Comparison of the effects of atropine and glycopyrrolate on cognitive function following general anaesthesia.

Tests of orientation, concentration and short-term visual memory were used to assess 72 patients 1 day before, and 2 days after, elective major surgery. Patients were premedicated with papaveretum and either atropine or glycopyrrolate, before receiving a standard general anaesthetic. Those who had received atropine showed significant postoperative short-term memory deficit (P less than 0.01), but no change in orientation or concentration. Those who had been given glycopyrrolate showed no significant cognitive changes after surgery. As glycopyrrolate does not cross the blood-brain barrier freely, these findings support the involvement of central cholinergic mechanisms in the deterioration of cognitive function in the postoperative period.