Why Routine Irrigation of Indwelling Urinary Catheters Is Not Recommended
Routine catheter irrigation—whether with antimicrobials or normal saline—should not be performed because it is ineffective at preventing catheter-associated bacteriuria (CA-bacteriuria), catheter-associated urinary tract infections (CA-UTI), or catheter obstruction, while being time-consuming and costly. 1
The Evidence Against Routine Irrigation
Antimicrobial Irrigation Does Not Work
The 2009 IDSA guidelines provide the strongest evidence against routine catheter irrigation:
- Antimicrobial irrigation should not be used routinely to reduce or eradicate CA-bacteriuria (Grade A-I) or CA-UTI (Grade A-II) 1
- Studies using chlorhexidine bladder instillation twice daily showed no effect on CA-bacteriuria levels or CA-UTI rates compared to normal saline 1
- A randomized double-blind study of 89 patients with neurogenic bladders found no benefit from twice-daily irrigation with neomycin-polymyxin or acetic acid versus sterile saline 1
Normal Saline Irrigation Is Equally Ineffective
Normal saline irrigation should not be used routinely to reduce CA-bacteriuria, CA-UTI, or obstruction in patients with long-term indwelling catheterization (Grade B-II) 1
The evidence is compelling:
A randomized crossover trial of 32 women with long-term catheterization compared 10 weeks of once-daily normal saline irrigation versus no irrigation 1
Results showed identical outcomes for:
- Prevalence and species of CA-bacteriuria
- Incidence of catheter obstructions
- Febrile episodes including CA-UTIs 1
Another study of 1,000 catheter days found irrigation was a costly and time-consuming procedure with no clinical benefit except a minor decrease in catheter plugging 2
Why Irrigation Fails: Understanding the Pathophysiology
The fundamental problem is that bacteria enter the bladder primarily along the catheter-urethral interface, not through the catheter lumen 1. Irrigation addresses the wrong route of infection. Once bacteria establish biofilms on catheter surfaces, they become inherently protected from antimicrobials and cannot be effectively removed by irrigation 1.
The One Exception: Short-Term Surgical Catheterization
Antimicrobial irrigation may be considered in selected patients undergoing surgical procedures with short-term catheterization to reduce CA-bacteriuria (Grade C-I) 1
Evidence supporting this limited exception:
- In 57 orthopedic patients with single or short-term intermittent catheterization, povidone-iodine irrigation reduced CA-bacteriuria from 28% to 4% (p=0.03) 1
- In 89 men undergoing transurethral operations, postoperative chlorhexidine irrigation reduced CA-bacteriuria from 36.7% to 12.8% (p<0.02) 1
However, even in surgical patients, there is insufficient data to recommend irrigation for preventing CA-UTI (as opposed to just bacteriuria) 1
Common Pitfalls to Avoid
Do not irrigate to prevent obstruction in long-term catheterized patients: Despite the theoretical appeal, evidence shows no benefit for preventing catheter blockage from encrustation 1
Do not confuse continuous irrigation for bleeding with infection prevention: When continuous irrigation is used to prevent obstruction from blood clots (e.g., post-TURP), maintain a closed system—this is different from routine infection prevention 3
Do not add antimicrobials to drainage bags: This practice also lacks evidence for reducing CA-bacteriuria or CA-UTI (Grade A-I) 1
What Actually Works Instead
Focus efforts on evidence-based interventions:
- Minimize catheter duration: Remove catheters as soon as clinically appropriate 3
- Maintain a closed drainage system: Never break the closed system 4
- Use proper insertion technique with appropriate catheter size (14-18 French) 5
- Daily meatal cleansing with soap and water (not antiseptics) 6
- Secure the catheter properly to prevent urethral trauma 5
The most recent 2025 ISID guidelines explicitly list catheter irrigation as a "not advisable intervention" for CAUTI prevention, reinforcing that this practice should be abandoned in routine care 3.