Predictors of Perforated Acute Appendicitis: A Retrospective Study from a Single Institution

Purpose. Prompt appendectomy has long been the standard of treatment for acute appendicitis, due to the risk of progression and subsequent postoperative complications. This study aimed to identify independent predictors of acute complicated appendicitis. Methods. Data were obtained from a retrospective database that recorded all appendicitis cases at the Chi-Mei Medical Center Data. There were 480 consecutive patients undergoing appendectomy for suspected acute appendicitis between January and December 2010. Two patient groups, without perforation (N = 332) and with perforation (N = 92), were analyzed to compare clinical characteristics, hospital stay, and post-operative complications. Results. Ninety-two patients with appendiceal perforation and 332 patients with simple appendicitis were confirmed pathologically. The overall perforation rate of appendicitis was 21.70% (92/424), and the negative appendectomy rate was 11.67% (56/480). Univariate and multivariate logistic regression analysis identified 2 independent factors associated with appendiceal perforation, the duration of abdominal pain for over 3 days (odds ratio (OR): 3.03, 95% confidence interval (CI): 1.62-5.65, p ＜ 0.001) and a C-reactive protein level over 30 mg/dl (OR: 5.38, 95% CI: 2.52-11.50, p ＜ 0.001). Conclusions. Computed tomography (CT) scanning has been shown to be highly accurate for diagnosing appendicitis, but it has not been specifically evaluated for perforated appendicitis. Combining the results of higher C-reactive protein levels obtained in the emergency department and patient delay are the predominant factors determining the incidence of complicated appendicitis.