Can an infected kidney stone be associated with high fever?

Infected Kidney Stones and High Fever

Yes, infected kidney stones can definitely be associated with high fevers of 103°F or higher, and this represents a urologic emergency requiring immediate intervention to prevent life-threatening sepsis.

Pathophysiology and Clinical Presentation

Infected kidney stones, also known as "infection stones," are strongly associated with urinary tract infections and can present with severe symptoms:

• Infected stones are most commonly composed of magnesium ammonium phosphate (struvite) and/or calcium carbonate apatite 1
• These stones form due to urinary tract infections with urease-producing bacteria, which can reside within the stone itself 2
• When stones cause obstruction, they can lead to obstructive pyelonephritis, which can rapidly progress to urosepsis 3

Key Clinical Features

• High fever (≥102.2°F/39°C) is a common presentation of infected stones 1
• Other symptoms include:
  • Rigors/shaking chills
  • Flank pain or tenderness
  • Nausea and vomiting
  • Mental status changes (particularly in elderly patients) 3
  • Changes in urine color or odor
  • Dysuria and increased urinary frequency

Diagnostic Approach

When a patient presents with high fever and suspected kidney stone:

1. Laboratory evaluation:

   • Urinalysis and urine culture (to identify infection and causative organisms)
   • Complete blood count (leukocytosis suggests infection)
   • Serum chemistries including creatinine (to assess renal function) 1
   • Blood cultures if sepsis is suspected

2. Imaging studies:

   • Renal ultrasound or CT scan to:
     • Confirm stone presence
     • Assess for hydronephrosis (indicating obstruction)
     • Quantify stone burden 1

Management of Infected Stones with High Fever

The presence of high fever with a kidney stone represents a urologic emergency:

1. Immediate intervention:

   • Prompt drainage of the affected kidney is essential and may be life-saving 4
   • Options include:
     • Percutaneous nephrostomy (PCN)
     • Retrograde ureteral stenting
     • Antegrade ureteral stenting if retrograde approach fails 1

2. Antimicrobial therapy:

   • Broad-spectrum antibiotics should be initiated immediately
   • Therapy should be tailored based on culture results when available

3. Definitive stone management:

   • Complete stone removal is the goal to eradicate causative organisms 2
   • Delay definitive stone management until the infection has cleared 4
   • Treatment options include:
     • Percutaneous nephrolithotomy (PNL)
     • Combination of PNL and shock wave lithotripsy (SWL)
     • SWL monotherapy
     • Open surgery in select cases 1

Risk Factors and Prevention

Certain factors increase the risk of developing infected stones with high fever:

• Presence of indwelling nephrostomy tube or stent 5
• Positive urine culture prior to intervention
• Kidney or upper ureteral stones (vs. mid/lower ureteral stones) 5
• History of recurrent UTIs
• Anatomical abnormalities of the urinary tract

Important Clinical Considerations

1. Stone composition matters:

   • Magnesium ammonium phosphate (MAP) stones are associated with higher rates of postoperative fever (14.7%) compared to carbonate apatite (CA) stones (3.8%) 6
   • Gram-negative bacteria are more commonly found in MAP stone cultures 6

2. Elderly patients require special attention:

   • May present with atypical symptoms
   • Changes in mental status may be the only sign of infection
   • Higher risk of urosepsis due to age-related immune changes 3

3. Prevention strategies:

   • Adequate hydration
   • Prompt treatment of urinary tract infections
   • Regular follow-up for patients with known stone disease 3

Conclusion

High fever (103°F) is a serious and common presentation of infected kidney stones that requires immediate medical attention. The combination of obstruction and infection can rapidly progress to life-threatening sepsis if not promptly addressed with drainage procedures and appropriate antimicrobial therapy.