Electrolyte measurement - myths and misunderstandings- Part II

Introduction
Accurate and timely measurement of electrolytes is of paramount
importance in the critically ill. Beside the clinical implications arising
from adverse effects of dyselectrolytemia, electrolytes are also used to
calculate anion gap (AG), strong-ion difference (SID) and osmolarity,
all of which may have important therapeutic implications. The clinician
today not only has access to assays in central laboratory with progressively shorter turn around time, but also increasingly point of care
(POC) testing with the blood gases providing almost immediate results.
It is important to understand some of the common misunderstandings
and limitations with these measurements, as not only it can help minimize diagnostic errors, but also some of the artefacts may hint towards
covert diagnosis. In this two- part series, we discuss these measurements in the often complex scenario of critically ill patients