Chlorhexidine vs Iodine for UTI Prevention in Women's Surgery

observational-study PMID: 34973179

Chlorhexidine vs Iodine for UTI Prevention in Women's Surgery

Quick Summary: A study compared two common antiseptics—chlorhexidine gluconate and povidone-iodine (iodine)—used to clean the vagina before urogynecologic surgery, like procedures for bladder or pelvic issues. The goal was to see if chlorhexidine works as well as iodine in preventing urinary tract infections (UTIs) after surgery. Researchers found chlorhexidine was not inferior to iodine, meaning it's a safe alternative with similar infection rates and no more irritation.

What The Research Found

This trial tested if chlorhexidine could match iodine's ability to reduce post-surgery UTIs, the most common infection after these operations. Key results showed:
- UTI Rates at 2 Weeks: 10% in the chlorhexidine group vs. 17% in the iodine group. Chlorhexidine met the "not inferior" standard, proving it works at least as well.
- Longer-Term UTIs: At 6 weeks, culture-confirmed UTIs were similar (around 8-13% in both groups), with no big differences.
- Other Infections: Surgical site infections were rare overall (just 2.5% of participants), and rates were the same between groups.
- Side Effects: Vaginal irritation happened in about 7.4% of women in both groups—no extra discomfort with chlorhexidine.
Overall, both antiseptics performed similarly, but chlorhexidine is easier to find and better for people allergic to iodine.

Study Details

Who was studied: 119 women having urogynecologic surgery, like fixes for urinary incontinence or pelvic organ prolapse. They were split evenly: 61 got chlorhexidine and 58 got iodine. Groups were similar in age, health history, and surgery types.
How long: Women were followed for up to 6 weeks after surgery, with check-ins at 2 and 6 weeks to track infections.
What they took: Before surgery, participants received vaginal cleaning with either a 0.125% chlorhexidine gluconate solution or 10% povidone-iodine solution. It was applied by irrigating or swabbing the vagina as part of routine prep—no pills or ongoing treatments.

What This Means For You

If you're facing urogynecologic surgery, this study shows you have options for pre-surgery vaginal cleaning to lower UTI risk. Chlorhexidine is a good pick if you're allergic to iodine (common in shellfish allergies) or just want an accessible alternative—it's widely available and causes similar mild irritation. Talk to your doctor about it; both options keep infection rates low (under 20%), but choosing the right one can make prep easier and safer. This doesn't change overall surgery risks, but it supports using chlorhexidine without worry for better comfort.

Study Limitations

Keep these in mind to understand the full picture:
- Small Group Size: Only 119 women were studied, focused on UTIs—not enough to fully compare rare infections like surgical wounds.
- Specific to One Type of Surgery: Results apply mainly to urogynecologic procedures in women; it might not hold for other surgeries or men.
- Short Follow-Up Time: Checks stopped at 6 weeks, so we don't know about longer-term effects.
- Self-Reported Symptoms: Some UTI diagnoses relied on how women felt, which can vary, and exact cleaning methods weren't super detailed.
- Single Location: Done at one center, so results might differ in other hospitals. More studies are needed for broader proof, especially on wound infections.

Key Findings

The study concluded that chlorhexidine gluconate was noninferior to povidone-iodine for preventing symptomatic urinary tract infections (UTIs) within 2 weeks after urogynecologic surgery (10% vs 17%; relative risk [RR] 0.6; 95% confidence interval [CI] [-∞, 1.3]). Secondary outcomes, including culture-proven UTIs at 2 and 6 weeks and surgical site infections (2.5% overall), showed no significant differences between groups. Vaginal irritation rates were also similar (7.4% in both).

Study Design

This was a randomized controlled noninferiority trial conducted among women undergoing urogynecologic surgery. A total of 119 participants were enrolled (61 in the chlorhexidine group, 58 in the iodine group), with analyses focused on those completing follow-up. The study duration included postoperative assessments at 2 and 6 weeks. Noninferiority was defined as an upper 95% CI limit for RR <1.5.

Dosage & Administration

Participants received either 0.125% chlorhexidine gluconate or 10% povidone-iodine vaginal antisepsis before surgery. The solutions were applied via vaginal irrigation or swabbing as part of standard preoperative preparation. Specific volumes, application times, or re-administration protocols were not detailed in the summary.

Results & Efficacy

Primary Outcome: Symptomatic UTI at 2 weeks: 10% (chlorhexidine) vs 17% (iodine) (RR 0.6; 95% CI [-∞, 1.3]). Noninferiority was confirmed as the upper CI limit (1.3) was below the predefined margin (1.5).
Secondary Outcomes:
Culture-proven UTI at 2 weeks: 8% vs 12% (RR 0.7; 95% CI [-∞, 1.5]).
Symptomatic UTI at 6 weeks: 13% vs 17% (RR 0.8; 95% CI [-∞, 1.5]).
Surgical site infections: 2.5% overall (3/119), with no between-group differences.
Vaginal irritation: 7.4% in both groups (4/54).
Statistical Significance: The primary outcome’s CI crossed 1.0, indicating no statistically significant superiority, but noninferiority criteria were met.

Limitations

Sample Size: The study was powered only to assess noninferiority for UTIs, not surgical site infections (rare events limited analysis).
Population Specificity: Results apply only to women undergoing urogynecologic surgery; generalizability to other populations or procedures is uncertain.
Short Follow-Up: Outcomes were measured up to 6 weeks, leaving long-term safety and efficacy unexamined.
Methodological Gaps: Lack of detailed administration protocols (e.g., volume, duration) and reliance on self-reported UTI symptoms.
Single-Center Data: Potential biases from a single study setting.

Clinical Relevance

For patients undergoing urogynecologic surgery, chlorhexidine offers a safe alternative to iodine for vaginal antisepsis, particularly for those with iodine allergies. The comparable UTI rates (10% vs 17%) and similar irritation profiles support its use, though clinicians should note the noninferiority design does not prove equivalence or superiority. The low surgical site infection rate (2.5%) suggests both agents are effective in preventing wound infections, but larger studies are needed to confirm this. These findings align with guidelines recommending chlorhexidine for iodine-allergic patients, though further research on broader populations and longer-term outcomes is warranted.

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