The eFAST protocol in Trauma Patients in the Emergency Department: Diagnostic Accuracy in a Multicenter Retrospective Study

ABSTRACT Background Extended Focused Assessment with Sonography for Trauma (eFAST) is a rapid bedside ultrasound examination commonly used during the initial evaluation of trauma patients in the Emergency Department. Its main role is to support early recognition of potentially life-threatening thoracic and abdominal injuries. While eFAST is generally considered highly specific, its ability to exclude traumatic lesions remains limited, especially when compared with contrast-enhanced computed tomography (CT) in haemodynamically stable patients. Objectives This study aimed to assess the diagnostic accuracy of eFAST, using contrast-enhanced CT as the reference standard, for the detection of free fluid or bleeding in the abdominal, pleural and pericardial spaces, and for the diagnosis of pneumothorax. Secondary aims were to describe differences between survivors and non-survivors and to evaluate whether agreement between eFAST and CT was associated with in-hospital mortality. Methods A multicentre retrospective study was conducted in three Level II Emergency Departments: AOU Modena, AUSL Cesena and AOU Ferrara. Adult trauma patients admitted to the Emergency Department with a red triage code between 2023 and 2024 were included if they had undergone FAST or eFAST followed by contrast-enhanced chest and abdominal CT. Patients younger than 18 years and pregnant women were excluded. Diagnostic performance was evaluated by calculating sensitivity, specificity, accuracy, positive likelihood ratio (LR+) and negative likelihood ratio (LR−). Results Overall, 876 patients were included. Most were male, with a median age of 51 years and a median Injury Severity Score of 13. The cohort was mainly composed of haemodynamically stable patients and blunt trauma cases. eFAST showed very high specificity, above 98% in all assessed regions, with LR+ values greater than 18, confirming a strong rule-in value. By contrast, rule-out performance was limited, with LR− values above 0.5 across all windows. Sensitivity for abdominal free fluid was modest, ranging from 48.4% in the hepatorenal window to 16.7% for right pleural effusion. In thoracic assessment, sensitivity remained below 32%, while specificity exceeded 99%. No statistically significant association was found between eFAST–CT concordance and in-hospital mortality, which appeared to be more closely related to age, comorbidities and trauma severity. Conclusions This study confirms that eFAST is a valuable first-line tool for the early assessment of trauma patients, particularly when the examination is positive. High specificity and LR+ values indicate that positive ultrasound findings strongly support the presence of traumatic injury and may guide timely clinical decisions. However, the limited sensitivity and the occurrence of false-negative results show that eFAST cannot be used as a stand-alone test to exclude thoraco-abdominal injuries. Its use should therefore be integrated into a broader diagnostic pathway, including CT when indicated, to reduce the risk of missed lesions and improve patient safety.