The effects of the degree of surgical trauma and glucose load on concentration of thyrotropin, growth hormone and prolactin under enflurane anaesthesia.

Sixty patients undergoing gynecological surgery under enflurane nitrous-oxide anesthesia were studied. The goal was to investigate the effects of the degree of surgical trauma and glucose load on the pattern of TSH, GH and PRL secretion before, during and following surgery. For this purpose the patients were divided into four groups according to the severity of the operation and the type of fluid administered. The groups were as follows: group 1, major surgery--glucose solution; group II, major surgery--lactated Ringer solution; group III, minor surgery--glucose solution; group IV, minor surgery--no intravenous fluids. The three hormone concentrations, 45 min after the start of anesthesia, increased in all groups. The highest values for GH and PRL concentration were observed in group IV. This increase was followed by a decrease 24 h and 5 days after induction, at the end of the study, except in group IV where TSH and GH levels fell back to normal values more slowly. These results lead to the following conclusions: a) Enflurane does not suppress hormonal stress response to surgical trauma; b) A similar pattern is obtained for pituitary response, indicating that a general pituitary stimulus takes place in these situations; c) Glucose load plays an important role in pituitary hormonal response to surgical stress; d) There is no direct relationship between the degree of surgical trauma and the hormone levels in patients under enflurane anaesthesia.