As initial nutritional support, patients randomised to the 'EN combined with early PN' group will receive glucose 20% at 40 ml/hr. EN will be initiated in the evening of the second ICU hospitalisation day, PN will be started the morning of the third ICU hospitalisation day. The amount of PN to be given on any particular day will be the difference between calculated caloric needs and the calories delivered by EN the previous 24 hours. When EN covers 80% of calculated caloric needs PN will be stopped. When the patient is able to eat, the parenteral regimen will be reduced and eventually stopped. Whenever oral (+ enteral) intake is below 50% of calculated caloric needs, the PN will be (re)-started.