144 Nathan B. Talbot and Robert Richie 



receiving at least 75 grams of carbohydrate per m.^ per day 

 (Gamble, 1946-7). It was arbitrarily decided that a 15 per 

 cent decrease in body water, sodium, potassium or protein or 

 a 75 per cent depletion of body fat (calorie) stores constituted 

 a significant and potentially serious loss. 



As indicated by the upward trend from left to right of the 

 curves of Fig. 3, infants and children up to three years of age, 

 when deprived of any one of the substances represented, are 

 apt to become depleted two to four times faster than adults. 

 For example, infants will develop as serious a degree of water 

 depletion within one and a half days as adults do in the course 

 of about five days of total thirsting. Likewise, infants de- 

 prived of electrolytes or protein or calories may lose an 

 appreciable portion of their body stores of these items after 

 nine to 17 days of deprivation.* By contrast, it takes 20 to 

 35 days for adults to become similarly depleted under condi- 

 tions where homeostatic conservation forces are operating 

 efficiently. These observations indicate that in infants who 

 must be maintained by parenteral fluid therapy for more than 

 a few days, special attention should be given to the provision 

 not only of water, carbohydrate and the main extracellular 

 and intracellular electrolytes, but also of maintenance allot- 

 ments of calories and either preformed protein or amino acids. 

 The same would apply to older children and adults who are 

 depleted or have to be sustained by parenteral fluid therapy 

 for more than a week or ten days. 



Fig. 4 deals with the opposite phenomenon of overloading. 

 Here again it has been necessary to make arbitrary decisions 

 concerning the size of the overload and the degree of retention 

 to be considered significant. It was decided to postulate rates 

 of input that were ten per cent in excess of adult physiological 

 maximum tolerance or ceiling values. The end-point values 

 for the retentions of toxic degree resulting from these physio- 

 logically excessive rates are related to the respective average 

 normal body content values at each age as follows : total body 



* The rate of loss would be considerably greater under conditions of zero 

 carbohydrate intake (Gamble, 1946-7). 



