Skin antisepsis is an important part of clinical practice. As the body's largest organ, the skin performs a vital function in preventing pathogenic organisms from entering the body, but it also harbours bacteria of varying loads that can be transmitted to the bloodstream during procedures that compromise the skin's barrier function. Common clinical procedures such as the insertion of central venous catheters (CVCs) and other vascular access devices (VADs) can result in bacterial migration to the patient's bloodstream from either the patient's skin or the healthcare environment (Pandit et al, 2021), including the health professional, the physical environment and the air (Clare and Rowley, 2021). The epic3 guidelines note that catheter-related bloodstream infections (CRBSI) are ‘among the most dangerous complications associated with health care’ (Loveday et al, 2014). Effective skin antisepsis that helps minimise the risk of CRBSI is therefore critical to achieving good outcomes from surgery involving vascular access procedures, and creating the best conditions for recovery and healthy living after discharge.
Skin antisepsis is one of a number of important practices that together comprise aseptic technique. Appropriate personal protective equipment (PPE) is required, along with the appropriate use of medical products and devices to disinfect the skin. Related atraumatic procedures include removing hair before line insertion, and the use of clippers to do so.
Aseptic technique is a core competency of vascular access and other clinical procedures (Denton and Hallam, 2020). For more than two decades, aseptic technique has been a priority in NHS efforts to reduce healthcare-associated infections (HCAI), such as the NHS Saving Lives campaign (Clarke et al, 2019; Medical Audits Ltd, 2022). NHS Saving Lives promotes the use of care bundles for aseptic technique. Care bundles are:
‘Sets of evidence-based practices that, when implemented collectively, improve the reliability of their delivery and improve patient outcomes. [They] contribute to infection prevention, reduce unnecessary antibiotic prescribing, and may limit the development of antibiotic resistance in health care facilities.’
There is robust evidence that a care-bundle approach can reduce infection associated with intravenous lines (Bion et al, 2013).
Aseptic Non Touch Technique (ANTT®) is the standard model for aseptic technique in the NHS (Rowley and Clare, 2020) and is used variously in over 30 countries internationally. It comprises a comprehensive clinical practice framework for educating and practising effective aseptic technique in hospitals and community settings (Rowley et al, 2010; The Association for Safe Aseptic Practice (The-ASAP), 2015). Despite anecdotal claims that ANTT is a ‘checklist’ approach, it has been endorsed or referenced by stakeholder organisations, including the epic3 guidelines for preventing HCAI in hospitals (Loveday et al, 2014), the National Institute for Health and Care Excellence (NICE) (2012), and the Infusion Nurses Society guidelines for infusion therapy (Gorski et al, 2021).
Until the onset of COVID-19, there had been an overall reduction in HCAI mortality in England between 2007-2008 and 2020-2021 (UK Health Security Agency, 2021). The challenge of COVID-19 and evidence of continued variation in aseptic technique in the UK highlights the need for continued efforts to improve education and practice (Clare and Rowley, 2018). Historically, the standards for best practice have been variable, not always met, and have involved inadequate risk assessment, together with confusion over procedures and terminology (Clare and Rowley, 2018). Gerver et al (2020) found large variations in the incidence of bloodstream infections in NHS trusts in England. The standardisation of aseptic practice using an evidence-based intervention has been shown to substantially reduce CRBSI (Pronovost et al, 2006).
Research continues to improve understanding of the various factors that need to be addressed to reduce the risk of HCAI following skin antisepsis for vascular access procedures. The risk of microbial migration from the skin and infection transmission is increased by additional insertions of VADs, the use of the jugular vein, the patient's underlying condition and comorbidities, and compromised immunity (Baier et al, 2020; Pandit et al, 2021). There is evidence that the application of 2% chlorhexidine gluconate (CHG) in 70% isopropyl alcohol (IPA) to the skin in a way that minimises the risk of skin contact by the gloved hand provides rapid and effective skin antisepsis (McDonald et al, 2010; Roberts et al, 2022). More research to understand the routes of infection transmission from the skin to the bloodstream after skin antisepsis for the insertion of VADs and differences in the effectiveness of disinfectant solutions and applicators will enhance the evidence base for improvements in practice.
The Skin Antisepsis Roundtable's objectives were to reach a consensus on:
- How to improve skin antisepsis in hospital
- How to reduce variability in the practice of skin antisepsis
- How to improve training and compliance in skin antisepsis
- The role of different devices in improving skin antisepsis
- Best practice in disinfectant application technique
- Identifying methods for improvement of skin antisepsis integrated with the ANTT approach
- Identifying challenges to the implementation of the panel's recommendations.
The recommendations set out in this document apply to the care of adults in the UK. Skin antisepsis in children was not part of the inclusion criteria for the roundtable discussion. All countries of the UK except Northern Ireland were represented by the panel.
Current issues with skin antisepsis
CRBSI is common and can be fatal. There were an estimated 653 000 HCAIs in adults in NHS hospitals in England in 2016-2017, of which an estimated 7.3% were bloodstream infections (Guest et al, 2020). Pronovost et al (2006) estimated that CRBSI causes the death of up to 28 000 ICU patients each year in the USA. HCAIs have severe and widespread consequences. Guest et al (2020) estimated that across all NHS hospitals in England in 2016/2017, HCAIs cost £2.7 billion, and accounted for 28 500 patient deaths, as well as 79 700 days of absenteeism for front-line health professionals. This is because when patients get a HCAI, staff are also vulnerable to infection. Much of the death and morbidity caused by such infections could probably be prevented with evidence-based interventions. In a US study, Umscheid et al (2011) estimated that 65%–70% of CRBSIs were preventable.
Interventions for the introduction of evidence-based care bundles for catheter insertion and maintenance have shown substantial reductions in the transmission of infection following standardised training of health professionals in aseptic technique using the ANTT Clinical Practice Framework and compliance monitoring and practice audit (Pronovost et al, 2006; Conley et al, 2017; Khurana et al, 2018; Clarke et al, 2019; Shettigar et al, 2021). These results show that improving education can have a substantial positive impact on patient outcomes if accompanied by audit. Shettigar et al (2021) also found that including monitoring and compliance measures in new care bundles ‘improved compliance to components of ANTT over a long duration’, indicating the possibility of achieving a culture change in practice in the long term.
The focus of this consensus document is on how to improve aseptic technique during vascular access procedures, and associated care and maintenance of vascular access devices (VADs).
Skin antisepsis requires many separate pieces of equipment, from PPE to wipes and solutions. Many disinfectant solutions are available for skin antisepsis, although trials to date indicate that a 2% chlorhexidine solution with alcohol is more effective, probably because of a synergistic relationship between the ingredients (Frasca et al, 2010). However, chlorhexidine is reported to cause contact dermatitis in some cases (Becton Dickinson UK Limited, 2019), especially when not allowed to fully dry before applying film dressings and adhesive devices.
One disinfectant solution containing 2% CHG in 70% IPA and an applicator has been licensed by the Medicines and Healthcare products Regulatory Agency (MHRA) for disinfection of the skin before invasive medical procedures such as the insertion of vascular catheters. There is evidence that the combination of 2% CHG in 70% IPA solution is more effective at reducing skin colonisation than other disinfectants alone, CHG alone, or CHG in a lower concentration solution (Adams et al, 2005; Hibbard et al, 2005). One randomised controlled trial found that 2% CHG in 70% isopropyl alcohol was more effective than isopropyl alcohol alone at reducing the number of peripheral venous catheters that were colonised or contaminated (Small et al, 2008). Reichel et al (2009) found that alcohol supplemented with 0.5% or more CHG was significantly more effective than alcohol alone in the suppression of recolonisation at clinically relevant skin sites (P<0.05). Povidone iodine has been found to be less effective than chlorhexidine solution at reducing catheter colonisation and CRBSI (Chaiyakunapruk et al, 2002; Frasca et al, 2010; Lai et al, 2016). Guenezan et al (2021) found that CHG plus alcohol provides better protection against local infections and catheter colonisation than povidone iodine plus alcohol. A meta-analysis found that it is the combination of CHG with alcohol that is important for increasing effectiveness (Maiwald and Chan, 2012). A Cochrane review has found that, in the case of preventing infections in the use of central venous lines, more research is needed ‘to assess the effectiveness and safety of different skin antisepsis regimens in CVC care’ (Lai et al, 2016). It is interesting to note that Herruzo et al (2020) found that the MHRA-licensed 2% CHG in 70% IPA with applicator was more effective than the same solution made in a laboratory, suggesting that the manufacturing process may enhance its effectiveness.
The effectiveness of medical products also depends on the health professional's skill and proficiency in using them. If wipes and applicators are not used appropriately, according to the recommendations of manufacturers and ANTT, the risk of infection transmission is increased.
Available disinfectant solutions vary in quality and performance after removal from the packaging. They also vary in labelling and instructions for use, which can be confusing for the health professional when selecting the best one to use for a procedure. Many devices are available in multiple formulations, with little clarity about the intended use of each. Some formulations are more suitable for particular purposes such as cannulation, skin antisepsis or CVC insertion, but which one to use may not always be clear to the health professional. Wipes used to disinfect medical devices come in different sizes and different solution concentrations, and there is not always evidence available to support the use of a particular wipe for a given procedure.
Probably the most important causative factor of CRBSI is the migration of cutaneous microflora (Safdar and Maki, 2004). A number of factors increase the risk of infection during the insertion and maintenance of VADs. These include the location of the procedure, the patient's health and comorbidities, the condition of the skin, and the skill and knowledge of the health professional carrying out the procedure. Pandit et al (2021) found that being immunocompromised, central line insertion into the jugular vein and longer time of catheterisation were risk factors for infection. In a study of patients with haematological malignancies, benign diseases of hematopoiesis and solid tumours, independent risk factors included severe leukocytopenia, neutropenia and previous CVC insertion (Baier et al, 2020). The subclavian route is protective (Baier et al 2020; Pandit et al, 2021).
Recommendations
To promote compliance with best practice in aseptic technique, prevent HCAI and achieve good outcomes for patients, there is a need to ensure that health professionals select an appropriately designed, evidence-based product and delivery system for conducting skin antisepsis. The expert panel reviewed the use of a product licensed by the MHRA, which contains 2% CHG in 70% IPA, combined with an applicator that allows for the effective and efficient application of ANTT.
Many devices for skin antisepsis and wipes for disinfecting equipment are available for use in the UK. Their use is often based on local protocols and practice supported by minimal evidence. Labelling and packaging varies between manufacturers, and this may confuse health professionals about how to remove products from their packaging and use them in a manner that conforms to ANTT practice principles to minimise the risk of infection transmission.
In these circumstances, the choice of the available licensed medical product must be considered as best practice. Its licence is based on research evidence that has been published, reviewed and validated. Its use therefore gives health professionals confidence and also mechanisms of control for review and support if mistakes or failures occur. The evidence for the use of devices off-licence, however common their use, is less clear and likely carries greater risks for the patient and the health professional.
In addition, the applicator available as part of the MHRA-licensed product helps the health professional avoid contact and cross-contamination between the patient's skin and other Key-Parts or Key-Sites (The-ASAP, 2015) involved in a procedure, such as the health professional's hands and gloves and the solution-saturated sponge pad of the wipe (Table 1). The applicator of the MHRA-licensed product is designed for this purpose. The applicator's design includes ‘wings’ which allow the health professional easily to dispense the solution on to the pad for skin antisepsis, with minimal risk of contact of the gloved hand with Key-Parts. The MHRA-licensed product therefore meets requirements for evidence, ease of use, and non-touch application to the skin.
Table 1. ANTT terms and definitions
| General Aseptic Field eg a disinfected plastic tray or pulp tray | Promotes asepsis during procedures by providing basic protection from the procedure environment. Used when the procedure Key-Parts are easily and primarily protected by Micro Critical Aseptic Fields. Requires ‘General Management’ |
| Critical Aseptic Field eg a sterilised drape | Ensures asepsis during procedures by providing essential and primary protection from the procedure environment. Requires ‘Critical Management’ |
| Micro Critical Aseptic Field eg a syringe cap or needle cover | A small Critical Aseptic Field used to protect a Key-Part, eg a sterile cap, the inside of recently opened sterile packaging |
| Critical Aseptic Field Management | Provides primary protection. Only sterilised or aseptic equipment may come into contact with a Critical Aseptic Field. Sterilised gloves are required to maintain aseptic continuity. Essentially, all equipment are handled as Key-Parts, eg a sterile drape |
| Key-Part | The parts of procedure equipment that come into contact with Key-Sites, any liquid infusion, or with any other active Key-Parts connected to the patient via a medical device. If contaminated during a procedure, Key-Parts provide a route for the transmission of pathogens on to or into the patient, and present a significant infection risk |
| Key-Site | Open wounds and insertion and puncture sites for invasive medical devices |
Source: The-ASAP, 2015: 6.
The MHRA-licensed product cannot be used in all circumstances; for example, in the presence of chlorhexidine allergy. The expert panel clarified that, regardless of the medical device chosen, the manner of its use is critical to the prevention of infection. Health professionals need to attend closely to the indications for a particular wipe or product, and the instructions for its use. Important factors that reduce a device's efficacy include whether wipes are folded or unfolded, the length of time they are left opened before they are applied to the skin, and whether hands and fingers touch Key-Parts that must remain aseptic. The expert panel agreed that a wipe intended for disinfecting equipment such as hubs should not be used for skin antisepsis.
The expert panel recommended the following volumes of disinfectant solution of 2% CHG in 70% IPA to be applied depending on the purpose of skin antisepsis:
- A minimum of 1 ml for peripheral venous cannulation (PVC) to cover an area of skin 8x10 cm
- A minimum of 3 ml for central venous lines and midlines to cover an area of skin 15x15 cm.
These recommendations are in accordance with the summary of product characteristics for the MHRA-licensed 2% CHG in 70% IPA applicator (Becton Dickinson UK Limited (BD), 2019).
The surface area to be covered by the disinfectant solution should vary depending on the vascular access procedure intended (eg midline, peripherally inserted central catheter (PICC), or peripheral venous cannula (PVC)) and the size of dressing to be used. The summary of product characteristics for the MHRA-licensed product recommends 8x10 cm for 1 ml for PVC, 10x13 cm for 1.5 ml for PVC and 15x15 cm for 3 ml for midline and CVC (BD, 2019). It is important to ensure that the area of skin treated as aseptic during aseptic technique is larger than the area of the dressing (Barton, 2021).
The expert panel recommended that the MHRA-licensed 2% CHG in 70% IPA solution should be applied to the skin using bidirectional, back-and-forth strokes of the applicator to achieve sufficient friction to remove debris and bacteria in the upper layers of the skin, and penetrate to the stratum corneum to kill transient skin flora present there (Stonecypher, 2009). Hendley and Ashe (1991) found that the effectiveness of agents used for skin asepsis was related to their ability to penetrate into the stratum corneum. The consensus of the expert panel was to clean the skin with the applicator for 30 seconds (McDonald et al, 2001).
The expert panel recommended that, following application, the MHRA-licensed 2% CHG in 70% IPA solution should be left to air dry for 30 seconds. McDonald et al (2001) found that recommended drying times in a number of UK and US settings varied between 15 or 30 seconds and no specified time, depending on the disinfectant solution used. The authors highlighted the need to apply disinfectant ‘for an adequate time period’ and found that the optimal arm disinfection method should be left to dry for 30 seconds (McDonald et al, 2001; McDonald et al, 2010). The solution must be left to dry in the air; no blow-drying or towels should be used to dry the wiped skin. The skin should not be touched at all or palpated while the alcohol is allowed to dry, or after it has dried. There are several reasons why a 30-second dry-time is likely to be more effective. Alcohol kills bacteria as it dries, so sufficient time is needed for this to occur. Allowing sufficient time for the solution to dry before applying a dressing also helps reduce the risk of medical-adhesive related skin injury (MARSI), a common complication of vascular access (Fumarola et al, 2020; Barton, 2021).
The expert panel agreed that, in ideal circumstances, all the resources and equipment needed for skin antisepsis would be available to health professionals in a single pack with operational instructions. This is the case in Wales, where a standard cannulation pack has been available since 2015 in the context of mandated ANTT (Anonymous, 2015). However, procurement issues and a requirement to re-sterilise parts of the pack before use may preclude the introduction of this approach in other areas of the UK.
Chlorhexidine is reported to cause contact dermatitis in some cases (Frasca et al, 2010; BD, 2019). The observation of a possible chlorhexidine allergy must be documented in the patient's notes as in rare cases it can cause anaphylaxis (Loveday et al, 2014). Therefore the expert panel recommended a contingency procedure for those with an allergy to chlorhexidine. Alternative methods in the case of chlorhexidine allergy may include either povidone iodine in alcohol, as recommended by the Royal College of Nursing (RCN) (2016), or isopropyl alcohol alone. However, additional vigilance to ensure compliance with ANTT might be necessary, since both isopropyl alcohol alone and povidone iodine are less effective than 2% CHG in 70% IPA solution at reducing catheter colonisation and suppressing bacterial recolonisation around the vascular insertion site (Chaiyakunapruk et al, 2002; Adams et al, 2005; Hibbard et al, 2005; Small et al, 2008; Reichel et al, 2009; Frasca et al, 2010; Maiwald and Chan, 2012).
The expert panel agreed that its recommendations are well suited to be included in a care bundle. An ideal care bundle combines the provision of appropriate equipment with a structured approach to skills training along with surveillance to ensure compliance with training and to furnish intelligence for the investigation of failings (Jackson and Cooper, 2012). Care bundles have been used successfully to improve outcomes in skin antisepsis (Khurana et al, 2018). High-impact interventions for using care bundles to improve skin antisepsis are in development. The panel supports the need for a structured, multi-stakeholder, evidence-based approach to the improvement of skin antisepsis, which needs to be updated on a regular basis to ensure compliance with the latest evidence and best available equipment.
Critical to improving the practice of skin antisepsis, in addition to correct non-touch aseptic use of products with strict adherence to the manufacturer's instructions, is ensuring competence in cannulation and the insertion of PICC and midlines. Mandatory training in ANTT, including skin antisepsis is required for competent practice in these procedures.
The expert panel believes there is scope for a national educational resource on skin antisepsis that is open access. This should include a suite of resources that can be adapted to suit individual and local needs and preferences. Education needs to be provided in different formats for different learning styles and professional groups, with periodic reviews of competency. The content should be aligned with the guidelines of the ANTT Clinical Practice Framework (The-ASAP, 2015). Imprecise language about products and their use produces variation in practice. The panel agreed that ANTT terminology is the standard to be followed (The-ASAP, 2015). Future education resources on skin antisepsis should include patient stories, which are positively regarded by educators for enhancing students' engagement, learning and retention (Adam et al, 2017).
Education on ANTT and skin antisepsis should be part of foundational training for all health professionals. The ideal is to standardise this educational provision throughout the UK and establish 3-yearly competency assessments of health professionals' ANTT and skin antisepsis practice. Catheter-related infections pose such a serious risk to patients' life and health that training in aseptic technique needs greater rigour and regularity of training and competency assessment than currently provided. The expert panel believes standardised training must be supported by mandatory competency assessment, routine audit to evaluate competency and compliance, and periodic competency-based reassessment.
Ideally, an economic case needs to be made for the potential cost savings that can be achieved with the implementation of these recommendations. However, such a case is hindered by a lack of baseline data as well as data on the source of infection related to vascular access procedures. The expert panel acknowledges that currently there are insufficient data to make a robust health assessment on the benefits of this approach, and therefore emphasises the need for more research to provide those data. The panel proposed that a first step to addressing this evidence gap might be laboratory tests to identify and model bacteria counts, colony-forming units, and transmission routes that can occur after skin antisepsis. These data would serve as possible benchmarks to inform clinical assessments of infection transmission during vascular access procedures, and an economic case for more rigorous training and mandatory competency assessment.
Conclusion
Vascular access procedures can cause bloodstream infections related to catheter insertion and exit site infection. Such infections can pose a serious risk to patients' health, lives and recovery from surgery. There is evidence that improvements in skin antisepsis technique can be achieved, perhaps in the long-term, through the introduction of up-to-date, peer-reviewed care-bundle interventions for all health professionals involved in vascular access procedures and maintenance, supported by surveillance and monitoring of compliance. Such interventions have been shown to reduce infections and improve patient outcomes. More research is needed to address a critical gap in understanding the routes of infection transmission from the skin to the bloodstream after skin antisepsis for the insertion of VADs. As a result of this gap, more research is also needed to understand differences in the effectiveness of different disinfectant solutions and wipes.
This document of a roundtable discussion of UK experts sought a consensus on how to improve the quality and consistency of skin antisepsis practice. The expert panel's recommendations are summarised in Table 2.
Table 2. Expert panel's recommendations
| 1 | Use Medicines and Healthcare products Regulatory Agency (MHRA)-licensed 2% chlorhexidine gluconate in 70% isopropyl alcohol solution for skin asepsis except in patients with chlorhexidine allergy |
| 2 | Use the applicator of MHRA-licensed 2% chlorhexidine gluconate in 70% isopropyl alcohol solution, cleaning with bidirectional (back-and-forth) strokes for up to 30 seconds, then leaving the skin to air dry for 30 seconds |
| 3 | Use the ANTT Clinical Practice Framework and terminology as the standard for skin antisepsis |
| 4 | Make available standardised ANTT and skin antisepsis education with 3-yearly competency assessments for all UK health professionals |
| 5 | Include patient stories in UK health professional skin antisepsis education |
| 6 | In ideal circumstances, make all the resources and equipment needed for skin antisepsis available to health professionals in a single pack with operational instructions |
| 7 | Encourage more research to address the evidence gap on transmission of infection after skin antisepsis, such as laboratory tests to identify and model bacteria counts, and colony-forming units as a first step |
| 8 | These recommendations are well suited for inclusion in a care bundle |