Goal of study:
To assess the tissular and plasma kinetics of ertapenem;
To determine the optimal dosages in the patients according to norepinephrine administration:
- to assess muscular diffusion of free form of ertapenem after administration to mechanically ventilated patients requiring such a treatment. The patients are included in the groups "with norepinephrine" or "without norepinephrine" according to their hemodynamic status.
- to assess the plasma pharmacokinetics of ertapenem in mechanically ventilated patients treated or not by norepinephrine.
Open-label, prospective study performed in a single ICU (16 beds) of a tertiary hospital (700 beds).