Objective: To determine the frequency of isolated intraperitoneal fluid (II
F) on abdominal computed tomography (CT) in pediatric blunt trauma patients
and the association between IIF and clinically identifiable intra-abdomina
l injuries (IAIs) in these patients. Methods: The authors conducted a prosp
ective observational study of consecutive children <16 years old with blunt
torso trauma who underwent abdominal CT scanning while in the emergency de
partment (ED). All patients were evaluated by at faculty emergency physicia
n who documented the patient's physical examination. All CTs were interpret
ed by a single faculty radiologist masked to clinical data. The volume of i
ntraperitoneal fluid was quantified (small, moderate, large) and the presen
ce of organ injury visible on CT was noted. Patients were considered to hav
e IIF if the CT demonstrated intraperitoneal fluid and no solid organ injur
y. Patients with IIF Were followed through their hospitalizations or teleph
oned in one week if discharged home from the ED. Results: Five hundred twen
ty-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 wa
s 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 thes
e 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 disch
arged to home from the ED and were well at telephone follow-up; the remaini
ng 37 patients were hospitalized. Of the 42 patients with IIF, 7 patients (
17%, 95% CI = 7 to 31%) had IAIs subsequently identified (all gastrointesti
nal 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. Conc
lusions: Isolated intraperitoneal fluid occurs in 8% of pediatric blunt tra
uma patients undergoing abdominal CT, and IAIs are subsequently identified
in 17% of these patients. Patients with a small amount of IIF on CT who lac
k abdominal tenderness and have a normal level of consciousness are at low
risk for subsequently identified IAIs.