SURGICAL SHOCK 35 



dioxide. (4) All Henderson's work was upon animals 

 under experimental conditions. It is quite unsafe 

 to apply the results to human surgery without 

 study of the CO.^ content of the blood in man. 

 The writer has therefore made analyses of the 

 blood of patients and normal persons by means of 

 Barcroft's apparatus. A hypodermic syringeful of 

 blood was withdrawn from the median basilic or 

 other vein, and the CO2 content estimated immedi- 

 ately. It was found that in five patients showing 

 shock, three of whom died, the quantity of carbon 

 dioxide present was about 46*9 per cent, that is, 

 a fraction higher than the normal. In Yandell 

 Henderson's observations the CO.^ fell to 10 or 20 

 per cent. Two patients with cyanosis showed a 

 rise to 59-5 and 74-2 per cent, proving that the 

 method of estimation was capable of detecting the 

 variations. Janeway and Ewing have recently 

 published the results of some animal experiments 

 showing that excessive artificial respiration will 

 induce shock even if the CO^ content of the blood 

 is kept high. 



We conclude, therefore, that acapnia is not the 

 cause of ordinary surgical shock. We are still left 

 face to face with the problem of a falling blood- 

 pressure with normal heart and contracted arteries. 



THE OLIGEMIA THEORY OF COBBETT 

 AND VALE. 



There is one very tempting explanation of the 

 phenomena of shock to which attention must next 

 be directed. If the total blood volume were reduced 



