244 



INFLUENCE OF TEMPERATURE ON BIOLOGICAL SYSTEMS 



from an exposure to asphyxia which is lethal for controls at normal body 

 temperature. 



Since perhaps the most critical factor in recovery from shock is tissue 

 anoxia which occurs as a result of the cardiovascular failure, it is interesting 

 to note that successful use of hypothermia in treatment of shock in humans 

 has been reported by a number of workers (12, 17, 18, 49, 50, 101, 102). 



If hypothermia prolongs asphyxial survival because it reduces the 

 organism's need for oxygen, other treatments which reduce metabolic 

 requirements should have a similar sparing action in asphyxia. This 

 was found to be the case with sodium pentobarbital. Preliminary tests 



A Shortest Survival 

 V Longest Survival 

 O Means 



J- 



J- 



J. 



J. 



SO 100 ISO 200 2S0 300 



Fig. 4. Time of death of 197 j'oung adult guinea pigs exposed to 95% No + 5% COa 

 at different body temperatures. 



made at four temperatures within a range of 10°C showed that survival 

 times were longer than normal in the narcotized animals at all four 

 temperatures. In addition, it was noted that the survival times of the 

 coolest narcotized animals were twice those of the warmest. This is 

 an increase of 100% per 10°C decrease in temperature instead of 50% 

 as had previously been found for non-narcotized animals. Next, the 

 temperature range was increased and littermate pairs were tested at seven 

 temperatures over a range of 25°C (fig. 5). This confirmed the fact that 

 the beneficial effects of narcosis in asphyxia increase as the temperature 

 decreases. At 15°C the Nembutal-injected animals lived twice as long as 

 their water-injected littermates. Recovery of narcotized animals from an 

 exposure which was lethal for non-narcotized littermates was demon- 



