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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    the heart from defective venous inflow, due to reduction of the volume of blood in effective circulation, leads to a profound collapse of the arterial pressure; the loss of plasma into the tissues not only aggravates this defect of volume, but, by increasing the viscosity of the blood, further retards such flow through the capillaries as the low arterial pressure could otherwise maintain; and this retardation yet further checks the venous inflow to the heart. The blood travels very slowly round the body under such conditions, and the supply of oxygen to all the tissues becomes inadequate. This inadequacy is accentuated by defective oxygenation of the arterial blood, which remains dusky in colour even with artificial respiration. IV. Some Practical Suggestions and Enquiries. (a.) The point of most novel interest emerging from the above notes is the importance which the different sets of workers attribute to loss of plasma into the tissue spaces, as a factor in the production of the circulatory failure. The presence of such a factor was sug- gested by Henderson, Mann and others, but its extent and significance have hitherto been rather vaguely indicated. Such loss of fluid from the blood, causing both deficient volume and excessive viscosity, has for some time been clinically recognised as an essential factor in the collapse occurring in conditions like those of cholera and bacillary dysentery, in which the fluid is lost through more obvious channels. It is here suggested that clinical observation on changes in plasma-volume in traumatic shock, post-operative shock, and the toxemia of gas-gangrene may yield valuable information. The only instruments clinically applicable to the detection of such changes are the hamoglobinometer and the hematocrit. It will be evident that the interpretation of such observations will be a more compli- cated matter than that of results obtained under the controlled con- ditions of experiment; for an estimate of the plasma volume by these methods depends on the assumption that the volume and hamo- globin-content of the red corpuscles remains constant. It cannot, for example, be expected that a loss of plasma occurring in shock consequent on an extensive wound, with much haemorrhage, will be accompanied by an absolutely high hamoglobin-value or hemotocrit reading. Again, in a protracted case of toxemia from gas-gangrene, the observation will be vitiated by the probability that, though plasma may be draining from the vessels into the tissue spaces, a coincident destruction of red corpuscles is taking place. It is hoped, however, that a careful selection of suitable cases for observation, and attention rather to change of the corpuscular content, as shown in a series of observations at short intervals, than to the absolute initial value, will enable information to be obtained as to the signifi- cance of this factor. It may be suggested that cases of traumatic shock without serious haemorrhage, of post-operative shock, of intestinal obstruction, of extensive burning, of anaphylactic shock, and of the rapid, fulminating type of toxemia from gas gangrene, are likely to give relatively uncomplicated data for this purpose. (B.) The experimental results suggest that the removal of blood from effective circulation may be brought about in more than one