The Role of Focused Assessment with Sonography for Trauma (FAST) in Identifying Intra-Abdominal Injuries in Blunt Abdominal Trauma

Focused Sonography in Blunt Trauma Evaluation

Abstract

Blunt Abdominal Trauma (BAT) remains a diagnostic challenge, even for experienced trauma surgeons. Objective: To evaluate the diagnostic accuracy of Focused Assessment with Sonography for Trauma (FAST) in detecting intra-abdominal injuries among patients presenting with blunt abdominal trauma in a tertiary care emergency setting. Methods: This cross-sectional analytical study was conducted at the Emergency Department of Lady Reading Hospital, Peshawar, from May 2024 to February 2025. A total of 106 patients were enrolled, calculated using OpenEpi based on an expected FAST sensitivity of 78%, 20% IAI prevalence, 80% confidence level, and 5% margin of error. Patients with penetrating abdominal trauma or contraindications to FAST were excluded. Positive FAST was defined by free fluid in standard regions (perihepatic, perisplenic, pelvic, or pericardial). CT scan, interpreted by a radiologist, served as the reference standard for IAI—defined as evidence of organ laceration, hematoma, or active bleeding. FAST scans were performed by trained emergency physicians during initial assessment, with CT scans conducted within one hour in stable patients. Operator qualifications included certification in trauma ultrasonography. Results: Of the 106 patients, FAST demonstrated a sensitivity of 78.9%, specificity of 91.8%, and overall diagnostic accuracy of 84.9% in detecting IAI. There were no significant demographic or clinical differences between FAST-positive and FAST-negative groups. Data were analyzed using SPSS v23.0, with p < 0.05 considered significant. Conclusion: FAST is a valuable, rapid bedside screening tool for initial evaluation of BAT, offering high specificity and acceptable sensitivity.