What is the treatment for a patient with a catheter-associated urinary tract infection (CAUTI)?

Treatment of Catheter-Associated Urinary Tract Infection (CAUTI)

For symptomatic CAUTI, replace the catheter immediately if it has been in place ≥2 weeks before starting antibiotics, then initiate empirical therapy with intravenous third-generation cephalosporin (ceftriaxone 1-2 g daily or cefepime 1-2 g twice daily) for 7 days if symptoms resolve promptly, or 10-14 days for delayed response. 1

Critical First Step: Catheter Management

Replace the indwelling catheter before initiating antimicrobial therapy if it has been in place for ≥2 weeks. 1 This intervention significantly decreases polymicrobial bacteriuria, shortens time to clinical improvement, and lowers CA-UTI recurrence rates within 28 days (symptomatic relapse: 3 versus 11 patients without replacement, p = 0.015). 1

• Obtain a urine culture from the newly placed catheter before starting antibiotics, as CAUTIs have a wide spectrum of potential organisms with increased likelihood of antimicrobial resistance. 2, 1
• Remove the catheter entirely as soon as clinically appropriate, as duration of catheterization is the single most important risk factor for CAUTI development. 2, 3

Empirical Antibiotic Selection

For Moderate to Severe CAUTI or Systemic Symptoms

First-line options include: 2, 1, 4

• Intravenous third-generation cephalosporin (ceftriaxone 1-2 g daily or cefepime 1-2 g twice daily) - strongly recommended 2, 1, 4
• Amoxicillin plus an aminoglycoside 2, 4
• Second-generation cephalosporin plus an aminoglycoside 2, 4

For Mild to Moderate CAUTI

• Levofloxacin 750 mg orally once daily demonstrates superior microbiologic eradication rates and is specifically validated for CA-UTI. 1
• Avoid fluoroquinolones if: the patient has used them in the last 6 months, is from a urology department, or local resistance rates exceed 10%. 1, 4

Rationale for Broad-Spectrum Coverage

CAUTIs are caused by organisms with higher resistance rates than uncomplicated UTIs, including E. coli, Proteus spp., Klebsiella spp., Pseudomonas spp., Serratia spp., and Enterococcus spp. 2, 4 The microbial spectrum is broader, requiring more potent antibiotic regimens. 2

Treatment Duration

• 7 days if symptoms resolve promptly and patient is hemodynamically stable and afebrile for at least 48 hours. 2, 1, 4
• 10-14 days for patients with delayed response or persistent fever. 2, 1, 4
• 14 days for men when prostatitis cannot be excluded. 2, 4

Tailoring Therapy Based on Culture Results

• Local antimicrobial resistance patterns should guide empirical therapy choices. 2, 4
• Once culture and susceptibility results are available, narrow therapy to targeted antibiotics. 2
• Augmentin (amoxicillin-clavulanate) can be considered as targeted therapy after culture confirms susceptibility, or as oral step-down therapy after initial parenteral treatment and clinical improvement. 2

Critical Pitfalls to Avoid

Do NOT Treat Asymptomatic Bacteriuria

• Asymptomatic bacteriuria in catheterized patients should not be treated (except in pregnant women or patients undergoing urologic procedures with anticipated mucosal bleeding), as this increases antimicrobial resistance without preventing CA-UTI. 1, 5, 3
• Prophylactic antimicrobials should NOT be given routinely at the time of catheter replacement alone, as this promotes antimicrobial resistance without reducing CA-UTI. 1

Do NOT Delay Catheter Replacement

• Delaying catheter replacement if it has been in place ≥2 weeks is a critical error that compromises treatment success. 1

Recognize When Antibiotics Are Failing

• If fever persists beyond 72 hours despite appropriate antibiotics for a susceptible organism, investigate alternative infection sources (bloodstream infection, abscess, prostatitis) or non-infectious causes (drug fever, malignancy). 2
• Obtain blood cultures if not already done, as approximately 20% of hospital-acquired bacteremias arise from the urinary tract in catheterized patients. 2, 4
• Consider imaging (renal ultrasound or CT) to evaluate for complicated infection requiring urologic evaluation. 2

Special Considerations

• CAUTIs are the leading cause of secondary healthcare-associated bacteremia. 2, 4
• Do not rely solely on urine dipstick tests in elderly patients, as specificity ranges from 20% to 70%. 4
• For carbapenem-resistant Enterobacterales (CRE), use plazomicin, ceftazidime-avibactam, or polymyxin-based combination therapy. 4