Intra-abdominal free fluid without solid organ injury in blunt abdominal trauma: an indication for laparotomy.

Background: The optimal management of patients sustaining blunt abdominal trauma (BAT), in whom intra-abdominal free fluid but no solid organ injury is found on imaging, remains unclear. The purpose of this study was to determine the incidence and significance of this finding.

Methods: All patients presenting with suspected BAT to a provincial trauma center over a 30-month period were reviewed. A screening focused abdominal sonogram for trauma scan was obtained in every case. Stable patients with positive or indeterminate scans underwent computed tomographic scanning. Those with free fluid but without visible solid organ injury were studied. Radiologic interpretation, clinical management, and operative findings were analyzed.

Results: Twenty-eight of 1,367 patients (2%) met inclusion criteria. Twenty-one patients (75%) underwent exploratory laparotomy, which for 16 (76%) was therapeutic: bowel injuries were found in 10 patients, mesentery injuries in 6, and injuries to solid organs in 3. In five patients, laparotomy was nontherapeutic. Those with more than a trace of free fluid were significantly more likely to have a therapeutic procedure. Seven patients (25%) were observed, of whom two failed nonoperative management and underwent therapeutic laparotomies within 24 hours of admission for missed colon, splenic, and hepatic injuries. The presence of abdominal seat belt bruising or a Chance-type fracture in the study patients was associated with a 90% and 100% therapeutic laparotomy rate, respectively. Computed tomographic scan findings were variable and were not able to predict injury severity or need for surgery.

Conclusion: The finding of more than trace amounts of free fluid in the absence of solid organ injury in BAT is often associated with clinically significant visceral injury. Early laparotomy is recommended for these patients.