Duration of Antibiotic Therapy in the Treatment of Severe Postoperative Peritonitis Admitted in ICU

Inclusion Criteria: The eligible patients have to fulfill all the following criteria 1. patients admitted in intensive care unit 2. in the 24 hours following surgery for postoperative intra-abdominal infection (defined as gross pus or purulent effusion within the peritoneal cavity or in one or several collections). Postoperative infection will be defined as an infection observed in a delay of 60 days following a procedure (endoscopy, surgery (abdominal, urologic, gynecologic or vascular surgery or any surgery performed in the peritoneal or retroperitoneal space) or interventional radiology) 3. having peroperative microbiologic samples collected 4. receiving an empiric antibiotic therapy initiated within the first 24 hours after completion of surgery 5. with a written informed consent from the patient or the relative or the legal representative or with an emergency consent Non-inclusion criteria : Patients with one of the following criteria are eligible for the study : 1. age\<18 2. pregnancy 3. Duration of stay following inclusion \<72 hours 4. neutropenia (PMN\<500/mm3) due to chemotherapy or hematological disease 5. AIDS stage C 6. Immunosuppressive therapy or prolonged steroid therapy (≥0.5 mg/kg/d of prednisone or equivalent \>1 month 7. Bowel perforation following endoscopy treated in a delay \<6 hours after injury 8. Uterine perforation following a surgical procedure treated in a delay \<6 hours after injury 9. Moribund patient (SAPS II score \>65 within 12 hours preceding inclusion) 10. Limitation of treatment previously decided 11. Surgery considered as non curative by the surgeon 12. Patient included in another clinical trial evaluating an antimicrobial agent Secondary exclusion criteria: Among the eligible patients, those who have one of the following criteria will be excluded 1. Negative culture of the peritoneal fluid 2. Peritoneal culture exclusively fungal 3. Inadequate empiric antibiotic therapy (not targeting all the microorganisms cultured from peritoneal or blood cultures) within 24 hours after surgery 4. Death between D1 and D8