C-reactive protein: diagnostic aid in right lower quadrant abdominal pain
The aim of this study is to investigate the role of CRP and total leukocyte count in the investigation of right lower quadrant abdominal pain. Methods: 537 patients were included in this study who presented at the General Hospital of Amfissa with right lower quadrant abdominal pain, with a median age of 26 years. 335 patients were admitted in the Surgical Clinic and 195 of them underwent surgery. The preoperative laboratory findings were correlated with the histopathology of the excised appendices. Results: Patients who were finally diagnosed with non-specific abdominal pain had normal CRP levels, lower than 0.1mg/dl, and normal or slightly elevated white blood cell count, with the exception of 1 patient who had CRP level slightly above 0.1 mg/dl. Patients with uncomplicated acute appendicitis had increased CRP (1-3 mg/ dl) and elevated leukocyte count, with the exception of 5 patients who had CRP level less than 1 mg/dl. Finally, patients with gangrenous appendix had CRP values between 3 and 6 mg/dl and elevated leukocyte count, while perforated appendix was correlated with significantly raised levels of CRP (>10mg/dl) and elevated or normal leukocyte count. Sensitivity, specificity, positive predictive value and negative predictive value of CRP in diagnosing acute appendicitis was estimated at 97.27%, 99.34%, 99.44% and 96.79% respectively.
Conclusions: In patients presenting with right lower quadrant abdominal pain, normal CRP level and total leukocyte count, the diagnosis of acute appendicitis is extremely rare. Furthermore, CRP value above 10mg/dl is correlated with perforated appendix.