The loss of body protein leads to major complications, especially infection, impaired healing and profound weakness.

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The range of increased metabolic demands varies with the degree of burn or traumatic injury. An entire spectrum of abnormalities will be seen, due to degrees of the manifestation of the host "stress response" to injury. This abnormal metabolic response is initiated by factors from a wound or infection and perpetuated by a systemic release of stress hormones. The magnitude of systemic inflammation is dependent not only on the degree and persistence of the initial insult, but also the patient’s preprogrammed genetic response to a bodily insult.

Increased local metabolic activity and cellular work is required at the site of injury as well as in all systemic tissues. The wound consumes large quantities of energy and protein both by the large population of inflammatory cells and by the production of new tissue.

Catabolism or breakdown of tissue protein for fuel is a prominent response to burns and trauma. While anabolism or tissue synthesis is diminished.

Although the catabolic response to injury is well documented, the precise cellular effector mechanism, causing protein breakdown, is poorly understood. Of major concern is the impact of the ongoing protein loss on body composition. Homeostasis, depends on the appropriate amount of the two body compartments, lean body mass and fat mass. (See Body Composition Section)

Normal nutrient channeling is the metabolically controlled process whereby the macronutrients, carbohydrates and fat are used for ENERGY or ENERGY storage and protein is used for maintenance of LEAN BODY MASS and not for energy.

Nutrient utilization and nutrient channeling with the "stress response" is markedly different from that found in the non-stressed or starved state (where 90% of calories come from consumed carbohydrates or fat or from fat stores, with only 5-8% being derived from protein.) With the "stress response" seen after burns and trauma, approximately 30% of calorie need comes from protein with only 50% coming from fat. Even in the fed "stressed" state, 20-25% of calories will still come from protein. Since there are only 1,000 calories(250 grams protein x 4 ca/gram) available in a kilogram of muscle (compared with 10,000 calories in a kilogram of fat), a rapid lean body mass loss occurs even in the fed state.

An additional major problem for the major burn (trauma) patient is the fact that despite an inevitable loss of lean body mass, the rate of restoration of lost body protein is very slow. The rate of loss is ten times the rate of restoration of protein. The reason is that endogenous anabolic activity returns to normal very slowly during recovery and may remain decreased if any wound remains. However, the degree of anabolic activity drives the rate of protein synthesis adding an anabolic agent will markedly accelerate lean mass gain.