AETIOLOGY OF PROLONGED APNOEA AFTER SUXAMETHONIUM

Abstract

Forty-seven patients demonstrating prolonged apnoea after suxamethonium have been investigated in a 3-year survey carried out in south-east Scotland. Clinical information, and serrum cholinesterase studies using a new substrate, succinyldithiocholine, provide evidence on the aetiology of suxamethonium hypersensitivity. While 13 Patients possessed only variant forms of the serum enzyme, the remaining 34 patients appeared to have a catalytically active form of cholinesterase. The causes of prolonged apnoca in the latter group are discussed. The value of screening the relatives of patients with cholinesterase variants is demonstrated by the finding of 26 relatives “at risk” out of 123 screened.