UNANESTHRTIZF.I) POTKILOTHERMIC DOG— KF.LLER 



75 



nic.'iii l)li)()(l pressure has oceiirred, willi lurtlier slowing' of the l)ra(l\cr(»tic ])ulse. 

 ( )n rewarminjj, the mean IjIockI pressure rose hut the i)ulse rate chd uot rise and at 

 times rontinuecl to deerease. With the onset of shiverin_ii^, a rise in l)lood pressure 

 has eonsislentI\- heeu ol)ser\'ed. Also on eoolins^, res])iration has slowed in all animals 

 and on rewarniini; has returned to or ahoxe the initial rate. These features are illus- 

 trated hy the data from one experiment charted in figure 12. 



In the poikilotherms, the temperature of the paw toe pads has fallen sharply to 

 near that of the cool aml)ient air. The chest skin temperature has varied from 2 to 

 .■^^ C. below the deep colonic temperature. On rewarming, these skin temperatures 

 have risen sharply toward the ambient air temperature of 40-45° C. These features 

 are illustrated by the data from one experiment charted in figure 13. 



During cooling the operated dogs consistently showed a rise in arterial whole 

 l)lood COo while the changes in arterial whole blood pH, hematocrit and arterial 

 oxygen saturation have been variable. These features are illustrated by the data 

 from one experiment charted in figure 14. In our experience the anesthetized un- 

 operated dog with unassisted respiration has shown an earlier and greater altera- 

 tion in the chemical status of the blood during cooling than have the poikilotherms ; 

 in particular, the pH fall has been more constant and COj rise more marked. 



Some of the poikilothermic animals have shown irritability and excitement at the 



DOG NO. 391 



22 SEPT. 1955 



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BLOOD PRESSURE WWW A 



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 30 



Fig. 







12. 



12 3 4 5 



TIME -HOURS 



-Diagram of vital signs on cooling in a representative experiment. 



