Significance of the hormonal, adrenal, and sympathetic responses to burn injury

Under cognitive stress, hormone and neurotransmitter release is conventionally thought to serve in a compensatory manner facilitating the heightened mental awareness along with metabolic and cardiovascular activity that supports rapid increases in muscular work. Thermal injury unquestionably initiates a stress response, with a magnitude proportional to the severity of the injury. However, there are important characteristics of the injury response that contrast with the fight-or-flight response. These include prolonged hormone/neurotransmitter elevation, the absence of increased muscle work limiting metabolic demand, and the presence of massive tissue injury. The second surge of stress hormones is evoked by surgical débridement and complicates the severe metabolic derangements and compromised immune capacity characteristic of the burn course during the initial 7-10 days following injury. In this chapter we present the adrenomedullary-neurotransmitter activation and actions as separate from the adrenocortical activation and actions to clarify specific responses as we currently understand them.