Complicated acute appendicitis in children: the importance of stewarding antibiotic prescriptions.

Background: The aim was to assess the success of a three-drug regimen, consisting of cefazoline, metronidazole and gentamicine, for the antimicrobial treatment of complicated appendicitis and to investigate predictors of failure.

Methods: This retrospective study included patients who had undergone appendectomy for complicated appendicitis from 2013 to 2018. The shift to second-line antibiotics was considered a failure. The choice was based upon clinical deterioration. Patients were grouped into 2 groups: localized complicated appendicitis (LCA) and extensively complicated appendicitis (ECA) for the study purpose. Univariate and multivariate analysis were performed to identify predictors of failure.

Results: Ninety patients (65.2%) with LCA and 48 patients (35%) with ECA were included. Three-drug regimen failed in 50 patients (36%) with a higher rate in the ECA group (50%, p=0.017). In a multivariate analysis, this failure was found to be associated with ECA (adjusted OR 3.00 [1.2-7.4], p=0.041). Children with ECA experienced a longer hospital stay (median length 8 days, p < 0.001) and antimicrobial therapy (median length 8 days, p < 0.001). However, no difference in the rate of surgical site infections was found (p=0.514).

Conclusions: The institutional antibiotic stewardship program highlighted a high failure rate for the old threedrug regimen. A new protocol should be recommended, especially for the patients affected by ECA.