What is the management for leukocytes (white blood cells) in urine from a nephrostomy tube, indicating a potential urinary tract infection?

Management of Leukocytes in Urine from Nephrostomy Tube

When leukocytes are detected in urine from a nephrostomy tube, clinicians should obtain a urine culture, initiate appropriate antibiotics based on local sensitivity patterns, and consider nephrostomy tube exchange within 4 days of infection to prevent recurrent infection. 1, 2

Diagnosis and Initial Assessment

When leukocytes are found in nephrostomy urine, this indicates a potential urinary tract infection (UTI) that requires prompt evaluation:

• Obtain urine culture: Culture the nephrostomy urine before starting antibiotics to guide appropriate treatment 3
• Clinical assessment: Look for signs of systemic infection including fever, flank pain, altered mental status, or hemodynamic instability
• Laboratory evaluation: Complete blood count, renal function tests, and blood cultures if systemic symptoms are present

Antibiotic Management

Initial Empiric Therapy

• Start empiric antibiotics that cover common uropathogens based on local sensitivity patterns 1, 3
• First-line options for nephrostomy-associated UTIs:
  • Fluoroquinolones (e.g., ciprofloxacin) if local resistance is <10% 3
  • Third-generation cephalosporins (e.g., ceftazidime) which have shown superior clinical and microbiological cure rates compared to fluoroquinolones 1
  • For suspected complicated infection or sepsis: broad-spectrum coverage with piperacillin-tazobactam or meropenem

Targeted Therapy

• Adjust antibiotics based on culture and sensitivity results 3
• Duration of therapy:
  • 7-10 days for uncomplicated nephrostomy-associated UTI
  • 14-21 days for complicated infection or if bacteremia is present 3

Nephrostomy Tube Management

• Exchange the nephrostomy tube within 4 days of infection diagnosis when receiving concordant antibiotics 2
  • This approach has been shown to significantly reduce the risk of recurrent infection (OR 0.1; p = 0.048) 2
• Avoid routine nephrostomy cultures at the time of scheduled exchanges in asymptomatic patients 4
• Consider aborting stone removal procedures if purulent urine is encountered during endoscopic intervention, establish appropriate drainage, continue antibiotic therapy, and obtain a urine culture 1

Special Considerations

Patients with Stones

• If the nephrostomy was placed for stone disease, consider that:
  • Stone cultures often differ from bladder urine cultures 5
  • Preoperative nephrostomy drainage with renal urine culture and culture-specific antibiotic treatment may decrease the risk of postoperative infectious complications in high-risk patients 5

Antibiotic Prophylaxis

• Prophylactic antibiotics should be administered prior to nephrostomy tube placement or exchange, based on:
  • Prior urine culture results
  • Local antibiogram
  • Current best practice guidelines 1
• However, antibiotic prophylaxis may not prevent transient bacteremia during nephrostomy tube changes in patients with pre-existing bacteriuria 6

Prevention of Recurrent Infections

• Concordant antibiotic use (active against all identified organisms) is independently associated with decreased recurrent nephrostomy-related infections (OR 0.04; p = 0.008) 2
• Regular tube maintenance:
  • Keep the nephrostomy tube properly secured to prevent movement
  • Maintain a closed drainage system
  • Ensure adequate hydration to promote urine flow

Monitoring and Follow-up

• Assess clinical response within 48-72 hours of starting treatment 3
• If symptoms persist beyond 72 hours:
  • Reassess with repeat cultures
  • Consider changing antibiotics based on culture results
  • Evaluate for complications or anatomical abnormalities 3
• No routine post-treatment urinalysis or urine cultures are indicated for asymptomatic patients 3

Common Pitfalls to Avoid

1. Failing to exchange the nephrostomy tube during active infection, which increases risk of recurrence
2. Relying on bladder urine cultures rather than nephrostomy urine cultures, as concordance rates between the two are low 5, 4
3. Continuing antibiotics without tube exchange, which may lead to persistent or recurrent infection
4. Delaying treatment in patients with signs of sepsis, which can lead to increased morbidity and mortality

By following this structured approach to managing leukocytes in nephrostomy urine, clinicians can effectively treat infections, prevent recurrence, and minimize complications in these patients.