4 



Scientific Proceedings (93). 



lation of the intestines lasting from two to five hours is necessary. 

 In the studies of shock by Githens and Meltzer "the intestines 

 and stomach were dislocated and frequently handled." Wiggers 

 on the other hand states that a more regular and certain circu- 

 latory failure is induced when the intestinal loops are not manipu- 

 lated. Many investigators kept the animals under surgical anes- 

 thesia throughout the experiment or at least during the greatest 

 part of it. 



Generally the fall of blood pressure is the sole criterion of 

 shock. In the studies of Githens and Meltzer the fall of blood 

 pressure and also the disappearance of pain sense were taken as 

 criteria. They studied these phenomena an hour or more after 

 the discontinuation of ether. Of forty-two dogs, in fifteen the 

 blood pressure did not reach a level below 95 mm. within five 

 hours after opening the abdomen, and pain sense returned as 

 soon as the animals came out of ether. In only thirteen dogs 

 the blood pressure reached a level below 70 mm. within two and a 

 half hours and there was no return of pain sense. In these thir- 

 teen dogs the original blood pressure was not high. In eight dogs 

 the blood pressure sank to a lower level, but sensation of pain re- 

 turned when ether was discontinued. In six dogs sensation was 

 lost while blood pressure was still above 95 mm. of mercury. 



In experiments undertaken to throw light upon a certain prob- 

 lem in shock, we came across a method which seems to be effective 

 in producing shock in every case and fairly early. The signs of 

 shock were obtained with this method without exception in an 

 unbroken series of experiments on seven dogs and nine cats. The 

 method consists in repeated, strong compression with thumb and 

 finger of the small gut, care being taken to avoid traction upon 

 the mesentery. In all the animals the original blood pressure was 

 fairly high. The strongest effect was a fall of blood pressure from 

 145 to 45 mm. within one hour and four minutes (cat). In all 

 the animals a considerable fall of blood pressure was obtained 

 within about an hour and fifteen minutes. It seemed that when 

 the compression was produced during deep etherization, the fall 

 began early and was more profound and of longer duration. 

 Whether or not etherization had been deep, loss of pain sense was 

 noted early. In most instances the blood pressure rises moder- 



