Primary Outcome Measures:
- Exposition to antibiotics, defined by antibiotic-free days [ Time Frame: assessed 28 days after inclusion ] [ Designated as safety issue: Yes ]
- Mortality [ Time Frame: at Day 28 and Day 60 ] [ Designated as safety issue: No ]
Secondary Outcome Measures:
- Consumption of antibiotics expressed as the Defined Daily Dose/1000 ICU-days [ Time Frame: between D1 and D28 ] [ Designated as safety issue: Yes ]
- The length of ICU and hospital stay [ Time Frame: during the stay at the hospital ] [ Designated as safety issue: No ]
- The evolution of SOFA score parameters [ Time Frame: between D1 and D28 ] [ Designated as safety issue: No ]
- The number of mechanical ventilation-free days [ Time Frame: at D28 ] [ Designated as safety issue: No ]
- The acquisition cost of antibiotics [ Time Frame: between D1 and D28 ] [ Designated as safety issue: No ]
- The percentage of emerging multiresistant bacteria between D1 and D28, as assessed by microbiologic examination of all clinical samples. [ Time Frame: between D1 and D28 ] [ Designated as safety issue: No ]
- The percentages of relapses of infection [ Time Frame: between D1 and D28 ] [ Designated as safety issue: No ]
Clinical and laboratory signs are neither specific nor sensitive for diagnosis of sepsis in critically-ill patients. Because delaying antimicrobial therapy may be deleterious, broad-spectrum antibiotics are widely used in ICU -patients, even when they are not needed. In addition, only few well-designed studies concerning the duration of antibiotic treatment have been so far published. Consequently, many patients received antibiotics during the ICU stay. Many studies have shown that exposure to antibiotics, the so called "selection pressure" is an independent risk factor for acquisition of resistance in individual patients. Therefore, reducing antibiotic use is probably necessary to control antibiotic resistance. Many clinical studies have shown that procalcitonin (PCT) is able to distinguish the inflammatory response to infection from other types of inflammation and to distinguish bacterial from viral infections. Recent studies have shown that PCT guidance substantially and safely reduced antibiotic overuse in patients with lower respiratory tract infections. We aimed to evaluate the role of PCT in reducing the use of antibiotics in ICU adult patients. The study is a prospective, randomized, controlled intervention trial conducted in 9 centers, comparing a conventional strategy versus a PCT-guided strategy to start or to discontinue antibiotics, in patients with suspected community or hospital- acquired infection.