What is the treatment for a 68-year-old female with hyperkalemia?

Treatment of Hyperkalemia in a 68-Year-Old Female

For a 68-year-old female with a potassium level of 5.5 mmol/L, immediate treatment should include calcium gluconate to stabilize the myocardial membrane, followed by insulin with glucose to shift potassium intracellularly, and sodium polystyrene sulfonate to remove potassium from the body. 1

Initial Assessment and Risk Stratification

• Evaluate for ECG changes: peaked T waves, flattened P waves, prolonged PR interval, widened QRS complex
• Assess for symptoms: muscle weakness, paresthesia, depressed reflexes, respiratory difficulties
• Consider underlying causes: renal failure, medications (ACE inhibitors, ARBs, potassium-sparing diuretics, NSAIDs, heparin) 2

Treatment Algorithm Based on Severity

For Potassium 5.5 mmol/L (Moderate Hyperkalemia):

1. Stabilize myocardial cell membrane:

   • Calcium gluconate (10%): 15-30 mL IV over 2-5 minutes OR
   • Calcium chloride (10%): 5-10 mL (500-1000 mg) IV over 2-5 minutes 1

2. Shift potassium into cells:

   • Insulin and glucose: 10 units regular insulin with 25g glucose (50 mL of D50) IV over 15-30 minutes
   • Nebulized albuterol: 10-20 mg over 15 minutes
   • Sodium bicarbonate: 50 mEq IV over 5 minutes (especially if acidotic) 1, 3

3. Promote potassium excretion:

   • Furosemide: 40-80 mg IV (if renal function permits)
   • Sodium polystyrene sulfonate (Kayexalate): 15-50g orally or rectally with sorbitol 1, 4

Important Considerations and Precautions

• Medication review: Identify and adjust medications that may cause hyperkalemia (ACE inhibitors, ARBs, NSAIDs, potassium-sparing diuretics, heparin) 2

• Sodium polystyrene sulfonate warnings:

  • Avoid in patients with abnormal bowel function, constipation, or post-surgery
  • Risk of intestinal necrosis, especially when used with sorbitol
  • Monitor for hypokalemia and other electrolyte disturbances 4

• Monitoring requirements:

  • Frequent serum potassium measurements within each 24-hour period
  • ECG monitoring for cardiac conduction abnormalities
  • Watch for signs of hypokalemia during treatment (confusion, prolonged QT interval, prominent U waves) 1, 4

• For severe hyperkalemia (>6.5 mmol/L) or cardiac manifestations:

  • Consider dialysis if refractory to medical management or in severe renal failure
  • More aggressive and immediate intervention is required 1, 3

Long-term Management

• Identify and treat underlying cause
• Dietary potassium restriction
• Regular monitoring of serum potassium, especially in patients with heart failure or renal impairment
• Consider newer potassium binders (patiromer, sodium zirconium cyclosilicate) for chronic management 3

Special Considerations for Elderly Patients

• Elderly patients (>65 years) with comorbidities like heart failure, chronic kidney disease, or diabetes are at higher risk of complications from hyperkalemia
• Evidence suggests maintaining potassium ≤5.0 mmol/L is safer in these populations 1
• More frequent monitoring may be needed in elderly patients on medications that affect potassium levels 1

Remember that hyperkalemia of 5.5 mmol/L requires prompt intervention to prevent progression to life-threatening cardiac arrhythmias, especially in an elderly patient who may have underlying cardiovascular disease.