Cardiovascular changes during induction of anaesthesia. Influence of three anticholinergic premedicants.

The effects on cardiovascular changes during induction of anaesthesia and intubation of routine premedication with three different anticholinergic drugs, atropine, hyoscine, and glycopyrronium, were compared in a double blind trial. Administration of both atropine and hyoscine, whether intramuscularly or orally, was found to be associated with a high incidence of dysrhythmias. With glycopyrronium the incidence was much lower, but control patients receiving no anticholinergic premedication had no dysrhythmias. The heart rates and blood pressures were similar in all the groups during intubation and cuff inflation. A single dose of suxamethonium was not associated with any bradycardia. The need for routine anticholinergic drug administration should be reconsidered. However, if necessary, glycopyrronium appears to have an obvious advantage over atropine and hyoscine.