A pilot study of the changes of skin electrical conductance in patients undergoing general anaesthesia and surgery.

Change of skin electrical conductance have been monitored from induction of anaesthesia to recovery in two groups of patients. The first group receiving inhalational anaesthesia with halothane and spontaneous respiration demonstrated no changes in response to surgical stimulus. Some patients from the second group receiving muscle relaxation and ventilation with nitrous oxide and oxygen without halothane demonstrated changes in response to surgery. The changes are mediated by the sympathetic nervous system and the technique forms a simple monitor of sympathetic activity during surgery.