Perforated and non-perforated acute appendicitis - One disease or two entities?

Objective: To analyse the pattern of clinical presentation of perforated an d non-perforated acute appendicitis in 544 unselected patients treated surg ically for suspected acute appendicitis; to find out if their presentation differed. Design: Open prospective population-based study. Setting: Teaching hospital, western Norway. Patients: All 434 patients operated on for suspected acute appendicitis fro m the catchment area of a single hospital in whom the diagnosis was confirm ed. Interventions: Appendicectomy; history, clinical findings, and inflamma tory markers were recorded in all patients. Main outcome measures: Odds Ratio (OR) and 95% confidence interval (CI) obt ained by logistic regression analysis of symptoms and signs of acute append icitis with regard to independent predictors of perforation of the appendix . Receiver operating characteristic (ROC) curve analysis of inflammatory ma rkers. Results: The perforation rate was 20% (n = 88). Perforation was unlikely wh en abdominal pain was limited to the right iliac fossa, (OR 0.13, 95% CI 0. 05 to 0.33). Increased C-reactive protein (CRP) concentration > 50 U/L (OR 4.6, 95% CI 2.44 to 8.75) and greater age (by decade; OR 1.18, 95% CI 1.02 to 1.36) were independent predictors of perforation of the appendix. Conclusions: Clinical differences between perforated and non-perforated acu te appendicitis could be explained by the presence of advanced inflammation in patients with perforated appendicitis. Our data do not support the hypo thesis that they are two clinically different diseases.