Children younger than 18 years of age (0 to 17.9999 years) with blunt abdominal trauma presenting to the participating EDs within 24 hours of the traumatic event will be eligible if the do not meet any exclusion criteria and meet any one of the following inclusion criteria.

Inclusion Criteria:

1. Blunt torso trauma resulting from a significant mechanism of injury:

   • Motor vehicle collision: greater than 60 mph, ejection, or rollover
   • Automobile versus pedestrian/bicycle: automobile speed > 25 mph
   • Falls greater than 20 feet in height
   • Crush injury to the torso
   • Physical assault involving the abdomen

2. Decreased level of consciousness (Glasgow Coma Scale (GCS) score 9-14 or below age-appropriate behavior) in association with blunt torso trauma

3. Blunt traumatic event with any of the following (regardless of the mechanism):

   • Extremity paralysis
   • Multiple long bone fractures (e.g., tibia and humerus fracture)

4. History and physical examination suggestive of blunt torso trauma of any mechanism (including mechanisms of injury of less severity than mentioned above)

Exclusion Criteria:

The following patients will be excluded from the study:

1. Age-adjusted low blood pressure (Hemodynamic instability)

   • Patients will be excluded for prehospital or initial age-adjusted ED low blood pressure. This is because the standard evaluation of these patients involves immediate FAST based on prior work by our group. Low blood pressure is determined based upon the patient's age, and will be defined as a systolic blood pressure less than 70 mm Hg for patients younger than 1 month, less than 80 mm Hg for ages 1 month to 5 years, and less than 90 mm Hg for ages over 5 years.

2. Penetrating trauma: Patients who are victims of stab or gunshot wounds

3. Traumatic injury occurring > 24 hours prior to the time of presentation to the ED

4. Transfer of the patient to the ED from an outside facility with abdominal CT scan, diagnostic peritoneal lavage, or laparotomy previously performed

5. Transferred with FAST exam already performed at outside hospital

6. Patients with known disease processes resulting in intraperitoneal fluid including liver failure and the presence of ventriculoperitoneal shunts

7. Initial GCS score ≤ 8 as it is standard for children with GCS scores ≤ 8 to undergo abdominal CT if blunt abdominal trauma is suspected

8. Known pregnancy

9. Known prisoner

10. Known intra-abdominal injury diagnosed within 30 days prior of this ED visit