What is the management of hypokalemia (low potassium levels) and hyperkalemia (high potassium levels)?

Management of Hypokalemia and Hyperkalemia

The management of hypokalemia and hyperkalemia requires prompt recognition and targeted treatment based on severity, with oral potassium replacement preferred for mild-moderate hypokalemia and a stepwise approach using calcium, insulin with glucose, and potassium binders for hyperkalemia. 1, 2

Hypokalemia Management

Assessment and Severity Classification

• Mild: 3.0-3.5 mEq/L (may be asymptomatic)
• Moderate: 2.5-3.0 mEq/L
• Severe: <2.5 mEq/L (requires urgent treatment) 2, 3

Treatment Algorithm

1. Urgent treatment indications:

   • Potassium ≤2.5 mEq/L
   • Presence of ECG abnormalities
   • Neuromuscular symptoms (weakness, paralysis)
   • Cardiac ischemia or digitalis therapy 2, 4

2. Route of administration:

   • Oral replacement (preferred if K+ >2.5 mEq/L and functioning GI tract)

     • Dosing: Based on severity of deficiency
     • Monitor: Recheck serum potassium after 24-48 hours 2, 4

   • Intravenous replacement (for severe hypokalemia or inability to take oral medications)

     • Standard rate: ≤10 mEq/hour when K+ >2.5 mEq/L
     • Urgent cases (K+ <2 mEq/L or severe symptoms): Up to 40 mEq/hour with continuous ECG monitoring
     • Maximum: 200 mEq/24 hours (standard) or 400 mEq/24 hours (urgent cases)
     • Administration: Via central line for higher concentrations (300-400 mEq/L) 5

3. Address underlying causes:

   • Decrease diuretic doses if appropriate
   • Correct magnesium deficiency (often coexists)
   • Manage gastrointestinal losses
   • Consider potassium-sparing diuretics for chronic potassium wasting 2, 4

Important Considerations

• Small serum potassium deficits represent large total body deficits
• Repletion often requires substantial and prolonged supplementation
• Serum potassium is an inaccurate marker of total body potassium deficit 3, 4
• Avoid overcorrection which can lead to hyperkalemia

Hyperkalemia Management

Assessment and Severity Classification

• Mild: 5.1-5.9 mEq/L
• Moderate: 6.0-6.4 mEq/L
• Severe: ≥6.5 mEq/L 1, 2

Treatment Algorithm

1. Urgent treatment indications:

   • Potassium >6.5 mEq/L
   • ECG changes (peaked T waves, prolonged PR, widened QRS)
   • Neuromuscular symptoms
   • Rapid rise in potassium levels 1, 2

2. Immediate stabilization (for ECG changes):

   • Calcium gluconate: 10% solution, 15-30 mL IV
   • Onset: 1-3 minutes
   • Duration: 30-60 minutes
   • Purpose: Cardiac membrane stabilization 1

3. Potassium redistribution into cells:

   • Insulin with glucose: 10 units regular insulin IV with 50 mL of 25% dextrose
     • Onset: 15-30 minutes
     • Duration: 1-2 hours
   • Inhaled beta-agonists: 10-20 mg nebulized over 15 minutes
     • Onset: 15-30 minutes
     • Duration: 2-4 hours
   • Sodium bicarbonate: 50 mEq IV over 5 minutes (especially in acidosis)
     • Onset: 15-30 minutes
     • Duration: 1-2 hours 1

4. Potassium removal:

   • Potassium binders:
     • Patiromer (Veltassa): 8.4g once daily (onset: 7 hours)
     • Sodium zirconium cyclosilicate (Lokelma): 5-10g once daily (onset: 1 hour)
     • Sodium polystyrene sulfonate: 15-30g 1-4 times daily (avoid chronic use due to GI side effects) 1, 2
   • Loop diuretics (if renal function adequate)
   • Hemodialysis (for severe cases, especially with renal failure) 2

5. Eliminate contributing factors:

   • Discontinue potassium supplements
   • Adjust medications (ACE inhibitors, ARBs, NSAIDs, potassium-sparing diuretics)
   • Treat metabolic acidosis 6

Monitoring

• Continuous ECG monitoring for moderate to severe hyperkalemia (>6.5 mmol/L)
• Serial potassium measurements
• Watch for rebound hyperkalemia after treatment 1, 2

Special Considerations

High-Risk Populations

• Chronic kidney disease: Higher risk of hyperkalemia (up to 73% in advanced CKD)
• Heart failure patients: Maintain K+ ≤5 mmol/L as higher levels associated with increased mortality
• Neonates and pediatric patients: Vulnerable to rapid potassium shifts 1

Dietary Management

• Hyperkalemia: Limit potassium intake to <40 mg/kg/day; avoid high-potassium foods (bananas, oranges, potatoes, tomatoes, legumes)
• Hypokalemia: WHO recommends potassium intake of at least 3,510 mg/day for optimal cardiovascular health 1, 2

Medication Pitfalls

• Avoid NSAIDs in patients at risk for hyperkalemia, especially those on ACEIs
• Be cautious with rapid potassium correction in patients on digitalis (can precipitate digitalis toxicity)
• Separate patiromer from other medications by 3 hours 1, 6

By following these evidence-based approaches to managing potassium disorders, clinicians can effectively treat both hypokalemia and hyperkalemia while minimizing complications.