Can ultrasonography replace computed tomography in the initial assessment of children with blunt abdominal trauma?

Abstract

The evaluation of injured children with suspected blunt abdominal trauma (BAT) is clinically challenging. Computed tomography (CT) requires that patients be sedated, stable, and transportable, and even so, it is considered the diagnostic modality of choice for children with BAT. The authors questioned whether abdominal ultrasonography (US) performed during the initial assessment of the injured child is accurate enough to replace CT in the detection of intraabdominal injury. One hundred twenty-four children with BAT aged 2 to 14 years; (average, 8.3) were admitted to the authors' institution during 1992 and 1993. Some had associated injuries (head, 60; chest, 25; extremities, 15; pelvis, 5). The indications for US were pelvic, abdominal, or lower chest trauma, tenderness, or guarding; altered consciousness; microhematuria; and/or low hemoglobin/hematocrit values. Three patients underwent abdominal CT at the time of admission. For 121 children, an emergency US examination was performed using a 3.5-MHz transducer and a portable machine. The examination evaluated the kidneys, liver, and spleen for parenchymal injuries, and the subhepatic, subphrenic, and paracolic spaces and the pelvis for evidence of free peritoneal fluid. The presence of fluid and/or parenchymal injury was interpreted as a positive US result. Twenty-eight patients had positive US findings. Ten of these had a subsequent positive CT result, eight had a normal CT result, and 10 had a negative second US result. Eleven patients (with a total of 17 visceral injuries) were treated conservatively. One patient underwent emergency surgery for liver and caval injuries. Four patients required blood transfusions. Ninety-three of the 121 (78%) had a negative US result. For one of these patients, a subsequent CT scan showed a minor subcapsular splenic hematoma, which resolved spontaneously. The authors conclude that US is sensitive in detecting free peritoneal fluid or visceral injuries and is an effective screening modality. It has replaced abdominal CT in 76% of our patients with suspected BAT. In view of the reliability, simplicity, low cost, and bedside availability of US, the authors suggest that this modality be used in the initial assessment and diagnosis of children with suspected intraabdominal injury from blunt trauma.