Prolactin, LH, FSH, GH and cortisol response to surgery and the effect of epidural analgesia.

The prolactin, LH, FSH, growth hormone and cortisol responses to surgical stress were studied in female patients receiving halothane (general) anaesthesia or epidural analgesia. Plasma cortisol, prolactin, and growth hormone concentrations increased during surgery, and post-operatively in patients operated under general anaesthesia, but not in patients operated during epidural analgesia. Gonadotrophin concentrations were unchanged in the general anaesthesia group until 9 h after stimulation when levels decreased slightly. In contrast plasma gonadotrophin levels decreased immediately after the administration of epidural analgesia and during the following 9 h. It is concluded that neurogenic blockade inhibits the anterior pituitary response to surgical stress.