What is the treatment for kidney stones?

Kidney Stone Treatment

The treatment of kidney stones should begin with increased fluid intake to achieve a urine volume of at least 2.5 liters daily as the standard first-line approach, followed by appropriate medical or surgical interventions based on stone size and composition. 1

Initial Management and Diagnosis

• Diagnostic Evaluation:

  • CT scan is the preferred initial imaging test 1
  • Stone analysis should be obtained at least once when a stone is available 1
  • For high-risk or recurrent stone formers, a 24-hour urine collection analyzing volume, pH, calcium, oxalate, uric acid, citrate, sodium, potassium, and creatinine 1

• Conservative Management:

  • For uncomplicated ureteral stones ≤10 mm, observation with or without alpha-blockers as medical expulsive therapy (MET) is recommended 1
  • MET trial should be limited to maximum six weeks to avoid kidney injury 1
  • Pain management with appropriate analgesics is essential during acute episodes 2

Treatment Based on Stone Size

1. Stones <10 mm:

   • Medical expulsive therapy with alpha-blockers
   • If conservative measures fail, consider extracorporeal shock wave lithotripsy (ESWL) or ureteroscopy (URS) 1

2. Stones 10-20 mm:

   • ESWL if anatomy is favorable
   • Flexible ureteroscopy or percutaneous nephrolithotomy (PCNL) may be considered 1

3. Stones >20 mm or coraliform stones:

   • PCNL is recommended as first-line treatment 1
   • Complete stone removal is essential, especially for infection-related stones 1

Pharmacological Therapy

• For hypocitraturic calcium stone formers:

  • Potassium citrate is first-line therapy 1
  • Increases urinary pH from 5.3 to 6.2-6.5 1

• For hyperuricosuria and calcium stones:

  • Allopurinol (300 mg daily) if hyperuricosuria persists after alkalization 1
  • Not recommended as first-line therapy for urinary alkalinization 1

Dietary Modifications for Prevention

• Fluid intake: 2.5-3.0 L/day to achieve >2L urine output daily 1, 3
• Sodium restriction: ≤2,300 mg/day 1
• Protein intake: Reduce animal protein to 5-7 servings per week 1
• Calcium intake: Maintain normal dietary calcium (1,000-1,200 mg/day) - counterintuitively, low calcium diets increase stone risk 1
• Potassium-rich foods: Increase intake to boost urinary citrate excretion 1
• Beverage choices: Prefer coffee, tea, wine, beer, orange juice; avoid sugar-sweetened sodas 1
• Oxalate-rich foods: Limit intake 3
• Supplements: Avoid vitamin C and vitamin D supplements 3

Follow-up and Monitoring

• Obtain 24-hour urine specimen within six months of initiating treatment 1
• Annual follow-up with 24-hour urine specimen to assess adherence and metabolic response 1
• Periodic blood testing to monitor for adverse effects in patients on pharmacological therapy 1
• Repeat stone analysis if available, especially in patients not responding to treatment 1

Special Considerations

• For patients with bleeding disorders, URS is the first-line therapy 1
• Infected stones require immediate drainage, antibiotic therapy, and culture 1
• Specialized management for primary hyperoxaluria may include pyridoxine treatment 1

Common Pitfalls to Avoid

1. Restricting dietary calcium - This actually increases stone risk by allowing more oxalate absorption 1
2. Delaying intervention for infected stones - This is dangerous and requires immediate treatment 1
3. Prolonged medical expulsive therapy - Should not exceed six weeks to avoid kidney injury 1
4. Inadequate hydration - The cornerstone of prevention is maintaining adequate urine output 1, 3, 4
5. Neglecting follow-up - Regular monitoring with 24-hour urine collections is essential 1

The American Urological Association guidelines provide the most comprehensive and recent evidence-based approach to kidney stone management, emphasizing the importance of adequate hydration, appropriate medical therapy based on stone composition, and surgical intervention when indicated 1.