Need for feed: Determining metabolic phases of critical illness

The metabolic changes that occur in response to the severe stress that critical illness imposes on the body are increasingly thought of as adaptive strategies to preserve vital tissues and systems rather than defects. Therefore, scientific and medical priorities have progressed from preserving the normal to aiding the adaptation. The timing and nature of these adaptations vary highly between patients, various illnesses, and over time. As there are strong indications that the wrong timing, dose or composition of substrate is not beneficial and sometimes even harmful, it is of immense importance to obtain further insight into the metabolism of the critically ill. The studies making up this thesis, aimed to shed light on the different metabolic phases and subsequent nutritional needs in critical illness and clinical methods to determine these in the individual patient.