Hyperbilirubinemia is a significant indicator for the severity of acute appendicitis.

Purpose: This study aims to reveal more effective clinical or laboratory markers for the diagnosis of acute appendicitis and to score the severity based on a sufficiently large number of patients with acute appendicitis.

Methods: We identified 1,195 patients with acute appendicitis after excluding those with other causes of hyperbilirubinemia among the 1,271 patients that underwent a laparoscopic or an open appendectomy between 2009 and 2010. A retrospective chart review of the medical records, including laboratory and histologic results, was conducted. We then analyzed the data using univariate and multivariate analyses.

Results: Among the 1,195 patients, a laparoscopic appendectomy was performed in 685 cases (57.32%), and an open appendectomy was performed in 510 cases (42.68%). The univariate analysis demonstrated significant differences for white blood cell count (P < 0.0001), segmented neutrophils (P = 0.0035), total bilirubin (P < 0.0001), and systemic inflammatory response syndrome (SIRS) score between groups (P < 0.0001). The multivariate analysis demonstrated that total bilirubin (odds ratio, 1.772; 95% confidence interval, 1.320 to 2.379; P = 0.0001) and SIRS score (odds ratio, 1.583; 95% confidence interval, 1.313 to 1.908; P < 0.0001) have statistically significant diagnostic value for perforated appendicitis.

Conclusion: Hyperbilirubinemia is a statistically significant diagnostic marker for acute appendicitis and the likelihood of perforation.