The skin is the largest organ of the human body and healthy intact skin provides a barrier preventing the ingress of microbes. It is integral to human survival. When the skin is breached a cascade of events are triggered, that, all being well, result in wound healing. Healing times are dependent on several factors including the age of the patient, wound location, nature of the injury and underlying pathophysiology associated with the wound type. This article seeks to review the evidence associated with wound and periwound skin cleansing and highlights its importance in relation to patient outcomes.
Wound cleansing techniques
Evidence-based practice is a central tenet of the NHS and cost-effectiveness, value for money and quality assurance are key measures of this in practice (Department of Health, 2016). The number of patients living with a wound is rising (Guest et al, 2105) and this is largely attributed to an ageing patient population.
Trevelyan (1996) suggested three components of wound cleansing; technique, equipment choice and use of a topical agent. Wound cleansing techniques, as with other areas of wound care, have evolved. In the absence of visible debris, devitalised tissue or slough, the routine cleaning of acute wounds is largely discouraged (Flanagan, 2013). In chronic wounds, however, it is now recognised as standard practice to remove debris and slough and reduce biofilm formation (Percival and Suleman, 2015). The temperature of a cleansing solution has been widely debated, with some authors (Feinstein and Miskiewicz, 2009) suggesting that lowering the wound-bed temperature results in lower oxygen levels and leukocytes which are vital for fighting infection. Warmed solutions are favoured, however, this is not always practical in all clinical settings.
This article will focus on the use of normal saline, tap water, and combined surfactant and antimicrobial solutions, with the aim of providing some clarity on when to use which in practice. Sterile normal saline (0.9%) has traditionally been used widely. However, a systematic review by Fernandez and Griffiths (2012) found no difference in infection rates in acute, surgical and chronic wounds when cleansed with potable tap water as opposed to sterile normal saline. They concluded that tap waster is a safe and suitable alternative. Despite this evidence, tap water is not widely used in practice (Queirós et al, 2014; Wolcott and Fletcher, 2014), especially in inpatient settings as high numbers of bacteria have been found growing in and around washbasins (Jefferies et al, 2012).
It is paramount that clinicians follow local guidelines. If tap water is the preferred solution they should let the tap run for a few seconds to flush any impurities away prior to collecting it for use. The use of warm tap water is widely accepted as best practice for the care of leg ulcer patients. Its use in a lined bowl facilitates the cleansing of both the wound and the periwound skin on the lower leg. Patients are often unable to cleanse their lower legs as compression bandages are often prescribed to treat the underlying condition and they prevent access to the skin. The recently published Wounds UK (2019)Best Practice Statement on leg ulcers favour hosiery kits as they allow patients with a normal limb shape to self-care with dressing changes and skin cleansing as per their normal routine. Showering is the preferred method of cleansing chronic wounds by clinicians working in the field of wound care (Ljubic, 2013) and can improve patients' sense of wellbeing (Fernandez and Griffiths, 2012). Patient who have wounds in their groin, perianal or genital area are generally encouraged to shower daily, especially if there are high levels of wound exudate. When exudate spills onto periwound skin, maceration or excoriation may occur; this can lead to increased pain and discomfort. Patients with perianal wounds are often encouraged to shower after bowel movements to avoid faecal contamination of the wound (Harris et al, 2016).
Patients should be provided with education on solutions to avoid when caring for their wounds. The optimal pH of normal skin is widely accepted as between 4.0 and 7.0. This naturally occurring acid mantle is created from sweat and sebum and provides a protective barrier and maintains the natural healthy skin flora. A multicentre study published by Lambers et al (2006) suggested that the actual pH is largely dependent on individual routine and choice of cosmetic products. They pointed out that showering without soap can have a transient effect on skin pH; tap water in Europe has an average pH of 8.0, which can raise the skin pH to an average of 6.0, and takes up to 6 hours to normalise. Soaps have a profound impact on skin pH, which can lead to shedding of normal flora and can potentiate pathogens that commonly cause wound infection. Alkaline solutions (soaps, body washes and perfumed cleansers) should be swapped for pH neutral solutions that promote the barrier function of skin; the use of shower and bath emollients with or without antimicrobial properties are widespread and are preferable to soaps as they help maintain the skins barrier function (Dowsett et al, 2013).
For immunocompromised patients with diabetes, and those who have wounds with bone or tendon exposed, it is appropriate to use sterile solutions to reduce the risk of infection (Peate and Glencross, 2015). The National Institute for Health and Care Excellence (NICE) also recommended the use of sterile solutions for 48 hours postoperatively (NICE, 2013). Most postoperative primarily closed wounds will not need cleansing in this time frame. Toon et al (2015) recommended that when dressings are removed, patients be encouraged to shower as normal. Conversely, surgical wounds healing by secondary intention may need cleansing within 48 hours if there is blood loss, strikethrough not contained within the dressing, or if the patient reports excessive wound pain. In these instances NICE guidance should be followed.
Use of topical antimicrobials
Topical antimicrobials are commonly used to reduce the bacteria in chronic wounds, infected wounds and where chronicity is thought to be associated with the formation of a biofilm (a colony of mixed planktonic bacteria that excrete a slimy protective layer that increases their resistance to antibiotics). Cutting et al (2010) suggested that wounds with excess exudate, slough, necrosis and debris can potentiate infection and this warrants consideration for the use of topical antimicrobials (Vowden et al, 2011). Wolcott and Rhoads (2008) pointed out that topical antimicrobial agents have a broad spectrum of activity against most commonly found wound organisms. Chronic wounds are more likely to be colonised with bacteria and this is largely due to duration.
Antimicrobial resistance and resultant antimicrobial stewardship programmes have led to new interest in the use of antiseptics (Cooper and Kirketerp-Møller, 2018).
The Wounds UK (2013) best practice statement, The Use of Topical Antimicrobial Agents in Wound Management, suggested the use of antiseptic solutions in the following instances:
The document stated that use should be stopped once the wound improves.
There are several cleansing solutions available. The most commonly used are polyhexanide and betaine (PHMB) (Braun et al, 2014) and octenidine dihydrochloride. Both have been found to be less toxic to healthy cells than commonly used solutions (Hübner and Kramer, 2010) as well as being less painful for patients during their application. Both solutions have proven broad-spectrum effect (Bradbury and Fletcher, 2011; Chamanga et al, 2015). Octenidine dihydrochloride, however, is not effective against viruses and spores.
Biofilms are ten times more likely to form in chronic wounds than in acute ones (Percival and Suleman, 2015); this is because of chronicity and non-healing (Greener, 2011). Presence of biofilm should be suspected when wound progress stalls despite appropriate optimised care, for example, a stalled leg ulcer in full compression with no signs of oedema.
Maintaining the barrier function of periwound skin
Adhesive tapes and dressings can leave debris on the skin. Although some adhesives are designed to facilitate atraumatic removal others are more aggressive and inappropriate removal techniques can lead to skin trauma and stripping. Adhesives left on the skin can cause skin irritation and/or trauma associated with clothing or other items such as continence products adhering to the periwound area, which in turn can lead to shearing forces, which potentiate trauma and inflammation.
Exudate is an essential component of wound healing (Brown, 2017). In chronic wounds the exudate profile differs (World Union of Wound Healing Societies, 2019). In such instances the high levels of enzymes can lead to excoriation and erosion of the wound edges. Protection of the barrier function of the surrounding skin is essential, and authors have provided guidance on this in a number of publications (Dowsett and Allen, 2013; World Union of Wound Healing Societies, 2019). Tips include:
Conclusion
The available evidence on wound cleansing is largely based on local evaluation and case histories or expert opinion, as opposed to research. Decisions to cleanse a wound (and how) depend on the type of wound, appearance of the wound bed and periwound skin. In order to see and assess the wound bed or to remove debris, warm potable tap water is appropriate. However, in chronic wounds where biofilm/high bacterial load is suspected, timely use of a topical antiseptic solution is warranted for a defined timescale; use may prevent escalating symptoms/deterioration and/or the development of a wound infection.
Although nursing is a discipline based on tradition, it is also one of lifelong learning. It is imperative that clinicians adopt recommended best practice to ensure that practice variation is minimised and ritualistic practice abandoned in order to achieve consistent outcomes for service users. Comparative studies designed to address current knowledge gaps are needed before providing more definitive guidance to clinical staff and patients.