Recently I posted a message concerning how labs dealt with the
problems of measuring electrolytes in whole blood versus plasma
and potential for different reference ranges. This followed a fairly
extensive string of messages concerning electrolytes in plasma v
serum. I got almost no responses. Admittedly I did add a snide
remark about POCT but that surely should not put subscribers off!!
Next someone posts a message about sodium monophosphate
and within a short time there is a plethora of responses.
I can not believe that amongst the many participants in this list
there are not several with the same problem of using whole blood
for POCT in ICUs and elsewhere while using plasma or serum in
the lab. A few telephone calls to colleagues suggested that this
problem may be being ignored and a single reference range used.
If so some correction may be needed to the whole blood method
especially for sodium. Our brief experience has thrown up
differences of 6-7mmol/l Na in some samples. Surely enough to
alter clinical management.
Please can I have the views of others on this problem and
examples of how people solved it or I will just have to go back to
making up buffers - phosphate of course.
Mike Addison
Dr G Michael Addison
Department of Clincal Biochemistry
Royal Manchester Children's Hospital
Pendlebury
Manchester M27 4HA
Tel 44 (0)161-727-2250
Fax 44 (0)161-727-2249
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