Should indirect calorimetry be used as part of nutritional assessment?

The use of indirect calorimetry in the design of nutritional support regimens is poorly appreciated by clinicians, who fail to recognize the importance of providing a sufficient volume of enteral feeding to critically ill patients. In contrast to the overfeeding that routinely occurred in the past with the provision of total parenteral nutrition, patients placed on the enteral route of support tend to be underfed because of problems with intolerance and frequent cessation. Clearly identifying and coming as close as possible to the caloric goal may be required to achieve the therapeutic endpoints of enteral tube feeding (which include maintenance of gut integrity, attenuation of the stress response, prophylaxis against stress-induced gastropathy, and stimulation of immune function). Indirect calorimetry is a convenient, accessible, and highly accurate instrument for the measurement of caloric requirements and is a valuable tool for the optimization of nutritional support in the intensive care unit.