Is chlorhexidine (CHG) better than isopropyl alcohol (IPA) in reducing intravenous (IV) catheter-related infection risk?

From the Guidelines

Chlorhexidine (CHG) is superior to isopropyl alcohol (IPA) in reducing intravenous (IV) catheter-related infection risk, with a recommended concentration of 2% CHG in 70% IPA for skin preparation and catheter exit site cleaning. The most recent and highest quality study, published in 2024 1, demonstrates a significant reduction in blood culture contamination rates with the use of chlorhexidine compared to standard practice, with a relative risk (RR) of 0.44 (95% CI 0.23–0.81, P = 0.009) and an overall contamination reduction of 56.5%.

Key Points

• Chlorhexidine provides both immediate antimicrobial action and persistent activity, continuing to prevent bacterial growth for hours after application, whereas isopropyl alcohol alone only offers immediate disinfection without lasting protection.
• The combination of 2% chlorhexidine gluconate in 70% isopropyl alcohol is recommended for skin preparation before catheter insertion and for cleaning the catheter exit site.
• Proper application involves cleaning the insertion site with the chlorhexidine solution using a back-and-forth scrubbing motion for at least 30 seconds, followed by allowing it to completely air dry before insertion, typically taking 1-2 minutes.
• Chlorhexidine works by disrupting bacterial cell membranes and precipitating cellular contents, providing broader antimicrobial coverage than alcohol alone, particularly against gram-positive bacteria that commonly cause catheter-related bloodstream infections.
• For patients with chlorhexidine allergies, povidone-iodine can be used as an alternative, as indicated in earlier guidelines 1.

Application and Considerations

• The use of maximal barrier precautions during CVC insertion, including a sterile gown and sterile gloves, is also effective in reducing the risk of infection and is recommended 1.
• Ultrasound guidance for catheter placement is recommended as it may indirectly reduce the risk of contamination and infection by allowing for more precise placement and reducing tissue trauma 1.
• The choice of insertion site can also impact the risk of infection, with sites in the supraclavicular fossa, infraclavicular fossa, or midarm potentially carrying a lower risk of contamination compared to sites in the groin, neck, or antecubital fossa 1.

From the Research

Comparison of Chlorhexidine and Isopropyl Alcohol for IV Catheter-Related Infection Risk

• The study 2 compared the effectiveness of chlorhexidine-alcohol and povidone iodine-alcohol in preventing intravascular-catheter-related infections, and found that chlorhexidine-alcohol was associated with a lower incidence of catheter-related infections.
• Another study 3 discussed the use of 2% chlorhexidine gluconate in 70% isopropyl alcohol for skin antisepsis, and recommended its use for preventing healthcare-associated infections.
• The CLEAN 3 study 4 compared the effectiveness of chlorhexidine plus alcohol and povidone iodine plus alcohol in preventing short-term peripheral venous catheter infection and failure, and found that chlorhexidine plus alcohol provided greater protection against infectious complications.
• A protocol study 5 for the CLEAN 3 trial outlined the design and objectives of the study, which aimed to evaluate the effectiveness of chlorhexidine-alcohol and povidone iodine-alcohol in preventing short-term peripheral venous catheter-related infectious complications and catheter failure.
• A study 6 compared the effectiveness of 1% chlorhexidine-alcohol and povidone iodine for preventing central venous catheter-related infection during intensive chemotherapy, and found that chlorhexidine-alcohol significantly alleviated infectious complications.

Key Findings

• Chlorhexidine-alcohol is more effective than povidone iodine-alcohol in preventing intravascular-catheter-related infections 2, 4.
• Chlorhexidine-alcohol provides greater protection against short-term peripheral venous catheter-related infectious complications than povidone iodine-alcohol 4.
• The use of chlorhexidine-alcohol can potentially decrease catheter-related infection without causing adverse skin reactions in patients with haematologic malignancies 6.
• Isopropyl alcohol is often used in combination with chlorhexidine for skin antisepsis, but there is limited direct comparison between chlorhexidine and isopropyl alcohol alone in the context of IV catheter-related infection risk. However, the available evidence suggests that chlorhexidine-alcohol is a more effective combination than povidone iodine-alcohol 2, 4.