Would measurement of C-reactive protein reduce the rate of negative exploration for acute appendicitis?

Background: Appendicectomy for suspected acute appendicitis is a common pro cedure. The rate of normal appendices unnecessarily removed remains high (1 5-30%) despite several techniques and investigations used to improve the di agnostic accuracy, Many studies investigated the role of raised C-reactive protein in improving the diagnosis of acute appendicitis, but with conflict ing results, This study emphasises the impact of a normal (rather than rais ed) serum C-reactive protein in reducing the rate of negative explorations. Methods: In a double blind study, blood for the measurement of serum C-rea ctive protein (CRP) was collected pre-operatively from 78 patients just bef ore going to the operating room for appendicectomy. The histopathology of t he 78 appendices were grouped into positive (acute appendicitis) and negati ve (normal appendix). White blood count (WBC), CRP and the histopathology f indings were correlated. Results: Tn patients with histopathologically prov en acute appendicitis both the WBC count and serum CRP level were significa ntly raised (P=0.025 and P<0.000,1 respectively). Serum CRP level was norma l in 13 out of 15 negative explorations (normal appendix on histopathology) . The specificity and sensitivity of serum CRP was 86.6% and 93.6%, respect ively. Conclusion: A normal pre-operative serum CRP measurement in patients with suspected acute appendicitis is most likely associated with a normal appendix, Deferring surgery in this group of patients would probably reduce the rate of unnecessary appendicectomies.