Comparison of Outer Diameter of Appendix, C-reactive Protein, and Serum Bilirubin Levels in Complicated Versus Uncomplicated Appendicitis

Abstract

The primary objective of the present study was to compare outer diameter of the vermiform appendix on ultrasound, high-sensitivity C-reactive protein (hs-CRP), and serum bilirubin in complicated versus uncomplicated appendicitis. Eighty patients with a diagnosis of acute appendicitis clinically and with confirmation on ultrasound undergoing operative management were included for this prospective, observational study. All the patients underwent transabdominal ultrasonography for measurement of diameter of the appendix. Total serum bilirubin and hs-CRP levels were measured. The operative findings were objectively classified as a complicated appendix if perforation of the appendix, empyema or abscess formation, faecal peritonitis, and gangrenous appendix were noted. Chi-square test or Fisher’s exact test and unpaired ‘t’ test were used to compare categorical and continuous variables respectively. Receiver operating characteristics (ROC) curve was used for different cut-off points of appendicular diameter and hs-CRP. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Mean appendicular diameter and mean hs-CRP level were significantly higher among the patients with complicated appendicitis compared with the patients with uncomplicated appendicitis. Sensitivity was 86.1%, 94.4%, and 100.0% for appendicular diameter ≥ 7.95 mm, hs-CRP ≥ 6.60 mg/dL, and appendicular diameter ≥ 7.95 mm or hs-CRP ≥ 6.60 mg/dL respectively. Specificity was 88.6%, 90.9%, and 81.8% for appendicular diameter ≥ 7.95 mm, hs-CRP ≥ 6.60 mg/dL, and appendicular diameter ≥ 7.95 mm or hs-CRP ≥ 6.60 mg/dL respectively. Appendicular diameter and hs-CRP levels were useful to diagnose complicated appendicitis preoperatively.