer, while the unnecessary mobilization of resources and the transport of patients who turn out to have normal scans are the main argument against. This is a retrospective, multicenter, observational cohort study. It covers hospitals of the Essonne department that received grade C trauma patients managed by an Essonne SMUR team in 2025 and who received a whole-body CT. Cases will be identified from SMUR and SAMU activity records, then linked to the receiving hospitals' medical files. No intervention will be performed and no change to patient care is planned. Data will be extracted from SAMU dispatch records, emergency department files and radiology reports. Variables will include: * demographics and relevant medical history * mechanism of injury and pre-hospital clinical findings * time stamps for each care step (SMUR arrival on scene, hospital arrival, scan, specialist consultation, secondary transport, arrival at final destination) * whole-body CT findings * the level of care needed (local hospital, level 2 or level 1 trauma center) * secondary transfers, and the regulation time required for them Data will be recorded in a pseudonymized, secure database. Descriptive statistics will be used for the whole cohort. The proportion of abnormal whole-body CT scans will be reported with its 95% confidence interval.