Anxiety and endocrine responses to surgery: paradoxical effects of preoperative relaxation training.

It has been argued that surgery is a form of psychological stress, and that the response to it should therefore be modifiable by psychological means. To test this hypothesis, we assessed the effect of preoperative relaxation instructions on endocrine, cardiovascular, and subjective responses in 21 patients undergoing minor abdominal surgery. Controls (N = 19) received general procedural information. In the relaxation group only, there was a significant increase in cortisol and adrenaline concentration from immediately before induction of anesthesia to immediately after surgery. Noradrenaline values were unaffected by relaxation. In contrast, relaxation reduced state-anxiety on the preoperative day and the two postoperative days; maximal peroperative systolic and diastolic blood pressures were also reduced. The results are consistent with previous evidence that adrenaline and cortisol responses to surgery are greater in less anxious patients.