Scientific Proceedings (115). 



128 (1710) 



The concentration of sodium and potassium as compared with 

 that of calcium and magnesium in the serum of 

 patients with active infantile tetany. 



By F. F. TISDALL. B. KRAMER and J. HOWLAND. 



[From the Department of Pediatrics, Johns Hopkins University.] 



We have determined the sodium, potassium, calcium and 

 magnesium content of the serum of children suffering from active 

 infantile tetany. As most of the infants were quite small it 

 was only possible in a few cases to do the four determinations 

 on the serum of the same individual. The results are given in 

 Table L It is seen that the sodium content falls within the 

 limits of normal. The potassium content is apparently some- 

 what elevated. The concentration of calcium in the serum, as 

 previously shown, is markedly diminished while that of magnesium 

 is usually within normal limits. 





Sodium 



Potassium 



Calcium 



Magnesium 





Mg. per 100 Cc. 



Mg. per 100 Cc. 



Mg. per 100 Cc. 



Mg. per 100 C.C. 





324 



25.O 



5-6 



2.2 





330 



26.7 



6.2 



1.6 



3 



337 



19.O 



6.6 



2.1 



4 



323 



24.8 



5-8 



1-7 



5 



322 



28.4 



5-0 



2.9 



6 



324 



26.0 



5.2 



2.4 



7 







35 





8 







5-8 





9 







6.3 





10 







6-7 











6.0 





12 







6.7 





Average .... 



327 



24.9 



5-8 



2.1 



The average concentration of these elements in the sera of normal 

 children is singularly constant. The actual figures are as follows: 



Calcium 10 - n mg. per 100 cc. of serum. 



Magnesium 2 - 3 mg. per 100 cc. of serum. 



Sodium 325 -345 mg. per 100 cc of serum. 



Potassium 18.5- 20.5 mg. per 100 cc of serum. 



The (Na + K)/(Ca + Mg) ratio in the normal infant is therefore 



340 + 19 ' 5 = 27.6, 

 10.5+2.5 



