188 



PHYSIOLOGY OF INDUCED HYPOTHERMIA 



TABLE II 



Platelet counts (per cu. mm.) at maximum hypothermia 



' ^ 



Dog no. Aorta Spleen Liver Lung 



11 28.500 31,500 10,000 6,000 



12 24,000 55,000 13,500 10,000 



13 68,500 59,500 20,500 11,500 



18 41,000 38,500 25,500 20,000 



TABLE III 



Platelet counts 

 Temp. ° C. (per cu. mm.) 



il 286,000 



25 92,500 



20 45,500 



25 27,500 



30 77,500 



High inferior 



vena cava 

 platelet counts 

 (per cu. mm.) 



230,000 

 37,500 

 16,000 

 94,500 



118,000 



TABLE IV 



Aorta blood 



Platelet count WBC 



Temp. ° C. (percu. mm.) (per cu. mm.) 



Zl 365,500 6,500 



25 102,500 2,300 



20 24,500 1.800 



25 131,500 2,900 



30 186,000 3,400 



High inferior vena cava 



TABLE V 



Aorta blood 



Platelet count WBC 



Temp. ° C. (per cu. mm.) Hgb (per cu. mm.) 



11 332.000 13.6 14.800 



25 183,000 16.2 10,900 



20 68,500 19.3 6,250 



25 144,500 14.7 8,800 



30 220,000 12.4 10,850 



High inferior vena cava 



Platelet count 

 (per cu. mm. ) 



298,000 

 131,000 

 35,000 

 195,000 

 249,000 



Hgb 



13.3 

 15.7 

 18.7 

 12.7 

 13.1 



WBC 

 (per cu. mm. ) 



15,950 

 13,250 



6,500 



9,850 

 11,850 



mixture of blood from both the systemic and portal circulations. The resuUs show- 

 that the drop in platelet count high in the inferior vena cava preceded the drop in 

 platelets in the aorta. During rewarming the rise in platelets high in the inferior 

 vena cava also preceded that of the platelet rise in the aorta. In other words, it 

 seemed that the platelets were sequestered and later released from a site somewhere 

 between the aorta and the high inferior vena cava catheters. In tables \T and YII 

 we see the results obtained when the venous catheter was placed low in the inferior 

 vena cava — inferior to the entrance of the hepatic vein to the inferior vena cava. In 

 these two dogs it could be seen that the inferior vena cava blood no longer preceded 

 the aorta blood in the drop of platelets. This seems to indicate that the site of 

 platelet se({ucstration and sul)se(|uent i)latelet release is located in the portal, rather 

 than in the sy.stemic circulation. In table \'lll platelet comits are compared in the 



