What are the recommendations for antibiotics (Abx) and other interventions (bc) for a patient with an obstructing kidney stone and associated hydronephrosis?

Management of Obstructing Stone with Hydronephrosis

In patients with an obstructing kidney stone and hydronephrosis, immediately administer broad-spectrum antibiotics and urgently decompress the collecting system via either percutaneous nephrostomy or ureteral stenting if there is any suspicion of infection or sepsis; delay definitive stone treatment until the infection resolves. 1

Immediate Assessment for Infection

The critical first step is determining whether infection is present, as this transforms the clinical scenario into a urologic emergency:

• Obtain urine culture before and after decompression to guide antibiotic selection, as mandated by the European Association of Urology (EAU) guidelines 1
• Look for fever, elevated white blood cell count, elevated CRP, or signs of sepsis 1
• If purulent urine is encountered during any intervention, immediately abort stone removal, establish drainage, and continue antibiotics 1
• The obstructed infected kidney can rapidly progress to sepsis and death if not promptly decompressed 2, 3, 4

Urgent Decompression Protocol

When infection is suspected or confirmed in the setting of obstruction:

Choice of Decompression Method

Both retrograde ureteral stenting and percutaneous nephrostomy (PCN) are acceptable options, with selection based on clinical factors 1:

• Retrograde stenting advantages: Can be performed during the same session as eventual ureteroscopic treatment, associated with decreased hospital stay and ICU admission rates, and requires fewer subsequent interventions 5
• PCN advantages: Higher technical success rate, preferred for patients at high anesthetic risk, and better for pyonephrosis requiring larger tube decompression 5
• Neither method has been shown superior in randomized trials for resolving sepsis 6

Antibiotic Management

Start broad-spectrum antibiotics immediately upon suspicion of infection 1:

• Administer antibiotics within 60 minutes of any planned intervention 1, 7
• Cover both gram-positive and gram-negative uropathogens 1, 7
• Re-evaluate the antibiotic regimen based on culture results and antibiogram findings 1
• Tailor antibiotic selection to institutional or regional antimicrobial susceptibility patterns 1
• Continue antibiotics until infection resolves before attempting definitive stone treatment 1

Timing of Definitive Stone Treatment

Delay all definitive stone treatment until sepsis is completely resolved 1:

• This is a strong recommendation from the 2025 EAU guidelines 1
• Attempting stone removal in the presence of active infection significantly increases morbidity and mortality risk 2, 3
• Intensive care monitoring may become necessary during the acute infectious phase 1

Management Without Infection

If there is no evidence of infection but obstruction with hydronephrosis is present:

• Conservative management may be appropriate for stones <10 mm if pain is well-controlled, renal function is adequate, and close monitoring is possible 5, 7
• Medical expulsive therapy with alpha-blockers can be offered for stones >5 mm in the distal ureter 1
• Maximum conservative treatment duration should be 4-6 weeks 7

Absolute Indications for Urgent Intervention (Non-Infected Cases)

Proceed immediately to decompression or definitive treatment if 7:

• Intractable pain despite oral analgesics
• Progressive renal dysfunction
• Worsening hydronephrosis
• Development of urinary tract infection
• Anuria (complete obstruction) 1

Common Pitfalls to Avoid

• Never attempt definitive stone removal in the presence of active infection or purulent urine 1
• Do not delay decompression while waiting for culture results if infection is suspected clinically 1
• Avoid assuming the absence of infection based solely on lack of fever—obtain cultures before making this determination 1
• Do not use NSAIDs for pain control in patients with compromised renal function from obstruction, as they may further impair glomerular filtration 1