# Moving potassium is not removing potassium

Protect the heart, redistribute potassium, then remove the body load

Andrew Bland, MD, FACP, FAAP · October 20, 2026

![ Moving potassium is not removing potassium ](https://urinenephrology.org/2025_UDPA_Lectures_Live/assets/day1-potassium-compartments-2026-10-20.png)

## Protect and shift

Calcium treats cardiac membrane instability; it does not reduce potassium concentration or body stores. Insulin and beta agonists redistribute potassium into cells. Follow glucose after insulin and reassess potassium and the ECG because redistribution wears off.

## Remove: dialysis, gut and urine

Dialysis transfers potassium from blood into dialysate. Lokelma (sodium zirconium cyclosilicate) binds potassium in the gastrointestinal tract for fecal elimination. It is an option for acute hyperkalemia without cardiovascular compromise. With ECG toxicity or instability, use it as an adjunct while definitive treatment is arranged; it is not sole emergency rescue. Loop diuretics can add urinary potassium and fluid removal when useful residual function remains.

## Apply it to Case 1

HD began six weeks ago and urine output remains about 1 L/day. Trimethoprim can therefore impair residual renal potassium secretion; missed dialysis and a potassium salt substitute add risk. Urine volume does not quantify potassium clearance. Potassium 7.3 with a wide QRS and pulmonary edema requires calcium, shifting therapy and urgent HD. Lokelma can be given during the wait; a possible loop response must not delay the run.

## Discussion

Why can the potassium fall after insulin while the dialysis indication remains?

The potassium has moved into cells, not left the body. Rebound and the ongoing volume overload still matter. A gut binder can contribute to removal while HD is arranged but does not replace the emergency measures in this case.

## Sources

- [Source case](https://urinenephrology.org/2025_UDPA_Lectures_Live/case-based-lectures/cbl-01-the-missed-monday.html)
- [Hyperkalemia lecture](https://urinenephrology.org/2025_UDPA_Lectures_Live/electrolytes/potassium/hyperkalemia.html)
- [Velázquez et al.: renal mechanism of trimethoprim-associated hyperkalemia](https://pubmed.ncbi.nlm.nih.gov/8328738/)
- [Lokelma prescribing information: potassium binding and emergency-use limitation](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=90bf8e28-748d-4e4b-a19f-9cf483370eff)

For education. Read alongside the full case and lecture; use clinical judgment.