AST and ALT Elevation in Suspected Physical Abuse: Can the Threshold to Obtain an Abdominal CT be Raised?

BACKGROUND: Identification of abdominal injury (AI) in children with concern for physical abuse is important as it can provide important medical and forensic information. Current recommendations are to obtain screening liver function tests (LFTs) in all children with suspected physical abuse and an abdominal computed tomography (CT) when the aspartate aminotransferase (AST) or alanine aminotransferase (ALT) is >80 IU/L. This threshold to obtain an abdominal CT is lower than general trauma guidelines which use a cutoff of AST > 200 or ALT >125 IU/L.

METHODS: This was a retrospective review of children ages 0-60 months at a single pediatric tertiary care center who were evaluated for physical abuse and had AST or ALT >80 IU/L. Subjects were then stratified into two groups: mid-range (AST < 200 and ALT <125 IU/L) and high-range (AST > 200 and/or ALT >125 IU/L) LFTs.

RESULTS: Abdominal CTs were performed in 55% (131/237) of subjects, 38% (50/131) with mid-range LFTs and 62% (81/131) with high-range LFTs. AI was identified in 19.8% (26/131) of subjects. Subjects with AI were older than those without AI [mean age (SD) 18.7 (12.5) vs. 11.6 (12.2) months, p = 0.009]. The highest yield of abdominal CTs positive for AI was in the group with high-range LFTs with signs or symptoms of AI at 52.0% (13/25; 95% CI: 31.3-72.2%). The negative predictive value of having mid-range LFTs and no signs or symptoms of AI was 100% (95% CI: 97.0-100%).

CONCLUSIONS: Our data suggest that abdominal CT may not be necessary in children being evaluated for physical abuse who have AST < 200 and ALT <125 IU/L and do not have signs or symptoms of AI. This could limit the number of abdominal CTs performed.

LEVEL OF EVIDENCE: Level IV, Diagnostic Test/Criteria.