Thermogenic response to total parenteral nutrition in depleted patients with multiple organ failure

Nutrient-induced thermogenesis was studied in eight patients with severe nutritional depletion and multiple organ failure after abdominal surgery. Energy expenditure (EE) and RQ were recorded continuously over a period of 4 days. On each study day balanced total parenteral nutrition was administered during a period of approximately 16 h, followed by a period of low-energy glucose infusion. The total energy supply was in the order of 110% of the measured EE and the supply of glucose, fat and amino-acids was 2.6 +/- 0.4, 2.6 +/- 0.2 and 0.84 +/- 0.2 kJ x kg BW(-1) x h(-1) (mean +/- SD), respectively. The nutrient-induced thermogenesis, expressed as the rise in EE in percent of the energy content of the administered nutrients, was approximately 5%, which appears to be lower than previously observed in healthy individuals. A plateau in energy expenditure was reached after 6-8 h in response to parenteral nutrition. It is hypothesized that this plateau reflects the oxidative capacity and thus may be used as a guideline for nutritional therapy.