[A comparative study on the effect of halothan-N2O-anaesthesia and neuroleptanalgesia on plasma catecholamines during the intra- and postoperative period (author's transl)].

The influence of neuroleptanalgesia and halothane-N2O-anaesthesia on the activity of the sympathetic nervous system was studied continuously in the intra- and postoperative period in 2 groups of 10 patients undergoing abdominal operations. In the neuroleptanalgesia-group the noradrenaline level in plasma rose continuously during the course of the operation and this increase was highly significant. The adrenaline level in plasma increased as well, however this increase did not depend on the duration of the operation. In the halothane-N2O-group only a small increase of both adrenaline and noradrenaline in plasma could be demonstrated intraoperatively. One hour after the end of the operation the plasma levels of adrenaline and noradrenaline were elevated in both groups. The noradrenaline level was even higher after neuroleptanalgesia. Four hours after the end of surgery the levels of adrenaline and noradrenaline started to decrease, but were still above the preanaesthetic level. The increase of the concentration of catecholamines in plasma indicating an activation of the sympathetic nervous system was not associated with a corresponding increase in heart rate and blood pressure intra- as well as postoperatively in either group. Only in the neuroleptanalgesia-group was there a small, but insignificant increase of the systolic and diastolic pressure postoperatively.