Hyperkalemia + CKD – 5 or 10 Units of Insulin?

February 22, 2022

Written by Rebecca Breed

Spoon Feed
In patients with moderate renal dysfunction (eGFR 15-59 mL/min/m2), giving 10 units vs 5 units of IV insulin for hyperkalemia did not result in a statistically significant difference in rates of hypoglycemia. Administering 10 units was shown to lower serum K by ~0.3 mmol/L more than 5 units.

Why does this matter?
Hyperkalemia is a common ED presentation which can be life threatening if not treated promptly. Insulin is one of the mainstays of therapy but comes with its own life-threatening side effect of hypoglycemia. Therefore, it is important to balance potassium lowering with the risk of hypoglycemia. Prior studies showed greater risk of hypoglycemia in ESRD patients receiving 10 units of insulin, but what about the moderate group?

Is more always better?
This was a single center retrospective study that looked at the administration of 5 units vs 10 units of IV insulin for hyperkalemic patients with chronic kidney disease (CKD) stages 3a, 3b and 4 (eGFR 15-59 mL/min/m2). A total of 377 patients were included in the final analysis, with 49.3% receiving 5 units insulin and 50.7% receiving 10 units insulin. Severe hypoglycemia occurred twice in each group indicating no statistically significant difference. There was a greater reduction in serum potassium when patients received 10 units (-0.9 mmol/L vs -0.64 mmol/L, p = 0.001). Authors note that the patients receiving 5 units did have lower mean eGFR compared to those receiving 10. Results may also be skewed by other potassium lowering agents patients received, though authors report this was similar among groups.

Clinicians may have to make a quick decision regarding hyperkalemia treatment prior to getting back labs with eGFR. If the patient is not on ESRD, this study suggests it may be more beneficial to give 10 units of insulin up front. As always, monitor afterwards for hypoglycemia and have some dextrose on standby.

Source
5 versus 10 Units of Intravenous Insulin for Hyperkalemia in Patients With Moderate Renal Dysfunctions. J Emerg Med. 2022 Jan 17;S0736-4679(21)00773-3. doi: 10.1016/j.jemermed.2021.10.027. Online ahead of print.