Appropriate initial antibiotic therapy is crucial in the treatment of severe infections in patients with intensive care. Adequate spectrum and appropriate doses are the keys to achieving the therapeutic goal. Despite broad consensus on the spectrum and timing of antimicrobial therapy, antibiotic use varies according to various parameters including choice, dose, method of administration, duration of antibiotic therapy and de-escalation. an empirical attitude.

Therapeutic de-escalation is considered essential for the use of antibiotics and is now clearly established by different consensus. However, routine de-escalation has recently been questioned in a randomized, controlled study that did not demonstrate non-inferiority of de-escalation with an increase in the number of days of antibiotic therapy associated with an increased number of days. superinfection.

The components of the de-escalation described in the literature, are based on the reduction of the number of antibiotics, the strict observance of the spectrum of the antibiotic, the reduction of use of the antibiotic, the stopping of any inappropriate antibiotic treatment ( lack of in vitro activity).

De-escalation can be considered in different ways; there are significant variations between hospitals, countries, teams. A large European multicenter cohort is needed.

The main objective of this study is to describe empiric antibiotic therapy in intensive care and the modalities of de-escalation.

Appropriate initial antibiotic therapy is crucial in the treatment of severe infections in patients with intensive care. Adequate spectrum and appropriate doses are the keys to achieving the therapeutic goal. Despite broad consensus on the spectrum and timing of antimicrobial therapy, antibiotic use varies according to various parameters including choice, dose, method of administration, duration of antibiotic therapy and de-escalation. an empirical attitude.

Therapeutic de-escalation is considered essential for the use of antibiotics and is now clearly established by different consensus. However, routine de-escalation has recently been questioned in a randomized, controlled study that did not demonstrate non-inferiority of de-escalation with an increase in the number of days of antibiotic therapy associated with an increased number of days. superinfection.

The components of the de-escalation described in the literature, are based on the reduction of the number of antibiotics, the strict observance of the spectrum of the antibiotic, the reduction of use of the antibiotic, the stopping of any inappropriate antibiotic treatment ( lack of in vitro activity).

De-escalation can be considered in different ways; there are significant variations between hospitals, countries, teams. A large European multicenter cohort is needed.

The main objective of this study is to describe empiric antibiotic therapy in intensive care and the modalities of de-escalation (rate of de-escalation, incidence of mortality, length of stay in intensive care unit, relapse, rate of superinfection)

Inclusion Criteria:

• Age 18 years or older.
• Patient is admitted to an ICU and has an anticipated need of ICU support of at least 48 hours.
• Patient has a suspected or confirmed bacterial infection (community-, healthcare-, hospital- or ICU-acquired).
• Empirical antibiotic therapy is started for this infection at any time in the ICU or no more than 24 hours prior to ICU admission. If the initial antibiotic therapy is considered inadequate and another empirical scheme is chosen at ICU admission, this will be the empirical antibiotic of the study.
• Causative pathogen and susceptibility are unidentified at time of initiation of the antibiotic therapy.

Exclusion Criteria:

• Previous inclusion in this study for another infection - each patient can only be included once.

Critically ill patients receiving empirical antibiotic therapy for suspected or confirmed infections at the Intensive Care Unit