Localized infection, severe sepsis and septic shock were defined according to ACCP/SCCM consensus conference definitions (1992). All patients received standard treatment of localized infection, severe sepsis and septic shock including: source control, fluid infusion, catecholamine infusion, organ failure replacement and/or support therapy, intensive control of blood glucose and corticosteroid substitution therapy. Mechanically ventilated patients were sedated with midazolam and/or propofol infusion and no paralytic agents were used.