Relationship Between Chloride Content and Blood Cerebrospinal Fluid Bromide Ratio

Abstract

Conclusions

(1) The determination of the bromide content of a fluid containing chlorides, by the Walter method, is influenced by the amount of chlorides in that fluid. The loss of bromides is directly proportional to the amount of chlorides. Blood serum, cerebrospinal fluid, and water are, within narrow limits, similar in this respect. (2) The determination of the bromide content by the Walter method in chloride-free fluid is reliable, the margin of error being quite limited. (3) Blood and cerebrospinal fluid containing similar quantities of chlorides would be liable to the same error, and the bromide contents obtained would be reliable for purposes of comparison. (4) For absolute reliability the technique of the Walter method should be modified as follows: a. The blood should be diluted with a NaCl solution, the strength of which is equal to that of the blood, b. The chloride contents of the blood and cerebrospinal fluid should be determined, and in computing the actual amount of bromides allowances should be made for the loss due to the chlorides. The present investigation shows that the loss caused by 0.6% NaCl (which is the average NaCl concentration in blood serum) is about 27%. Further studies are being made to determine the exact losses due to NaCl concentrations ranging from 0.4% to 0.9%.