Incidence of unexplained intra-abdominal free fluid in patients with blunt abdominal trauma

BACKGROUND: Intra-abdominal free fluid is commonly caused by injuries of solid or hollow organs in patients suffering from blunt abdominal trauma (BAT). However, it presents a diagnostic dilemma for surgeons when free fluid is unexplained, especially in stable BAT patients. This study was to analyze the incidence of such unexplained free fluid in BAT patients and its diagnostic value in abdominal organ injury. METHODS: Altogether 597 patients with BAT who had been treated at our trauma center over a 10-year period were reviewed. Stable patients with free fluid but without free air or definite organ injury on abdominal computed tomography were studied. Clinical management and operative findings were analyzed. RESULTS: Thirty-four (5.70%) of the 597 patients met the inclusion criteria: 24 (4.02%) underwent therapeutic exploratory laparotomy: bowel injuries were found in 13, hepatic rupture in 3, colon rupture in 3, duodenal rupture in 2, spleen rupture in 1, pancreas rupture in 1, and gallbladder perforation in 1. In 2 patients, laparotomy was nontherapeutic. Those with moderate or large amounts of free fluid were more likely to suffer from a hollow viscus injury and have a therapeutic procedure. The mean time of hospital stay for the delayed laparotomy group was longer than that for the emergency group (19 5.12 vs. 12 2.24 days; t=2.73, P<0.01). CONCLUSIONS: There was a positive correlation between the amount of unexplained free fluid and the determination of intra-abdominal organ injury. The proportion of BAT patients who required surgical intervention was high, particularly those with a moderate or large amount of free fluid, and most of them suffered from a hollow organ injury. Emergency laparotomy is recommended for these patients.