Surgical stress

Surgical stress is the systemic response of the body to surgical injury. It is marked by activation of the sympathetic nervous system, endocrine responses and immunological and haematological changes, together forming an integrated physiological, neuroendocrine and inflammatory reaction to tissue injury. Key elements include release of catecholamines such as adrenaline, cortisol and inflammatory cytokines such as IL-1 and IL-6, which lead to hypermetabolism, catabolism and immune system changes, and to a raised risk of infection, muscle wasting and organ dysfunction. The response is thought to grow with the invasiveness of the operation. Measuring it is used in anaesthesia, physiology and surgery, to compare surgical techniques or anaesthetic protocols, since the method that provokes the smallest stress response is generally considered best for the patient.