[The importance of microbiological results for the treatment of complicated appendicitis-a monocentric case-control...

Patients with complicated appendicitis frequently develop postoperative septic complications. There are no uniform standards for the choice of perioperative antibiotic prophylaxis and the duration of postoperative antibiotic treatment. The purpose of this study was to investigate associations between microbiological samples and postoperative complications.

Patients with appendectomy and positive intraoperative swabs during 2013-2018 were included in this case-control study. Pathogen classes and their resistance patterns were evaluated in initial and follow-up swabs and compared in each of the groups with and without complications.

A total of 870 patients underwent surgery during the period studied. Pathogen detection succeeded in 102 of 210 cases (48.6%) with suspected bacterial peritoneal contamination. Conversion from laparoscopic to open intra-abdominal perforation and the presence of an abscess were independent risk factors for wound infections in the multivariate analysis. The combination of different classes of pathogens resulted in significantly increased overall resistance to ampicillin/sulbactam in both the initial swabs (57%) and the follow-up swabs (73%). Resistant E. coli strains combined with certain anaerobes were also regularly detected in postoperative intra-abdominal abscesses. Piperacillin/tazobactam was effective against 83% of positive swabs in our resistance tests.

Surgical treatment for complicated appendicitis remains the central therapeutic column. A regular review of the existing resistance patterns in perforated appendicitis can help to adjust and improve antibiotic treatment. Piperacillin/tazobactam should be used cautiously as a reserve antibiotic. A valid alternative is second or third generation cephalosporins in combination with metronidazole.