Lack of utility of measuring serum bilirubin concentration in distinguishing perforation status of pediatric appendicitis

Background Pediatric appendicitis is a common, potentially serious condition. Determining perforation status is crucial to planning effective management. Purpose Determine the efficacy of serum total bilirubin concentration [STBC] in distinguishing perforation status in children with appendicitis. Methods Retrospective review of 257 cases of appendicitis who received abdominal CT scan and measurement of STBC. Results There were 109 with perforation vs 148 without perforation. Although elevated STBC was significantly more common in those with [36%] vs without perforation [22%], the mean difference in elevated values between groups [0.1 mg/dL] was clinically insignificant. Higher degrees of hyperbilirubinemia [> 2 mg/dL] were rarely encountered [5%]. Predictive values for elevated STBC in distinguishing perforation outcome were imprecise [sensitivity 38.5%, specificity 78.4%, PPV 56.8%, NPV 63.4%]. ROC curve analysis of multiple clinical and other laboratory factors for predicting perforation status was unenhanced by adding the STBC variable. Specific analysis of those with perforated appendicitis and percutaneously-drained intra-abdominal abscess which was culture-positive for Escherichia coli showed an identical rate of STBC elevation compared to all with perforation. Conclusions The routine measurement of STBC does not accurately distinguish perforation status in children with appendicitis, nor discern infecting organism in those with perforation and intra-abdominal abscess.