Over de neuromusculaire werking van succinylcholine in combinatie met hexafluoreniumbromide (mylaxen)

SUMMARY This thesis is a report of the results of an investigation of the potentiation of succinylcholine (SCh), by hexafluorenium (Hf). Chapter I gives a survey of the existing publications devoted to Hf, from which it appears that several investigators are convinced that the potentiating action of this drug is due to an inhibition of cholinesterase activity. Our clinical experience with Hf led us to doubt this conclusion; muscular fasciculations were never observed, and bradycardia and salivation but seldom. In chapter II, a description is given of the experiments we performed, in order to investigate the validity of the theory of cholinesterase inhibition. Sections A and B of this chapter are devoted to a description of experiments performed on rabbits and mice. From the results of these, it is evident that Hf potentiates the action of SCh in these animals. In chapter II, section C, the results are given of experiments, carried out on rabbits, to determine the degree of cholinesterase inhibition produced by Hf. These clearly demonstrate, that the dose required for the potentation of SCh will produce little or no cholinesterase inhibition. Section D of chapter II gives a description of experiments performed on frog muscles. The results demonstrate that Hf does not potentiate the depolarizing effects of SCh. This conclusion gains considerable support from the results of experiments performed on cat muscles, which are reported in section E. Chapter III is devoted to a discussion of the results of the experiments, and to the general conclusions which may be drawn from them. These are: 1.The muscular relaxation, produced by succinylcholine, is independent of the depolarizing action of this agent. 2.Hexafluorenium potentiates the relaxant effects of SCh, but not the depolarization. 3.This potentiation by Hf is not due to an inhibition of cholinesterase. 4.These characteristic properties make the combination of Hf and SCh almost ideal, for the production of muscular relaxation during operations.