What is the management for kidney stones and pyelonephritis with mildly hydronephrosis?

Management of Kidney Stones and Pyelonephritis with Mild Hydronephrosis

In patients with kidney stones causing pyelonephritis and mild hydronephrosis, urgent decompression of the collecting system with either percutaneous nephrostomy (PCN) or retrograde ureteral stenting is mandatory, followed by appropriate antibiotic therapy and definitive stone management once infection is controlled. 1

Initial Management of Infected Obstructed Kidney

Urgent Decompression

• When infection is suspected with ureteral obstruction, the collecting system must be urgently drained to allow:
  • Drainage of infected urine
  • Antibiotic penetration into the affected renal unit
  • Prevention of sepsis progression 1

Decompression Options

1. Percutaneous nephrostomy (PCN)

   • May have higher technical success rate in relieving obstruction
   • Particularly useful in cases of extrinsic compression or obstruction at the ureteropelvic junction
   • Allows direct collection of infected urine for culture 1

2. Retrograde ureteral stenting

   • Alternative to PCN
   • Both are considered first-line treatment options for obstructive pyelonephritis 1

Antibiotic Therapy

• Start empiric antibiotics immediately after collecting urine cultures
• Initial intravenous antimicrobial regimen options:
  • Fluoroquinolone
  • Aminoglycoside (with or without ampicillin)
  • Extended-spectrum cephalosporin or penicillin (with or without aminoglycoside)
  • Carbapenem 1
• Tailor regimen based on local resistance patterns and susceptibility results
• Duration: 10-14 days for treatment with a β-lactam agent 1

Definitive Stone Management

Timing

• Delay definitive stone treatment until infection is controlled
• Complete stone removal is essential to prevent:
  • Further stone growth
  • Recurrent UTIs
  • Renal damage 2

Treatment Options Based on Stone Size and Location

For stones <10 mm:

• Medical expulsive therapy (MET) with tamsulosin 0.4 mg daily may facilitate passage
• Increases stone passage rates by approximately 29% compared to controls 2

For ureteral stones <10 mm:

• Observation with periodic evaluation or MET if symptoms are controlled 1

For renal stones ≤20 mm:

• SWL (shock wave lithotripsy) or URS (ureteroscopy) 1

For renal stones >20 mm:

• PCNL (percutaneous nephrolithotomy) as first-line therapy 1

For lower pole stones ≤10 mm:

• SWL or URS 1

Monitoring and Follow-up

• Follow patients with periodic imaging to:
  • Monitor stone position
  • Assess for hydronephrosis 1
• Most patients with uncomplicated pyelonephritis become afebrile:
  • 95% within 48 hours of appropriate antibiotic therapy
  • Nearly 100% within 72 hours 1
• If no improvement within 48-72 hours:
  • Evaluate with imaging
  • Repeat cultures
  • Consider alternative diagnoses 3

Important Considerations

• Avoid blind stone extraction with a basket; intraureteral manipulations should always be performed under direct ureteroscopic vision 1
• Complete stone removal is essential for preventing further stone growth, recurrent UTIs, and renal damage 2
• Hydration is important - patients should maintain fluid intake of 3.5-4 liters daily to produce at least 2-2.5 liters of urine per day 2
• Stone analysis should be performed at least once to guide preventive measures 2

Cautions and Pitfalls

• Failure to urgently decompress an obstructed infected kidney can lead to urosepsis and death
• Delaying decompression while waiting for antibiotics to work is dangerous
• Post-procedural bacteremia and sepsis are common when infected urinary tracts are drained, so preprocedural antibiotics are recommended 1
• Electrohydraulic lithotripsy (EHL) should not be utilized as first-line modality for intra-ureteral lithotripsy due to risk of ureteral mucosal damage 1

By following this approach, you can effectively manage patients with kidney stones and pyelonephritis with mild hydronephrosis, minimizing the risk of sepsis and preserving renal function.