Diagnostic Accuracy of AST and ALT for Detecting Liver Injury in Blunt Abdominal Trauma.

Introduction: Liver injury from blunt abdominal trauma (BAT) is typically diagnosed using computed tomography (CT); however, access to CT imaging is limited in some hospitals. Liver function tests may serve as adjuncts to improve diagnostic accuracy and reduce unnecessary CT scans. This study evaluates whether thresholds of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) can assist in diagnosing liver injury in BAT patients and support clinical decision-making. Methods: A retrospective and observational study was conducted at Saraburi Hospital from 2020 to 2023, including patients over 15 years old with BAT. Exclusion criteria included penetrating injuries, pregnancy, and laboratory testing delayed beyond 24 h after admission. Diagnostic performance of AST and ALT was assessed using receiver operating characteristic (ROC) curves and Youden's J statistic to determine the optimal cutoff values. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. Results: Of 565 patients, 160 (28.3%) were diagnosed with liver injuries confirmed by CT scan or laparotomy. AST and ALT demonstrated good discriminatory power, with area under the curve (AUC)-ROC values of 0.80 and 0.82. Using cutoff values of AST ≥120 U/L and ALT ≥105 U/L, sensitivity was 88.1% and 82.5%, while specificity was 71.4% and 81.0%. Incorporating these markers into the diagnostic model improved AUC-ROC from 0.762 to 0.891. Conclusions: AST and ALT significantly improved liver injury detection in BAT patients. Incorporating these biomarkers into early clinical assessment may reduce reliance on CT imaging, especially in the resource-limited settings.