Can perforated appendicitis Be diagnosed preoperatively based on admission factors?

The optimal initial treatment for selected patients with perforated appendicitis may be nonoperative. For this reason it is important to be able to diagnose perforated appendicitis preoperatively. The purpose of this study was to determine the accuracy of diagnosing perforated appendicitis using only admission factors. The study population was comprised of 366 adult patients who underwent appendectomy for presumed appendicitis during 1997. Admission factors associated with perforated appendicitis were determined using univariate and multivariate analyses. These variables were then used to formulate a rule for the diagnosis of perforated appendicitis. Sensitivity and specificity were calculated for this rule. The admission factors analyzed were sex, race, age, days of pain, temperature, heart rate, symptoms, physical examination findings, and laboratory findings. Multivariate regression analysis revealed days of pain, temperature, and localized tenderness outside the right lower quadrant to be significant (P <0.05). Using two or more days of pain, a temperature of >/=101 F (38.3 C), or localized tenderness outside the right lower quadrant as criteria to indicate perforation, we achieved a sensitivity of 86% and a specificity of 58% for distinguishing perforated from nonperforated appendicitis. We concluded that (1) perforated appendicitis cannot reliably be distinguished from nonperforated appendicitis based on admission factors, and (2) two or more days of pain, localized tenderness outside the right lower quadrant, and a temperature of >/=101 F (38.3 C) define a group of patients with appendicitis who have a high incidence of perforation.