A Retrospective Study of Patiromer as Adjunct to Insulin Therapy for Acute Hyperkalemia in the Emergency Department.

Objective: To investigate the clinical utility of administering patiromer as an adjunct to insulin for potassium reduction in patients presenting to the emergency department (ED) with hyperkalemia. Methods: This retrospective cohort study used electronic health record data to identify adults treated with at least one intravenous dose of regular insulin for hyperkalemia within the ED. Patients who were administered patiromer within one hour before or after their insulin dose were categorized as the intervention group. Matching was performed at a 1:1 ratio. The primary outcome, mean change in potassium from baseline to the latest value within the 4-12 hour interval, was compared. Secondary outcomes included net clinical benefit, defined as the mean difference in the number of potassium-lowering interventions minus the change in potassium. Results: The final analysis included 133 patients treated with patiromer plus insulin and 133 patients treated with insulin alone. Participants had a mean age of 71 years; 43% were female, 31% self-identified as Black, and 38% self-identified as Latinx. No significant changes were observed in potassium from baseline (mean levels 6.2 mEq/L in each group) to the 4-12 hour time frame (patiromer: -0.90 mEq/L, n=78 vs insulin-only: -0.98 mEq/L, n=81; p = 0.51). The calculated net clinical benefit of potassium reduction was -0.25 in favor of the patiromer plus insulin group; however, this difference did not reach statistical significance. In the subgroup of eGFR >30 mL/min, patiromer group received numerically less potassium-lowering interventions (0.63 vs 1.12, p = 0.057). Conclusion: In this study of patients with acute hyperkalemia in the ED setting, concurrent administration of patiromer did not result in more sustained potassium reduction compared to insulin alone in the overall cohort. The trend in favor of adjunct patiromer in the subgroup with adequate renal function warrants further investigation.