A multicenter study of the risk of intra-abdominal injury in children after normal abdominal computed tomography scan results in the emergency department

Study objective: We determine whether intra-abdominal injury is rarely diagnosed after a normal abdominal computed tomography (CT) scan result in a large, generalizable sample of children evaluated in the emergency department (ED) after blunt torso trauma. Methods: This was a planned analysis of data collected during a prospective study of children evaluated in one of 20 EDs in the Pediatric Emergency Care Applied Research Network. The study sample consisted of patients with normal results for abdominal CT scans performed in the ED. The principal outcome measure was the negative predictive value of CT for any intra-abdominal injury and those undergoing acute intervention. Results: Of 12,044 enrolled children, 5,380 (45%) underwent CT scanning in the ED; for 3,819 of these scan the results were normal. Abdominal CT had a sensitivity of 97.8% (717/733; 95% confidence interval [CI] 96.5% to 98.7%) and specificity of 81.8% (3,803/4,647; 95% CI 80.7% to 82.9%) for any intra-abdominal injury. Sixteen (0.4%; 95% CI 0.2% to 0.7%) of the 3,819 patients with normal CT scan results later received a diagnosis of an intra-abdominal injury, and 6 of these underwent acute intervention for an intra-abdominal injury (0.2% of total sample; 95% CI 0.06% to 0.3%). The negative predictive value of CT for any intra-abdominal injury was 99.6% (3,803/3,819; 95% CI 99.3% to 99.8%); and for injury undergoing acute intervention, 99.8% (3,813/3,819; 95% CI 99.7% to 99.9%). Conclusion: In a multicenter study of children evaluated in EDs after blunt torso trauma, intra-abdominal injuries were rarely diagnosed after a normal abdominal CT scan result, suggesting that safe discharge is possible for the children when there are no other reasons for admission.