40 SURGICAL SHOCK 



condition is already too grave to permit of major 

 surgery. The estimation of the specific gravity is 

 simple, only takes three minutes, and can be done 

 with a, drop or two of blood. It remains to be 

 determined just where the limits of safety lie. In 

 the two fatal cases there was a fall of o-oio. 



THE SUPRARENAL EXHAUSTION THEORY. 



Perhaps no one has definitely formulated any 

 such theory as yet, but it is certainly deserving of 

 examination. Recent physiological research has 

 shown that painful stimuli lead to a reflex outpouring 

 of adrenalin from the suprarenal glands into the 

 circulating blood. If this took place to a considerable 

 extent there would be a preliminary rise of blood- 

 pressure, followed, perhaps, by suprarenal exhaustion 

 and a profound fall of pressure in spite of a normal 

 heart and vasomotor centre. Bainbridge and Parkin- 

 son found absence of the chromaffin substance in the 

 medulla of the suprarenals in two patients who died 

 from shock. Priestlej'' found the same absence in 

 84 per cent of cases dying with a low blood-pressure. 

 Here, at least, is a prima facie case for the supra- 

 renal exhaustion theory. 



Examination of the chromaffin substance is not 

 a very convincing means of settling the problem. 

 It is quite probable that the chromaffin substance 

 and the adrenalin content run parallel, and there 

 are observations in support of this view, but it would 

 be much more satisfactory to make direct estimations 

 of the quantity of adrenalin in the blood and in the 

 suprarenal glands in cases of shock. For this purpose 



