What AST/ALT Threshold Warrants CT in Suspected Child Abuse?

May 29, 2024

Written by Michael Stocker

Spoon Feed
Current American Academy of Pediatrics (AAP) guidelines recommend a lower LFT threshold to obtain CT imaging for abdominal injury in children under 60 months old being evaluated for physical abuse than is recommended by general trauma guidelines – AST or ALT >80 IU/L vs AST>200 or ALT>125. This study suggests that, in the absence of signs and symptoms of abdominal injury, the higher LFT threshold may be sufficient…but let’s pump the brakes.

Less rads thanks to belly labs?
This single-site retrospective case series identified 237 kids under 60 months old presenting for physical abuse and found to have initial AST or ALT over 80 IU/L between 2011 and 2020. Of 131 (55.3%) who received abdominal CTs, 26(19.8%) had CT-identified abdominal injuries. Cases were grouped by LFTs: mid-range (AST 80-200; ALT 80-125), high-range (AST>200, ALT>125), and by presence of signs/symptoms of abdominal injury. No patients with midrange LFTs but no signs/symptoms of abdominal injury (41 children) had CT-identified injury – a negative predictive value of 100% (95%CI 97.0-100%). 2 of the 9 patients with mid-range LFTs and signs/symptoms of abdominal injury had CT-identified injury, both of whom presented in critical condition. Absence of signs/symptoms of abdominal injury was not sufficient to screen out injury in those with high-range LFT, 19.6% (11/56) of whom had CT-identified injuries. CT-identified injuries were most common in patients with signs/symptoms of abdominal injury and high-range LFTs, occurring in 13 of 52 children, 52% (95%CI 31.3-72.2%). Limitations include small size and risk of confirmation bias given the timing of provider documentation and imaging results.

How will this change my practice?
While I’m encouraged by the opportunity to reduce radiation in this vulnerable cohort, a single-site case review is not a practice-changer on its own. I’ll be sticking to my institution’s practice guidelines on this one and looking forward to future studies.

Source
AST and ALT Elevation in Suspected Physical Abuse: Can the Threshold to Obtain an Abdominal CT be Raised? J Trauma Acute Care Surg. 2024 Apr 11. doi: 10.1097/TA.0000000000004329. Epub ahead of print. PMID: 38527969