## Management of Infected Obstructed Kidney (Pyonephrosis) **Key Point:** An infected obstructed kidney (pyonephrosis) is a urological emergency requiring immediate drainage BEFORE definitive stone management. Antibiotics alone without drainage are inadequate and risk sepsis and renal loss. ### Clinical Diagnosis of Pyonephrosis **Classic Triad:** 1. Fever (> 38°C) 2. Obstructing stone on imaging (hydronephrosis + perinephric stranding) 3. Pyuria and positive urine cultures **Additional features in this case:** - Positive blood cultures (bacteraemia) - Perinephric stranding (inflammation/infection) - Acute presentation with systemic toxicity ### Emergency Management Algorithm ```mermaid flowchart TD A[Infected Obstructed Kidney]:::urgent --> B[Immediate Drainage Required]:::action B --> C{Renal Function & Anatomy}:::decision C -->|Normal function, accessible| D[Percutaneous Nephrostomy]:::action C -->|Severely impaired, solitary| E[Percutaneous Nephrostomy]:::action D --> F[Start Broad-Spectrum Antibiotics]:::action E --> F F --> G[Blood & Urine Cultures]:::action G --> H[Stabilize for 4-6 weeks]:::action H --> I[Definitive Stone Management]:::action I --> J{Stone Characteristics}:::decision J -->|< 10 mm| K[ESWL or Ureteroscopy]:::action J -->|> 10 mm| L[Ureteroscopy or PCNL]:::action ``` ### Step-by-Step Management **1. Immediate Drainage (within 24 hours)** - **Percutaneous nephrostomy** is the preferred route for acute pyonephrosis - Allows rapid decompression and urine culture - Avoids risk of pushing infected urine up the ureter (retrograde approach contraindicated) - Alternative: **JJ ureteric stent** if percutaneous access not feasible (less preferred in acute infection) **2. Antimicrobial Therapy** - Start empirical broad-spectrum antibiotics immediately after blood/urine cultures - **Regimen**: Ceftriaxone 2 g IV 12-hourly + gentamicin 5–7 mg/kg IV once daily (or fluoroquinolone if allergy) - Adjust based on culture sensitivities - Continue for 7–10 days minimum **3. Supportive Care** - IV fluids for hydration and sepsis management - Monitor urine output and renal function - Serial imaging (ultrasound) to confirm drainage adequacy **4. Definitive Stone Management (after 4–6 weeks)** - Once infection is cleared and renal function stabilized - Choice depends on stone size, location, and renal function - For a 12 mm proximal ureteric stone: **ureteroscopy with laser lithotripsy** or **ESWL** **High-Yield:** Never attempt retrograde instrumentation (ureteroscopy, ureteric stent) in acute pyonephrosis—risk of pushing infected urine into bloodstream and worsening sepsis. **Clinical Pearl:** The "Golden Rule" of pyonephrosis: **Drain first, treat stone later.** Drainage is life-saving; stone removal is definitive but can wait. **Mnemonic:** **DRAIN** = **D**rainage (percutaneous), **R**esuscitation (fluids), **A**ntibiotics (broad-spectrum), **I**nvestigation (cultures), **N**ow (don't delay). --- ## Why Other Options Are Incorrect **Antibiotics alone + ureteroscopy**: Antibiotics without drainage are inadequate in pyonephrosis and risk sepsis progression. Retrograde ureteroscopy in acute infection risks pushing infected urine into the bloodstream, worsening bacteraemia and sepsis. **Antibiotics + ESWL in 48 hours**: ESWL is not appropriate for acute pyonephrosis. The kidney must be drained first. Waiting 48 hours without drainage risks rapid deterioration and septic shock in an already febrile patient. **Open pyelolithotomy**: Invasive surgical approach reserved for rare cases (e.g., failed percutaneous access, complex anatomy). Percutaneous drainage is less morbid and is the standard emergency approach.
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