Re-evaluation of liver transaminase cutoff for CT after pediatric blunt abdominal trauma

Current guidelines for computed tomography (CT) after blunt trauma were developed to capture all intra-abdominal injuries (IAI). We hypothesize that current AST/ALT guidelines are too low leading to unnecessary CT scans for children after blunt abdominal trauma (BAT).

Patients who received CT of the abdomen after blunt trauma at our Level I Pediatric Trauma Center were stratified into a high risk (HR) (liver/spleen/kidney grade ≥III, hollow viscous, or pancreatic injuries) and low risk (LR) (liver/kidney/spleen injuries grade ≤II, or no IAI) groups.

247 patients were included. Of the 18 patients in the HR group, two required surgery (splenectomy and sigmoidectomy). Transfusion was required in 30% of grade III and 50% of grade IV injuries. Eleven (5%) patients in LR group were transfused for indications other than IAI, and none were explored surgically. Both AST (r = 0.44, p < 0.001) and ALT (r = 0.43, p < 0.001) correlated with grade of liver injury. Using an increased threshold of AST/ALT, 400/200 had a negative predictive value of 96% in predicting the presence of HR liver injuries.

The current cutoff of liver enzymes leads to over-identification of LR injuries. Consideration should be given to an approach that aims to utilize CT in pediatric BAT that identifies clinically HR injury.