# Hyperkalemia: remove potassium while the clock runs

Andrew Bland, MD, FACP, FAAP · October 21, 2026

Gut, dialysis and useful urinary clearance are removal routes; none should delay cardiac stabilization.

## Lokelma: early gut binding is useful, but it is not immediate rescue

Sodium zirconium cyclosilicate (SZC; Lokelma) binds potassium within the gastrointestinal lumen, including both the small and large intestine, and increases fecal potassium loss. With the studied initial regimen of 10 g three times daily, serum potassium reduction was observed at one hour and continued over the following 48 hours. That is an onset signal, not a guarantee of adequate correction at one hour. The US label states that it should not be used as emergency treatment for life-threatening hyperkalemia. It may be an adjunct while effective emergency treatment and removal are arranged; do not substitute it for calcium, shifting treatment or urgent dialysis. Consider bowel function, sodium-related edema and separation from interacting oral medications.

## Why SPS is a poor emergency choice

Sodium polystyrene sulfonate (SPS; Kayexalate) has delayed and unpredictable potassium lowering, often taking hours to days, with limited evidence for rapid emergency benefit. Its labeling includes serious gastrointestinal injury, including ischemia, necrosis and perforation; sorbitol adds risk. It also supplies sodium and can affect other medications. It is not a dependable emergency bridge and should not be the reason to defer dialysis. This does not imply that every use of SPS is prohibited; it explains why it is a poor choice for this unstable case.

## Dialysis starts a process, not an instantaneous result

Call the dialysis team early and establish whether usable access is already present. Staff mobilization, assessment, an access procedure when necessary, machine safety checks, dialyzer and circuit priming, and connection all precede clearance. Readiness can take tens of minutes to hours, depending on local resources; no universal machine-setup time is defensible. Ask for the actual estimated start time and escalate a delay that exceeds the patient's clinical tolerance. Potassium removal begins when treatment runs, not when the order is entered. Continue temporizing treatment and monitoring during preparation; check for post-dialysis rebound.

## Still making urine? Look for a reversible drainage problem

Residual urine output makes a urinary contribution possible, but urine volume does not measure potassium clearance. If retention, a blocked catheter or obstructive AKI is plausible, assess bladder volume and catheter patency and decompress retention when indicated. A Foley can relieve lower-tract obstruction and measure output when those indications exist. It is not a universal first step and does not treat upper-tract obstruction by itself. Useful renal function and appropriate perfusion are still needed for potassium excretion; a loop diuretic may assist selected patients. Do not delay cardiac protection or urgent dialysis while waiting for a urinary response. After decompression, monitor for post-obstructive diuresis, volume loss and electrolyte changes.

## Apply the parallel plan to Case 1

Mr. Hartman has a widened QRS, missed dialysis, pulmonary edema and insufficient potassium clearance despite residual urine. Protect the heart, shift potassium, call for urgent dialysis, and consider an appropriate gut binder while the team prepares. Assess retention if the history, examination or low output suggests it. An early potassium fall after insulin does not remove the body load or resolve pulmonary edema. State when each treatment started, when its effect may fade, and when the next potassium, ECG and glucose assessment is due.

## Sources

- [Lokelma US prescribing information: mechanism, onset and emergency limitation](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7f7ed64d-8480-4143-a207-29c24a0b9363)
- [Manufacturer mechanism information: small and large intestine](https://www.lokelma-hcp.com/)
- [SPS prescribing information: delayed effect and GI injury warnings](https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=03a0b525-5e48-4e76-b1fa-700eab10d20a&version=104)
- [SPS suspension prescribing information: hours-to-days onset](https://dailymed.nlm.nih.gov/dailymed/getFile.cfm?setid=3c3b02a3-9a75-40a5-889d-97318faf881f&type=pdf)
- [UK Kidney Association: urgent dialysis and monitoring](https://www.ukkidney.org/health-professionals/guidelines/treatment-acute-hyperkalaemia-adults-0)
- [Obstructive uropathy: acute and chronic medical management](https://pubmed.ncbi.nlm.nih.gov/36704657/)