Full or hypocaloric nutritional support for the critically ill patient: is less really more?

In critically ill patients we typically observe a catabolic response and changes in metabolic demands varying from increased energy expenditure during the initial inflammatory response to decreased energy expenditure in later phases of critical illness. In addition, sedation and immobilization may reduce exercise-induced energy expenditure in all stages of intensive care unit (ICU) stay. Therefore, it is recommended to estimate energy expenditure based on indirect calorimetry. However, the availability of such devices in ICUs is low. As a consequence most healthcare providers still use formulae to calculate the estimated energy expenditure, although these estimates have been shown to be unreliable (1).