What are the treatment guidelines for kidney stones?

Treatment Guidelines for Kidney Stones

Acute Pain Management

NSAIDs are the first-line treatment for acute renal colic pain, superior to opioids in efficacy with fewer side effects. 1

• Diclofenac, ibuprofen, or metamizole should be used at the lowest effective dose to minimize cardiovascular and gastrointestinal risks 1
• Exercise caution with NSAIDs in patients with reduced glomerular filtration rate as they may impact renal function 1
• Opioids (hydromorphine, pentazocine, or tramadol) should be reserved as second-line agents when NSAIDs are contraindicated or ineffective 2, 1
• Avoid pethidine due to high vomiting rates 1

Conservative Management vs. Surgical Intervention

Ureteral Stones ≤10 mm

For uncomplicated ureteral stones ≤10 mm, observation with medical expulsive therapy using alpha-blockers is the recommended first-line approach. 2, 1

• Alpha-blockers (tamsulosin) provide the greatest benefit for stones >5 mm in the distal ureter, with stone-free rates of 77.3% compared to 54.4% with placebo (OR 3.79,95% CI 2.84-5.06) 2
• Conservative management requires well-controlled pain, absence of sepsis, and adequate renal functional reserve 1
• Maximum duration of conservative treatment should be 4-6 weeks from initial presentation 3, 1
• Mandatory periodic imaging is required to monitor stone position and assess for hydronephrosis 1

Ureteral Stones >10 mm

• For distal ureteral stones >10 mm, ureteroscopy (URS) is the first-line surgical treatment 1
• For distal stones <10 mm that fail conservative management, both ureteroscopy and shock wave lithotripsy (SWL) are acceptable options 1

Surgical Management of Renal Stones

Renal Stones <10 mm

For renal stones <10 mm regardless of location, ureteroscopy or shock wave lithotripsy are recommended first-line options. 2, 4

• Spontaneous passage rates are 75% for stones <5 mm and 62% for stones ≥5 mm 4
• For asymptomatic, non-obstructing caliceal stones up to 15 mm, active surveillance is a viable option 4

Renal Stones 10-20 mm

For non-lower pole renal stones 10-20 mm, both shock wave lithotripsy and ureteroscopy are acceptable first-line treatments. 4

• URS is associated with higher single-procedure stone-free rates but has slightly higher complication rates 4
• For lower pole stones 10-20 mm, ureteroscopy or percutaneous nephrolithotomy (PCNL) are recommended 2
• SWL is acceptable for lower pole stones 10-20 mm only with favorable conditions (broad infundibulo-pelvic angle, short infundibulum, short skin-to-stone distance, wide infundibulum, or shockwave favorable stone composition) 2

Renal Stones >20 mm

For renal stones >20 mm regardless of location, percutaneous nephrolithotomy should be offered as first-line therapy. 2, 4

• PCNL offers higher stone-free rates (94% vs. 75% for URS) and is less dependent on stone composition, density, and location 4
• SWL is not recommended for stones >20 mm or for cystine staghorn calculi 4
• PCNL complications include fever (10.8%), transfusion (7%), thoracic complications (1.5%), and sepsis (0.5%) 4

Procedural Considerations

Shock Wave Lithotripsy (SWL)

• Routine pre-stenting is not recommended before SWL as it provides no benefit and causes frequent stent-related symptoms 2, 4, 1
• Alpha-blockers may be prescribed after SWL to facilitate passage of stone fragments 4
• SWL complications include fever (10.8%), need for transfusion (7%), and sepsis (0.5%) 4

Ureteroscopy (URS)

• A safety wire is required during the procedure 4
• Laser or pneumatic lithotripsy may be used with semi-rigid ureteroscopes, while laser lithotripsy is preferred for flexible URS 4
• Routine stent placement is not recommended after uncomplicated URS 2, 4
• Alpha-blockers and anti-muscarinics may be prescribed to reduce stent discomfort if stenting is required 4
• For patients on antithrombotic therapy that cannot be discontinued, flexible URS is recommended 4

Percutaneous Nephrolithotomy (PCNL)

• Noncontrast CT is recommended prior to performing PCNL 2
• Tubeless PCNL (no nephrostomy tube) or totally tubeless (without nephrostomy tube or ureteral stent) can be considered in uncomplicated cases to reduce pain and hospital stay 2, 4

Emergency Situations Requiring Urgent Intervention

In cases of obstructing stones with suspected infection and sepsis, urgent drainage of the collecting system with a ureteral stent or nephrostomy tube is mandatory before definitive stone treatment. 4, 1

• Delay definitive stone treatment until sepsis is resolved 1
• Collect urine for antibiogram testing before and after decompression 1
• Administer antibiotics immediately and adjust based on culture results 1
• Urinalysis and/or urine culture should be obtained prior to surgical intervention to rule out urinary tract infection 2

Medical Management for Stone Prevention

Calcium Stones

• Thiazide diuretics should be offered to patients with high or relatively high urine calcium and recurrent calcium stones 3
• Potassium citrate therapy should be offered to patients with recurrent calcium stones and low or relatively low urinary citrate 3

Uric Acid Stones

For uric acid stones, oral chemolysis with alkalinization using potassium citrate or sodium bicarbonate is strongly recommended as first-line therapy, with a target pH 7.0-7.2. 3, 1

• The success rate of oral chemolysis is approximately 80.5%, with 15.7% requiring further intervention 1
• Patients should monitor urine pH and adjust medication accordingly 1

Cystine Stones

• First-line therapy includes increased fluid intake, restriction of sodium and protein intake, and urinary alkalinization 3

Brushite Stones

• Potassium citrate is first-line pharmacological therapy for brushite stone formers with hypocitraturia or elevated urine pH 3
• Thiazide diuretics should be offered to brushite stone formers with hypercalciuria 3

Preoperative Evaluation

• Obtain detailed medical and dietary history to identify conditions, habits, or medications that may predispose to stone disease 3
• Serum chemistries including electrolytes, calcium, creatinine, and uric acid should be ordered 3
• Urinalysis including dipstick and microscopic evaluation should be performed to assess urine pH, indicators of infection, and identify crystals 3
• Renal ultrasonography is the recommended first-line imaging modality 3, 5
• Noncontrast CT is helpful to determine the optimal surgical intervention 2

Follow-up and Monitoring

• A single 24-hour urine specimen for stone risk factors should be obtained within six months of initiating treatment to assess response to dietary and/or medical therapy 3
• After initial follow-up, a single 24-hour urine specimen should be obtained annually or with greater frequency, depending on stone activity 3
• Periodic blood testing should be performed to assess for adverse effects in patients on pharmacological therapy 3
• Follow-up imaging is recommended to monitor for stone growth, which would indicate the need for intervention 4

Common Pitfalls to Avoid

• Do not offer prolonged conservative management beyond 4-6 weeks without reassessment 1
• Do not use routine stenting before shock wave lithotripsy 1
• Avoid using NSAIDs in patients with significantly reduced renal function without careful monitoring 1
• Do not neglect to address underlying metabolic abnormalities that contribute to stone formation 3
• Do not prescribe allopurinol as first-line therapy for uric acid stones instead of urinary alkalinization with potassium citrate 3
• Nephrectomy may be considered when the involved kidney has negligible function 4