What are the common causes of hyperkalemia?

Common Causes of Hyperkalemia

Hyperkalemia is most commonly caused by decreased renal potassium excretion, medication effects (particularly RAAS inhibitors), and transcellular potassium shifts. 1, 2

Major Etiologies of Hyperkalemia

1. Decreased Renal Excretion

• Kidney disease:
  • Acute kidney injury (AKI)
  • Chronic kidney disease (CKD) - affects up to 73% of patients with advanced CKD 1
  • Hyporeninemic hypoaldosteronism 3
• Volume depletion - paradoxically increases hyperkalemia risk 1

2. Medication-Induced Hyperkalemia

• RAAS inhibitors:
  • Angiotensin-converting enzyme inhibitors (ACEIs)
  • Angiotensin II receptor blockers (ARBs)
  • Direct renin inhibitors 4
• Potassium-sparing diuretics:
  • Spironolactone, eplerenone (aldosterone antagonists)
  • Amiloride, triamterene 4
• Other medications:
  • NSAIDs - significantly increase hyperkalemia risk, especially when combined with ACEIs 1
  • Calcineurin inhibitors (cyclosporine, tacrolimus)
  • Heparin and derivatives
  • Trimethoprim
  • Pentamidine 4

3. Transcellular Shifts

• Acidosis - causes potassium to shift from intracellular to extracellular space
• Insulin deficiency/hyperglycemia 2
• Medications affecting transmembrane potassium movement:
  • Beta-blockers
  • Calcium channel blockers
  • Suxamethonium
  • Mannitol 4

4. Excessive Potassium Intake

• Dietary sources - high-potassium foods:
  • Processed foods
  • Bananas, oranges
  • Potatoes, tomatoes
  • Legumes
  • Yogurt, chocolate 1
• Potassium supplements
• Potassium-containing medications 4
• Blood transfusions (particularly rapid or massive) 1

5. Tissue Breakdown

• Rhabdomyolysis
• Tumor lysis syndrome
• Hemolysis
• Severe burns/trauma 5

Special Considerations

High-Risk Populations

• Heart failure patients - hyperkalemia occurs in up to 40% of these patients 1
• Diabetic patients - especially with diabetic nephropathy 6
• Neonates and pediatric patients - particularly vulnerable to rapid potassium shifts 1

Clinical Pearls

• Even patients with normal renal function can develop hyperkalemia when taking ACEIs/ARBs 1
• The benefits of RAAS inhibitors often outweigh the risks in heart failure and CKD patients, so dose reduction rather than discontinuation is preferred 1
• Patients with CKD have adaptive mechanisms to increase potassium excretion per nephron, but these mechanisms have limitations 3

Monitoring and Prevention

• Regular monitoring of serum potassium is essential in high-risk patients
• ECG monitoring is recommended for patients with moderate to severe hyperkalemia 1
• Lifestyle modifications:
  • Limit potassium intake to <40 mg/kg/day
  • Sodium restriction (<2g/day)
  • Regular physical activity
  • Weight reduction if overweight/obese 1

Understanding these common causes of hyperkalemia is crucial for early recognition and appropriate management to prevent potentially life-threatening complications.