ACIDOSIS 



69 



apparent attempt of the organism to hold back sufficient CO 2 to restore 

 to normal the over-alkaline reaction. There is a moderate diuresis^ and 

 bicarbonate is excreted in the urine at a rate that may be several grams 

 per hour (Davies, Haldane, and Kennaway). Ammonia almost completely 



Maximum tolerated pH range 



80 



10 20 



30 



40- 50 60 70 80 90 

 Millimeters C0 2 tension 



100 110 120 



Fig. 2. Normal and abnormal variations of the BHCO S , H 2 C0 3 , CO 2 tension, and 

 pH in arterialized human whole blood drawn from resting subjects. The bicarbonate 

 CO 2 at any point is obtained by subtracting from the total C0 2 the relatively small 

 amount present as H 2 C0 3 indicated by the slanting line near the bottom of the figure. 



The minimum and maximum normal arterial C0 2 tensions and bicarbonate 

 concentrations, indicated by the lower left and upper right corners of Area 5, are 

 about twice as far from the means as are the normal extremes for these values 

 heretofore estimated from alveolar air and arterial blood analyses. The wide range 

 indicated by the diagram may be due 'to the fact that technical errors have widened 

 in all directions the ranges indicated by the boundaries of Area 5. More accurate 

 data will perhaps show this area to be smaller, and the extremes therefore nearer 

 the means. 



Another reason in part perhaps responsible for the fact that the extreme BHCO 3 

 and CO 2 tension values of Area 5 exceed the normally observed extremes is, that 

 there would be only one chance out of many that maximum pH and minimum BHCO 3 

 should occur in the same individual (e.g., if levels of each so far from the mean are 

 taken as to include only 1 individual out of 20, presumably only 1 out of 400 would 

 show both minima at once). Consequently it would not be surprising if the extreme 

 normal limits of C0 2 tension and BHCO 3 concentration have hitherto escaped observa- 

 tion, or have been observed so rarely as not to be regarded normal. 



With more accurate technique and a larger number of observations, it appears 

 probable that the limits of normal arterial CO 2 tension and bicarbonate concentration, 

 indicated theoretically by a graphic estimation like the above, will coincide with 

 those observed. 



disappears from the urine, and the titratable acid may become even a 

 negative quantity. Palmer has noted a transient albuminuria. 



The most marked and characteristic clinical effect is the development 

 of symptoms of tetany when the alkalinization proceeds sufficiently far 

 (Howland and Marriott, 1918 ; Harrop, 1919 ; MacCallum, Lintz, Leggett, 

 and Boas, 1920; McCann, 1918). 



