Impact of SPN on Infection Rate, Duration of Mechanical Ventilation & Rehabilitation in ICU Patients

Rationale: Enteral nutrition (EN) in the intensive care (ICU) patients is recommended as a standard of care. However, EN alone is often associated with insufficient energy intakes and increased complication rates. Recently the investigators proposed to decrease this deficit by combining EN and supplemental parenteral nutrition (SPN) whenever EN is insufficient ( 5 days, expected survival > 7 days, no contraindication to EN, obtained informed consent from themselves or their next of keen. Exclusion criteria: refusal of consent, age 1,5 liter/d), patients receiving PN. Nutrition: At day 3 after admission, if energy input is < 60%; patients are randomized into either the "Control group" (EN alone) or the "SPN group" (EN + PN) to reach 100% of their predicted energy needs. Tight glycaemic control (target 6.0 to 8.3 mmol/l) to be achieved according to our local practice by insulin administration. Study endpoints: * Primary: nosocomial infections (CDC criteria) * Secondary: Mechanical ventilation duration, ICU and hospital length of stay, antibiotic free days, ICU complications (extra-renal epuration, neurological, cardiac and respiratory complications), energy and protein balance, 28 days clinical outcome.