Serum potassium concentration in hyperglycemia of diabetes mellitus with long-term dialysis

Severe hyperkalemia (serum potassium level >6 mmol per liter [mEq per liter]), often with electrocardiographic disturbances, was noted at presentation in 30% of 73 hyperglycemic episodes (serum glucose concentration >25 mmol per liter [455 mg per dl]) observed in 15 in-hospital patients with insulin-dependent diabetes mellitus who were receiving long-term hemodialysis or peritoneal dialysis. Serum glucose concentration and total carbon dioxide content correlated significantly with the presenting serum potassium concentration. Treatment with parenteral insulin alone resulted in a decrease of the serum glucose value from 41 +/- 14 (standard deviation) to 11 +/- 5 mmol per liter (P <.001) and of serum potassium level from 5.2 +/- 1.2 to 4.0 +/- 0.6 mmol per liter (P <.001). The changes in serum glucose concentration and in carbon dioxide content and the serum potassium concentration at hyperglycemia were found to be independent correlates of the decrease in potassium concentration during treatment. Insulin alone resulted in correction of hyperkalemia in all instances. Posttreatment hypokalemia was noted in only two instances, each associated with both ketoacidosis and low-normal serum potassium concentration at hyperglycemia. Giving insulin is the only treatment usually needed for the hyperkalemia of hyperglycemia in patients on ongoing dialysis.