Influence of mere opening the abdomen, of state of shock, and of subsequent section of sciatic nerve upon the blood flow from the femoral vein in cats

Abstract

From a series of experiments performed for the purpose of solving a certain problem in shock, a few definite facts were selected to be put on record. The following results were obtained from experiments on fourteen cats. The rate of the blood flow from the femoral vein shortly before opening the abdomen was taken as the unit, i. e., 100 per cent. The figures indicate the time required for the flow of the same amount of blood, and hence express an inverse ratio to the rate; e.g., 200 per cent. indicates that the rate was half as fast. Influence of opening the abdomen.—The average time of flow from the femoral vein shortly after opening the abdomen in the fourteen cats is 136 per cent., that is, an average decrease of 36 per cent. in the rate. A decrease in rate of flow occurred in every experiment but one. The maximum decrease (in one cat) was 84 per cent. This result means that after the mere exposure of the abdominal viscera (before any change in volume and composition of the blood could have taken place) a slowing of the flow from the extremities takes place. In interpreting this fact the statement of H. Fischer, the first writer on shock from a physiological point of view, is worth considering, namely, that a certain degree of engorgement of the veins of the abdominal viscera can be observed immediately after opening the abdomen. This occurrence may be the cause of the slowing of the flow from the veins of the extremities. As far as we know these facts have not been observed or discussed by any experimental or surgical writers. It may be mentioned that there was a variable but generally a moderate fall of blood pressure immediately after opening the abdomen; but there was no definite proportion between the fall of blood pressure and the decrease in the rate of flow.