Diagnostic Value of Serial Ultrasound in Blunt Abdominal Trauma

Ultrasound has widely been used to assess patients with blunt abdominal trauma and detect free fluid in the abdomen. Nevertheless, different studies reported different false negative for this imaging technique.
The present study was conducted to evaluate the diagnostic value of the repetitive ultrasound in diagnosis of free intraperitoneal fluid.
In this study, 125 patients with abdominal blunt trauma were recruited prospectively for ultrasound evaluation. Ultrasound and CT- scan were performed for all recruited patients in the study. In case of positive ultrasound or CT-scan (free fluid in the peritoneal cavity), patients underwent surgical operation. In the presence of negative ultrasound and CT-scan, and if the patient was alert and had stable vital signs, then, he/she would undergo exact supervision. In such patients, ultrasound and CT-scan were repeated 12 and 24 hours after admission. If any of the tests were positive, the patient underwent laparotomy. Moreover, if ultrasound and CT-scan examinations were negative 24 hours after admission, the patients with normal laboratory tests were discharged according to the surgeon's decision. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.
Of the 125 patients with abdominal blunt trauma, 90 patients finally underwent laparotomy. Based on the surgical outcome as the gold standard, the initial, 12 hours, and 24 hours sensitivity were measured to be 19.8%, 75.2%, and 82.2%, respectively. These numbers for specificity were 91.7, 75, and 70.8, respectively; they were 90.9, 92.6, and 92.2 for PPV, and 21.3, 41.8, and 48.5 for NPV, respectively.
The sensitivity of ultrasound to detect intraperitoneal fluid in blunt abdominal trauma cases will be increased by repeated ultrasound examinations.