What is the stepwise management of severe hyperkalemia with ECG changes (e.g., serum potassium ≥6.5 mmol/L)?

Stepwise Management of Severe Hyperkalemia with ECG Changes

For severe hyperkalemia (≥6.5 mmol/L) with ECG changes, immediately administer IV calcium to stabilize the cardiac membrane, followed simultaneously by insulin-glucose and nebulized albuterol to shift potassium intracellularly, then initiate definitive potassium removal via loop diuretics or hemodialysis depending on renal function. 1, 2

Step 1: Immediate Cardiac Membrane Stabilization (Within 1-3 Minutes)

Administer IV calcium first—this is your only immediate protection against fatal arrhythmias. 1, 2

• Calcium gluconate 10%: 15-30 mL IV over 2-5 minutes (preferred for peripheral access) 1, 2, 3
• OR calcium chloride 10%: 5-10 mL (500-1000 mg) IV over 2-5 minutes (more potent, use if central access available) 1, 2
• Onset: 1-3 minutes; Duration: 30-60 minutes only 1, 2
• Critical: Calcium does NOT lower potassium—it only temporarily protects the heart 1, 2
• Repeat the dose if no ECG improvement within 5-10 minutes 1, 2, 3
• Continuous cardiac monitoring is mandatory during and after administration 1, 2

Important Caveats for Calcium Administration:

• Never delay calcium while waiting for repeat potassium levels if ECG changes are present—ECG abnormalities indicate urgent need regardless of the exact potassium value 1, 2, 3
• Do not administer calcium through the same IV line as sodium bicarbonate (precipitation will occur) 2
• Use calcium cautiously in patients with elevated phosphate levels (risk of calcium-phosphate precipitation) 2

Step 2: Intracellular Potassium Shift (Administer All Simultaneously)

Give all three agents together for maximum effect—they work additively and provide the greatest potassium reduction. 1, 2

Insulin-Glucose (First-Line, Most Reliable)

• 10 units regular insulin IV push + 25g dextrose (50 mL D50W) 1, 2, 3
• Onset: 15-30 minutes; Peak: 30-60 minutes; Duration: 4-6 hours 1, 2
• Expected reduction: 0.5-1.2 mEq/L 2
• CRITICAL: Never give insulin without glucose—hypoglycemia can be fatal 1, 2, 3
• Monitor blood glucose closely after administration 2, 3
• Can be repeated every 4-6 hours if hyperkalemia persists, with careful glucose and potassium monitoring 1

Nebulized Albuterol (Additive Effect)

• 10-20 mg albuterol in 4 mL nebulized over 10-15 minutes 1, 2, 3
• Onset: ~30 minutes; Duration: 2-4 hours 1, 2
• Expected reduction: 0.5-1.0 mEq/L 2
• Can be repeated every 2 hours if needed 1, 2
• Combined insulin-glucose plus albuterol is more effective than either alone 1, 2

Sodium Bicarbonate (ONLY with Metabolic Acidosis)

• 50 mEq IV over 5 minutes ONLY if pH <7.35 AND bicarbonate <22 mEq/L 1, 2, 3
• Onset: 30-60 minutes (slower than insulin or albuterol) 1, 2
• Do NOT use without documented metabolic acidosis—it is ineffective and wastes time 1, 2, 3
• Poor efficacy when used alone 1, 3

Step 3: Definitive Potassium Removal (Within Hours)

Remember: Calcium, insulin, and beta-agonists are temporizing measures only—they do NOT remove potassium from the body. 1, 2

Loop Diuretics (If Adequate Renal Function)

• Furosemide 40-80 mg IV 1, 2
• Effective only when eGFR >30 mL/min and patient is non-oliguric 1, 2
• Increases renal potassium excretion by stimulating flow to collecting ducts 1, 2

Hemodialysis (Most Reliable and Effective Method)

Hemodialysis is the gold standard for severe hyperkalemia and should not be delayed in appropriate patients. 1, 2, 4

Absolute indications for hemodialysis: 1, 2

• Serum potassium >6.5 mEq/L unresponsive to medical therapy
• Oliguria or anuria
• End-stage renal disease
• Ongoing potassium release (tumor lysis syndrome, rhabdomyolysis)
• Severe renal impairment (eGFR <15 mL/min)
• Persistent ECG changes despite medical management

In hemodynamically unstable patients (hypotensive, requiring vasopressors), continuous renal replacement therapy (CRRT) is preferred over intermittent hemodialysis to minimize rapid fluid shifts. 2

Potassium Binders (Sub-Acute Management, NOT for Immediate Crisis)

• Sodium zirconium cyclosilicate (SZC/Lokelma): 10g three times daily for 48 hours, then 5-15g once daily 1, 2
  • Onset: ~1 hour (suitable for more urgent outpatient scenarios) 1, 2
• Patiromer (Veltassa): 8.4g once daily with food, titrated up to 25.2g daily 1, 2
  • Onset: ~7 hours (for sub-acute/chronic control) 1, 2
  • Must be separated from other oral medications by ≥3 hours 2
• Sodium polystyrene sulfonate (Kayexalate): AVOID due to risk of bowel necrosis, colonic ischemia, and lack of efficacy data 1, 2, 5

Step 4: Medication Management During Acute Episode

Temporarily hold or reduce these medications when potassium >6.5 mEq/L: 1, 2

• RAAS inhibitors (ACE inhibitors, ARBs, mineralocorticoid receptor antagonists)
• NSAIDs
• Potassium-sparing diuretics (spironolactone, amiloride, triamterene)
• Trimethoprim-containing agents
• Heparin
• Beta-blockers
• Potassium supplements and salt substitutes

After acute resolution (once potassium <5.0 mEq/L): 1, 2

• Restart RAAS inhibitors at a lower dose—these provide mortality benefit in cardiovascular and renal disease 1, 2
• Initiate a potassium binder (SZC or patiromer) to enable continuation of life-saving RAAS therapy 1, 2
• Do NOT permanently discontinue RAAS inhibitors—use potassium binders to maintain these medications 1, 2

Step 5: Monitoring Protocol

Acute Phase:

• Re-measure serum potassium 1-2 hours after insulin/glucose or beta-agonist therapy 1, 2, 3
• Continue potassium checks every 2-4 hours until stable 1, 2
• Obtain repeat ECG to confirm resolution of peaked T waves, widened QRS, or prolonged PR interval 1, 2, 3
• Monitor blood glucose closely to prevent hypoglycemia 2, 3

Post-Acute Phase:

• Check potassium within 1 week after initiating or escalating RAAS inhibitors 1, 2
• Reassess 7-10 days after starting a potassium binder 1, 2
• Individualize monitoring frequency based on eGFR, heart failure, diabetes, or history of hyperkalemia 1, 2

Critical Pitfalls to Avoid

• Do NOT delay calcium administration while awaiting repeat potassium levels when ECG changes are present 1, 2, 3
• Never give insulin without glucose—hypoglycemia can be fatal 1, 2, 3
• Do NOT use sodium bicarbonate without documented metabolic acidosis (pH <7.35, bicarbonate <22 mEq/L)—it is ineffective and wastes time 1, 2, 3
• Do NOT rely solely on ECG findings—they are highly variable and less sensitive than laboratory tests; absence of ECG changes does not rule out dangerous hyperkalemia 1, 3
• Do NOT permanently discontinue RAAS inhibitors—use potassium binders to maintain these life-saving medications 1, 2
• Recognize that calcium, insulin, and beta-agonists are temporizing measures only—they do NOT remove potassium from the body 1, 2
• Consider pseudohyperkalemia (from hemolysis, repeated fist clenching, poor phlebotomy technique) when ECG findings don't match laboratory values 1, 3