Blood Flow from Femoral Vein in Cats. 



7 



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 compo- 

 sition 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 physio- 

 logical 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 occur- 

 rence 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. 



The rate of blood flow in shock. 1 — When the blood pressure had 

 fallen to about 70 mm. of mercury, the animals were considered 

 in shock; in the majority of cases it fell to 60 mm. or less; the low- 

 est pressure reached was 30 mm. In every cat the blood flow in 

 shock was slower than just after opening the abdomen. On the 

 average it was 301 per cent, of the original. The decrease in the 

 rate of flow seemed in a general way to follow the degree of fall 

 of blood pressure, but was not absolutely proportional. 



Influence of cutting the sciatic nerve upon blood flow in shock. — 

 After section of the sciatic nerve the rate of blood flow increased 

 markedly in eleven cats, slightly in two and in one there was a 

 slight decrease. The average increase over the flow in shock was 

 about one third, that is, the time of flow decreased from 301 to 

 196 per cent., but the average rate was still only about half as 



1 In the present series of experiments the blood obtained from the femoral vein 

 was mixed with a small amount of sodium citrate and reinjected through the jugular 

 vein. Hemorrhage therefore was not a factor in the production of shock in these 

 experiments. 



