Diagnostic accuracy of Focused Assessment with Sonography for Trauma for blunt abdominal trauma in the Eastern Region of Saudi Arabia

Abstract

Objectives: To determine the diagnostic accuracy of Focused Assessment with Sonography for Trauma (FAST) in blunt abdominal trauma caused by motor vehicle accidents at our Hospital in Dhahran city.

Methods: This descriptive, observational study was conducted in the Radiology Department at King Fahad Military Medical Complex Dhahran, Saudi Arabia between September 2016 and September 2017. All adult patients (n=105) involved in motor vehicle accidents with blunt abdominal injury on presentation were retrospectively reviewed for FAST and CT scans for detection of free fluid. Focused assessment with sonography for trauma studies were conducted or supervised by senior registrar of general surgery (trauma team leader). Computed tomography findings were reviewed by 2 experienced radiologists. High and low-grade solid abdominal visceral (liver, spleen, kidney) injuries were identified on CT scans. Focused assessment with sonography for trauma and CT scan findings were identified as 'positive' and 'negative' for presence and absence of free fluid respectively. Outcomes of FAST were presented on a 2x2 contingency table.

Results: Sensitivity of FAST in detecting intraperitoneal free fluid was calculated as 76.1% (95% confidence interval [CI], 64.14-85.69%), specificity 84.2% (95% CI, 68.75-93.98%) and accuracy 79% (95% CI, 70.01-86.38%). Focused assessment with sonography for trauma detected free fluid in most cases of high-grade solid visceral injuries. Nearly half of true-negative cases were having low grade visceral or other injuries.

Conclusion: Focused assessment with sonography for trauma is an important tool in initial assessment of suspected blunt abdominal injury patients with high sensitivity and specificity. A negative FAST does not exclude low grade solid visceral or other injuries.