What is the best course of action for a patient, 3 days post-discharge, with a history of obstructing ureteral stone and infection, currently on Augmentin (amoxicillin-clavulanate), presenting with right-sided flank pain, chills, nausea, and abnormal labs, including leukocytosis, hematuria, and elevated liver enzymes, after undergoing stent placement for a ureteral stone with a urine culture positive for Klebsiella?

Immediate Urinary Tract Decompression and Antibiotic Escalation Required

This patient requires emergent urinary tract imaging to assess stent patency and immediate broad-spectrum IV antibiotic escalation, as Augmentin is insufficient for treating obstructive pyelonephritis with potential stent failure. 1

Critical Assessment of Current Situation

This patient presents with classic signs of recurrent obstructive pyelonephritis despite recent stent placement and ongoing oral antibiotics. The constellation of flank pain (8/10), chills, pyuria (500 WBC/uL), significant hematuria (250 Ery/uL), leukocytosis (12.43), and elevated liver enzymes suggests either:

• Stent occlusion or malposition requiring urgent imaging 1
• Inadequate antibiotic coverage for the known Klebsiella infection 2, 1
• Device-related infection from the recently placed stent 3

The elevated liver enzymes (AST 54, ALT 71, Alk Phos 199) may indicate ascending infection or sepsis-related hepatic dysfunction, warranting immediate intervention. 1

Immediate Diagnostic Steps

Urgent Imaging

• Non-contrast CT or renal ultrasound must be performed immediately to assess for hydronephrosis, stent position, and potential abscess formation 4, 1
• The presence of hydronephrosis would confirm stent failure and necessitate immediate decompression 1

Laboratory Priorities

• Obtain blood cultures and repeat urine culture before escalating antibiotics to guide definitive therapy 2
• The urinalysis findings (leukocyte esterase with 15-19 WBC and significant bacteriuria) have 88% sensitivity and 79% specificity for UTI, confirming active infection 1

Antibiotic Management

Why Augmentin is Inadequate

Augmentin must be discontinued and replaced with IV antibiotics immediately. 1 Here's why:

• Antibiotics alone are insufficient for obstructive pyelonephritis—survival with medical therapy alone is only 60% compared to 92% with decompression 1
• While high-dose amoxicillin-clavulanate (2875mg BID) can treat ESBL-producing Klebsiella in select outpatient cases, this patient's presentation with systemic symptoms and potential obstruction requires parenteral therapy 5
• Standard Augmentin dosing has only 70% success rates for resistant organisms and is inadequate for acute obstructive infection 6

Recommended IV Antibiotic Regimen

Start ceftriaxone 1-2g IV daily as first-line empiric therapy. 1 The evidence is compelling:

• Ceftriaxone demonstrates superiority over fluoroquinolones in both clinical and microbiological cure rates for obstructive pyelonephritis 1
• When used for preprocedural prophylaxis in high-risk patients, ceftriaxone reduced serious postprocedural sepsis complications from 50% to 9% 3, 2
• This covers expected uropathogens including Klebsiella, which commonly colonizes ureteral stents 3

Alternative Considerations

If the patient has risk factors for ESBL-producing Klebsiella (prior ESBL infection, recent antibiotic exposure), consider:

• Piperacillin-tazobactam or carbapenem (meropenem/ertapenem) as empiric therapy 7
• Tailor antibiotics once culture and susceptibility results return 2

Urinary Decompression Strategy

If Imaging Shows Obstruction

Emergent decompression is lifesaving and non-negotiable. 1 Two equivalent options exist:

1. Retrograde ureteral stent exchange (preferred if technically feasible)

   • Decreases hospital stay and ICU admission rates compared to nephrostomy 2, 1
   • Can be performed under conscious sedation given pain concerns 2
   • Caution: Prolonged manipulation can worsen urosepsis, so proceed efficiently 1

2. Percutaneous nephrostomy (PCN)

   • Most appropriate if patient appears septic or stent exchange is technically difficult 1
   • Provides larger tube decompression for pyonephrosis 3
   • Yields bacteriological information to guide antibiotic therapy 1

Post-Decompression Monitoring

• Close monitoring for worsening sepsis is required immediately intraprocedure and postprocedure, as bacteremia commonly occurs when infected urinary tracts are drained 1
• Monitor vital signs, mental status, and lactate levels closely 1

Prevention of Recurrent Infection

Device Management

The main risk factor for device-related urinary infections is the length of time the device remains in place. 3 Therefore:

• Schedule routine stent exchanges every 3 months to prevent recurrent infection 2
• Maintain clean exit site (if PCN placed) with antiseptic use and regular dressing changes 3, 2
• Consider chlorhexidine-impregnated dressings if frequent infections occur 3, 2

Antimicrobial Stewardship

Critical pitfall to avoid: Do NOT treat asymptomatic bacteriuria between symptomatic episodes. 2 This approach:

• Fosters antimicrobial resistance 2
• Paradoxically increases recurrent UTI episodes 2
• Only obtain urine cultures when symptomatic 2

Preprocedural Prophylaxis for Future Exchanges

For this high-risk patient (history of infected stone, recent UTI), use targeted prophylaxis based on prior culture results:

• Ceftriaxone or ampicillin-sulbactam preprocedurally reduces sepsis complications from 50% to 9% 3, 2
• Targeted prophylaxis based on colonizing organisms appears more protective than standard prophylaxis 3

Definitive Stone Management

• Delay definitive stone treatment until sepsis is resolved 1
• Plan for stent removal once underlying pathology is definitively treated and infection cleared 1
• Consider ureteroscopy with stone extraction once patient is stable 2

Common Pitfalls to Avoid

1. Never rely on antibiotics alone for obstructive pyelonephritis—decompression is essential 1
2. Do not continue oral antibiotics in a patient with systemic symptoms and potential obstruction 1
3. Do not delay imaging—stent patency must be confirmed urgently 1
4. Avoid treating asymptomatic bacteriuria between episodes, as this increases resistance 2
5. Do not forget preprocedural antibiotics for future stent exchanges in this high-risk patient 3, 2