Predictive factors of perforated appendicitis: Impact of the C-reactive protein level

Perforated appendicitis without an associated abscess necessitates emergency surgery. However, it is difficult to predict the presence of perforation before surgery, and the predictive factors are still unclarified. Our purposes were to characterize a patient population with perforated appendicitis without an associated abscess to identify the preoperative predictive factors of appendiceal perforation.

We retrospectively identified 150 patients who underwent appendectomy for acute appendicitis at our institution from June 2018 to November 2020. Logistic regression analysis was performed to analyze the concurrent effects of various factors on the prevalence of perforated appendicitis.

Forty (29%) of 150 patients had appendiceal perforation detected intraoperatively. Of these 40 patients, only 19 had appendiceal perforation detected on preoperative computed tomography. Multivariable analysis found that a higher C-reactive protein level, higher total bilirubin level, and the presence of an appendiceal fecalith were independent predictive factors for appendicitis with perforation.

Our analysis suggests that the presence of an appendiceal fecalith, a total bilirubin level of more than 21.38 μmol/L, and a C-reactive protein level of more than 3.0 × 10⁴ μg/L are predictive factors of perforated appendicitis.