Infected stones and struvite nephrolithiasis

Definition

Infected stones are associated with urease-producing bacteria (Proteus, Klebsiella, Pseudomonas) and can rapidly perpetuate recurrent infection.

Treatment must combine infection control with removal of as much stone material as possible.

Diagnosis

• Assess symptoms of infection.
• Urinalysis and urine culture.
• CBC, kidney function.
• In a systemic response, measure lactate and obtain a blood culture.
• Imaging (ultrasonography/CT) identifies obstruction and stone burden.

Emergency care

• In infected obstruction, perform immediate drainage (stent or nephrostomy).
• Antibacterial therapy (intravenous, broad-spectrum, guided by local resistance patterns).
• Definitive stone removal after clinical stabilization.

Definitive treatment

• After infection control, remove the stone completely or as completely as possible.
• Residual infected material increases the risk of recurrence.
• Preferred methods: PCNL and combined endoscopic approaches.

Prevention

• Stone composition analysis.
• Microbiological testing.
• Control of metabolic factors.
• Correction of urological abnormalities that perpetuate infection.

Algorithm