ABSTRACT
The stress response refers to the series of hormonal, inflammatory, and metabolic and psychological changes that occur in response to trauma or surgery. Surgery serves as a useful model of the stress response because the changes that occur can be observed from a well-defined starting point, but similar features occur in trauma burns, severe infection, and strenuous exercise (1). Catabolic changes predominate with suppression of anabolic hormones and resultant substrate mobilization. Muscle protein loss occurs, leading to a negative nitrogen balance; salt and water retention is also an important feature. Generally, the response of the body is in proportion to the severity of the insult or trauma. For example, intra-abdominal surgery has a greater impact than superficial skin surgery.
