What are the treatment options for kidney stones?

Kidney Stone Treatment

For acute kidney stones, start with intramuscular diclofenac 75 mg for pain control, then determine treatment based on stone size and location: stones <10 mm can be managed conservatively with medical expulsive therapy using tamsulosin, while larger stones require surgical intervention with ureteroscopy (URS) as first-line for most ureteral stones and percutaneous nephrolithotomy (PCNL) for renal stones >20 mm. 1, 2, 3

Acute Pain Management

• Administer intramuscular diclofenac 75 mg immediately for acute renal colic, which should provide pain relief within 30 minutes 3
• NSAIDs are superior to opioids because they directly decrease ureteral smooth muscle tone and spasm, have fewer side effects, and carry no dependence risk 3
• Reserve opioids (morphine with cyclizine) only when NSAIDs are contraindicated due to cardiovascular disease, gastrointestinal comorbidities, renal insufficiency, heart failure, or peptic ulcer risk 3
• Patients must receive medical assessment within 30 minutes to exclude life-threatening conditions like ruptured aortic aneurysm (especially >60 years) or ectopic pregnancy 3

Emergency Indications Requiring Immediate Hospital Admission

• Shock or fever (suggests infected obstructed kidney—a urologic emergency) 3
• Failure to respond to analgesia within one hour 3
• Abrupt recurrence of severe pain after initial relief 3
• Sepsis and/or anuria require urgent decompression via percutaneous nephrostomy or ureteral stenting 2

Conservative Management vs. Surgical Intervention

When to Observe (Conservative Management)

• Stones ≤10 mm with controlled symptoms can be observed with periodic evaluation for 4-6 weeks maximum 1, 4
• Patients must have well-controlled pain, no clinical evidence of sepsis, and adequate renal functional reserve 1
• Prescribe tamsulosin (alpha-blocker) as medical expulsive therapy, particularly for stones >5 mm in the distal ureter 4, 3
• Instruct patients to drink fluids targeting >2.5 L urine output daily and strain urine to catch stones for analysis 3, 5
• Follow-up imaging within 7 days to monitor stone position and assess for hydronephrosis 1, 3

When to Intervene Surgically

For stones >10 mm, surgical treatment is required in most cases 1, 4

Surgical Treatment Algorithm by Stone Location and Size

Distal Ureteral Stones

• URS is first-line treatment for stones >10 mm 1
• For stones <10 mm, both URS and extracorporeal shock wave lithotripsy (ESWL) are acceptable, though URS yields significantly higher stone-free rates with a single procedure 1
• URS has higher complication rates (3-6% ureteral injury, 1-2% stricture) compared to ESWL but better efficacy 1

Proximal Ureteral Stones

• URS is recommended as first-line treatment regardless of stone size 1
• ESWL is an equivalent option for stones <10 mm 1

Renal Stones (Pelvis, Upper/Middle Calyx)

• For stones <20 mm: flexible URS (fURS) or ESWL are first-line treatments 1
• For stones >20 mm: PCNL is the standard first-line treatment 1, 2
• For stones 10-20 mm, PCNL is an additional option 1

Lower Pole Renal Stones

• Stones <10 mm: fURS or ESWL 1
• Stones 10-20 mm: fURS or PCNL 1
• Stones >15 mm: fURS or PCNL 1

Asymptomatic Renal Stones

• Active surveillance is acceptable for asymptomatic, non-obstructing stones up to 15 mm 1
• Surgical treatment is indicated for stone growth, associated infection, or specific vocational reasons 1

Technical Considerations for Surgical Procedures

ESWL Best Practices

• Routine prestenting before ESWL does not improve stone-free rates but may reduce steinstrasse 1
• Decrease shockwave frequency from 120 to 60-90/min to improve stone-free rates and reduce tissue damage 1
• Use stepwise energy ramping to minimize renal injury 1
• ESWL is contraindicated in pregnancy, bleeding disorders, uncontrolled UTI, severe obesity, arterial aneurysm near stone, or anatomic obstruction distal to stone 1
• Prescribe alpha-blockers after ESWL to facilitate passage of stone fragments 1

URS Best Practices

• Complete stone removal is the goal; use Ho:YAG laser as gold standard for lithotripsy 1
• Routine prestenting is not required but may improve outcomes for renal stones 1
• Routine post-URS stenting is unnecessary after uncomplicated procedures and may increase morbidity 1
• Stenting is advised with trauma, residual fragments, bleeding, perforation, UTI, or pregnancy 1
• Prescribe alpha-blockers if stent is placed to reduce discomfort; consider antimuscarinics 1
• fURS is recommended when antithrombotic therapy cannot be stopped 1

PCNL Considerations

• PCNL is classified as high bleeding risk procedure 1
• Patients on antithrombotic therapy should be referred to internist before PCNL 1

Stone Type-Specific Medical Management

Uric Acid Stones

• First-line: potassium citrate to alkalinize urine to pH 6.0 (oral chemolysis) 2, 4
• This can dissolve existing stones and prevent new formation 2

Cystine Stones

• Potassium citrate to raise urinary pH to 7.0 2
• Increase fluid intake, restrict sodium and protein 4

Struvite Stones

• Complete surgical removal is necessary 2
• Medical therapy alone is insufficient 2

Calcium Stones (Prevention of Recurrence)

• Thiazide diuretics for hypercalciuria 4, 6
• Potassium citrate for hypocitraturia 4, 6
• Maintain dietary calcium at 1000-1200 mg/day (not supplements) 4, 5
• Limit sodium to 2-3 g/day 5
• Limit animal protein to 0.8-1.0 g/kg/day 5

Post-Treatment Follow-Up

• Obtain 24-hour urine collection within 6 months of treatment to assess metabolic risk factors 4
• Repeat annually or more frequently depending on stone activity 4
• Confirm stone clearance with imaging 2
• Obtain stone analysis at least once to guide metabolic evaluation 4, 3

Critical Pitfalls to Avoid

• Never use opioids as first-line for acute pain—NSAIDs are superior and avoid dependence 3
• Never delay admission for fever with obstruction—this is a urologic emergency requiring immediate drainage 3
• Never routinely stent before ESWL—it doesn't improve outcomes 1
• Never routinely stent after uncomplicated URS—it increases morbidity without benefit 1
• Never prescribe allopurinol as first-line for uric acid stones—potassium citrate for alkalinization is correct 4
• Never use calcium supplements for stone prevention—dietary calcium is preferred 4