GENERAL METABOLISM— HORVATH and SPURR 



11 



20.0 r 



SHIVERING 



log y • 00274X - 0.1172 



,, NON-SHIVERING 

 logy 'OOSrix- 0.6926 



375 35.5 



RECTAL TEMP. "C. 



33.5 



31.5 



295 



275 



25.5 ; 23.5 



Fig. 2.- — Oxygen consumption, under condition of sliivering and in the ab.sence of shivering, 

 during progressive reduction of the rectal temperature in 24 experiments on 19 dogs. Points 

 indicate the mean values and vertical lines the extremes of variation at each temperature level. 



The level of activity of oxygen consumption as well as other physiological func- 

 tions of the hypothermic animals shows an exponential decline with decreasing body 

 temperatures. This decline is not greater than expected and can be expressed as 

 being physiologically adequate for the situation existing at the time. 



Considerable attention has been given to the problem of spontaneous versus con- 

 trolled respiration. Oxygen consumption in relation to body temperature does not 

 appear to be affected by the mode of ventilation of the lungs.-" Oxygen supplies to 

 the tissues apparently are adequate in either instance. The major point of contro- 

 versy hinges not tipon any metabolic differences but upon the relative incidence of 

 ventricular fibrillation observed. Spurr ct al.'-^ did not find a greater incidence of 

 fibrillation in their spontaneously breathing dogs than other investigators who em- 

 ployed controlled respiration. 



Oxygenation of arterial blood even when l)reathing room air appears to be fully 

 adequate.-- However, Dill and Forbes^" have noted a decrease in arterial pOi from 

 98 mm. Hg. at 37.1° C. to 70 mm. at 27.8° CJ This decrease was attributed to 

 altered rates of diffusion through lung nieml)ranes and was supported by the find- 

 ing of pulmonary edema in one patient and on Walther's-"' demonstration of pul- 

 monary edema in cooled rabbits. This ano.xemia, evidenced by cyanosis and relieved 

 by oxygen inhalation, was also noted by Woodruff-'^ who similarly found pulmonary 

 edema in one of his dogs. Although development of a state of anoxia during hypo- 



t At 20° C. approximatelv 32 per cent more oxvgen is physicallv dissolved in plasma than at 

 38° C. 



