Utilization of a clinical prediction rule for abdominal-pelvic CT scans in patients with blunt abdominal trauma.

This study aims to determine if a clinical prediction (CP) rule to identify patients at low risk for intra-abdominal injury (IAI) is being utilized in patients undergoing abdominal computed tomography (CT) following blunt abdominal trauma. A retrospective review of adult patients with blunt abdominal trauma undergoing abdominal CT scans was performed. The CP rule was positive if any of the following were present: systolic blood pressure <90 mmHg; urinalysis >25 red blood cells/high power field; Glasgow Coma Scale score <14; abdominal tenderness; costal margin tenderness; femur fracture; hematocrit <30 %; or pneumothorax or rib fracture on chest X-ray. The CP rule was negative if all variables were negative. Acute intervention was defined as therapeutic laparotomy or angiographic embolization. All variables in the CP rule were obtained in 218/262 (83 %; 95 % confidence interval (CI), 78, 88 %) patients. Of the 44 patients without complete CP rule assessment, 1 (2.3 %; 95 % CI, 0.1 %, 12.0 %) had an IAI but did not undergo therapeutic intervention. IAI was present in 11 (6.7 %; 95 % CI, 3.4, 11.6 %) of the 165 patients with at least one CP rule positive and 4 (36 %; 95 % CI, 11, 69 %) underwent therapeutic intervention. In the CP rule-negative patients, IAI was identified in 1/53 (1.9 %; 95 % CI, 0, 10.1 %) and no therapeutic intervention was required. An important percentage of patients undergoing abdominal CT are not assessed for or have a negative CP rule. Improved implementation of this CP rule may reduce unnecessary abdominal CT scans in patients presenting with blunt abdominal trauma.