🚽 Chapter 102: Health Care–Associated Infection: UTI (CA-UTI)

Catheter-associated urinary tract infection · Definitions · Polymicrobial bacteriuria · Diagnosis · Empiric antibiotics · Prevention strategies · Indwelling catheter

🔍 Core Concepts: Catheter-Associated UTI

📌 Definition (CA-UTI)
Symptoms/compatible signs + ≥10³ CFU/mL of ≥1 bacterial species in catheter urine specimen (or voided midstream within 48h of catheter removal).
🦠 Organisms
Short-term catheter: E. coli, Klebsiella, Enterococcus, Pseudomonas. Long-term catheter: polymicrobial (Proteus, Morganella, Providencia).
⚠️ Symptoms
Fever, flank pain, CVA tenderness, altered mental status, suprapubic pain. In infants: apnoea, bradycardia, irritability.
🧪 Diagnosis
Urine culture from freshly placed catheter or voided after removal. Blood cultures if pyelonephritis suspected. Pyuria/odor alone not diagnostic.
💊 Treatment
Remove catheter if possible. Empiric: ceftriaxone, ertapenem, or cefepime/meropenem if critically ill. Duration 5-7d (uncomplicated) to 10-14d (complicated/ICU).
🛡️ Prevention
Avoid unnecessary catheters; remove as soon as possible; aseptic insertion; closed drainage; condom catheters or intermittent cath as alternatives. No routine irrigation or prophylactic antibiotics.
📈 CA-ASB
Asymptomatic bacteriuria (≥10⁵ CFU/mL, no symptoms) – do NOT treat except in pregnancy or urologic procedures.

🩺 Stepwise Management of Catheter-Associated UTI

1
Recognize signs & obtain appropriate cultures
New fever, flank pain, CVA tenderness, or unexplained change in mental status. Collect urine from freshly placed catheter (or voided if catheter removed within 48h). Send for culture and sensitivity.
2
Remove or replace indwelling catheter
If catheter has been in place >2 weeks, replace before culture. For treatment, remove catheter if no longer needed. If catheter must stay, consider replacement to hasten symptom resolution.
3
Start empiric antibiotics based on severity
Stable, no upper tract signs: ceftriaxone, ertapenem, or ciprofloxacin. Critically ill: meropenem, cefepime, or piperacillin-tazobactam. Duration: 5-7d (uncomplicated) to 10-14d (complicated, ICU, persistent symptoms).
4
De-escalate based on culture & susceptibility
Narrow to oral step-down (fluoroquinolone, TMP-SMX, nitrofurantoin) if clinically improving and pathogen susceptible. Treat candiduria only if symptomatic and risk factors (remove catheter, fluconazole).
5
Prevent future CA-UTI
Daily review of catheter necessity. Use aseptic insertion, closed drainage system. Alternatives: condom catheters, intermittent catheterization, or bladder scanners. Avoid routine irrigation or antibiotic prophylaxis.