What is the treatment for hyperkalemia?

Treatment of Severe Hyperkalemia (K+ 6.5 mEq/L)

A potassium of 6.5 mEq/L is a medical emergency requiring immediate hospital admission and urgent treatment to prevent life-threatening cardiac arrhythmias, regardless of symptoms. 1, 2, 3

Immediate Assessment (Within Minutes)

• Obtain an ECG immediately to assess for cardiac manifestations including peaked T waves, flattened P waves, prolonged PR interval, or widened QRS complex 1, 2
• Rule out pseudohyperkalemia by verifying proper blood sampling technique (no fist clenching, no hemolysis, prompt processing) 1, 4
• Any ECG changes mandate emergency treatment regardless of the exact potassium level 1, 2

Emergency Treatment Algorithm

Step 1: Cardiac Membrane Stabilization (Start Immediately if ECG Changes Present)

Administer intravenous calcium first to protect against arrhythmias within 1-3 minutes: 5, 1, 4

• Calcium gluconate 10%: 15-30 mL IV over 2-5 minutes (preferred for peripheral access) 1, 4
• Alternative: Calcium chloride 10%: 5-10 mL IV over 2-5 minutes (central line preferred) 1, 4
• Critical caveat: Calcium does NOT lower potassium—it only stabilizes the cardiac membrane temporarily (30-60 minutes) 5, 1, 4
• May repeat dose if no ECG improvement within 5-10 minutes 4
• Continuous cardiac monitoring is mandatory during and after administration 4

Step 2: Shift Potassium Intracellularly (Administer Simultaneously)

Give all three agents together for maximum effect: 5, 1, 4

• Insulin 10 units regular IV + 25g dextrose (50 mL of D50W) - onset 15-30 minutes, lasts 4-6 hours 5, 1, 4

  • Must give glucose with insulin to prevent hypoglycemia 5, 4
  • Monitor glucose every 1-2 hours for 4-6 hours after administration 4
  • Can repeat every 4-6 hours if hyperkalemia persists 4

• Nebulized albuterol 10-20 mg in 4 mL - onset 30 minutes, lasts 2-4 hours 5, 1, 4

  • Use as adjunctive therapy with insulin 5, 4

• Sodium bicarbonate 50 mEq IV over 5 minutes ONLY if metabolic acidosis present (pH <7.35, bicarbonate <22 mEq/L) 5, 1, 4

  • Do NOT use if no acidosis—it is ineffective and potentially harmful 5, 4
  • Onset 30-60 minutes 5, 4

Step 3: Remove Potassium from Body (Initiate Within 1 Hour)

Choose based on renal function and clinical context: 5, 1, 4

• Loop diuretics (furosemide 40-80 mg IV) if adequate kidney function (eGFR >30 mL/min) and patient is not oliguric 5, 1, 4

• Hemodialysis is the most effective and reliable method for severe hyperkalemia, especially if: 5, 1, 4, 3

  • Oliguria or end-stage renal disease present 5, 4
  • Refractory to medical management 5, 3
  • Ongoing tissue breakdown or potassium release 5

• Newer potassium binders (preferred over sodium polystyrene sulfonate): 1, 4, 6

  • Sodium zirconium cyclosilicate (SZC/Lokelma) 10g three times daily for 48 hours - onset within 1 hour, then 5-15g daily for maintenance 4, 6
  • Patiromer (Veltassa) 8.4g once daily - onset ~7 hours, less useful acutely 4, 6

Medication Management During Acute Episode

At K+ 6.5 mEq/L, temporarily discontinue or reduce RAAS inhibitors (ACE inhibitors, ARBs, mineralocorticoid antagonists) 1, 2, 4

• Also review and hold: NSAIDs, potassium-sparing diuretics, trimethoprim, heparin, beta-blockers, potassium supplements, salt substitutes 5, 4

Monitoring Protocol

• Recheck potassium every 2-4 hours after initial treatment until stable below 5.5 mEq/L 4
• Continuous cardiac monitoring until potassium <6.0 mEq/L 1, 2
• Monitor glucose hourly for 4-6 hours after insulin administration 4

After Acute Resolution: Preventing Recurrence

Once potassium <5.5 mEq/L, initiate potassium binder and restart RAAS inhibitors at lower dose (if indicated for heart failure or proteinuric kidney disease): 5, 1, 4

• Start SZC 5-10g daily or patiromer 8.4g daily 4, 6
• Do NOT permanently discontinue RAAS inhibitors—they provide mortality benefit in cardiovascular and renal disease 1, 2, 4
• Recheck potassium within 1 week of restarting RAAS inhibitors 5, 4

Critical Pitfalls to Avoid

• Never delay treatment while waiting for repeat lab confirmation if ECG changes are present 1, 2
• Never use sodium bicarbonate without metabolic acidosis—it is ineffective and wastes time 5, 4
• Never give insulin without glucose—hypoglycemia can be life-threatening 5, 4
• Remember that calcium, insulin, and beta-agonists are temporizing measures only—they do NOT remove potassium from the body 5, 4
• Do not rely solely on ECG findings—they are variable and less sensitive than lab values 4
• Avoid sodium polystyrene sulfonate (Kayexalate)—it has delayed onset and risk of bowel necrosis 4, 6