Patients with clinical acute appendicitis should have pre-operative full blood count and C-reactive protein assays.

INTRODUCTION: The role of inflammatory markers in the diagnosis of acute appendicitis has not been clearly defined. The aims of this prospective audit were to define the role of the serum markers of inflammation total white cell count, neutrophil count and C-reactive protein in the diagnosis of acute appendicitis with particular reference to the discrimination between uncomplicated and complicated appendicitis, and the prediction of abscess. PATIENTS AND METHODS: The author compiled a prospective database over a 13-month period of all appendicectomies performed. After five exclusions (three having no notes for review and two having confounding second morbidity in the presence of a normal appendix), the data relating to 75 patients were analysed.
RESULTS: In patients judged on clinical grounds to require laparotomy for suspected acute appendicitis, white cell count and neutrophil count distinguish acute appendicitis from normal appendices when used as categorical variables, though they do not reflect the presence of abscess. C-reactive protein neither distinguishes appendicitis from normal, nor predicts abscess when used as a categorical variable, though higher levels suggest abscess.
CONCLUSIONS: Laboratory tests of the white cell count, neutrophil count and C-reactive protein are more effective in supporting a clinical diagnosis of acute appendicitis in patients with typical clinical features than in excluding the diagnosis.