Role of energy metabolism in nutrition management of critically ill patients

Indirect calorimetric measurements were made with a MedGraphics Critical Care Monitor (CCM) desktop analysis system in the observation of critically ill and malnourished patient's energy expenditure. In 15 critically ill patients, predicted energy requirements based on 1.75 times BEE calculated by Harris-Benedict formula or corrected Harris-Benedict formula averaged 32.7% and 27.8% greater than metabolic expenditure measured by indirect calorimetry respectively. In the 20 unstressed malnourished patients, predicted energy requirements based on the Harris-Benedict (BEE) formula averaged 15% to 20% higher than metabolic expenditure measured by indirect calorimetry. When the critically ill patients' total energy intakes were 1.2 times resting energy expenditure, their nutritional state could be maintained in normal conditions. While the malnourished patients were provided with 1.5 x REE in energy intake, the malnourished state could be reversed. We believed that the critically ill and malnourished patients' energy expenditures are better measured than predicted and their nutritional regimens should be guided under the computerized indirect calorimetry.