Monitoring C-reactive protein levels during medical management of acute appendicitis to predict the need for surgery

To clarify the role of medical treatment in the management of acute appendicitis and the value of C-reactive protein (CRP) for predicting its failure.

Patients with clinically diagnosed acute appendicitis, confirmed by imaging studies, were enrolled in this study. We measured leukocyte counts and CRP levels and recorded success and recurrence rates and the efficiency of medical treatment during follow-up. The efficiency of CRP values to predict failure of medical treatment was evaluated using receiver operating characteristics (ROC) curve analysis.

The subjects comprised 193 patients (mean age 30.9 years) who received medical treatment for acute appendicitis. The mean follow-up period was 12.3 (6–24) months and the early success rate of medical treatment was 86.5 % (160/185). Fifteen (9.3 %) patients suffered recurrence during follow-up. The leukocyte and CRP levels in these two groups of patients were not significantly different at the beginning of the treatment, but the increase in the CRP value differed significantly between the two groups during the follow-up period (p < 0.001). ROC curve analysis suggested that the optimum CRP cut-off point for unsuccessful medical treatment was 80.8 mg/L, with 81.82 % sensitivity and 84.34 % specificity (p < 0.001).

The success rate for treating acute appendicitis medically is high, with antibiotic treatment being effective as the firstline therapy for many unselected patients. An increase in CRP levels to 80.8 mg/L and above seems to be a meaningful parameter for determining a lack of response to medical treatment.