Clinical significance of isolated intraperitoneal fluid on computed tomography in pediatric blunt abdominal trauma

The finding of isolated free intraperitoneal fluid (FIPF) on computed tomography of the abdomen (CTA) in children after blunt trauma is of unclear clinical significance and raises suspicion for a solid or hollow viscus injury. In our institution, pediatric blunt trauma patients presenting with isolated FIPF on CTA who are hemodynamically stable and have no peritoneal signs on initial physical examination (iPE) have been historically approached nonoperatively. We reviewed our level 1 trauma center experience with this subset of the trauma population and sought to (1) justify an initial nonoperative approach and (2) identify early predictors of the eventual need for surgical exploration.

Data on all trauma patients less than 14 years of age admitted to our hospital from 2001 to 2006 after Blunt Abdominal Trauma (BAT) whose screening CTA showed FIPF and no other radiographic signs of solid or hollow viscus injury were retrieved from the local trauma registry. Clinical progress, operative findings, and follow-up were obtained by hospital and office chart review, as well as telephone contact. Mechanism of injury (MOI); Injury Severity Score (ISS); Revised Trauma Score; Pediatric Trauma Score (PTS); the presence of abdominal tenderness or external signs of injury on iPE; and quantity, location, and density of the FIPF were statistically analyzed as possible early predictors of the eventual need for surgical exploration.

A total of 670 children admitted to our institution after blunt trauma were evaluated with CTA during the time of enrollment. Isolated FIPF was found in 94 individuals (14%). Mean age was 9.7 (+/-SD 3.2) years; 52% were males. Motor vehicle crash was the most common MOI. Mean PTS was 10.6 (+/-SD 1.8). Mean ISS was 10.2 (+/-SD 7.2). Free intraperitoneal fluid was most commonly found in only one intraperitoneal region (93%). Most patients (97%) were discharged home without undergoing a surgical procedure. Three other patients developed peritonitis on serial physical examination and were surgically explored. Hollow viscus injuries were found in 2 of these individuals and treated with primary repair or segmental bowel resection. All surgical patients enjoyed a full recovery, with no postoperative complications. The presence of abdominal tenderness on iPE and the quantity of FIPF on initial CTA were the only studied variables to reach statistical significance as predictors of the eventual need for operative intervention. Follow-up after hospital discharge was obtained in 46.8% (44/94) and averaged 124.9 weeks.

To the best of our knowledge, this is the largest series of pediatric blunt trauma patients with isolated FIPF on CTA ever reported. Our findings justify an initial nonoperative approach for the management of these individuals. Abdominal tenderness on iPE and the quantity of FIPF on initial CTA were predictors of the eventual need for operative intervention.