Characteristics of the hypermetabolic response to burn injury include:

A. Elevation of core temperature, skin temperature, and core-to-skin heat transfer.

C. A marked increase of blood flow to the burn wound.

E. Oxidation of stored lipid as the major source of metabolic energy.

DISCUSSION: At thermal neutral and higher temperatures, the core temperature, skin temperature, and core-to-skin heat transfer in burn patients remain elevated, but metabolic rate can be diminished in patients with burns of more than 50% of the body surface by maintaining the ambient temperature above 30؛ C. Blocking evaporative water loss by application of an impermeable membrane is not attended by a consistent diminution in metabolic rate, indicating that the burn patient is not externally cold but is internally warm. The hypermetabolism in burn patients is temperature sensitive but not temperature dependent. Even though earlier measurements described a curvilinear relationship between metabolic rate and extent of burn, recent measurements have shown that metabolic rate increases in linear fashion and rises to levels of twice normal in patients with burns of 75% and more of the total body surface. Lipid stores are the major source of metabolic fuel that is oxidized for energy, and not lean body mass, which undergoes proteolysis to provide the amino acids necessary for protein synthesis and wound healing as well as gluconeogenic processes that provide fuel for tissues requiring glucose. Blood flow to a burned limb is markedly increased as compared with flow in an unburned limb of the same patient, and the flow increase is directed to the wound per se, not the underlying muscles.