Memorandum upon surgical schock and some allied conditions.

Date:
1917
Catalogue details

Licence: Public Domain Mark

Credit: Memorandum upon surgical schock and some allied conditions. Source: Wellcome Collection.

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    like conditions. It must be remembered, however, that failure of the heart from any cause will be attended by some degree of blood-con- centration, if the process is sufficiently gradual. More work 1s needed before the significance of the phenomenon in these cases can be estimated with confidence. Ti. Concurrently with the foregoing investigations, F. A. Bainbridge and J. W. Trevan have been conducting an investigation into the genesis of shock by other means, and the same factor of concentra- tion of the blood has presented itself in their observations. Their experiments hitherto have been mainly concerned with the effects on the portal and systematic venous pressures, and on the general dis- tribution or blood in the circulation, produced by repeated injections or by long-continued, slow infusion of adrenaline. The enquiry was suggested by the fact, demonstrated by Elliott, Cannon and others, that extreme emotion or severe pain, which are factors in some cases of shock, are accompanied by an outpouring of adrenaline from the suprarenal glands. Bainbridge and Trevan have injected adrenaline slowly into a systemic vein in anesthetised dogs for 20 minutes or longer, at a rate sufficient to maintain the arterial pressure at a supranormal level comparable with that attained during moderate stimulation of a sensory nerve. During the injection the portal pres- sure rose to and remained at a high level, while the systemic venous pressure was not significantly altered, or even fell slightly. Mean- while readings with the hamoglobinometer and the hamotocrit showed a steady decrease in the volume of the blood-plasma rela- tively to that of the corpuscles. In one case the haemoglobin-value rose from an initial 95 p.c. to 129p.c. Such a relative increase of corpuscular content would involve a large increase in the viscosity of the whole blood; an actual determination showed an increase of viscosity in the proportion of 6.8 to 9.1. When the injection of adrenaline was stopped, the arterial pres- sure rapidly fell to a low level while the portal pressure remained high, and the animal passed into a condition of shock, with feeble pulse and shallow respiration. The relation of the portal and systemic venous pressures indicated an obstruction of some kind to the flow of blood through the liver. This was made further evident, in the later stages of the effect, by the sriking turgidity of the liver itself. If the flow of lymph from the thoracic duct was recorded, it was observed to undergo a striking acceleration, as the obstruction in the liver developed in consequence of the infusion of adrenaline. The nature of this obstruction is not yet clear, and will be the subject of further investigation. Its effect, especially after the cessation of the inflow of adrenaline has allowed a dilatation of the splanchnic arterioles, is a collection of a large part of the blood in the congested splanchnic area. When to this is added the steady loss of fluid from the blood by exudation into the tissues, it will be seen that the final result, as regards the activity of the heart and the general circula- tion, will be closely similar to that described above in connection with Dale and Laidlaw’s experiments. The failure of the output of