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 excess potassium from the body through various elimination 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 potassium levels:
- 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, ventricular fibrillation, asystole, or PEA 1
Urgent Treatment for Severe or Symptomatic Hyperkalemia
Step 1: Cardiac Membrane Stabilization
- Administer IV calcium gluconate 10% solution (15-30 mL) 1
- Onset: 1-3 minutes
- Duration: 30-60 minutes
- Mechanism: Stabilizes cardiac membranes without affecting potassium levels
Step 2: Shift Potassium Intracellularly
Insulin with glucose: 10 units regular insulin IV with 50 mL of 25% dextrose 1
- Onset: 15-30 minutes
- Duration: 1-2 hours
- Most reliable agent for promoting transcellular shift 2
Inhaled beta-agonists: 10-20 mg nebulized albuterol over 15 minutes 1
- Onset: 15-30 minutes
- Duration: 2-4 hours
- Can be used alone or to augment insulin effect 2
Sodium bicarbonate: 50 mEq IV over 5 minutes (only if metabolic acidosis present) 1
- Onset: 15-30 minutes
- Duration: 1-2 hours
- Limited efficacy when used alone 3
Step 3: Remove Potassium from Body
Hemodialysis: Most rapid and effective method for eliminating potassium 1
- Indicated for severe, refractory hyperkalemia or renal failure
Loop diuretics: Promote renal excretion of potassium 1
- Only effective with adequate renal function
Cation exchange resins: Sodium polystyrene sulfonate (SPS) 4
Newer potassium binders: Patiromer and sodium zirconium cyclosilicate (SZC) 1
- More selective than SPS
- SZC has faster onset (1 hour) compared to patiromer (7 hours)
Non-Urgent Management of Chronic Hyperkalemia
Medication review: Identify and modify medications contributing to hyperkalemia 1
- Consider dose reduction rather than complete discontinuation of RAAS inhibitors
- Avoid NSAIDs and potassium supplements
Dietary modifications: 1
- Limit dietary potassium to <40 mg/kg/day
- Avoid high-potassium foods
- Avoid potassium-containing salt substitutes
- Pre-soaking root vegetables can reduce potassium content by 50-75%
Maintain adequate hydration 1
Regular monitoring: 1
- Check potassium and renal function within 1-2 weeks of initiating or changing ACE inhibitor dose
- Monitor potassium levels at least monthly for first 3 months, then every 3 months
Special Considerations
Sodium polystyrene sulfonate cautions: 4
- Contraindicated in obstructive bowel disease
- Risk of intestinal necrosis, especially when used with sorbitol
- May cause electrolyte disturbances including severe hypokalemia
- Monitor for fluid overload in sodium-sensitive patients
Common pitfalls: 1
- Relying solely on ECG changes (may be absent despite dangerous hyperkalemia)
- Complete discontinuation of RAAS inhibitors without attempting dose reduction
- Overlooking drug interactions that increase hyperkalemia risk
- Ignoring renal function when managing hyperkalemia
Risk factors for hyperkalemia: 1
- Renal dysfunction
- Advanced age
- Male gender
- Diabetes mellitus
- Heart failure
- Medications (RAAS inhibitors, beta blockers, potassium-sparing diuretics)
The treatment approach should be tailored based on the severity of hyperkalemia, presence of symptoms, ECG changes, and underlying causes, with immediate intervention for severe or symptomatic cases.