Isolated free fluid on abdominal computed tomography in blunt trauma: watch and wait or operate?

Isolated free fluid (FF) on abdominal CT in stable blunt trauma patients can indicate the presence of hollow viscus injury. No criteria exist to differentiate treatment by operative exploration vs observation. The goals of this study were to determine the incidence of isolated FF and to identify factors that discriminate between patients who should undergo operative exploration vs observation.

A review of blunt trauma patients at a Level I trauma center from July 2009 to March 2012 was performed. Patients with a CT showing isolated FF after blunt trauma were included. Data collected included demographics, injury severity, physical examination, CT, and operative findings.

Two thousand eight hundred and ninety-nine patients had CT scans, 156 (5.4%) of whom had isolated FF. The therapeutic operative group included 13 patients; 9 had immediate operation and 4 failed nonoperative management. The nonoperative/nontherapeutic operation group consisted of 142 patients with successful nonoperative management and 1 patient with a nontherapeutic operation. Abdominal tenderness was documented in 69% of the therapeutic operative group and 23% of the nonoperative/nontherapeutic group (odds ratio = 7.5; p < 0.001). The presence of a moderate to large amount of FF was increased in the therapeutic operative group (85% vs 8%; odds ratio = 66; p < 0.001).

Isolated FF was noted in 5.4% of stable blunt trauma patients. Blunt trauma patients with moderate to large amounts of FF without solid organ injury on CT and abdominal tenderness should undergo immediate operative exploration. Patients with neither of these findings can be safely observed.