Suxamethonium and Cardiac Rhythm

eleven of our families-69 individuals in all.9 Kalow's observations were largely confirmed, and at this hospital we now determine as a matter of routine the "dibucaine number" of every plasma with a pseudocholinesterase level below 30 Warburg units (normal 65-120). This decides whether the low result indicates loss of liver function or is due to an inherited defect. For example, a level of 29 units indicates in the normal a considerable loss of active liver tissue, and in the heterozygote a much milder condition. It is hoped that Dr. Adrianvala's observation and conclusion will not be interpreted as contradicting the article and letter by Dr. L. Kaufman and his colleagues.5 10 Examination of families of patients who exhibited suxamethonium apnoea with pseudocholinesterase deficiency is not merely an academic exercise but can be of great importance to hitherto undiscovered homozygotes. They are not only hypersensitive to suxamethonium but also to pseudocholinesterase inhibitors used in agriculture, in the car and aircraft industry, as well as in many other fields of twentiethcentury endeavour.-We are, etc.,