Preoperative diagnostic role of hyperbilirubinaemia as a marker of appendix perforation

This retrospective study investigated preoperative markers of appendix perforation in 351 acute appendicitis cases: group 1, appendicitis not histologically confirmed; group 2, appendicitis without perforation or gangrenous changes; and group 3, histologically confirmed perforated appendicitis with gangrenous changes. In group 3, symptom duration was significantly longer, and white blood cell (WBC) and bilirubin values significantly higher, than for the other groups. Symptom duration, gender, bilirubin and elevated WBC were significantly associated with early diagnosis of acute appendicitis in univariate analysis. Multivariate analysis identified increased WBC counts and male gender as independent variables for the early diagnosis of acute suppurative appendicitis, and symptom duration, total bilirubin and elevated WBC as independent variables for identifying appendix perforation amongst acute suppurative appendicitis patients. Receiver operating characteristic curve analysis showed good discrimination of bilirubin and moderate discrimination of WBC as markers of appendix perforation. It is concluded that assessment of preoperative total bilirubin is useful for the differential diagnosis of perforated versus acute suppurative appendicitis, whereas WBC assessment is effective for diagnosing the presence versus absence of appendicitis. Symptom duration, WBC and total bilirubin should be used as independent parameters in the early diagnosis of appendix perforation.