What is the recommended management for nephrolithiasis (kidney stone) pain?

Management of Nephrolithiasis Pain

NSAIDs are the first-line treatment for renal colic due to kidney stones, with diclofenac, ibuprofen, or metamizole being preferred options over opioids. 1

Initial Pain Management Approach

First-Line Therapy

• NSAIDs: Preferred due to their superior efficacy in reducing inflammation and pressure within the urinary collecting system
  • Options include diclofenac, ibuprofen, or metamizole
  • Use the lowest effective dose to minimize cardiovascular and gastrointestinal risks
  • Caution: NSAIDs may impact renal function in patients with low glomerular filtration rate 1, 2

Second-Line Therapy

• Opioids: Reserved for when NSAIDs are contraindicated or ineffective
  • Preferred options: hydromorphone, pentazocine, or tramadol
  • Avoid pethidine due to higher rates of vomiting and greater likelihood of requiring additional analgesia 1

Diagnostic Approach During Pain Management

• Ultrasound: First-line imaging modality (sensitivity 45%, specificity 94% for ureteral stones) 1, 2
• KUB radiography: Helps differentiate between radioopaque and radiolucent stones
• Non-contrast CT: Standard for acute flank pain after ultrasound to assess stone location, burden, density, and anatomy 1
• Laboratory tests: Urine dipstick, serum creatinine, uric acid, ionized calcium, sodium, potassium, blood cell count, and C-reactive protein 1

Emergency Situations Requiring Immediate Intervention

• Sepsis with obstruction: Urgent decompression via percutaneous nephrostomy or ureteral stenting is strongly recommended
• Anuria with obstruction: Requires immediate intervention
• Management protocol for sepsis/obstruction:
  1. Immediate antibiotics
  2. Urgent system decompression
  3. Urine collection for antibiogram before and after decompression
  4. Delay definitive stone treatment until sepsis resolves 1

Adjunctive Therapies

• Medical Expulsive Therapy (MET): α-blockers (off-label) are recommended for stones >5 mm in the distal ureter to facilitate passage 1
• Hydration: Maintain adequate fluid intake to achieve urine output of at least 2-2.5 liters per day 2

Special Populations Considerations

• Pregnant women: Ultrasound is first-line imaging, followed by MRI if needed, with low-dose CT as last resort 1
• Children: Ultrasound is first-line imaging, followed by KUB or low-dose CT if additional information is needed 1
• Patients with ADPKD: Medical treatment should be the same as in the general population, but obstructing stones should be managed by centers of expertise 1

Common Pitfalls to Avoid

1. Delaying analgesia: Pain control should be initiated promptly
2. Overreliance on opioids: NSAIDs should be first-line when not contraindicated
3. Inadequate hydration: Maintaining proper fluid intake is essential for stone passage
4. Missing signs of infection: Fever, elevated WBC, or positive urine culture with obstruction constitutes a urologic emergency
5. Inappropriate NSAID use: Avoid in patients with significant renal impairment, active peptic ulcer disease, or severe cardiovascular disease

Long-term Management After Acute Episode

• Stone analysis: Recommended for all first-time stone formers 1
• Preventive measures:
  • High fluid intake (3.5-4 liters daily for adults)
  • Dietary modifications based on stone composition
  • Medications such as potassium citrate for appropriate patients 2
  • Medical expulsive therapy for facilitating stone passage 1

By following this evidence-based approach to nephrolithiasis pain management, clinicians can effectively control pain while minimizing complications and facilitating stone passage when appropriate.