What is the immediate treatment for hyperkalemia?

Immediate Treatment for Hyperkalemia

For severe hyperkalemia (≥6.5 mEq/L) or any ECG changes, immediately administer IV calcium to stabilize cardiac membranes, followed by insulin with glucose and nebulized albuterol to shift potassium intracellularly, then initiate definitive potassium removal strategies. 1

Step 1: Assess Severity and Cardiac Risk

Check ECG immediately - the presence of peaked T waves, flattened P waves, prolonged PR interval, or widened QRS mandates urgent treatment regardless of the potassium level 1. These changes indicate life-threatening cardiac instability requiring immediate intervention 2, 3.

Severity classification:

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

Critical caveat: Exclude pseudohyperkalemia from hemolysis or improper sampling before initiating aggressive treatment 1, 4. Repeat the measurement with proper technique if there is any doubt.

Step 2: Cardiac Membrane Stabilization (Acts in 1-3 Minutes)

Administer IV calcium immediately if potassium >6.5 mEq/L OR any ECG changes are present 1, 4:

• Calcium gluconate 10%: 15-30 mL IV over 2-5 minutes 1
• Calcium chloride 10%: 5-10 mL (500-1000 mg) IV over 2-5 minutes (preferred for more rapid effect) 1

Onset: 1-3 minutes 1, 4
Duration: 30-60 minutes (temporary) 1, 4

Critical point: Calcium does NOT lower serum potassium - it only protects against arrhythmias by stabilizing cardiac membranes 1, 4. You must simultaneously initiate potassium-lowering therapies.

Administration considerations:

• Use calcium chloride through central line when possible due to tissue injury risk with peripheral extravasation 1
• Monitor heart rate during administration and stop if symptomatic bradycardia occurs 1
• If no ECG improvement within 5-10 minutes, repeat the dose 1, 4

Step 3: Shift Potassium Into Cells (Acts in 15-30 Minutes)

Give all three agents together for maximum effect 4:

Insulin with Glucose (Primary Agent)

• 10 units regular insulin IV + 25g glucose (50 mL D50W) over 15-30 minutes 1
• Onset: 15-30 minutes 1
• Duration: 4-6 hours 1
• Monitor glucose closely to prevent hypoglycemia, especially in patients with low baseline glucose, no diabetes, female sex, or altered renal function 4

Nebulized Beta-2 Agonist (Adjunctive)

• Albuterol 10-20 mg nebulized over 15 minutes 1
• Onset: 15-30 minutes 1
• Duration: 2-4 hours 1, 4
• Can reduce potassium by approximately 0.5-1.0 mEq/L 1

Sodium Bicarbonate (ONLY if Metabolic Acidosis Present)

• 50 mEq IV over 5 minutes 1
• Use ONLY if pH <7.35 and bicarbonate <22 mEq/L 1, 4
• Onset: 30-60 minutes 4
• Ineffective without concurrent acidosis 4

Critical warning: These are temporizing measures only - rebound hyperkalemia can occur after 2-4 hours 1, 4. You must initiate definitive potassium removal strategies.

Step 4: Eliminate Potassium From Body (Definitive Treatment)

For Adequate Renal Function:

Loop diuretics: Furosemide 40-80 mg IV 1, 4

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

For All Patients (Subacute Management):

Newer potassium binders (preferred over traditional resins) 1:

• Patiromer (Veltassa): 8.4 g once daily, titrate up to 25.2 g daily; onset ~7 hours 4
• Sodium zirconium cyclosilicate (Lokelma): 10 g three times daily for 48 hours, then 5-15 g once daily; onset ~1 hour 4

Avoid sodium polystyrene sulfonate (Kayexalate) - associated with bowel necrosis and limited efficacy 4

For Severe/Refractory Cases:

Hemodialysis - most effective and reliable method for severe hyperkalemia, especially with renal failure, oliguria, or cases unresponsive to medical management 1, 2, 5

Step 5: Address Underlying Causes

Immediately review and hold contributing medications 4:

• RAAS inhibitors (ACE inhibitors, ARBs, mineralocorticoid antagonists) - temporarily hold if K+ >6.5 mEq/L 4
• Potassium-sparing diuretics (spironolactone, amiloride, triamterene) 4
• NSAIDs 1, 4
• Trimethoprim, heparin, beta-blockers 4
• Potassium supplements and salt substitutes 1, 4

Monitoring Protocol

• Recheck potassium every 2-4 hours during acute treatment phase until stabilized 4
• Continuous cardiac monitoring mandatory during calcium administration and for patients with initial ECG changes 4
• Monitor glucose closely after insulin administration to prevent hypoglycemia 4
• After acute resolution, check potassium within 1 week, then individualize based on CKD stage, heart failure, diabetes, or history of hyperkalemia 4

Critical Pitfalls to Avoid

• Never delay treatment while waiting for repeat labs if ECG changes are present 4
• Never give insulin without glucose - hypoglycemia can be life-threatening 4
• Never use sodium bicarbonate without metabolic acidosis - it is ineffective and wastes time 4
• Never rely on calcium alone - it is temporizing only; failure to initiate concurrent potassium-lowering therapies will result in recurrent arrhythmias within 30-60 minutes 4
• Do not permanently discontinue RAAS inhibitors in patients with cardiovascular disease or proteinuric CKD - use potassium binders to maintain these life-saving medications 1, 4

Special Populations

Dialysis patients: Hemodialysis is definitive treatment; monitor for rebound hyperkalemia 4-6 hours post-dialysis 4, 5

CKD patients: Maintain RAAS inhibitors using potassium binders rather than discontinuing these renoprotective medications 4

Patients on digoxin: Maintain strict potassium control (4.0-5.0 mEq/L) as hyperkalemia increases digoxin toxicity risk 1