Management of Hyperkalemia
The treatment of hyperkalemia requires a stepwise approach based on severity, with immediate membrane stabilization using calcium gluconate for cardiac protection, followed by insulin with glucose to shift potassium intracellularly, and finally potassium removal from the body through binders or dialysis. 1
Assessment and Classification
Hyperkalemia is defined as serum potassium >5.0 or >5.5 mEq/L (mmol/L). The severity can be assessed based on potassium levels and ECG changes:
- Mild: 5.5-6.5 mmol/L - Peaked/tented T waves
- Moderate: 6.5-7.5 mmol/L - Prolonged PR interval, flattened P waves
- Severe: >7.0 mmol/L - Widened QRS, deep S waves, sinusoidal pattern 1
Emergency Treatment Algorithm
Step 1: Cardiac Membrane Stabilization
- Calcium gluconate 10%: 15-30 mL IV over 2-5 minutes
- Onset: 1-3 minutes; Duration: 30-60 minutes
- Important: Calcium only protects the heart temporarily and does not lower potassium levels 1
- Most effective for main rhythm disorders due to hyperkalemia 2
Step 2: Shift Potassium into Cells
- Insulin with glucose: 10 units regular insulin IV with 50 mL of 25% dextrose
- Nebulized albuterol: 10-20 mg over 15 minutes
- Sodium bicarbonate: 50 mEq IV over 5 minutes (if metabolic acidosis present)
Step 3: Remove Potassium from the Body
- Diuretics: Furosemide 40-80 mg IV (if renal function adequate) 1
- Potassium binders:
- Hemodialysis: Most effective method for severe hyperkalemia, especially in renal failure 1
Important Considerations
Sodium Polystyrene Sulfonate (Kayexalate)
- Not for emergency treatment of life-threatening hyperkalemia due to delayed onset 6
- Typical dose: 15-60g daily, administered as 15g doses 1-4 times daily 6
- Administer at least 3 hours before or after other oral medications 6
- Contraindications: Obstructive bowel disease, neonates with reduced gut motility 6
- Warning: Cases of intestinal necrosis reported, especially with concomitant sorbitol 6
Medication Management
- Review and adjust medications that can cause hyperkalemia:
- ACE inhibitors/ARBs
- NSAIDs
- Potassium-sparing diuretics
- Potassium supplements 1
- Consider reducing dose rather than discontinuing ACE inhibitors/ARBs due to their cardiovascular benefits 1
Special Populations
- Pediatric patients: 0.1 unit/kg insulin with 400 mg/kg glucose 1
- Chronic kidney disease: Higher risk of hyperkalemia (up to 73% in advanced CKD) 1
- Heart failure: Hyperkalemia occurs in up to 40% of patients 1
Dietary and Lifestyle Modifications
- Limit potassium intake to <40 mg/kg/day
- Avoid high-potassium foods: bananas, oranges, potatoes, tomatoes, legumes, processed foods 1
- Sodium restriction (<2g/day), regular physical activity, weight reduction if overweight/obese 1
Common Pitfalls to Avoid
- Relying solely on ECG changes: Absent or atypical ECG changes do not exclude the need for immediate intervention 7
- Using sodium polystyrene sulfonate for emergent treatment: It has delayed onset and should not be used for life-threatening hyperkalemia 6
- Inadequate glucose administration with insulin: Provide 50g glucose with 10 units insulin or 60g with 20 units insulin to prevent hypoglycemia 3
- Overlooking medication causes: Always perform an extensive search for medications that may have contributed to hyperkalemia 7
- Neglecting to monitor glucose levels: Frequent monitoring is essential when using insulin therapy 3
Remember that the combination of therapies (such as insulin-glucose plus nebulized beta-agonists) may be more effective than single interventions for severe hyperkalemia 4.