Abstract
Introduction
The purpose of this study is to evaluate the diagnostic value of C-reactive protein (CRP) to identify complicated appendicitis (defined as perforation, abscess or gangrenous appendicitis) versus simple appendicitis.
Methods
A retrospective study was performed in the emergency department (ED) of Prince of Wales Hospital in the New Territories of Hong Kong. The clinical records of patients admitted to the surgical wards via the ED over 17 months were reviewed by a research assistant. We included all patients aged >13 years who had a provisional diagnosis of “acute appendicitis” or “right lower quadrant pain”. We excluded patients with pregnancy, previous appendicectomy, incomplete medical records or no CRP levels determined before operation and those who discharged themselves from hospital against medical advice after admission. The outcome of this study was the CRP level in relation to the presence of complicated appendicitis. ROC curve analysis was employed to identify the optimum cut-off level of CRP which had the best sensitivity and specificity to identify complicated appendicitis compared to simple appendicitis.
Results
Forty-two patients were diagnosed to have acute appendicitis, 31 of whom had complicated appendicitis. CRP level was higher in the group of complicated appendicitis (p<0.05). We identified an optimum cut-off value for CRP of 40.1 mg/L to discriminate between complicated and non-complicated appendicitis. The sensitivity and specificity of CRP to identify complicated appendicitis were 71.0% and 100% respectively at this cut-off level.
Conclusion
High CRP levels could possibly predict the diagnosis of complicated appendicitis and facilitate more appropriate surgical care. This finding needs to be confirmed in prospective and larger multicentre studies. (Hong Kong j.emerg.med. 2014;21:354-360)