Erythrocyte electrolyte abnormalities

In contrast to lymphocytes and skeletal muscle cells, erythrocyte electrolytes may be easily determined. In this study Na, K, and Mg concentrations in plasma and erythrocytes of 100 consecutive ICU patients were compared to evaluate their potential clinical usefulness. The predictive indices of electrolyte changes in plasma vs. those in erythrocytes were low for all of the electrolytes studied. The erythrocyte Mg assessment was particularly useful for the high frequency of abnormalities observed, because it was less affected than plasma Mg by such transitory clinical states as hemodilution or lipolysis. The erythrocyte K was less frequently altered; no patient with a high K deficit was studied, excluding one patient with Crohn's disease. Finally, abnormally high erythrocyte Na levels correlated closely with some pathologic status, in particular respiratory failure.