A comparative clinical study focusing on the antimicrobial efficacies of chlorhexidine gluconate alcohol for patient skin preparations

Effect of aqueous olanexidine versus alcohol-based chlorhexidine for surgical skin antisepsis on incidence of surgical site infections in gastrointestinal surgery: multicentre randomised controlled clinical trial (OEDO trial) protocol

INTRODUCTION

Surgical site infections (SSIs) are among the most common nosocomial infections in surgery patients. Two types of preparations, povidone-iodine and chlorhexidine-alcohol, are commonly used in preoperative antiseptic procedures worldwide. However, there are inconsistencies among international guideline recommendations concerning skin antiseptics. This trial aimed to evaluate the superiority of olanexidine, which reduced SSI rates more than povidone-iodine in our previous randomised trial, over chlorhexidine-alcohol in clean-contaminated surgery.

METHODS AND ANALYSIS

This multicentre randomised controlled clinical trial will compare two antiseptics (1.5% olanexidine and 1.0% chlorhexidine-alcohol) to prevent SSI in clean-contaminated gastrointestinal surgeries with surgical wounds. On providing consent, patients aged <18 years will be included. The primary outcome will be the postoperative 30-day overall SSI rate, while the secondary outcomes will be the postoperative 30-day superficial incisional SSI rate, deep incisional SSI rate, organ/space SSI rate, positive bacterial wound culture rate, cultured bacterial strains, rates of intervention-related toxicity and allergic events (eg, erythema, pruritus, dermatitis and other symptoms of allergy around the region disinfected by the antiseptic during surgery), rate of reoperations due to SSI, medical economic effect indicators (based on health insurance claims) and hospital duration. The Mantel-Haenszel method will be used to estimate the adjusted risk ratio and its 95% CI for the primary analysis, which will compare the treatment effects.

ETHICS AND DISSEMINATION

The protocol was approved by the Institutional Review Board of Keio University School of Medicine and subsequently by the board of each participating site. Participant recruitment began in January 2023. The final results will be published in medical journals after international peer review.

TRIAL REGISTRATION NUMBER

UMIN000049712.

Quantifying exposure to chlorhexidine from decontamination of peripheral intravenous injection ports

BACKGROUND

Annually, almost 2 billion peripheral intravenous cannulas (PIVCs) are placed worldwide. In response to concerns of infectious complications, chlorhexidine is increasingly utilised for maintenance decontamination of PIVC injection ports. Concomitantly, the allergenic potential of chlorhexidine exposures has been highlighted by several case reports, implicating it as a trigger when used for this seemingly innocuous process. Given how widespread this application is, elucidating potential chlorhexidine exposure is needed to gauge its risks and benefits.

OBJECTIVE

To examine and quantify if chlorhexidine is entrained when used for PIVC injection port cleaning.

METHODS

Twenty benchtop PIVC set-ups were cleaned with 2% chlorhexidine and 70% alcohol wipes, following three different pragmatic protocols. Each set-up was injected with 10 ml ultrapure water, and samples tested by liquid chromatography-electrospray tandem mass spectrometry for entrained chlorhexidine.

RESULTS

Chlorhexidine was detected in every sample. Mean concentrations and standard deviations from each protocol were 41.47 ppb (4.08), 54.76 ppb (17.46), and 65.84 ppb (7.01). One-way ANOVA indicated a statistical difference between at least two groups (df = 2, F = 24.11, p < .00001), with Tukey's testing verifying significantly different mean concentrations between all groups (p < .01).

CONCLUSIONS

Using 2% chlorhexidine and 70% alcohol swabs to decontaminate PIVC injection ports resulted in consistent entrainment of chlorhexidine, with varying amounts correlated to how it was applied. These results validate case reports attributing anaphylactic/allergic reactions to suspected intravenous chlorhexidine entrainment and should factor into future risk-benefit assessments for its use in PIVC maintenance antisepsis policies and protocols.

Efficacy of surgical skin preparation with chlorhexidine in alcohol according to the concentration required to prevent surgical site infection: meta-analysis

Background

A combination of chlorhexidine gluconate and alcohol (CHG–alcohol) is recommended for surgical skin preparation to prevent surgical site infection (SSI). Although more than 1 per cent CHG–alcohol is recommended to prevent catheter-related bloodstream infections, there is no consensus regarding the concentration of the CHG compound for the prevention of SSI.

Methods

A systematic review and meta-analysis was performed. Four electronic databases were searched on 5 November 2020. SSI rates were compared between CHG–alcohol and povidone-iodine (PVP-I) according to the concentration of CHG (0.5 per cent, 2.0 per cent, 2.5 per cent, and 4.0 per cent).

Results

In total, 106 of 2716 screened articles were retrieved for full-text review. The risk ratios (RRs) of SSI for 0.5 per cent (6 studies) and 2.0 per cent (4 studies) CHG–alcohol were significantly lower than those for PVP-I (RR = 0.71, 95 per cent confidence interval (c.i.) 0.52 to 0.97; RR = 0.52, 95 per cent c.i 0.31 to 0.86 respectively); however, no significant difference was observed in the compounds with a CHG concentration of more than 2.0 per cent.

Conclusions

This meta-analysis is the first study that clarifies the usefulness of an alcohol-based CHG solution with a 0.5 per cent or higher CHG concentration for surgical skin preparation to prevent SSI.

Efficacy comparison of chlorhexidine and iodine preparation in reduction of surgical site infection: A systemic review and meta-analysis

BACKGROUND

Chlorhexidine and povidone-iodine are the most common disinfectants used in preoperative skin preparation. However, there is no consistent conclusion regarding the prevention of surgical site infection (SSI) and bacterial culture data.

OBJECTIVE

To assess the efficacy of chlorhexidine and povidone-iodine in the prevention of postoperative SSI and relevant bacterial data.

DESIGN

Systematic Review and Meta-Analysis SETTINGS: N/A PARTICIPANTS: N/A METHOD: Literature relevant to "skin antisepsis" and "surgical site infections" was retrieved from PUBMED, Web of Science, EMBASE, CINHAL and CNKI. The incidence of SSI was the primary outcome, while the secondary outcome was bacterial data from the infected incision. All data were analyzed with Revman 5.3 and Stata Statistical Software.

RESULTS

A total of 36 studies were identified in this study, which included 16,872 participants. This study revealed that chlorhexidine is superior to povidone-iodine in the prevention of postoperative SSI (risk ratio [RR], 0.73; 95% confidence interval [CI], 0.61-0.87; p = 0.019, I² = 39%). Further meta-regression analysis revealed that the effect of chlorhexidine was directly associated with the type of incision, but failed to differentiate between the subgroups divided according to the type of incision. With respect to bacteria colonization, the most common bacteria for chlorhexidine arm were propionibacterium's, while the most common bacteria for the iodine arm were staphylococci species.

CONCLUSION

In comparison to povidone-iodine, chlorhexidine showed better results in preventing postoperative SSI.

Chlorhexidine Allergy: Current Challenges and Future Prospects

Chlorhexidine is a synthetic bisbiguanide antiseptic and was introduced in healthcare use in 1954. Allergy to chlorhexidine has been increasingly reported particularly in the perioperative and medical procedural settings. The hypersensitivity reactions range from mild cutaneous reactions to anaphylaxis or death. There are many products and medical devices containing chlorhexidine that sometimes lack standardized labeling. With the various routes of chlorhexidine exposure, accidental or recurrent reactions in chlorhexidine-allergic patients have been reported. Therefore, we aim to review the most recent evidence in clinical manifestations, diagnostic methods, management, and preventive measures with a focus on the unique features of chlorhexidine allergy.

Anaphylaxis after disinfection with 2% chlorhexidine wand applicator

A 54-year-old man with end-stage renal failure attended for dialysis. Within seconds of applying 2% w/v chlorhexidine (ChloraPrep 3 mL Wand Applicator) to the skin surrounding the insertion point of his dialysis catheter (Tesio catheter), he developed pruritus, urticaria, shortness of breath, hypotension and reduced responsiveness. Treatment for anaphylaxis was initiated with rapid improvement of his symptoms, and he made a full recovery. Allergy to chlorhexidine was confirmed with skin testing, and the patient was warned against all future exposure to chlorhexidine. Subsequent dialysis without chlorhexidine was uneventful.

Induced sporicidal activity of chlorhexidine against Clostridium difficile spores under altered physical and chemical conditions

Background

Chlorhexidine is a broad-spectrum antimicrobial commonly used to disinfect the skin of patients to reduce the risk of healthcare-associated infections. Because chlorhexidine is not sporicidal, it is not anticipated that it would have an impact on skin contamination with Clostridium difficile, the most important cause of healthcare-associated diarrhea. However, although chlorhexidine is not sporicidal as it is used in healthcare settings, it has been reported to kill spores of Bacillus species under altered physical and chemical conditions that disrupt the spore’s protective barriers (e.g., heat, ultrasonication, alcohol, or elevated pH). Here, we tested the hypothesis that similarly altered physical and chemical conditions result in enhanced sporicidal activity of chlorhexidine against C. difficile spores.

Principal Findings

C. difficile spores became susceptible to heat killing at 80°C within 15 minutes in the presence of chlorhexidine, as opposed to spores suspended in water which remained viable. The extent to which the spores were reduced was directly proportional to the concentration of chlorhexidine in solution, with no viable spores recovered after 15 minutes of incubation in 0.04%–0.0004% w/v chlorhexidine solutions at 80°C. Reduction of spores exposed to 4% w/v chlorhexidine solutions at moderate temperatures (37°C and 55°C) was enhanced by the presence of 70% ethanol. However, complete elimination of spores was not achieved until 3 hours of incubation at 55°C. Elevating the pH to ≥9.5 significantly enhanced the killing of spores in either aqueous or alcoholic chlorhexidine solutions.

Conclusions

Physical and chemical conditions that alter the protective barriers of C. difficile spores convey sporicidal activity to chlorhexidine. Further studies are necessary to identify additional agents that may allow chlorhexidine to reach its target within the spore.

Use of a policy-driven education program to reduce central line-associated bloodstream infection rates

Central line-associated bloodstream infections (CLABSIs) account for a significant portion of hospital-acquired infections. Current research supports the use of chlorhexidine for site cleansing and staff education programs on infection-control practices to reduce CLABSI rates. This project evaluates the efficacy of implementing site cleaning policies and protocols and formal staff education in reducing CLABSI rates in a critical access hospital. Efficacy was measured by infection rates per 1000 catheter days through a retrospective chart review before and after implementation of a policy and protocol bundle and staff education.