The use of antimicrobial dressings can play an essential role in the prevention and management of wound infection when appropriate choices and treatment regimens are utilised.
Antimicrobial agents are used to inhibit microorganisms. The term is normally synonymous with the term biocide, and includes antiseptics, disinfectants and antibiotics. Antiseptics are used topically on a wound or on intact skin (World Union of Wound Healing Societies [WUWHS], 2008). Disinfectants are chemical agents that are used on inanimate objects, such as instruments and trolleys, and in wound care. Examples include alcohol and sodium hypochlorite. Some agents have been used for centuries to treat wounds (Brennan and Leaper, 1985; Leaper, 1986; McDonnell and Russell, 1999).
Antiseptics and disinfectants largely have a broad spectrum of antimicrobial activity; however, microbial resistance has recently been reported (Maillard, 2006). Antibiotics are natural or semi-synthetic substances that act selectively on specific target sites. Antibiotic resistance has been increasing since 1950 and some microbial strains exhibit multiple drug resistance.
Antimicrobial dressings (wound dressings)
An ideal antimicrobial dressing should ideally possess the following properties:
- Ease of use
- Low cost
- Less risk of antimicrobial resistance (WUWHS, 2008).
These benefits (listed below) should outweigh any negative effects on patients, for example, cytotoxicity, mutagenity and allergenicity.
Properties of the ideal antimicrobial dressing (Vowden and Cooper, 2006)
- Broad spectrum of activity against microorganisms including resistant strains
- Bacteriocidal, not only bacteriostatic
- Rapid but sustained activity
- Suitable for the use on broken skin/mucus membrane
- Non-irritant and non-toxic to tissue/environment
- Easily soluble in a non-toxic carrier
- Not inhibited by body fluids, wound exudate or biofilms
- Stable, easy to use and store
- Assists in wound bed preparation, e.g. debridement/moisture management
- Reduces malodour
- Conforms to site and shape of wound
- Satisfies patient and clinician expectation.
Microorganisms are often present in wounds (Bowler et al, 2001). Normally, host defence mechanisms promote wound healing and wounds heal successfully without infection. Therefore, the wound bioburden and the immune system must have been in balance (European Wound Management Association [EWMA], 2006). It is important to note that a holistic assessment of the wound and patient is essential for successful wound treatment and management.
The following signs and symptoms accompany wound infection: erythema, swelling, pain, purulence, malodour and localised heat. Infected wounds may produce different signs and symptoms (Moffatt, 2005). In patients whose acute wounds become infected, signs and symptoms may be treated without any complications; however, in chronic wounds, diagnosis may rely on signs such as increased discharge, delayed healing, epithelial bridging, wound breakdown, abscess formation, decolouration of the wound bed, friable granulation tissue and pocketing at the base of the wound (Cutting and Harding, 1994; Moffatt, 2005). It should be noted that for patients with diabetes, systemic antimicrobial therapy should be administered in conjunction with standard wound care therapy (Lipsky et al, 2012).
Selecting an antimicrobial dressing
Antimicrobial therapy should provide optimal conditions to support wound healing (Kingsley, 2009). Manufacturers' instructions should be followed carefully as different antimicrobial dressings have different physical properties. Wound assessment is crucial, as specific products need to fulfil the general treatment requirements. It is also important to take a holistic approach with the patient when a treatment regimen is being decided upon (Vowden and Cooper, 2006, MeReC, 2010).
Antimicrobial dressings also fall under the following categories:
For more information, please see their individual category entries.
Antimicrobial therapy usage
Antimicrobial dressings are recommended for the prevention of infection in patients at high risk of wound infection, in the treatment of localised wound infection and in conjunction with systemic antibiotic treatment. Treatment with antimicrobial dressings should be monitored closely. Any failure to respond appropriately should be noted and a reassessment of the wound undertaken to identify alternative treatment. In normal wound healing, antimicrobial dressings should be used for 14–21 days (Best Practice Statement, 2010). Debridement of sloughy, necrotic tissue and pus should be undertaken, as these are media for bacterial growth. Proper hygiene measures should be carried out, including cleansing the wound (Vowden and Cooper, 2006).
Not all wounds respond to antimicrobial dressings and consequently microbiological and blood cultures allow for the selection of the appropriate treatment regimen and observation of spreading/systemic infection respectively. Furthermore, optimising the patient's immune response to fight infection by improving nutritional intake, hydration, monitoring glycaemia index in patients with diabetes, will enhance their healing potential.
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European Wound Management Association (2006) Position Document: Identifying criteria for wound infection. MEP Ltd, London
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Lipsky BA, Berendt AR, Cornia PB, et al (2012) 2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis 54(12): 132–73
Maillard JY (2006) Focus on silver. World Wide Wounds. Available online.
McDonnell G, Russell AD (1999) Antiseptics and disinfectants: activity, action and resistance. Clin Microbiol Rev 12(1): 147–79
MeReC Bulletin (2010) Evidence-based prescribing of advanced wound dressings for chronic wounds in primary care. MeReC Bulletin 21(1)
Moffatt C (2005) Identifying criteria for wound infection. In: European Wound Management Association (EWMA). Position document: Identifying criteria for wound infection. MEP Ltd, London
Vowden P, Cooper RA (2006) An integrated approach to managing wound infection. In: European Wound Management Association (EWMA) Position Document: Management of Wound Infection. MEP Ltd, London: 2–6
World Union of Wound Healing Societies (2008) Principles of Best Practice: Wound Infection in Clinical Practice. An International Consensus. MEP Ltd, London