76 DONALD D. VAN SLYKE 



Relation of Changes in the Acid-Base Balance of the 

 Blood to Changes in the Other Body Fluids 



As has been already shown, the intercellular fluids other than blood 

 plasma have, so far as studied, been found under normal conditions to 

 approximate the blood plasma in bicarbonate and hydrion concentrations. 

 There is evidence that in changes from the normal the other body fluids 

 follow more or less promptly the blood plasma. Van Slyke and Cullen 

 (1917) found that when acid was injected into the circulation the fall 

 in blood bicarbonate was only about one-sixth as great as it would have 

 been had the acid all remained in the blood ; the other five-sixths of the 

 acid must have gone into the other body fluids and the tissues, or drawn 

 alkali from them. Palmer and Van Slyke (1918) found similarly that 

 when bicarbonate is administered, the rise in blood bicarbonate was ap- 

 proximately that calculated on the assumption that the alkali was not re- 

 tained in the blood, but was distributed evenly through all the body fluids. 

 Collip and Backus (a) (1920) found the bicarbonate of the spinal fluid fol- 

 lows that of the venous blood plasma. When the latter was lowered by 

 continued etherization, or by shock (handling of intestines) the bicarbonate 

 of the spinal fluid also fell and to about the same level, although more 

 slowly. When the alkali reserve of the blood was raised by bicarbonate 

 injection, the spinal fluid bicarbonate rose in the course of a few hours to 

 approximately the same level. 



Methods for Determining the State of Acid-Base 

 Balance of the Body 



The available methods may be classified as either functional or direct. 

 In the former the presence of one or more of the functional abnormalities 

 caused by acidosis is taken as evidence of its existence. The functional 

 abnormalities thus used really represent unusual efforts of the organism 

 to regain a normal acid-base balance. The effort is likely to vary in in- 

 tensity as the degree of the disturbance in the balance, and hence to indi- 

 cate with some degree of accuracy the severity of the disturbance. Such 

 an effort is the hyperpnea of acidosis with the resultant lowering of the 

 alveolar CO 2 tension, in the obvious attempt to lower the blood H 2 COo 

 and maintain thereby a normal pH. Such an effort also is the increased 

 hourly excretion of ammonia and titratable acid in the urine, and of the 

 specific acids responsible for the disturbance, as in the ketonuria of dia- 

 betes. Observations of such functional activities are and will be of value 

 in detecting acidosis, but they contain an inherent source of error in that 

 they presuppose a normal response of the respective functions to the 



