Long-term measurements of energy expenditure in severe burn injury

The objective of this study was to evaluate resting energy expenditure (REE ) in spontaneously breathing and artificially ventilated burn patients duri ng the entire intensive care period. In 27 patients with 51 +/- 20% body su rface area burned (BSAB) the REE was determined via indirect calorimetry. T hree groups were Formed according to the mortality prognosis index of Zawac ki et al. In groups A, B, and C the predicted mortality rates were <20%, 20 % to 80%, and >80%, respectively. The frequency of acute respiratory distre ss syndrome (ARDS), sepsis, renal failure, and mortality increased from gro up A toward group C, The REE test revealed wide individual variation and wa s usually overestimated by all tested formulas. The mean REE was comparable in groups A, B, and C during the first 20 days (49 +/- 16% vs. 59 +/- 21% vs. 57 +/- 18% above the REE calculated by the Harris-Benedict equation, or HBEE). The REE of patients in groups A and B declined after this period, w hereas the long-term ventilated patients in the prognostically unfavorable group C showed a high REE up to the 45th day, usually accompanied by severe organ dysfunction and major metabolic disorders. During this time a nutrit ional regimen meeting the actual REE could not be achieved. In the clinical situation when indirect calorimetry is not available, REE can be stated to be 50% to 60% above HBEE in patients with >20% BSAB far at least 20 days. Expecting a stable clinical course in patients with a predicted mortality o f <20% (group A), oral nutrition usually seems sufficient after a short per iod of artificial nutritional support (1 week). Patients with a predicted m ortality of more than 20% have a complication-burdened clinical course and a prolonged period of ventilation (groups B and C). These patients need par enteral and enteral nutrition for at least 20 days after trauma to prevent severe malnutrition.