SÉANCE DU 19 OCTOBRE 899 



The method of producin^ standard shock may be briefly outlined 

 again, Under morphine, elher anasthesia, and with aseptic tech- 

 nique, the inferior vena cava is so occluded as to attempt to hold Ihe 

 arteriai pressure at 40 millim. Hg for two hours and fifteen minutes. 



After removing the clamp the behavior of the arteriai pressure is 

 followed for at least two hours and then the animal is treated or kept 

 as a control. Animais that live longer than 48 hours we believe 

 hâve recovered from shock, whatever their subséquent fate may be ; 

 the reasons for drawing the line hère cannot be presented in an abs- 

 tract. 



Sometimes, even when the clamp is light, the arlerial pressure 

 remains above 40 for a variable time; occasionally it does not reach 

 40 at ail. Such cases as a rule do very well subsequently. And, in 

 gênerai, those in which the pressure reaches 40 late, do better than 

 Ihose in which it cornes down early. Therefore ail cases in which the 

 pressure failed to reach 40 at ail are excluded from the séries. And one 

 of the methods of calculating our results excludes arbitrarily those 

 instances that lived and in which more than 30 minutes were required 

 to bring pressure down to 40 millim. Hg. 



During the clamping period failure of the heart sometimes causes the 

 death of the animal. In a few instances of imminent cardiac failure 

 the animal recovered and was carried through the stage of treatment. 

 It has been found, however, that ail of thèse " cardiac "cases didbadly 

 subsequently; not a single one lived longer than 3 days. This fact 

 must be taken into account in compiling the statistics ; therefore we 

 give in one of the columns the results obtained by excluding the car- 

 diac cases that died within 48 hours. 



After removing the clamp the arteriai pressure rises. If the pressure 

 begins to fall consistently, even if slowly, before 2 hours elapse, the 

 animal invariabiy dies, whether treated or not. The cases, therefore, 

 are excluded from the séries. 



And finally cases in which, at autopsy, extensive abdominal hemor- 

 rhage is found, also are excluded. This hemorrhage is accidentai and 

 results from mechanical injury of t-he liver by the clamp. 



The number of animais we hâve used now totals 182. A few of thèse 

 died of accidents that hâve rio bearings upon the problem in hand; a 

 number were employed for the purpose of standardizing shock and for 

 studying the action of the fluids injected on blood volume and alkaline 

 réserve. There were left 135, of which 77 were " Acceptable ". Of 

 thèse, 21 were " controls ", 20 were in the " British Gommittee " séries^ 

 16 in the " carbonate" séries, and 20 in Ihe " glucose" séries. In 

 tables 1, 2, 3 and 4 the esseutial détails. of each of thèse séries and the 

 significance of thèse terms, are shown, while table S submarizes thèse 

 and other results. 



