Refractory Potassium Repletion due to Magnesium Deficiency

To the Editor.—  The excellent and timely article by Whang et al¹ regarding refractory potassium repletion as a consequence of magnesium deficiency supports our routine use of magnesium replacement in uncontrolled diabetes mellitus.^2-4 Further, their recommendation that hypokalemic patients receive magnesium replacement until the serum level is measured lends credence to the use of so-called balanced multi-electrolyte solutions (eg, Plasmalyte) instead of the standard "normal saline."We^2-4 have used these solutions plus supplemental magnesium sulfate to treat uncontrolled diabetes mellitus for 20 years with a mortality rate, in a municipal hospital, below those reported from many tertiary-care institutions. We have not seen the occasional episode of tetany reported in some patients with diabetic ketoacidosis who were given phosphate replacement, and we believe that this is due to routine Mg⁺⁺ replacement.⁴Balanced multi-electrolyte solutions provide Mg⁺⁺, K⁺, and a reduced chloride content (replaced by bicarbonate precursors) compared