KLKCTROl.VTl-: TRANSFER— GC )I.T. AX 39 



K/Na RATIO 

 HYPOTHERMIA ANOXIA 



Fig. 3. — Changes in K/Na ratio during hypotliermia witli normal oxygenation and during anoxia 

 at normal and hypothermic temperatures. 



Thus, the increased excitahihty of the myocardium in well oxygenated hypo- 

 thermic dogs and in animals suhjected to anoxia has a common chemical denomina- 

 tor in the decreased K/Na ratio. 



The inability of anoxic tissue to retain its potassium and to repel sodium is well 

 documented in the literature. The same, though much milder, disturl)ance in the 

 hypothermic myocardium can be interpreted as the result of the prolongation of the 

 activity phase with increased potassium permeability during the long Q-T interval, 

 or a kind of Fenn effect in slow motion. 



It is not too difficult to understand that if all the other organs in hypothermia 

 "go to sleep," the heart still has to stay awake and to go on with its work. Althotigh 

 the passengers in the cabins of the ship are all asleep, the fellows down in the boiler 

 room still have to shovel the coal, and they lose potassium while lifting their load. 

 They do not shovel the coal as fast as when their temperature was high, but now 

 each single move takes much longer and they are not given enough time off to 

 recover from their potassitim loss. 



The increased solubility of oxygen in water and plasma at temperatures close 

 to 0° C. when oxygen dissociation from hemoglobin is negligible, can asstime biologi- 

 cal importance in large nonhibernating mammals. If the blood of dogs is circulated. 



