io8 



Scientific Proceedings (33). 



tion by ligature or stenosis of the branches of the renal artery. 

 The operation is harmless and very simple. The results obtained 

 by Dr. Jane way show that it is efficient. 



56 (394) 



A modification of the Riva-Rocci method of determining blood- 

 pressure for use on the dog. 



By THEODORE C. J ANEW AY. 



\^Fro7n the Rockefeller Institute for Medical Research.'\ 



Previous studies of the blood-pressure changes in living animals, 

 by repeated direct measurements from the femoral or carotid, 

 while accurate from the standpoint of the blood-pressure at the 

 moment of observation, have been of very limited value. When 

 used as a means of following the changes occurring over long 

 periods of time, as in the study of experimental kidney insuffi- 

 ciency, it is questionable whether a single pre-operative reading, 

 with several post-operative ones, afford in themselves any basis 

 for the conclusions drawn. The figures given by Volkmann for 

 the blood-pressure of different animal species show readings from 

 the dog of 104, 123, 143, 157, 166 and 172 mm., a variation so 

 wide that, in the light of our knowledge of the fluctuations of 

 blood-pressure in man, it suggests strongly the fallacy of any con- 

 clusions drawn from a comparison of two or three measurements 

 at long intervals. 



To obtain some more definite idea of the changes occurring 

 from day to day in experimental animals, I have endeavored to 

 apply to the dog the commonly employed clinical methods. After 

 various attempts, the most satisfactory method was found to be a 

 modified Riva-Rocci cuff applied to the lower foreleg, the pulse 

 being palpated in the artery at the bend of the ankle or in the 

 plantar aspect of the paw. A rubber bag 7.5 x 15 cm., with a 

 slightly larger outer leather cuff, will fit almost any dog, the fore- 

 leg being not less than 8 cm. in length, and from 11 to 14 cm. in 

 circumference in a large number of laboratory dogs examined. 

 For small dogs a cuff 5x11 cm. is adequate. Measurements are 

 greatly facilitated by using a pressure bottle connected with the 

 cuff and the manometer through valves operated by foot pedals, 



