Background:The identification of intra-abdominal injuries (IAI) in children with blunt trauma may be difficult. Clinicians often use laboratory tests to aid in the diagnosis of IAI, however, the utility of these tests is unclear.

Objective: To determine the utility of laboratory tests for detecting IAI in children with blunt trauma.

Methods: We prospectively evaluated patients (pts) <16 years old with blunt trauma to the thorax or abdomen over a 14 month period. Each pt was examined by the faculty physician in the emergency department (ED) and had a standardized laboratory evaluation. Physical examination findings were recorded prior to knowledge of laboratory results. Indications for diagnostic abdominal imaging and/or surgery (AI/S) were recorded. Pts were followed through the hospital course if admitted or had a follow-up telephone call one week after discharge from the ED. Alanine aminotransferase > 125 U/L or aspartate aminotransferase > 200 U/L were considered to represent abnormally elevated liver function tests (LFTs).

Results: 570 pts were entered into the study. Of these, 349 (61%) had AI/S, and 61 (11%) had IAI (23 splenic, 30 liver, 9 kidney, 2 pancreatic, 2 adrenal, and 14 gastrointestinal injuries). 236 pts had no indications for AI/S on physical examination of the abdomen or central nervous system (no abdominal pain or tenderness, normal mental status) or urinalysis (< 20 RBCs/hpf) and 11 (5%) of these pts had IAI. Six (55%) of the 11 had abnormally elevated LFTs, versus 5 (2%) of the 225 pts without IAI. The clinical utility of abnormally elevated LFTs for detecting IAI was therefore: Sensitivity 55%(95% confidence interval (CI) 23-83%), specificity 98% (95% CI 95-99%), positive predictive value 55% (95%CI 23-83%), negative predictive value 98%(95%CI 95-99%).

Conclusions:LFTs are useful in identifying IAI in children with blunt trauma who do not have other indications for AI/S. Table

Table 1 No caption available.
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