Negative computed tomography can safely rule out clinically significant intra-abdominal injury in the asymptomatic patient after blunt trauma: Prospective evaluation of 1193 patients

BACKGROUND Computed tomography of the abdomen and pelvis (CTAP) is highly specific for injury identification and commonly used in the evaluation of blunt trauma patients. Despite this, there is no consensus on the required clinical observation period after negative imaging, often impacting patient flow and hospital cost. The purpose of this study was to evaluate the use of CTAP after blunt trauma and the need for observation after negative imaging. METHODS A prospective analysis at a large Level I trauma center was conducted from November 2014 to May 2015. All blunt trauma patients, older than 14 years with CTAP on admission were included. Symptomatic patients were defined as having abdominal pain or external signs of trauma on admission. The main outcome was missed injury. RESULTS Over the study period, there were 1,468 blunt trauma admissions, of which 1,193 patients underwent CTAP. Eight hundred six (67.6%) patients were evaluable on admission (Glasgow Coma Scale score, 15), and of these, 327 (40.6%) were symptomatic, 479 (59.4%) asymptomatic. Among the evaluable asymptomatic patients, there were 65 (13.6%) positive computed tomography scans including 11 patients with grade III, IV, or V solid organ injury and three that required operation. In the 414 evaluable asymptomatic patients with negative imaging, median length of stay was 3 days, and there were zero missed injuries. All images were reviewed by an attending radiologist. CONCLUSION Abdominal imaging after trauma is justified in the appropriate clinical setting to evaluate for significant abdominal injury regardless of symptomatology. In asymptomatic, evaluable patients with a negative CTAP, clinically significant abdominal injury is unlikely, and these patients may be considered for early discharge or disposition to another treatment service. LEVEL OF EVIDENCE Diagnostic, level III; Therapy, level IV.