Adverse effects of suxamethonium. Failure of prevention by atracurium or fazadinium.

One hundred patients were allocated randomly to pretreatment with atracurium 2.5 mg, atracurium 5 mg, fazadinium 3.75 mg or saline 3 minutes before the injection of suxamethonium. The effect upon neuromuscular conduction was studied by recording the mechanical response of the adductor pollicis muscle to indirect stimulation of the ulnar nerve using repeated 2 Hz train of four stimuli. Blood samples were taken at intervals for the measurement of serum potassium. There was no significant difference in the incidence of postoperative muscle pains between the groups in the first 72 hours following anaesthesia. The use of the larger pretreatment dose of atracurium resulted in clinically significant neuromuscular blockade in three of the subjects. Minimal changes in serum potassium occurred in all patients but there was no statistical difference between the groups.