Evaluation for intra-abdominal injury in children after blunt torso trauma: can we reduce unnecessary abdominal computed tomography by utilizing a clinical prediction model?

BACKGROUND: Blunt trauma is a leading cause of morbidity and mortality in children. Despite the potential for malignancy, increased cost, limited small bowel injury detection sensitivity, and the low incidence of injury requiring operative intervention, the use of computed tomographic (CT) scan in pediatric blunt trauma evaluation remains common. Previous studies suggest that a clinical model using examination and laboratory data may help predict intra-abdominal injuries (IAIs) and potentially limit unnecessary CT scans in children.

METHODS: A retrospective chart review of all blunt "trauma alerts" for patients younger than 16 years during an 18-month period was performed at a Level I trauma center. Clinical factors, which might predict blunt IAI (hemodynamics, abdominal examination, serology, and plain radiographs), and potential limitations to performing a reliable abdominal examination (altered mental status, young age) were reviewed. A previously defined clinical prediction model based on six high-risk clinical variables for blunt IAI (hypotension, abnormal abdominal examination, elevated aspartate aminotransferase, elevated amylase, low hematocrit, and heme-positive urinalysis) was applied to each patient.

RESULTS: Of the 125 "trauma alert" patients who sustained blunt trauma during the study period, 97 underwent abdominal CT scan, with only 15 identified as IAI. Our prediction rule would have identified 16 of 17 patients with IAI (SE, 94%) as high-risk and missed only 1 patient (grade I spleen laceration, which did not require operation) (negative predictive value, 99%). Of the 83 patients with no risk factors for IAI based on the prediction rule, 54 underwent a negative abdominal CT scan. Of these 54 patients, only 22 had a potential limitation to a reliable abdominal examination. Application of our prediction rule could have prevented unnecessary CT scan in at least 32 patients (33%) during an 18-month period.

CONCLUSION: Use of a prediction model based on high-risk variables for IAI may decrease cost and radiation exposure by reducing the number of abdominal CT scans in children being evaluated for blunt abdominal trauma.