Incidence of Hypoglycemia When Employing Two Different Insulin Dosing Strategies for the Treatment of Hyperkalemia

Hyperkalemia is a potentially life-threatening electrolyte abnormality, especially when potassium levels are 6.5 mEq/L or above. Treatment often includes intravenous (IV) insulin, which carries the risk of hypoglycemia, and even more so in chronic kidney disease (CKD). A recent meta-analysis explored an insulin dose of 5 units, which may reduce the risk of hypoglycemia without compromising potassium reduction. There is a lack of literature comparing 5 units and 10 units of insulin for hyperkalemia treatment in patients with normal renal function, where the hypoglycemia risk post-insulin administration may be lower. This study aims to compare safety and efficacy in patients with normal and decreased renal function treated for hyperkalemia with 5 or 10 units of IV insulin.

This retrospective chart review included adult patients with a potassium of 6.5 mEq/L or above that received either 5 or 10 units of insulin. Patients were excluded if they were pregnant, had a pre-insulin glucose less than 70 mg/dL, or did not have post-insulin potassium and/or blood glucose levels. The primary outcome was frequency of hypoglycemia (blood glucose less than 70 mg/dL) after insulin administration. Secondary outcomes included effect on potassium levels, order set use, and severe hypoglycemia (blood glucose less than 50 mg/dL). Descriptive statistics were used to evaluate outcomes and chi squared or T-tests to designate significance.

A total of 436 patients were enrolled, and 401 patients were included in the analysis (282 patients in the 5-unit group and 119 patients in the 10-unit group). Of these patients, 82.29% had a CKD diagnosis and 37.16% had end-stage renal disease. For the primary outcome, 35/282 (12.41%) of the 5-unit group had a post-insulin glucose of less than 70 mg/dL, compared to 11/119 (9.24%) of the 10-unit group (p=0.36). There was no significant difference between groups in severe hypoglycemia (p=0.55). Of the normal renal function subgroup, there were no hypoglycemic events. The average decrease in serum potassium was 1.38 for the 5-unit group and 1.54 for the 10-unit group (p=0.07)

When comparing 5 and 10 units of insulin in the treatment of hyperkalemia, there were no statistically significant differences in rates of hypoglycemia or change in serum potassium. Larger studies are needed to focus on outcomes in patients with normal renal function.