Identification of children with intra-abdominal injuries after blunt trauma.

Study Objective: We sought to determine the utility of laboratory testing after adjusting for physical examination findings in the identification of children with intra-abdominal injuries after blunt trauma.

Methods: The study was a prospective observational series of children younger than 16 years old who sustained blunt trauma and were at risk for intra-abdominal injuries during a 2(1/2)-year period at an urban Level I trauma center. Patients were examined by faculty emergency physicians and underwent standardized laboratory testing. Clinical and laboratory findings were recorded on a standardized data sheet. Intra-abdominal injury was considered present if an injury was documented to the spleen, liver, pancreas, kidney, adrenal glands, or gastrointestinal tract. We performed multiple logistic regression and binary recursive partitioning analyses to identify which physical examination findings and laboratory variables were independently associated with intra-abdominal injury.

Results: Of 1,095 enrolled patients, 107 (10%, 95% confidence interval [CI] 8% to 12%) had intra-abdominal injuries. The mean age was 8.4+/-4.8 years. From both analyses, we identified 6 findings associated with intra-abdominal injury: low systolic blood pressure (adjusted odds ratio [OR] 4.1; 95% CI 1.1 to 15.2), abdominal tenderness (adjusted OR 5.8; 95% CI 3.2 to 10.4), femur fracture (adjusted OR 1.3; 95% CI 0.5 to 3.7), serum aspartate aminotransferase concentration more than 200 U/L or serum alanine aminotransferase concentration more than 125 U/L (adjusted OR 17.4; 95% CI 9.4 to 32.1), urinalysis with more than 5 RBCs per high-powered field (adjusted OR 4.8; 95% CI 2.7 to 8.4), and an initial hematocrit of less than 30% (adjusted OR 2.6; 95% CI 0.9 to 7.5).

Conclusion: After adjusting for physical examination findings, laboratory testing contributes significantly to the identification of children with intra-abdominal injuries after blunt trauma.