Incidence and significance of free fluid on abdominal computed tomographic scan in blunt trauma

Objective: To determine the incidence and significance of free fluid on abdominal CT in blunt trauma. Design: Retrospective chart review. Methods: All blunt trauma patients with an abdominal computed tomographic scan from August of 1993 to December of 1995 were identified from the trauma registry at a Level 1 trauma center. A total of 1,159 computed tomographic scans were performed; records of 18 patients were excluded for incomplete records. Official reports of computed tomographic scans were reviewed for free fluid, solid organ injury, bladder injury, and pelvic fracture. Results: Free fluid without solid organ injury was found in 3% (34 of 1141). Laparotomy was performed because of free fluid in 13 patients. There were six small bowel injuries and one diaphragm injury for a therapeutic laparotomy rate of 54%. Ten patients had trace free fluid and did not undergo laparotomy; none had a missed small bowel injury. Conclusions: The presence of more than trace amounts of free fluid without solid organ injury in patients with blunt trauma is a strong indication for exploratory laparotomy. Patients with isolated trace amounts of free fluid can be safely observed.