What is the treatment for hyperkalemia?

Treatment of Hyperkalemia

The treatment of hyperkalemia requires a stepwise approach based on severity, with immediate stabilization of cardiac membranes using IV calcium gluconate, followed by shifting potassium intracellularly with insulin/glucose, and ultimately removing potassium from the body through various methods. 1

Assessment and Classification

Hyperkalemia is classified as:

• Mild: 5.0-5.5 mmol/L
• Moderate: 5.6-6.5 mmol/L
• Severe: >6.5 mmol/L 1

ECG changes correlate with severity:

• 5.5-6.5 mmol/L: Peaked/tented T waves
• 6.5-7.5 mmol/L: Prolonged PR interval, flattened P waves
• 7.0-8.0 mmol/L: Widened QRS, deep S waves

• 10 mmol/L: Sinusoidal pattern, VF, asystole, or PEA 1

Acute Treatment Algorithm

1. Stabilize Cardiac Membrane (Immediate)

• Administer IV calcium gluconate 10% solution (15-30 mL)
• Onset: 1-3 minutes
• Duration: 30-60 minutes
• Indication: ECG changes or severe hyperkalemia 1

2. Shift Potassium Intracellularly (15-30 minutes)

• First-line: 10 units regular insulin IV with 50 mL of 25% dextrose
  • Onset: 15-30 minutes
  • Duration: 1-2 hours 1
• Adjunctive therapy: Inhaled beta-agonists (10-20 mg nebulized over 15 minutes)
  • Onset: 15-30 minutes
  • Duration: 2-4 hours 1
• For acidosis: Sodium bicarbonate (50 mEq IV over 5 minutes)
  • Onset: 15-30 minutes
  • Duration: 1-2 hours
  • Only if metabolic acidosis is present 1, 2

3. Remove Potassium from Body (Hours)

• Most effective: Hemodialysis
  • Indication: Severe hyperkalemia, renal failure, or failure of other measures 1, 3
• Subacute treatment: Cation exchange resins (sodium polystyrene sulfonate)
  • Dosage: 15-60g orally daily (divided into 15g doses 1-4 times daily) or 30-50g rectally every 6 hours
  • Note: Not for emergency treatment due to delayed onset 1, 4
• Additional measures: Loop diuretics (if renal function adequate) 1, 3

Newer Potassium Binders

For chronic hyperkalemia management:

• Patiromer: Onset 7 hours, acts in colon, moderate selectivity
• Sodium zirconium cyclosilicate (SZC/Lokelma): Onset 1 hour, acts in small and large intestines, high selectivity 1

Important Considerations and Pitfalls

1. Do not rely solely on ECG: Absent or atypical ECG changes do not exclude the need for immediate intervention 3

2. Drug interactions:

   • Take other oral medications at least 3 hours before or after sodium polystyrene sulfonate 4
   • Avoid concomitant use of sorbitol with sodium polystyrene sulfonate due to risk of intestinal necrosis 4
   • Cation-donating antacids may reduce resin effectiveness 4

3. Monitoring requirements:

   • Check potassium and renal function within 1-2 weeks of initiating or changing ACE inhibitor dose
   • Monitor potassium levels at least monthly for the first 3 months, then every 3 months thereafter 1

4. Sodium polystyrene sulfonate limitations:

   • Not for emergency treatment due to delayed onset
   • Contraindicated in obstructive bowel disease
   • Risk of intestinal necrosis and other serious gastrointestinal events 4

5. Avoid complete discontinuation of RAAS inhibitors without attempting dose reduction first, as this is associated with poorer clinical outcomes 1

Dietary and Lifestyle Modifications

• Limit dietary potassium to <40 mg/kg/day
• Avoid high-potassium foods
• Avoid potassium-containing salt substitutes
• Maintain adequate hydration
• Avoid NSAIDs which can worsen hyperkalemia 1

The treatment approach should be tailored based on the severity of hyperkalemia, presence of ECG changes, and underlying causes, with the primary goal of preventing life-threatening cardiac arrhythmias while addressing the underlying cause.