[Energy requirements of surgically treated, injured and infected patients]

There is always a distinct increase in energy expenditure in postoperative, posttraumatic and septic patients. In order to predict this increase in energy expenditure an enormous number of formulas have been developed. However, the problem with all these formulas is that they cannot sufficiently take into account the peculiarities of the underlying disease, the general and nutritional condition or the varying influence of the phase of disease. Furthermore, all these patients continuously show a considerable change in body weight which can be attributed to a shifting of the water balance. In all of these cases any calculation of energy expenditure based on body weight will inevitably be incorrect. Therefore, it is recommended that predicting formulas only be used as orienting guidelines in all uncomplicated postoperative or posttraumatic courses. In patients with multiple injuries or septic complications the real energy expenditure should be measured by indirect calorimetry in order to adapt energy intake during enteral or parenteral nutrition to the very different metabolic situations.