Diagnostic value of inflammation markers in predicting perforation in acute sigmoid diverticulitis.

Background: The importance of inflammation markers in predicting perforation in acute sigmoid diverticulitis is not well known. Predicting perforation by clinical examination alone may be hazardous. If perforation is suspected, then appropriate diagnostic tools such as computed tomography (CT) are indicated, and surgical intervention might be necessary.
Methods: A cohort of consecutive patients with acute sigmoid diverticulitis diagnosed by CT and with complete laboratory findings (n = 247) were retrospectively divided into two groups, one with perforation (n = 86) and another without (n = 161). The latest values of C-reactive protein (CRP), white blood cell count (WBC), and serum bilirubin, as well as the activity of the alkaline phosphatase (AP) measured during the 48 h period before the CT scan, were assessed.
Results: In the Wilcoxon rank sum test CRP and WBC correlate significantly (p < 0.05) with perforation in acute sigmoid diverticulitis, whereas the logistic regression model shows only CRP to correlate significantly (p = 0.001) with perforation. The sensitivities/specificities for perforation are 98%/5% for elevated CRP (>5 mg/l), 86%/27% for a CRP higher than 50 mg/l, 44%/81% for a CRP higher than 150 mg/l, 28%/93% for a CRP higher than 200 mg/l, 88%/44% for elevated WBC (>10 × 10(9)/l), 35%/90% for hyperbilirubinemia (>20 μmol/l), and 35%/91% for elevated AP (>110 U/l).
Conclusions: A CRP below 50 mg/l suggests a perforation to be unlikely in acute sigmoid diverticulitis, whereas a CRP higher than 200 mg/l is a strong indicator of perforation.