What is the immediate management for hyperkalemia (elevated potassium level) in a hemodialysis patient?

Management of Hyperkalemia (K+ 7 mEq/L) in Hemodialysis Patients Before Dialysis

For a hemodialysis patient presenting with potassium of 7 mEq/L before their scheduled dialysis session, proceed immediately to dialysis as the definitive treatment while simultaneously administering intravenous calcium gluconate for cardiac membrane stabilization if any ECG changes are present. 1, 2, 3

Immediate Assessment

• Obtain an ECG immediately to assess for peaked T waves, flattened P waves, prolonged PR interval, or widened QRS complexes—these findings mandate urgent treatment regardless of the exact potassium level 1, 2
• Verify the result is not pseudohyperkalemia from hemolysis, repeated fist clenching, or poor phlebotomy technique before initiating aggressive treatment 2
• Note that ECG findings can be highly variable and less sensitive than laboratory values, so their absence does not exclude the need for treatment at this potassium level 1, 2

Acute Management Algorithm

Step 1: Cardiac Membrane Stabilization (if ECG changes present)

• Administer calcium gluconate 10%: 15-30 mL IV over 2-5 minutes (or calcium chloride 10%: 5-10 mL IV over 2-5 minutes) with continuous cardiac monitoring 2
• Effects begin within 1-3 minutes but last only 30-60 minutes and do NOT lower potassium—this is purely for cardiac protection 1, 2
• Repeat the dose if no ECG improvement within 5-10 minutes 1, 2

Step 2: Intracellular Potassium Shift (while preparing for dialysis)

• Administer regular insulin 10 units IV with 25g dextrose (25% dextrose 100 mL) to shift potassium intracellularly, with onset in 15-30 minutes and duration of 4-6 hours 1, 2
• Add nebulized albuterol 10-20 mg in 4 mL as adjunctive therapy, with effects lasting 2-4 hours 1, 2
• Monitor glucose closely to prevent hypoglycemia, especially in patients without diabetes, females, and those with altered renal function 2

Step 3: Definitive Treatment

• Proceed to hemodialysis immediately—this is the most effective and reliable method for potassium removal in dialysis patients with severe hyperkalemia 1, 2, 3
• Dialysis is the definitive treatment and should not be delayed if the patient is scheduled for dialysis that day 3

Critical Pitfalls to Avoid

• Do NOT use sodium bicarbonate unless concurrent metabolic acidosis is documented (pH <7.35, bicarbonate <22 mEq/L)—it is ineffective without acidosis and wastes time 1, 2
• Do NOT rely on sodium polystyrene sulfonate (Kayexalate) for acute management—it has delayed onset of action (hours) and is not indicated for life-threatening hyperkalemia 4, 3
• Do NOT delay dialysis to administer temporizing measures if the patient is already scheduled for dialysis—calcium, insulin, and beta-agonists only buy time and do not remove potassium from the body 2, 3
• Never give insulin without glucose—hypoglycemia can be life-threatening 2

Chronic Management Between Dialysis Sessions

For Recurrent Pre-Dialysis Hyperkalemia (K+ >5.5 mEq/L)

• Initiate sodium zirconium cyclosilicate (SZC) 10g once daily on non-dialysis days to maintain pre-dialysis potassium 4.0-5.5 mEq/L 1, 5
• SZC reduces serum potassium within 1 hour and has been specifically studied in hemodialysis patients with persistent hyperkalemia 1, 5
• In the DIALIZE study, once-daily SZC on non-dialysis days effectively maintained normal pre-dialysis potassium levels over 8 weeks 1

Dialysate Potassium Considerations

• Use dialysate potassium concentration of 3.0 mmol/L combined with SZC on non-dialysis days rather than 2.0 mmol/L dialysate alone—this approach reduces cardiac arrhythmias and post-dialysis hypokalemia 5
• A recent 2025 study demonstrated that 3.0 mmol/L dialysate potassium with SZC reduced atrial fibrillation episodes (rate ratio 0.52) and other clinically significant arrhythmias (rate ratio 0.47) compared to 2.0 mmol/L dialysate without SZC 5
• Lowering dialysate potassium concentration too aggressively (to 2.0 mmol/L) increases the risk of arrhythmias due to rapid potassium shifts 6, 5

Medication Review

• Eliminate or reduce contributing medications: NSAIDs, trimethoprim, heparin, beta-blockers, potassium supplements, and salt substitutes 2
• Do NOT discontinue RAAS inhibitors if the patient has cardiovascular disease or proteinuric kidney disease—instead, use potassium binders to maintain these life-saving medications 2

Monitoring Protocol

• Check potassium levels 24-48 hours after initiating SZC therapy to assess response 1
• Monitor for hypokalemia, which may be even more dangerous than hyperkalemia in dialysis patients 2, 5
• Assess for signs of fluid overload if using potassium binders, as SZC contains sodium 1

Key Clinical Pearls

• Prolonged fasting between dialysis sessions can provoke hyperkalemia—this can be prevented by administration of intravenous dextrose if the patient is unable to eat 3
• Dietary potassium restriction has limited evidence for efficacy and may deprive patients of heart-healthy foods—focus instead on pharmacologic management 7, 8
• The combination of higher dialysate potassium (3.0 mmol/L) with SZC on non-dialysis days represents the most recent evidence-based approach to prevent both hyperkalemia and dangerous post-dialysis hypokalemia 5