Diagnostic Value of Elevated Liver Transaminase in Hemodynamically Stable Patients with Blunt Abdominal Trauma

ABSTRACT

PURPOSE: A patient at the emergency department (ED) with blunt abdominal trauma may still have the possibility of liver injury, even though they are hemodynamically stable. Computed tomography (CT) scanning or ultrasonography (US) is available if they are hemodynamically stable. However ultrasonography (US) has technical differences between physicians depending on their skill and computed tomography (CT) is expensive and time consuming, while liver transaminase is widely available, relatively inexpensive. Therefore, we studied diagnostic value of liver transaminase as a screening test for liver injury in hemodynamically stable patients with blunt abdominal trauma. METHODS: From March 2000 to February 2001, we treated 44 hemodynamically stable patients with suspected blunt abdominal trauma who were patients with elevated liver transaminase. An evaluation protocol including patient's age, sex, injury mechanism, history, physical examination, Glasgow Coma Scale (GCS), Revised Trauma Score (RTS), Injury Severity Scale (ISS), liver transaminase, abdominal US and abdominal CT was prospectively performed on all patients by residents and the staff of the emergency department. Based on the confirmed diagnosis of abdominal CT, patients were divided into two groups group I with liver injury and group II without liver injury. We analysed the two groups by using the t-test and the chisquare test, and calculated the sensitivity, the specificity and the predictive value of serum aspartate aminotransferase (AST) and serum alanine aminotransferase (ALT) by using multiple cutoff values. RESULTS: There were 34 male patients (76.3%) and 10 female patients (23.7%) and the average age of all patients was 37 years. Triage RTS and GCS were, respectively, 11.7+/-0.7 and 13.9+/-2.1 in group I, and 11.4+/-1.2 and 13.2 +/-3.5 in group II, the differences between the two groups were statistically insignificant. The ISS was 26.8+/-9.4 in group I and 21.1+/-8.0 in group II, and the differences was statistically significant. AST and ALT were, respectively, 288.0+/-113.7 IU/L and 177.9+/-95.8 IU/L in group I and 148.1+/-84.8 IU/L and 95.1+/-59.8 IU/L in group II. The maximum value of the highest sensitivity and minimal specificity of AST and ALT, calculated using the receiver operator curve, were AST > 256.3 IU/L and/or ALT > 122.0 IU/L, for which the sensitivity and the specificity were 61.1% and 84.6%, and the positive and the negative predictive values were 73.3% and 75.8%, respectively. CONCLUSION: We recommend that all patient with suspected blunt abdominal trauma be evaluated using serum liver transaminase as a screening test for liver injury even though they are hemodynamically stable. If AST > 256.3 IU/L and/or ALT 122.0 >IU/L, they should be evaluated with abdominal CT to confirm liver injury.