Elevated serum levels of bromine do not always indicate pseudohyperchloremia.
BACKGROUND
We encountered a case of bromism that was found to be due to pseudohyperchloremia. Hyperchloremia is known to be able to reveal existing bromism, but the fact that bromine (Br(-)) influences chloride (Cl(-)) in assays that use ion electrode machines is not widely known.


METHODS
We assayed samples by an ion electrode method, using four types of machines. Different amounts of Cl(-) or Br(-) were added to each sample.


RESULTS
With the addition of Cl(-) to the samples, the assayed Cl(-) concentrations were proportional to the amount of added Cl(-). With the addition of Br(-) to the samples, the assayed Cl(-) concentrations, as measured by all machines, were increased, but the amounts of the increase differed significantly, and were not proportional to the amount of Br(-) added. In particular, in the machine most markedly influenced by additional Br(-), the Cl(-) concentrations increased from 94.9 to 139.6 mEq/l with the addition of 10 mEq/l of Br(-). Conversely, in the least influenced machine, Cl(-) values increased from 95.0 to 103.0 mEq/l with the addition of 10 mEq/l of Br(-).


CONCLUSIONS
The influence on the Cl(-) assay of the addition of Br(-) varied significantly between different ion electrode machines. Clinical nephrologists therefore need to be able to recognize the characteristics of the specific machines used in their hospitals.
Ito
Takayasu
T
Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, 2-174 Edo-bashi, Tsu, Mie, 514-8507, Japan. takayasu@clin.medic.mie-u.ac.jp
Ishikawa
Eiji
E
Matsuda
Yoshikazu
Y
Tanoue
Akiko
A
Fujimoto
Mika
M
Matsuo
Hiroshi
H
Murata
Tomohiro
T
Hiramoto
Takuya
T
Ito
Masaaki
M
Nomura
Shinsuke
S
D000328:Adult; D001774:Blood Chemical Analysis / Q000295:instrumentation* / Q000379:methods; D001966:Bromine / Q000097:blood*; D002712:Chlorides / Q000097:blood*; D004566:Electrodes; D005260:Female; D006801:Humans
D002712:Chlorides; D001966:Bromine