Iodine vs Chlorhexidine: Preventing Surgical Infections

randomized-controlled-trial PMID: 27879993

Iodine vs Chlorhexidine: Preventing Surgical Infections

Quick Summary: This study compared two common skin cleaners—povidone-iodine (which contains iodine) and chlorhexidine gluconate—for stopping infections after abdominal surgery. Researchers found no big difference in infection rates between the two, both keeping risks low at around 6%. This means either option works well for most patients, but certain surgeries carry higher risks.

What The Research Found

In this trial, doctors tested if one skin antiseptic worked better than the other to prevent surgical-site infections (SSIs), which are infections that happen where the surgeon cuts into the skin. The key takeaway? Povidone-iodine and chlorhexidine gluconate performed about the same.

Overall SSI rate was 5.8% across all patients—no real edge for either cleaner (5.6% for chlorhexidine and 6.0% for povidone-iodine).
The most common germ causing infections was Enterococcus faecalis, a type of bacteria often found in the gut.
Some surgeries were riskier: Biliary-pancreatic procedures (like those on the bile ducts or pancreas) had a much higher infection rate of 20.5%, compared to just 1.0% for upper gastrointestinal surgeries and 1.5% for liver removals.
Older age (60 or above) and the type of cut made during surgery raised infection chances, but the choice of cleaner didn't change that.

These results come from a solid statistical test showing no meaningful difference (P = 0.853), meaning the small gap in rates is likely just chance.

Study Details

Who was studied: 534 adults having open abdominal surgeries that involve clean but possibly contaminated areas, like upper gut, liver, or pancreas operations. These were real patients from 2011 to 2014, randomly split into two equal groups.
How long: Patients were followed for 30 days after surgery to check for infections—enough time to catch most early problems.
What they took: No pills or internal treatments; this was about skin prep right before surgery. One group got chlorhexidine gluconate (a soap-like cleaner) applied to the skin, the other got povidone-iodine (a brownish liquid antiseptic with iodine). Both were used as standard hospital protocols by the surgical team.

What This Means For You

If you're facing abdominal surgery, this study shows you can trust either povidone-iodine or chlorhexidine for skin cleaning—neither is clearly better at fighting infections. Talk to your doctor about allergies (some people react to iodine) or costs, as that might sway the choice.

For most surgeries, your infection risk stays low (under 6%) with proper cleaning.
If your procedure involves the pancreas or bile ducts, ask about extra steps like stronger antibiotics, since infections hit 1 in 5 patients there.
Over 60? Or worried about the incision type? Push for close monitoring after surgery to catch issues early.
Everyday tip: While this is for surgery, iodine-based cleaners like povidone-iodine are also used for minor cuts at home—knowing they're effective can ease your mind for basic wound care.

Study Limitations

No study is perfect, and this one has a few caveats to keep in mind—explained simply so you know what to watch for.

Sample size of 534 might miss tiny differences between the cleaners, especially in smaller surgery groups like the 127 pancreatic cases.
Only tracked infections for 30 days, so rare late-bloomers could be overlooked.
Focused on open abdominal surgeries in one hospital setting—results might not fit other operations, like laps or different body areas.
Didn't detail exact strengths or how the cleaners were applied, so it's hard to copy exactly in other places.
No mention of blinding (hiding which cleaner was used), which could subtly bias results.

Overall, this adds to evidence that both antiseptics are reliable, but more research could refine choices for high-risk cases. (Registered as NCT01495117 on ClinicalTrials.gov for full details.)

Key Findings

The study found no statistically significant difference in surgical-site infection (SSI) rates between preoperative skin antisepsis using chlorhexidine gluconate (5.6%) and povidone-iodine (6.0%) in patients undergoing clean-contaminated abdominal surgery (P = 0.853). Enterococcus faecalis was the most common causative organism. Subgroup analysis revealed significantly higher SSI rates in biliary-pancreatic surgery (20.5%) compared to upper gastrointestinal (1.0%) and hepatic resection (1.5%). Age ≥60 years and incision type were identified as independent risk factors for SSI.

Study Design

This was a randomized controlled trial (RCT) conducted between 2011–2014, enrolling 534 patients undergoing open clean-contaminated abdominal surgery (upper gastrointestinal, hepatobiliary, or pancreatic). Participants were randomly assigned to either chlorhexidine gluconate or povidone-iodine antisepsis. The primary endpoint was SSI occurrence within 30 days post-surgery. Secondary endpoints included microbial etiology and SSI risk factors.

Dosage & Administration

The study compared two skin antisepsis protocols: chlorhexidine gluconate and povidone-iodine. Specific concentrations or application methods (e.g., alcohol-based vs aqueous solutions) were not detailed in the provided summary. Both agents were applied per standard surgical protocols by the operating team before incision.

Results & Efficacy

Overall SSI rate: 5.8% (31/534 patients).
Chlorhexidine gluconate: 5.6% SSI (15/267).
Povidone-iodine: 6.0% SSI (16/267).
Effect size: Absolute risk difference of 0.4% (P = 0.853), indicating no significant efficacy gap.
Subgroup analysis: Biliary-pancreatic surgery had a 20.5% SSI rate versus 1.0–1.5% for other procedures (P < 0.001).
Risk factors: Age ≥60 years (P = 0.020) and incision type (P = 0.003) were significantly associated with SSI.

Limitations

Sample size: 534 participants may have limited power to detect small differences in SSI rates.
Subgroup analysis: Biliary-pancreatic surgery subgroup had only 127 patients, potentially underpowered for robust conclusions.
Follow-up duration: 30-day postoperative monitoring might miss delayed infections.
Blinding: Not explicitly mentioned, risking performance bias.
Generalizability: Focused on open abdominal surgeries; results may not apply to other procedures or populations.
Antiseptic protocols: Lack of detail on concentrations or application techniques limits reproducibility.

Clinical Relevance

For clean-contaminated abdominal surgeries, both chlorhexidine gluconate and povidone-iodine demonstrate comparable efficacy in preventing SSI. Clinicians may prioritize cost, availability, or patient-specific factors (e.g., allergies) when selecting an antiseptic. The high SSI rate in biliary-pancreatic procedures highlights a need for enhanced infection-control strategies in this subgroup. Older patients (≥60 years) and those with specific incision types may require closer postoperative monitoring. These findings support current guidelines advocating for individualized antiseptic selection in abdominal surgery settings.

Word count: 398