The role of focused abdominal sonography for trauma (FAST) in pediatric trauma evaluation.

PURPOSE: With increasing concerns about radiation exposure, we questioned whether a structured program of FAST might decrease CT use.

METHODS: All pediatric trauma surgeons in our level 1 pediatric trauma center underwent formal FAST training. Children with potential abdominal trauma and no prior imaging were prospectively evaluated from 10/2/09 to 7/31/11. After physical exam and FAST, the surgeon declared whether the CT could be eliminated.

RESULTS: Of 536 children who arrived without imaging, 183 had potential abdominal trauma. FAST was performed in 128 cases and recorded completely in 88. In 48% (42/88) the surgeon would have elected to cancel the CT based on the FAST and physical exam. One of the 42 cases had a positive FAST and required emergent laparotomy; the others were negative. The sensitivity of FAST for injuries requiring operation or blood transfusion was 87.5%. The sensitivity, specificity, PPV, and NPV in detecting pathologic free fluid were 50%, 85%, 53.8%, and 87.9%.

CONCLUSIONS: True positive FAST exams are uncommon and would rarely direct management. While the negative FAST would have potentially reduced CT use due to practitioner reassurance, this reassurance may be unwarranted given the test's sensitivity.