Diagnostic Value of C-Reactive Protein for Detection of Acute Appendicitis in Adults

Acute appendicitis is a common cause of abdominal pain and it can be difficult to diagnose, especially during the early stages. 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 C-reactive protein and the other serum markers of inflammation, total white cell and neutrophil count in the diagnosis of acute appendicitis in adult. Patients and

In a prospective analytic setting, 100 patients with the probable diagnosis of acute appendicitis (Alvarado score ≤5) that had referred to Tabriz Pediatric Hospital during 2007-08 were studied. The CRP, WBC count and neutrophil percentage were checked on admission in all patients and were compared between the patients with and without definite diagnosis of acute appendicitis according to the result of histopathologic study or follow up (as the gold standard methods) via Student t-test, Mann-Whitney U test, Chi-Square test and Fisher’s Exact test.

A total of 52 males and 48 females with the mean age of 20.6±4.1 years were recruited. Fifty four (54%) patients revealed to have definite acute appendicitis. Patients with final diagnosis of acute appendicitis had significantly greater values of inflammatory markers. Elevated CRP had sensitivity (62.7%), specificity (68.3%), positive predictive value (74%) and negative predictive value (56%) which are not enough for diagnosis. Only 2 patients with normal markers had acute appendicitis.

This study showed that despite the elevation of these inflammatory markers in patients with acute appendicitis, mere reliance on laboratory findings in managing the patients with equivocal appendicitis would not make sense. Combination of the clinical suspicion with these laboratory data is recommended. Normal values of all of these markers are very unlikely in pathologically confirmed appendicitis in adult.