386 



PHYSIOLOGY OF INDUCED HYPOTHERMIA 



8r 



7 - 



6- 



5- 



§ 4 



3- 



2 - 





Control Cooling ChlorpromazineChiorpromazineCniorpromazine Cniorpromozine 



5mg. 5 mg. 50mg. 50mg. 



+ Cooling +Cooling 



Fig. 4. — Experimental hemorrhagic shock, hypotensive time. 



Discussion. The hemorrhagic shock preparation used in this experiment is 

 fairly well standardized and has heen uniformly associated with a high mortality 

 in previous studies hoth in our lal)oratory and by other workers. Accordingly, it 

 offers an excellent method of controlled evaluation of the various therapeutic factors 

 employed in "artificial hibernation." Although there are nuiuerous reports of the 

 clinical application of hibernation to a wide variety of situations in which shock 

 is believed to be affected beneficially, there is a paucity of data on its use under 

 controlled experimental conditions. Jaulmes ct al^'' eiuploying Wigger's method 

 of inducing hemorrhagic shock, demonstrated an ai)parent protective action. l)ut 

 no attempt was made to ascertain the action of the individual factors, since both 

 drugs and cooling were applied to the small number of dogs eiuployed. 



This study tends to support the concept that artificial hibernation does offer some 

 protective action against "irreversibility" in experimental hemorrhagic shock, al- 

 though the results should be interpreted cautiously. Whether applied separately or 

 in combination, surface cooling and chlorproiuazine produced a significantly bene- 

 ficial effect upon the course of the shock, but the significance and meclKUiism of this 

 alteration are not entirely clear. 



Surface cooling preceding l)k'e(ling significanllN' increases survival and suggests 

 an increased tolerance to shock as manifest l)y tolerance to the hypotension and 

 blood loss. ;\])proximately one-fotirth of the animals were a])parently compensated 



