Importance of evaluating organ parenchyma during screening abdominal ultrasonography after blunt trauma.

OBJECTIVE: To determine the benefit of screening ultrasonography for parenchymal abnormalities as well as free fluid during screening abdominal ultrasonography in patients with blunt trauma.

METHODS: A total of 2693 patients with blunt trauma who were triaged to a level 1 trauma center underwent screening abdominal ultrasonography in the resuscitation suite. Examinations were performed by experienced sonographers and included a screen for free intraperitoneal fluid and evaluation of the abdominal organ parenchyma and heart for traumatic injury. Screening ultrasonographic findings were reviewed and compared with findings from autopsy, laparotomy, diagnostic peritoneal lavage, computed tomography, repeated ultrasonography, cystography, and clinical outcome. Imaging studies of all patients with confirmed or suspected injuries were reviewed to identify those in whom parenchymal findings aided diagnosis.

RESULTS: One hundred seventy-two patients were found to have evidence of abdominal injury due to blunt trauma on the basis of clinical data, imaging, laparotomy, or autopsy. Forty-four of these patients had no sonographic evidence of hemoperitoneum at the time of initial ultrasonography. Screening ultrasonographic findings were positive for injury in 19 of 44 patients on the basis of parenchymal findings or small retroperitoneal collections of fluid thought to be indicative of trauma. In the remaining 25 patients, screening ultrasonography showed no abnormalities, and injuries were detected by repeated ultrasonography, subsequent computed tomography, or diagnostic peritoneal lavage performed for suspected occult injury on the basis of clinical parameters. In addition, 47 of 126 injured patients with sonographically detected free fluid had parenchymal findings that helped localize injury. Sixteen of those patients were taken to the operating room on the basis of clinical and sonographic findings without undergoing computed tomography.

CONCLUSIONS: The inability to show injuries with no hemoperitoneum or with delayed hemoperitoneum has been shown to be a limitation of ultrasonography in patients with blunt trauma. In our series, 26% of all patients with documented injuries had no free fluid visible on screening ultrasonography Attention to findings other than free fluid allowed detection in 43% of injured patients without sonographic evidence of hemoperitoneum.