Preoperative Chlorhexidine Bathing for Total Knee Replacement
Yes, patients should bathe with chlorhexidine gluconate (CHG) before total knee replacement—specifically using 2% CHG-impregnated cloths the night before and morning of surgery, which significantly reduces surgical site infections compared to standard soap preparation.
Evidence-Based Recommendation
The most compelling evidence comes from orthopedic-specific research demonstrating substantial infection reduction with preoperative CHG protocols:
Sequential CHG bathing reduces periprosthetic joint infection with an adjusted odds ratio of 0.14 (95% CI: 0.03-0.54, p=0.005) when patients bathe the entire lower limb with 2% CHG the night before surgery 1
CHG cloth protocols show 0.6% infection rates versus 2.2% with standard in-hospital preparation only in knee arthroplasty patients—a statistically significant reduction 2
Meta-analysis demonstrates an odds ratio of 0.25 (95% CI: 0.13-0.50) for CHG-cloth use versus non-compliance with preoperative washing in orthopedic surgery 3
Specific Protocol for TKR
Application Method
- Provide patients with two packets of 2% CHG-impregnated cloths 4, 2
- First application: Evening before surgery (entire lower limb)
- Second application: Morning of surgery (entire lower limb)
- This is in addition to standard intraoperative skin preparation with 0.5% CHG in alcohol 5
Why This Concentration and Method
The guideline evidence for central line insertion recommends 0.5% CHG in alcohol for immediate skin antisepsis 5, but this applies to intraoperative preparation. For preoperative bathing, the research consistently supports 2% CHG cloths or 4% CHG soap 4, 1, 2. The cloths offer superior adherence and coverage compared to soap-based preparations.
Supporting Rationale
Microbiological Efficacy
- CHG provides persistent antimicrobial activity that continues after application
- Achieves 100% median reduction in bacterial colonization (IQR: 100-100) from baseline to pre-antisepsis in the operating room 4
- Greater bacterial reduction after first preparation compared to 4% CHG soap (100% vs 99.9%, p=0.0001) 4
Safety Profile
- Side effects are mild and infrequent 4
- FDA labeling confirms safety for external use with standard precautions (avoid eyes, ears, mucous membranes) 6
- High patient and healthcare worker satisfaction despite some ecological concerns 4
Critical Implementation Points
What to Avoid
- Do not use CHG in the genital area as preoperative preparation 6
- Do not apply to open wounds involving more than superficial skin layers 6
- Ensure complete drying before surgical site palpation or incision 7
Patient Instructions
Patients must understand to:
- Apply cloths to the entire surgical limb, not just the knee
- Use both packets as directed (evening and morning)
- Allow skin to air dry completely
- Report any allergic reactions immediately
Comparison to Alternatives
While povidone-iodine remains an alternative, CHG demonstrates superior efficacy:
- Faster onset and longer duration of action than povidone-iodine 7
- Retains efficacy in presence of blood 7
- Epidural catheters were six times less likely to be colonized with CHG versus povidone-iodine preparation 7
Clinical Bottom Line
For hip and knee arthroplasty specifically, the evidence-based protocol is: 2% CHG cloth application the night before and morning of surgery, followed by either 0.5% CHG in alcohol or alternative antiseptic for immediate preoperative skin preparation in the operating room 8. This dual approach—preoperative bathing plus intraoperative antisepsis—provides optimal infection prevention for total knee replacement procedures.
The mortality and morbidity benefits are clear: reducing surgical site infections from 2.2% to 0.6% translates to fewer reoperations, shorter hospital stays, reduced antibiotic exposure, and improved quality of life outcomes 2.