An Address on the Influence of Position upon Local Circulation
Authors: J. Lister
Journal: BMJ (1879)

The facts obtained from these researches seem to us to warrant the following conclusions.i.Both chloroform and ethidene administered to animals have a decided effect in reducing the blood-pressure, while ether has no appre- ciable effect of this kind.2. Chloroform reduces the pressure much more rapidly and to a greater extent than ethidene.3. Chloroform has sometimes an unexpected and apparently capricious effect on the heart's action, the pressure being reduced with great rapidity almost to nzil, while the pulsations are greatly retarded or even stopped.The occurrence of these sudden and unlooked for effects on the heart's action seems to be a source of serious danger, all the more that in two instances they occurred more than a minute after chloroform had ceased tobe administered andafter the recovery of the 6lood-pressure.4. Ethidene reduces the blood-pressure by regular gradations, and not, so far as observed, by sudden and unexpected depressions.5. Chloroform may cause death in dogs by primarily paralysing either the heart or the respiration.The variations in this respect seem to de- pend to some extent on individual peculiarities of the animals; in some, the cardiac centres are more readily affected, in others, the respiratory.But peculiarities in the condition of the same animal very probably have some effect in determining the vulnerability of these two centres re- spectively, and they may both fail simultaneously.6. Inmostcases, respirationstopsbeforethe heart'saction; but therewas one instance in whichrespiration continued when the heart had stopped, and only failed a considerable number of seconds after the heart had resumed.7. The use of artificial respiration was very effective in restoring animals in danger of dying from the influence of chloroform.In one instance, its prolonged use produced recovery, even when the heart had ceased beating for a considerable time.8. Under the use of ethidene, there was on no single occasion an absolute cessation either of the heart's action or of respiration, although they were sometimes very much reduced.It can, therefore, be said that, though not free from danger on the side of the heart and respira- tion, this agent is in a very high degree safer than chloroform.9. These results confirm and amplify those stated in a previous re- port, to the effect that ethidene does not compromise the heart as does chloroform.By the method of experimentation then employed, the effect on the blood-pressure could not be determined ; and altogether the results here obtained are more exact and unequivocal.It may be added that since the last report ethidene has been given to a number of patients of all ages, with results which may be described as satisfactory.Given freely at first, it produced anTesthesia as rapidly as chloroform, and the effect could readily be kept up by comparatively small subsequent doses.The only drawback is that in some cases it produced vomiting; but it has not been determined that it does so more frequently than chloroform, over which it has the further advantage of producing less excitement and being more agreeable to the patients.Isobutyl chloride was given to three patients, but it produced consi- derable excitement and proved an imperfect an-esthetic.In concluding this report, the Committee would express the belief that, so far as purely physiological tests go, ethidene has proved itself as * T'he paper, as now published, embraces some considerations on which I did not enter at the time of its delivery, and also some fact subsequently ascertained.