[Surgical stress and immunosuppression]

Perioperative psychological and physiological stress can suppress cell-mediated immunity, including the decrease of T lymphocytes and natural killer (NK) cells in the number and activities. A stronger immunosuppression is found in larger postoperative stress than in smaller one, which may interfere with the recovery from the surgical hurt. Generally, the surgical stress-induced immunosuppression can recover, which depends on the degree of surgical injury. The mechanisms through which surgical stress induces the immunosuppression are closely related to hypothalamus-pituitary-adrenocortical axis, sympathetic nervous system, cytokines, opioids and T cell signal molecule. Some strategies may be used to prevent surgical stress-induced immunosuppression, which includes analgesic drugs devoid of immunosuppressive effects and protease inhibitor.