UMEM Educational Pearls

Prior studies have found that patients are at an increased risk for hypoglycemia when administered insulin for the acute management of hyperkalemia when they have renal dysfunction.  A new single-center, retrospective study investigated the risk of hypoglycemia and the overall effect of potassium lowering in patients with renal dysfunction and stratified outcomes based on the CKD level.

Patients were included if they were ordered insulin for hyperkalemia using a hospital driven order set and had CKD stages 3a, 3b, and 4.  They were excluded if they had dialysis within 6h of insulin administration, had DKA, or no repeat labs.  The hospital order set encourages 5 units of insulin instead of 10 when “renal failure” is present without clear guidance.

377 patients were included: 186 received 5 units and 191 received 10 units.  The average age was 65 years old, predominantly male, weighing 90 kg.  In the 5 unit group, significantly more patients had CKD stage 4 (60% v 30%) and in the 10 unit group, significantly more patients were CKD stage 3a (p<0.001).  The baseline serum potassium was 6 in each group.

The hypoglycemia incidence was not different between groups, with severe hypoglycemia occurring twice per group.  All patients received dextrose according to the protocol.

There was a significant difference in the reduction of serum potassium between the 5 and 10 unit groups: -0.63 mmol/L vs -0.9 mmol/L (p 0.001).

Bottom line:  Hypoglycemia occurred even with insulin dose reduction.  Potassium lowering was higher in patients who received the 10 unit dose.

 

References

Finder SN, McLaughlin LB, Dillon RC. 5 versus 10 units of intravenous insulin for hyperkalemia in patients with moderate renal dysfunction.