Plasma Potassium Changes in Anuric Hyperglycemia Treated with Insulin

Abstract

We followed sequentially the plasma potassium concentration in five, essentially anuric, hyperglycemic patients with no known abnormality of potassium metabolism and treated only with insulin. Acid-base balance, external potassium and fluid balance, and weights did not change during observation. The following changes in plasma potassium concentration (ΔΚ) were noted: In initial hyperkalemia (three patients) ΔΚ was −1.8±0.1mmol/l (p<0.005). In normokalemia (one patient) ΔΚ was −1.3mmol/l. In hypokalemia (one patient) ΔΚ was +0.1mmol/l. The correlation between the starting potassium concentration and the change in potassium concentration was −0.88 (p=0.05). ConclusionsWhen only parenteral insulin is used for treatment and acid-base balances and body weights do not change during treatment in anuric hyperglycemia: a) The change in potassium concentration is dependent on the starting plasma potassium concentration, b) hyperkalemic patients will drop their plasma potassium concentration toward normal, and c) hypokalemic patients may not need potassium replacement.