Focused assessment with sonography in trauma (FAST): Experience of a tertiary hospital in Southeast Asia

Abstract

Objective: This study compares the positive predictive value (PPV) and negative predictive value (NPV) of focused assessment with sonography in trauma (FAST) versus abdominal-pelvic computed tomography scans (CTAP) after blunt abdominal injury as well as the need for abdominal surgery. We also sought to determine if any false negative ultrasound studies were associated with significant morbidity. The results were compared with other studies. Design: Retrospective cross-sectional study. Setting: A tertiary hospital. Methods: Cases were retrieved from the trauma registry and electronic medical records in a tertiary hospital in Singapore over a two year period from 1 January 2009 to 31 December 2010. Exclusion criteria included penetrating trauma and burns. The sonographic finding, computed tomography finding, and the outcome of the patients were retrieved. Diagnostic characteristics including predictive values were calculated. Results: A total of 476 patients were enrolled. Four hundred fifty-nine patients had FAST performed with fifty (10.9%) being positive. Forty-nine patients (21.7%) out of 226 patients had CTAP which showed abnormalities and nineteen (4.0%) patients underwent surgery. Comparing FAST to detect abnormalities on CTAP, the PPV and NPV were 0.590 and 0.863 respectively. Comparing FAST with the need for surgery, the PPV and NPV were 0.280 and 0.990 respectively. Four patients (0.98%) had negative FAST but required surgery. There were no significant adverse outcomes or surgical intervention in patients with normal vital signs, normal initial physical examination and negative FAST findings but who did not have a CTAP. Conclusions: In patients with an initial normal physical examination and negative FAST, emergent CTAP may be avoided.