Diagnostic value of serum bilirubin and liver enzyme levels in acute appendicitis

Background: Acute appendicitis (AA) is one of the most common indications for emergency abdominal surgery. Objective: To assess the diagnostic and prognostic value of serum bilirubin and liver enzyme levels in the management of acute appendicitis. Methods: Consecutive emergency department patients referred for a surgical consult for suspected AA were prospectively enrolled in the study. Data regarding demographic, clinical and laboratory results were recorded. Receiver operating characteristic (ROC) curve was performed for all evaluated parameters. Clinical and laboratory markers were evaluated for diagnostic accuracy and correlation to the clinical severity, histology reports, and length of hospital stay. Results: The study was comprised of 100 consecutive patients. ROC curve analysis revealed white blood cell count, absolute neutrophil count (ANC), C-reactive protein, total-bilirubin and direct-bilirubin levels as significant factors for diagnosis of AA. The combination of serum bilirubin levels, alanine transaminase levels, and ANC yielded the highest area under the curve (0.898, 95% confidence interval 0.835–0.962, P < 0.001) with a diagnostic accuracy of 86%. In addition, total and direct bilirubin levels significantly correlated with the severity of appendicitis as described in the operative and pathology reports (P < 0.01). Total and direct bilirubin also significantly correlated with the length of hospital stay (P < 0.01). Conclusions: Serum bilirubin levels, alone or combined with other markers, may be considered as a clinical marker for AA correlating with disease existence, severity, and length of hospital stay. These findings support the routine use of serum bilirubin levels in the workup of patients with suspected AA.