A Comparison of Insulin Doses for the Treatment of Hyperkalemia in Patients with Renal Insufficiency.

STUDY OBJECTIVE

To compare the safety and efficacy of 5 units versus 10 units of insulin for the treatment of hyperkalemia in patients with renal insufficiency.

DESIGN

Retrospective cohort study.

SETTING

Large academic medical center emergency department.

PATIENTS

Between March 1, 2008, and February 29, 2016, 675 patients met the inclusion criteria of age 18 years and older, serum potassium greater than 5 mEq/L, renal insufficiency, 5 units or 10 units of intravenous regular insulin administered in the emergency department, and blood glucose documented within 5 hours after insulin administration. Of these patients, 133 (19.7%) received 5 units of insulin and 542 (80.3%) received 10 units of insulin.

MEASUREMENTS AND RESULTS

The primary outcome was incidence of hypoglycemia (blood glucose < 70 mg/dl). Secondary outcomes were incidence of severe hypoglycemia (blood glucose < 40 mg/dl) and change in serum potassium after insulin therapy. Hypoglycemia occurred in 26 of 133 patients receiving 5 units of insulin (19.5%) and in 155 of 542 patients receiving 10 units (28.6%) (difference = -9.1%, 95% confidence interval [CI] -16.8% to -1.3%). Severe hypoglycemia occurred in 4 of 133 patients (3.0%) and 37 of 542 patients (6.8%) receiving insulin 5 units and 10 units, respectively (difference = -3.8%, 95% CI -7.4% to 0%). Change in serum potassium was similar between groups (-1.0 ± 0.8 vs -1.0 ± 0.7 mEq/L, difference = 0, 95% CI -0.1 to 0.1).

CONCLUSION

In patients with renal insufficiency and hyperkalemia, 5 units of insulin reduced serum potassium to the same extent as 10 units of insulin but with a lower rate of hypoglycemia. Further controlled studies are needed to confirm these findings.