508 PARENTERAL NUTRITION 



PARENTERAL NUTRITION 



The remainder of this lecture will be given over to 

 the practically important problem of parenteral feeding. 



The physician is often enough brought face to face with 

 a case in which the incapacity of the diseased gastro-intes- 

 tinal apparatus brings with it an impossibility of providing 

 the body with the food necessary for maintenance of life. 

 Here the question forces itself upon him whether it may not 

 be possible to introduce the food into the body, disregarding 

 the intestinal tract, by direct ' ' parenteral ' ' route. The feel- 

 ing that this is a problem in which the physiological chemist 

 can render an important and immediate service to the prac- 

 titioner of medicine finds expression in the large number of 

 experimental studies, which in the course of the last few 

 years have been directed especially to the question of paren- 

 teral protein administration. What results have been 

 obtained f 



Parenteral Introduction of Protein. The older physiolo- 

 gists were for the most part of the opinion that heterologous 

 protein introduced into the system is not assimilated, but is 

 simply passed out with the urinary excretion. This, how- 

 ever, as a matter of fact is by no means entirely true. It is 

 true that sometimes an albuminuria is observed after par- 

 enteral administration of protein 64 ; eggalbumin seems to 

 pass into the urine especially easily. (In normal human be- 

 ings albuminuria has been noted after the ingestion of six 

 raw eggs, evidently due to portions of the albumin which 

 passed the intestinal wall without undergoing cleavage.) 65 

 However, elimination of this sort is by no means the rule. 

 There is no doubt that the economy is able to retain and con- 

 sume large amounts of parenterally introduced specifically 

 foreign protein (among others, for example, foreign blood 

 serum, 66 egg albumin, 67 casein, 68 or vegetable albumin 69 ). 



*Cf. W. Cramer (Physiol. Instit., Edinburgh), Jour, of Physiol., 57, 146, 

 1908; J. Castaigne and M. Chiray, C. R. Soc. de Biol., 60, 218, 1906. 

 05 W. Cramer, 1. c., p. 157. 



