Diagnostic power of inflammatory markers in predicting severity of appendicitis.

BACKGROUND/AIMS: Severity of inflammation may be a risk factor for negative outcome in non-operative therapy of appendicitis. However, optimal screening test for predicting the pathological severity of appendicitis has not been established. METHODOLOGY: 632 consecutive patients who underwent appendectomy at a single institute were retrospectively reviewed. Clinical parameters are compared among the three pathological grades: simple (G1), gangrenous (G2), and perforated appendicitis (G3). The diagnostic power of inflammatory markers (WBC count and CRP concentration) in discriminating the advanced appendicitis from the milder one was evaluated. RESULTS: CRP concentration was well correlated with the severity of appendicitis (p>0.0001), while WBC count showed only slight increase in advanced pathology (G1 vs. G2-G3). In receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) was remarkably higher in CRP (AUC 0.809) compared with that in WBC count (AUC 0.617), suggesting that CRP is a more sensitive test in discriminating the pathological severity of appendicitis. Multivariate analysis confirmed that CRP concentration >6.2mg/dL (OR: 5.12; 95% CI: 2.17-12.7) and diameter >12mm (OR: 4.33; 95% CI: 1.98-9.90) were strong predictive factors for advanced appendicitis. CONCLUSIONS: CRP concentration may be a potent objective predictor of pathological severity in appendicitis. Combination with the other diagnostic modalities may improve the diagnostic accuracy in predicting the severity of appendicitis.