Severe bradycardia following propofol-suxamethonium sequence.

Anaesthesia was induced with propofol 2.5 mg kg-1 followed by suxamethonium 1.5 mg kg-1 in six young healthy females undergoing laparoscopy. ECG was monitored continuously. In two unpremedicated patients, this was followed by severe sinus bradycardia, while no bradycardia was observed in the other four patients who were premedicated with atropine 0.6 mg i.m. These observations suggest that propofol-suxamethonium sequence may be followed by severe bradycardia in patients who have not received atropine. The bradycardia may be prevented by premedication with atropine. In contrast to thiopentone, propofol apparently lacks central vagolytic activity and may exert a central vagotonic effect which can exaggerate the muscarinic effects of suxamethonium.