Surgical stress

Surgical stress is the systemic response to surgical injury and is characterized by activation of the sympathetic nervous system, endocrine responses as well as immunological and haematological changes.^{[1][2][3][4][5]} Measurement of surgical stress is used in anaesthesia, physiology and surgery.

Analysis of the surgical stress response can be used for evaluation of surgical techniques and comparisons of different anaesthetic protocols. Moreover, they can be performed both in the intraoperative or postoperative period. If there is a choice between different techniques for a surgical procedure, one method to evaluate and compare the surgical techniques is to subject one group of patients to one technique, and the other group of patients to another technique, after which the surgical stress responses triggered by the procedures are compared. Absent any other difference, the technique with the least surgical stress response is considered the best for the patient.^{[6][7][8][9][10][11][12][13][14][15][16][excessive citations]}

Similarly, a group of patients can be subjected to a surgical procedure where one anaesthetic protocol is used, and another group of patients are subjected to the same surgical procedure but with a different anaesthetic protocol. The anaesthetic protocol that yields the least stress response is considered the most suitable for that surgical procedure.^{[17][18][19][20][21][22][23][24][25][26][27][28][29][excessive citations]}

It is generally considered or hypothesized that a more invasive surgery, with extensive tissue trauma and noxious stimuli, triggers a more significant stress response.^{[30][31][32][33][34][35]}

However, duration of surgery may affect the stress response which therefore may make comparisons of procedures that differ in time difficult.^[36]