Focused Assessment with Sonography for Trauma (FAST) in the Early Diagnosis of Visceral Injuries in Trauma Patients: A Narrative Review

Focused Assessment with Sonography for Trauma (FAST) has become a cornerstone of early trauma evaluation due to its rapid execution, bedside availability, and noninvasive nature. Its primary role is the detection of free fluid, serving as an indirect marker of significant intra-abdominal injury. However, the accuracy of FAST for diagnosing specific visceral injuries remains variable, particularly when distinguishing solid organ from hollow viscus lesions. This narrative review analyzes current evidence regarding the role of FAST in the early diagnosis of visceral injuries in trauma patients. A structured literature search was conducted in PubMed, SciELO, and Scopus databases. The diagnostic performance of FAST, its clinical applicability in hemodynamically unstable and stable patients, and its limitations in comparison with computed tomography are discussed. The findings indicate that FAST is highly specific for detecting hemoperitoneum and is particularly valuable in unstable patients, where it facilitates rapid surgical decision-making. Nevertheless, its limited sensitivity for isolated visceral and hollow viscus injuries underscores the need for integration with clinical assessment and advanced imaging.