What is the immediate treatment for hyperkalemia?

Immediate Treatment for Hyperkalemia

For life-threatening hyperkalemia (≥6.5 mEq/L or any ECG changes), immediately administer intravenous calcium to stabilize the cardiac membrane, followed simultaneously by insulin with glucose and nebulized albuterol to shift potassium intracellularly, then arrange definitive potassium removal via hemodialysis or diuretics. 1

Severity Assessment

Before initiating treatment, classify the severity and verify the result is not pseudohyperkalemia from hemolysis or poor phlebotomy technique 2:

• Mild hyperkalemia: 5.0-5.9 mEq/L 1
• Moderate hyperkalemia: 6.0-6.4 mEq/L 1
• Severe hyperkalemia: ≥6.5 mEq/L (life-threatening) 1

Critical point: ECG changes (peaked T waves, flattened P waves, prolonged PR interval, widened QRS) indicate urgent treatment regardless of the potassium level 1. However, ECG findings are highly variable and less sensitive than laboratory values—do not rely on them alone 2.

Three-Step Treatment Algorithm

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

Administer intravenous calcium first to protect against fatal arrhythmias 2:

• Calcium chloride (10%): 5-10 mL (500-1000 mg) IV over 2-5 minutes 1

  • Provides more rapid increase in ionized calcium than calcium gluconate 1
  • Preferred in critically ill patients 1
  • Must use central venous catheter when possible—extravasation through peripheral IV causes severe tissue injury 1

• Calcium gluconate (10%): 15-30 mL IV over 2-5 minutes (alternative) 1

  • Safer for peripheral IV access 1
  • Preferred in pediatric patients (20 mg/kg or 0.2 mL/kg) 1

Monitor heart rate during administration and stop if symptomatic bradycardia occurs 1. Effects begin within 1-3 minutes but last only 30-60 minutes 2. Repeat dosing may be necessary if no ECG improvement within 5-10 minutes 2. Remember: calcium does NOT lower serum potassium—it only temporarily stabilizes the cardiac membrane 1, 2.

Step 2: Shift Potassium into Cells (Onset 15-30 Minutes, Duration 4-6 Hours)

Administer all three agents together for maximum effect 2:

• Insulin with glucose: 10 units regular insulin IV with 25g glucose (50 mL of D50W) over 15-30 minutes 1

  • Onset within 15-30 minutes, effects last 4-6 hours 1
  • Always give glucose with insulin to prevent life-threatening hypoglycemia 2
  • Can be repeated every 4-6 hours if hyperkalemia persists, with careful monitoring of glucose and potassium every 2-4 hours 2
  • Patients at higher risk for hypoglycemia: low baseline glucose, no diabetes, female sex, altered renal function 2

• Nebulized albuterol: 10-20 mg in 4 mL over 15 minutes 1

  • Reduces serum potassium by approximately 0.5-1.0 mEq/L 1
  • Effects last 2-4 hours 2
  • Can augment insulin/glucose effects 1

• Sodium bicarbonate: 50 mEq IV over 5 minutes ONLY if metabolic acidosis is present (pH <7.35, bicarbonate <22 mEq/L) 1, 2

  • Effects take 30-60 minutes to manifest 2
  • Do not use without metabolic acidosis—it is ineffective and wastes time 2
  • Promotes potassium excretion through increased distal sodium delivery 2

Critical warning: These are temporizing measures only—they do NOT remove potassium from the body 2. Rebound hyperkalemia can occur after 2 hours 1. Treatment with definitive potassium-lowering agents must be initiated early to prevent rebound 1.

Step 3: Eliminate Potassium from Body (Definitive Treatment)

Choose based on renal function and clinical urgency 2:

• Loop diuretics (if adequate renal function): Furosemide 40-80 mg IV 1

  • Increases renal potassium excretion 1
  • Only effective with adequate kidney function 1

• Hemodialysis: Most effective and reliable method for severe hyperkalemia 1, 2

  • Indications: Severe cases unresponsive to medical management, oliguria, end-stage renal disease 2
  • Should not be delayed in appropriate patients 2

• Potassium binders (for subacute/chronic management):

  • Sodium zirconium cyclosilicate (SZC/Lokelma): 10g three times daily for 48 hours, then 5-15g once daily 2

    • Onset of action: ~1 hour 2
    • Preferred for both acute (≥5.8 mEq/L) and chronic management 2

  • Patiromer (Veltassa): 8.4g once daily, titrated up to 25.2g daily 2

    • Onset of action: ~7 hours 2
    • Better for chronic management 2

  • Sodium polystyrene sulfonate (Kayexalate): 15-50g orally or rectally 1

    • Significant limitations: Delayed onset, risk of bowel necrosis 2
    • Should not be used for acute emergency treatment 3
    • Reserved for subacute treatment only 1

Medication Management During Acute Episode

Immediately review and temporarily discontinue or reduce 2:

• RAAS inhibitors (ACE inhibitors, ARBs, mineralocorticoid antagonists) if K+ >6.5 mEq/L 2
• NSAIDs 2
• Potassium-sparing diuretics 2
• Trimethoprim 2
• Heparin 2
• Beta-blockers 2
• Potassium supplements and salt substitutes 2

After Acute Resolution: Preventing Recurrence

For patients on RAAS inhibitors with cardiovascular disease or proteinuric kidney disease, do NOT permanently discontinue these life-saving medications 2:

• K+ 5.0-6.5 mEq/L: Initiate potassium binder (patiromer or SZC) and maintain RAAS inhibitor therapy 1, 2
• K+ >6.5 mEq/L: Temporarily discontinue/reduce RAAS inhibitor, initiate potassium binder, then restart RAAS inhibitor at lower dose once K+ <5.5 mEq/L 1, 2

Monitoring protocol 2:

• Check potassium within 1 week of starting or escalating RAAS inhibitors 2
• Reassess 7-10 days after initiating potassium binder therapy 2
• More frequent monitoring in high-risk patients: CKD, heart failure, diabetes 2

Critical Pitfalls to Avoid

• Never delay treatment while waiting for repeat lab confirmation if ECG changes are present 2
• Never give insulin without glucose—hypoglycemia can be fatal 2
• Never use sodium bicarbonate without metabolic acidosis—it is ineffective 2
• Never rely solely on ECG findings—they are variable and less sensitive than labs 2
• Remember calcium, insulin, and beta-agonists are temporary only—they do NOT remove potassium 2
• Do not use sodium polystyrene sulfonate for emergency treatment—delayed onset of action 3
• Monitor closely for hypoglycemia and hypokalemia during and after treatment 1, 2