What is the appropriate management for a patient presenting with kidney stones and an elevated White Blood Cell (WBC) count?

Management of Kidney Stones with Elevated WBC Count

For patients presenting with kidney stones and elevated white blood cell count, prompt evaluation for urinary tract infection is required, with appropriate antibiotic therapy and consideration of urgent decompression for obstructive stones causing pyelonephritis or sepsis. 1, 2

Diagnostic Approach

Initial Assessment

• Obtain urinalysis to check for hematuria, pyuria, and pH 1, 2
• Collect urine culture before starting antibiotics to guide targeted therapy 1, 2
• Order blood tests including:
  • Complete blood count (elevated WBC >11 × 10^9/L suggests infection) 1
  • C-reactive protein (≥50 mg/L indicates possible infection) 1
  • Serum creatinine to assess kidney function 2
  • Electrolytes 1

Imaging

• Non-contrast CT scan is strongly recommended as the primary imaging modality for patients with suspected kidney stones 1
• Ultrasound can be used as first-line imaging with 45% sensitivity and 94% specificity 2
• KUB radiography helps differentiate between radioopaque and radiolucent stones 2

Treatment Algorithm

1. For Kidney Stones with Signs of Infection/Sepsis

• If obstructive pyelonephritis or sepsis is present:

  • Immediate urinary drainage via percutaneous nephrostomy or ureteral stent 3, 4
  • Broad-spectrum antibiotics with coverage for gram-negative organisms 1, 4
  • Blood cultures should be obtained before antibiotic initiation 1
  • Fluid resuscitation and hemodynamic support for septic patients 3

• Once infection is controlled:

  • Complete stone removal is essential, especially for infection stones 5, 4
  • Consider definitive stone management only after infection has cleared 6

2. For Non-Obstructive Stones with Mild Elevation in WBC

• Appropriate antibiotic therapy based on culture results 2
• Pain management with NSAIDs as first-line treatment 2
• Increased hydration to maintain urine output of at least 2 liters per day 2
• Medical expulsive therapy may be considered for appropriate candidates

3. Stone Management Based on Size and Location

Stone Size	Location	Recommended Treatment
<10 mm	Renal pelvis or upper/middle calyx	ESWL or flexible URS
10-20 mm	Renal pelvis or upper/middle calyx	ESWL or flexible URS
<10 mm	Lower pole	Flexible URS or ESWL
10-20 mm	Lower pole	Flexible URS or PCNL
>20 mm	Any location	PCNL
[2]

Special Considerations

Antibiotic Selection

• For urinary tract infections associated with stones:
  • Use lipid-soluble antibiotics (e.g., trimethoprim-sulfamethoxazole, fluoroquinolones) for better penetration into infected areas 1
  • Consider local antimicrobial resistance patterns 1
  • For severe infections or sepsis, use broad-spectrum antibiotics initially, then narrow based on culture results 3, 4

Monitoring Response

• Follow WBC count and inflammatory markers (CRP) to assess response to therapy 1, 3
• Higher WBC and neutrophil counts at presentation may actually predict better spontaneous stone passage in non-infected cases 7
• Repeat imaging to confirm resolution of obstruction if present initially

Prevention of Recurrence

• Stone analysis for all first-time stone formers 2
• Dietary modifications based on stone composition:
  • Maintain adequate calcium intake (1,000-1,200 mg daily) 2
  • Reduce sodium and animal protein intake 2
  • Increase fluid intake to produce at least 2 liters of urine per day 2
• Treat any underlying metabolic disorders 2

Common Pitfalls to Avoid

• Delaying drainage in obstructive pyelonephritis, which can lead to sepsis and death 5, 4
• Starting antibiotics before obtaining urine cultures 1
• Attempting definitive stone treatment before controlling infection 6
• Confusing elevated WBC due to inflammatory response to stone with actual infection 7
• Inadequate follow-up imaging to ensure complete stone clearance, especially with infection stones 5