Indirect calorimetry: a rarely used specific tool

Abstract

Indirect calorimetry is recognized as the gold standard in the assessment of energy expenditure in clinical nutrition. In the intensive care setting, only a small proportion of patients are evaluated, using this tool, and most of the practitioners use predictive equations. These equations, however, have a little accuracy and could lead to large mistakes. On the other hand, indirect calorimetry technique has limitations, such as financial aspects, patient’s clinical conditions of ventilation and stability, and lack of air leakage. The consequences of mistaking energy requirements have been recently studied in many prospective studies. Underfeeding seems to lead to increased malnutrition and its deleterious consequences, while overnutrition can induce increased infection rate (catheter-related infections and ventilator associated pneumonia), mainly if parenteral nutrition is used. Therefore, the use of a goal-directed protein-energy target is recommended and indirect calorimetry may be useful in the determination of this goal.