Significance of minimal or no intraperitoneal fluid visible on CT scan associated with blunt liver and splenic injuries: A multicenter analysis

Background: The use of ultrasound (U/S) for the evaluation of patients with blunt abdominal trauma is gaining increasing acceptance. Patients who woul d have undergone computed tomographic (CT) scan may now be evaluated solely with U/S. Solid organ injuries with minimal or no free fluid may be missed by surgeon sonographers. Objective: The purpose of this study was to describe the incidence and clin ical importance of liver and splenic injuries with minimal or no free intra peritoneal fluid visible on CT scan. We hypothesized that these solid organ injuries occur infrequently and are of minor clinical significance. Methods: Patient records and CT scans were reviewed for the presence of and outcome associated with blunt liver and splenic injuries with minimal (<25 0 mt) or no free fluid detected by an attending radiologist. Data were coll ected from six major trauma centers during a 4-year period before the intro duction of U/S and included demographics, grade of injury (American Associa tion for the Surgery of Trauma scale), need for operative intervention, and outcome. Results:A total of 938 patients with liver and splenic injuries were identi fied. In this group, 11% of liver injuries and 12% of splenic injuries had no free fluid visible on CT scan and could be missed by diagnostic peritone al lavage or U/S. Of the 938 patients, 267 (28%) met the inclusion criteria ; 161 had injury to the spleen and 125 had injury to the liver. In the 267 patients studied, 97% of the injuries were managed nonoperatively. However, 8 patients (3%) required operative intervention for bleeding. Compared wit h the liver, the spleen was significantly more likely to bleed (p = 0.01), but the grade of splenic injury was not related to the risk for hemorrhage (p = 0.051). Conclusion: Data from this study suggest that injuries to the liver or sple en with minimal or no intraperitoneal fluid visible on CT scan occur more f requently than predicted but usually are of minimal clinical significance. However, patients with splenic injuries may be missed by abdominal U/S. We found a 5% associated risk of bleeding. Therefore, abdominal U/S should not be used as the sole diagnostic modality in all stable patients at risk for blunt abdominal injury.