Chlorhexidine Outperforms Ethanol in Preventing AVF Infections During Buttonhole Cannulation: Trial Finds
Sweden: In a significant advancement for dialysis care, researchers from Linkoping University, Sweden, have found that chlorhexidine is more effective than ethanol in reducing bacterial presence during buttonhole cannulation in patients undergoing haemodialysis via arteriovenous fistula (AVF). The study, led by Karin Staaf and colleagues from the Department of Health, Medicine and Caring Sciences, was published in BMC Nephrology.
AVF infections are commonly caused by the patient's own skin bacteria, and the buttonhole technique—where needles are inserted at the same site each time—increases this risk due to repeated skin penetration. While proper disinfection is essential to mitigate this risk, there has been limited evidence guiding the optimal disinfectant choice. This study aimed to determine whether chlorhexidine offers superior protection compared to ethanol in this setting.
The randomized, crossover trial involved patients undergoing haemodialysis, comparing 5 mg/mL chlorhexidine in 70% ethanol against 70% ethanol alone, both with and without prior arm washing. Bacterial samples were collected at multiple time points: before disinfection, immediately after, and two and four hours post-disinfection, across four dialysis sessions. Additionally, scabs from the buttonhole tract were analyzed to identify the types of bacteria present and whether they matched the patient's normal skin flora.
The key findings were as follows:
- Chlorhexidine significantly reduced bacterial presence immediately after disinfection compared to ethanol (1.4% vs. 10.8% positive cultures).
- Two hours after application, chlorhexidine continued to suppress bacterial regrowth more effectively than ethanol, even when ethanol was used with arm washing.
- Four hours post-disinfection, chlorhexidine still showed superior control over bacterial regrowth compared to ethanol.
- Scab cultures closely matched the patients’ normal skin flora, highlighting the critical need to control this source of contamination.
Though the study demonstrated promising results, the researchers acknowledged several limitations. The use of colony-forming units (CFU/mL) as a surrogate marker rather than actual infection rates was necessary due to the ethical and logistical challenges of a large-scale infection trial. The single-centre nature of the study, its small sample size, and the fact that it was only single-blinded may also influence generalizability. Furthermore, patient behavior during dialysis—such as using the disinfected arm for support or covering it—may have introduced variability in outcomes.
Despite these constraints, the research provides valuable insight into infection control practices in dialysis units. The use of chlorhexidine not only delays bacterial regrowth but also potentially reduces the overall risk of AVF-related infections. As the authors emphasized, preventing infections caused by patients’ own skin flora is a critical responsibility for dialysis providers, and adopting chlorhexidine-based disinfection protocols could be a step forward in achieving this goal.
The authors concluded, "The study adds to the growing body of evidence suggesting that chlorhexidine may be a more reliable option than ethanol for disinfection in buttonhole cannulation, thereby enhancing patient safety in haemodialysis settings."
Reference:
Staaf, K., Scheer, V., Serrander, L. et al. Disinfection with chlorhexidine is more effective than ethanol for buttonhole cannulation in arteriovenous fistula: a randomized cross-over trial. BMC Nephrol 26, 402 (2025). https://doi.org/10.1186/s12882-025-04230-z
