Isolated Intraperitoneal Fluid on Abdominal Computed Tomography in Children with Blunt Trauma

OBJECTIVE: To determine the frequency of isolated intraperitoneal fluid (IIF) on abdominal computed tomography (CT) in pediatric blunt trauma patients and the association between IIF and clinically identifiable intra-abdominal injuries (IAIs) in these patients. METHODS: The authors conducted a prospective observational study of consecutive children <16 years old with blunt torso trauma who underwent abdominal CT scanning while in the emergency department (ED). All patients were evaluated by a faculty emergency physician who documented the patient's physical examination. All CTs were interpreted by a single faculty radiologist masked to clinical data. The volume of intraperitoneal fluid was quantified (small, moderate, large) and the presence of organ injury visible on CT was noted. Patients were considered to have IIF if the CT demonstrated intraperitoneal fluid and no solid organ injury. Patients with IIF were followed through their hospitalizations or telephoned in one week if discharged home from the ED. RESULTS: Five hundred twenty-seven children with blunt trauma were enrolled into the study. The mean age (+/-SD) was 7.4 +/- 4.7 years, and the median pediatric trauma score was 10 (range -2 to 12). Eighty-eight patients (17%; 95% CI = 14% to 20%) had intraperitoneal fluid on CT scan and 42 (48%; 95% CI = 37% to 59%) of these patients had IIF. Of the 42 patients with IIF, five patients (all without abdominal tenderness and with a small amount of IIF on CT scan) were discharged to home from the ED and were well at telephone follow-up; the remaining 37 patients were hospitalized. Of the 42 patients with IIF, 7 patients (17%, 95% CI = 7 to 31%) had IAIs subsequently identified (all gastrointestinal injuries) during their evaluations. Six of the seven patients with IIF and subsequently identified IAIs had abdominal tenderness on examination in the ED. The remaining patient had a decreased level of consciousness. CONCLUSIONS: Isolated intraperitoneal fluid occurs in 8% of pediatric blunt trauma patients undergoing abdominal CT, and IAIs are subsequently identified in 17% of these patients. Patients with a small amount of IIF on CT who lack abdominal tenderness and have a normal level of consciousness are at low risk for subsequently identified IAIs.