[Bacteriological profile and antibiotic treatment of postoperative peritonitis]

During the postoperative peritonitis (PPO) the main stay of treatment is the choice of probabilistic antibiotictherapy, it is also the main prognostic factor The aim of our study was to identify anappropriate antibiotic protocol to the current ecology of our unit. It was a retrospective study including 102 patients over a period of 09 years from 1 January 2003 to 3O November 2011. All of them are supported for the treatments off postoperative peritonitis in surgical intensive care unit of a service of general surgery a university hospital Charles Nicolle of Tunis. All bacteriological data (germs and sensitivity), and the terms of therapeutic modality for the empirical antibiotic therapy were listed. The incidence of PPO was Q90%.The average age of our patients was 57 +/- 18 years. The sex ratio was 1.08. One hundred and seven (107) microorganisms were isolated from 72 samples (44 microbial mono, 28 multi microbial). The frequency of gram-positive cocci (GPC) was 16.82%, the Gram-negative bacilli (BGN) was 82.2%. The Enterobacteriaceae have proved particularity resistant. Thus, the ampicillin resistance was 87.14%, that the C3G was 33.80%, the Piperacillin to Tazobactam combination, was 36.5% and that the association Ticarcillin-clavulanic acid was 43.6%. For non-fermenting BGN, Pseudomonas aeruginosa was sensitive to ticarcillin in 80% of cases, to ceftazidime in 66.6% of cases, PiperacillinTazobactam--in 71.43% of cases, imipenem in 85 72% of cases, colimycin in 100% of cases and Amiklin in 71.43% of cases. For CGP, enterococci were resistant to ampicillin in 50% of cases and vancomycin in 0% of cases. The majority of patients received triple antibiotic therapy (59.8%) or combination therapy (34.3%). The main associations were: cefotaxime + Gentamycin + Metronidazole (35.2%), Amikacin Imipenem + + Metronidazole (12.7%), Imipenem + amikacin (9.8%), Piperacillin / Tazobactam + amikacin (9.8%) + amikacin and ertapenem (5.88%). Probabilitic antibiotic therapy was addapted in 69.4% of cases. The average duration of the prescribed antibiotic was 11 days +/- 6 days. The mortality rate was 39.2%, was 32.23 days. The isolated microorganisms are those of the intestinal flora which is generally changed and thus the bacteria are selected then are multidrug resistant. Prescribing antibiotics should consider probabilistic. Thus, Imipenem-Amiklin combination seems appropriate to our ecology. This empiric antibiotic therapy is secondarily adapted to the results of susceptibility testing to limit the selection of multi-resistant organisms.