I 10 



Scientific Proceedings (33). 



that I may demonstrate one of the animals now Hving with 

 reduced kidney substance and hypertension. 



I have made blood-pressure readings, by the rough method 

 previously described, on twenty-three dogs, over a period of fifteen 

 months. As a guide to normal readings in the dog I have figures 

 from twelve dogs that were in good health, several of these being 

 finally checked by direct carotid tracings. In these twelve dogs 

 the average pressure, calculated from a number of readings on 

 each, lay between 91 and 119 mm., the highest individual reading 

 being 130 mm., and the lowest 85 mm. A number of observa- 

 tions made before operation on the ten nephrectomized dogs 

 showed an average blood-pressure between 90 and 117 mm.; 

 highest reading was 135 mm., lowest 80 mm. These readings 

 average lower than those obtained in man, but the method as 

 applied to the dogs is more comparable to the results of Gartner 

 in man, since the artery used is more peripheral, and the pressure 

 within it more subject to fluctuations due to variations in local vaso- 

 motor tone. As I have already said, however, the errors are all 

 on the side of too low readings ; therefore, with a sufficient number 

 of pre-operative readings to give a fair average, the finding of a 

 marked rise in blood-pressure subsequently cannot be attributed 

 to errors inherent in the method. 



The dogs studied were operated on by Dr. Carrel as already 

 described, with the exception of one after the method used by 

 Bradford, Passler, and Pearce. Four died from too extreme reduc- 

 tion of the arterial blood supply of inanition, and one of an abscess 

 unrelated to the operation. All showed a slight rise in pressure 

 in the first three to seven days, with subsequent fall, except one 

 dog that died of extensive resection in four days. The most strik- 

 ing of the fatal cases showed the following : 



Five dogs are still living, one having been operated on 105 

 days ago, the others a shorter time. This dog, No. 12, shows the 

 following clear result : 



Blood-pressure, mm. Hg. 



Maximum. Minimum, Average. 



Before operation, 15 days. 

 After operation, 21 days.. 

 Terminal period, 14 days, 



110 100 106 



135 120 127 



1 10 70 83 



