May liver transaminases substitute for computed tomography in evaluation of blunt liver injury? With special emphasis on serum cut-off levels

Abstract

Background: Although computed tomography (CT) has become the standard diagnostic modality for patients with blunt liver trauma, it is costly and results in a marked increase in radiation exposure. Purpose of this study was to establish cut-off values for transaminases, and to interrogate the necessity of CT. Methods: Transaminase levels of all patients with blunt abdominal trauma admitted to our clinic from 2009 to 2014 were analysed, and compared to radiological findings and final outcome. Classification of injury was done according to the American Association for the Surgery of Trauma (AAST)'s hepatic injury scale. Chisquare and Mann–Whitney U tests were used for statistical analyses, and receiver operating characteristic (ROC) curve was performed to define the cut-off values for aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Results: Of the 285 patients with blunt abdominal trauma, 50 (17.5%) had radiological evidence of liver injury (Group 1). Remaining 235 (82.4%) had no liver injury (Group 2). Group 1 had significantly increased AST and ALT values compared to Group 2 (p=0,001). AST as well as ALT levels were significantly higher in patients with major liver injury. Optimal cut-off values for AST and ALT were 313 IU/L and 250 IU/L, respectively, with 95% specificity. There was no mortality in both groups. Conclusion: Liver transaminases can be used effectively in eliminating unnecessary use of CT. This allows for cost-effective use of resources, and eliminates the risks of radiation.