Electroencephalographic changes and arousal time after atropine or glycopyrrolate

General anaesthesia for supratentorial neurosurgery

Anaesthesia for the surgical treatment of supratentorial tumours requires an understanding of: the pathophysiology of a localised or generalised increase in intracranial pressure (ICP), the regulation and maintenance of intracerebral perfusion, avoidance of secondary systemic insults to the brain, and the effects of anaesthetic drugs on ICP, cerebral perfusion and cerebral metabolism. Knowledge of the therapeutic options available for decreasing ICP, brain bulk and brain tension perioperatively is also essential. Potential complications which may present during supratentorial neurosurgery include massive intraoperative haemorrhage and seizures. The fact that the surgeon is operating on a tensed brain is also a potential source of difficulty. The need to monitor brain function and environment during surgery poses a challenge to the anaesthesiologist, as does the achievement of rapid emergence from anaesthesia with the adequate use of anaesthetic drugs.

Split-dose atropine versus glycopyrrolate with neostigmine for reversal of gallamine-induced neuromuscular blockade

The effects of a split-dose of atropine sulphate versus a single dose of glycopyrrolate given with neostigmine for the reversal of gallamine-induced neuromuscular blockade were studied in 55 patients undergoing gynaecological surgery. The patients were randomized to receive either a single dose of glycopyrrolate (7 micrograms.kg-1) or two doses of atropine (8 micrograms.kg-1 each), given with an interval of 1 min. There were no differences between the two methods with respect to percentage heart rate changes, salivation or arousal time. Four patients demonstrated cardiac arhythmias in the atropine group, whereas none occurred in the glycopyrrolate group (P less than 0.05). It is concluded that a split-dose of atropine has similar chronotropic effects to a single dose of glycopyrrolate for the reversal of gallamine-induced neuromuscular blockade. However, the finding of a higher incidence of cardiac arrhythmias in the atropine group suggests that this reversal regime should be reserved for patients without cardiac disease.

Glycopyrrolate compared with atropine in association with ketamine anaesthesia

Atropine and glycopyrrolate given intravenously before the induction of a ketamine anaesthesia to diminish salivary secretion were compared for their effect on psychotomimetic side-effects, awakening time and heart rate. Though atropine is a tertiary amine that crosses the blood-brain barrier, which glycopyrrolate as a quaternary ammonium compound does not, it did not increase the incidence of psychotomimetic side-effects nor did it significantly prolong the awakening time after ketamine anaesthesia. During intubation the increase in heart rate was significantly higher following atropine than following glycopyrrolate.