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Chronic wounds in primary care: advanced wound and antimicrobial dressings

Key learning points:

  • Many people live for years with chronic wounds and lack a confirmed diagnosis
  • High quality research is required to improve our understanding of how we can help wounds to heal
  • A national formulary and a national educational programme could improve the lives of over a million people living with chronic wounds


Community nurses care for 1.45 million people with wounds each year.1 Around 47% of wounds are acute wounds, 28% are leg ulcers and 21% are pressure ulcers2. Approximately 39% of wounds will not have healed after 12 months3. Choosing appropriate dressings can assist in wound healing.
In March 2016, The National Institute for Health and Care Excellence (NICE) released an evidence summary, Chronic wounds: advanced wound dressings and antimicrobial dressings, that discusses the best available evidence for advanced wound dressings and antimicrobial dressings.4 This aimed to review the evidence for particular types of dressing as a resource for individual prescribers. It concludes that there is little high quality evidence to guide dressing choice. The decision on the type of dressing should be based on a careful clinical assessment of the wound and the patient’s general health, circumstances and preferences.
This article aims to explore the type of wounds encountered by community nurses and to provide advice on choosing the right dressing.

What type of wounds do community nurses encounter?
Research indicates that community nurses care for 730,000 people with leg ulcers, 169,000 people with diabetic foot ulcers and 153,000 people with pressure ulcers each year. Only 278,000 of patients with leg ulcers have a formal diagnosis of a venous ulcer; the others are not classified.1 These data exclude people living in care homes. The NHS spends around £110 million a year on advanced wound dressings and antimicrobial dressings. Evidence to guide choices is not well known and is of poorer quality than in other areas of prescribing.4

Venous leg ulcers
A chronic venous leg ulcer is ‘an open lesion between the knee and the ankle joint that remains unhealed for at least four weeks and occurs in the presence of venous disease’.5
Venous leg ulcers arise as a result of chronic insufficiency and treatment should aim to improve venous circulation.

Dressings for venous leg ulcers
Venous leg ulcers should be dressed using an ABCD approach

  • Assessment.
  • Best practice in dressing selection.
  • Compression therapy.
  • Decision-making with the patient.

Any choice of dressing should be based on the principles of maintaining appropriate moisture balance and removing barriers to healing. The aim is to maintain a warm moist wound without macerating or damaging the skin around the wound. It may be necessary to protect the periwound skin with a barrier cream or film. Assessment of the wound bed enables the nurse to determine if the wound is necrotic, sloughy, granulating, epithelising or displaying signs of infection.
Necrotic tissue or eschar is dead, devitalised tissue. It may be black or brown in colour. Necrotic tissue is initially brown and soft but becomes hard and black as it dehydrates. It can delay healing and provide a focus for infection. Necrotic tissue can be removed using surgical sharp debridement. This should only be carried out by appropriately trained and competent nurses.
Larvae can be used to remove necrotic tissue. These are available on prescription and are either introduced directly into the wound (free range) or applied to the wound in a dressing (this looks like a tea bag with perforations).
Hydrocolloid, hydrogel and honey dressings can be used to rehydrate necrotic wounds and facilitate debridement.
Sloughy tissue or slough is also dead tissue. It appears to be yellow and glutinous. It is made up of dead cells and can look fibrous and stringy. It can adhere to the wound bed, delay healing and increase the risk of infection. It can sometimes be removed using sharp debridement. Treatment options include larval therapy and dressings such hydrocolloids, hydrogels and honey dressings, which facilitate debridement. Exuding sloughy wounds may benefit from an alginate dressing. This will gel on contact with exudate and will protect the peri-wound skin from maceration.
Granulation tissue is pink and does not bleed easily. If granulation tissue is bright red and bleeds easily this may be an indication of infection. The aims of dressing the granulating wound are to prevent any trauma on dressing removal, which can damage granulating tissue, and to maintain appropriate moisture balance.
Treatment options include foam, alginate and hydrocolloid dressings.
Epithelising tissue is pale pink and normally there is little exudate. A range of dressings can be used including film, hydrocolloid and foam varieties.
It is important to consult the patient and be guided by their experience as they may find some dressings more comfortable than others.

Pressure ulcers
The European Pressure Ulcer Advisory Panel 2010 guidance defines a pressure ulcer as ‘a localised injury to the skin and/or underlying tissue, usually over a bony prominence, as a result of pressure, or pressure in combination with shear. A number of contributing or confounding factors are also associated with pressure ulcers; the significance of these factors is yet to be elucidated.’6
The European Pressure Ulcer Advisory Panel classifies pressure ulcers in four grades according to the depth of tissue damage.3

  • Grade 1 describes intact skin with non-blanchable erythema.
  • Grade 2 describes partial thickness skin loss with superficial ulceration or a blister.
  • Grade 3 involves full thickness skin loss with damage of subcutaneous tissue that may extend down to underlying fascia.
  • Grade 4 involves extensive destruction of skin, tissue necrosis or damage to muscle, bone or supporting structures.


Dressings to manage pressure ulcers
The NICE evidence summary,Chronic wounds: advanced wound dressings and antimicrobial dressings, commented on the poor quality of clinical evidence to inform practice.4 It was not able to make recommendations about specific types of dressings. There is no evidence of any difference between hydrogel or alginate dressings and other dressings in terms of complete wound healing or adverse effects. It is not possible to draw conclusions that inform clinical practice and the authors recommend that clinicians consider costs and wound management properties when choosing dressings.7,8 Their guidance is divided into three categories:
1. Don’t use gauze to dress pressure ulcers.
2. Do provide dressings that promote the optimal healing environment. Discuss type of dressing with the patient or relatives if appropriate.
3. Consider:

  • Using dressings that provide a warm, moist environment for grade 2, 3 and 4 pressure ulcers.
  • The position of the ulcer, the amount of exudate, the frequency of dressing changes and patient comfort when choosing dressings.
  • The cost effectiveness of dressings.

Dressings to prevent pressure ulcers
It is common practice for nurses to apply precautionary dressings to areas of the body that they consider vulnerable to pressure damage. Foam heel pads may be applied to the heels of people with poor mobility and hydrocolloid dressings may be applied to skin considered vulnerable to damage. A meta-analysis on the use of dressings to prevent pressure ulcers found that compared with standard care alone, the risk of developing pressure ulcers was reduced with hydrocolloid dressings, foam and film dressings. Fewer people in the foam dressings group developed pressure ulcers compared with the hydrocolloid group. The authors note that the studies have many limitations and stressed that dressings do not replace best practices, such as repositioning, skin care, good nutrition and continence management.8
Additionally, the NICE evidence summary authors refer clinicians to guidance on pressure ulcer prevention, which does not include the use of precautionary dressings.

Diabetic foot ulcers
Diabetic foot ulcers arise because of nerve damage (neuropathic), reduced blood flow (ischaemic) or as a result of the combination of neuropathic and ischaemic changes (neuroischaemic). The person should be referred to a multidisciplinary foot care team within 24 hours of the problem being diagnosed. There is a risk of rapid deterioration and need for amputation.10
Treatment involves optimising diabetic control, evidence-based wound care, tackling infection and relieving pressure.11 Infection should be treated with antibiotics using the appropriate route, according to the severity of the infection.11,13
Wound debridement (undertaken by appropriately trained specialists) leads to accelerated healing.12
The NICE evidence summary found no clear evidence that any ‘advanced’ wound dressing was superior to basic dressings and recommends that nurses use their clinical judgment, taking account of patient comfort, preference and costs.

Dressings to prevent or treat infection
In clinical practice, three types of dressing - silver, honey and iodine - are commonly used to treat or prevent infection.13 The theory is that reducing the bacterial count in a wound will prevent or treat critical colonisation and infection.14
A review of silver dressings and creams used to treat burns found that they did not promote wound healing or prevent infection. A meta-analysis of silver dressings used to treat leg ulcers found that wounds healed more quickly when silver was used, but the evidence reviewed was of low quality and the meta-analysis used an atypical approach. There is moderate-quality evidence that honey helps to heal burns and infected post-operative wounds more quickly. There is low-quality evidence relating to use in other wounds.15
A review of the use of iodine found that it was an effective and safe antiseptic agent that enhanced wound healing, particularly in chronic and burn wounds. Parts of the review were well conducted, but concerns about the quality of trials mean that further research is required.

Benefits of different dressings
Choosing the right dressing for the right patient is an art as well as a science. The nurse should consider the position of the wound, the state of the wound bed, the need for conformability, the risk of contamination, the fragility of surrounding skin, the frequency of dressing changes and patient comfort.
If the person has a sacral pressure ulcer, for example, the nurse will require a dressing that is conformable. If the patient is incontinent the wound is at risk of contamination so an impermeable dressing will be required. If the sacral pressure sore is deep, a cavity dressing and a secondary dressing may be required.
If the person has fragile skin, some adhesive dressings may be contraindicated because they may damage periwound skin. In some cases, a person may react to a certain adhesive or find a particular dressing uncomfortable.
Certain dressings such as alginates are suitable when a wound is heavily exuding. Others, such as hydrocolloids, are suitable when a wound is necrotic. The nurse should become familiar with the different types so that a dressing can be chosen to meet particular needs.
No one dressing is suitable for all wounds - or indeed the same wound as it passes through different stages of healing.

A national formulary
The Chronic wounds: advanced wound dressings and antimicrobial dressings NICE summary4 concludes that there is little high quality evidence to guide dressing choice. Many of the trials on dressings are poorly carried out. Some are sponsored or conducted by dressing manufacturers and compare a specific dressing with dressings that are no longer routinely used - such as gauze.4 The decision on which type of dressing is most appropriate should be based on a careful clinical assessment of the person’s general health, the wound and the person’s circumstances and preferences. The authors of the NICE guidance suggest that local formularies provide a means of rationalising dressing choices.
There are currently in England:

  • 209 clinical commissioning groups (including 199 now authorised without conditions).
  • 154 acute trusts (including 101 foundation trusts).
  • 56 mental health trusts (including 44 foundation trusts).
  • 37 community providers (12 NHS trusts, six foundation trusts and 19 social enterprises).
  • 10 ambulance trusts (including five foundation trusts).
  • 7,875 GP practices.
  • 853 for-profit and not-for-profit independent sector organisations, providing care to NHS patients from 7,331 locations.

Each organisation could spend time and effort developing a local formulary that will be almost identical to that of other trusts, which could be a huge waste of resources. The time could be used more effectively to improve practice and support patients.
People with wounds have the right to a clear diagnosis of the type of chronic wound they have and access to effective treatment to enable the wound to heal. Many of the trials on wound dressings are poorly carried out, are sponsored or conducted by dressing manufacturers and compare a specific dressing with dressings that are no longer routinely used such as gauze dressings4.
Nurses need access to robust evidence that informs practice and guides their choice of dressings. This should provide specific advice on problematic wounds, such as sacral pressure ulcers at risk of contamination and on frequency of dressing changes and known adverse effects such as pain or stripping of the skin on removal.
The national supply chain aims to provide a national formulary for wounds.16 The formulary group is independent and will examine seven categories of dressings, design a service specification for each, agree the standards against which a product does or does not meet that specification and compare brands of dressing within the category. The benefits of this approach are that nurses in clinical practice will have access to independent information. Currently many trials are sponsored by dressing manufacturers and compare their dressing against dressings that we seldom use now such as gauze. Nurses will be able to compare dressings so if two manufacturers produce a foam dressing the nurse will be able to compare not only costs but also in terms of effectiveness and price. For instance, if a wound is wet, it might be worth prescribing a more costly dressing that will absorb more exudate before it has to be changed.
The nurse might be able to determine which of two similar sized foam dressings is best at absorbing exudate and so might be able to make the decision to prescribe dressing B because the wound is wet and this dressing will absorb more fluid and will require less frequent changes. The nurse might decide that the exudate is minimal so the extra cost of higher absorbancy may not be justified. If two dressings perform similarly but one is more expensive, the most cost effective can be used. The formulary can be used to bulk buy, negotiate discounts and encourage competition. It is hoped that the formulary will also empower nurses and give them a voice in prescribing, purchasing and driving forward developments in dressings.
The decision to provide a national formulary for wounds has received a mixed reception from nurses and has been opposed by the dressings manufacturers. There are concerns that it will limit the clinicians’ ability to prescribe and that cost will triumph over efficacy. There are also concerns that no one will comply with the new formulary and that it is a waste of time and effort. The NHS spends around £5 billion a year managing an estimated 2.2 million wounds and around £110 million of that is spent on advanced wound dressings.17 It could be argued that any savings made on dressings would be tiny in comparison with what could be saved if all patients with chronic wounds had access to effective, holistic evidence-based care.
The work on the national wound care formulary continues and will hopefully generate savings. The money saved could be used to fund research and improve patient care.

References
1. Guest JF, Ayoub N, McIlwraith T, Uchegbu I, Gerrish A, Weidlich D, Vowden K, Vowden P. Health economic burden that wounds impose on the National Health Service in the UK. BMJ Open 2015;5(12):e009283. ncbi.nlm.nih.gov/pmc/articles/PMC4679939/ (accessed 18 August 2016).
2. Vowden KR, Vowden P. A survey of wound care provision within one English health care district. Journal of Tissue Viability 2009;1:2-6.
3. Vowden KR, Vowden P. A survey of wound care provision within one English health care district. Journal of Tissue Viability 2009;1:2-6.
4. NICE. Chronic wounds: advanced wound dressings and antimicrobial dressings, 2016. nice.org.uk/guidance/esmpb2 (accessed 18 August 2016).
5. Scottish Intercollegiate Guidelines Network. Management of chronic venous leg ulcers, 2010. sign.ac.uk/pdf/sign120.pdf (accessed 18 August 2016).
6. European Pressure Ulcer Advisory Panel. International Guideline: Prevention of Pressure Ulcers: Quick Reference Guide, 2010.
epuap.org/guidelines/Final_Quick_Prevention.pdf (accessed 18 August 2016).
7. Dumville JC, Stubbs N, Keogh SJ et al. Hydrogel dressings for treating pressure ulcers. Cochrane Database of Systematic Reviews 2015a;2:CD011226. journalslibrary.nihr.ac.uk/__data/assets/pdf_file/0003/147333/Hydrogel-dressings-for-treating-pressure-ulcers.pdf (accessed 18 August 2016).
8. Dumville JC, Keogh SJ, Liu Z et al. Alginate dressings for treating pressure ulcers. Cochrane Database of Systematic Reviews 2015b;5:CD011277.onlinelibrary.wiley.com/doi/10.1002/14651858.CD011277.pub2/abstract;jsessionid=447973525F3B2D87A928C636B2162E3D.f03t01 (accessed 18 August 2016).
9. Huang L, Woo KY, Liu LB et al. Dressings for preventing pressure ulcers: a meta-analysis. Advances in Skin & Wound Care 2015;28:267-73.researchgate.net/publication/277086692_Dressings_for_Preventing_Pressure_Ulcers_A_Meta-analysis (accessed 18 August 2016).
10. NICE. Diabetic foot problems: prevention and management [NG19], 2016. nice.org.uk/guidance/ng19/chapter/1-Recommendations#care-within-24-hours-of-a-person-with-diabetic-foot-problems-being-admitted-to-hospital-or-the-2 (accessed 18 August 2016).
11. Kerr M. Foot care for people with diabetes: the economic case for change. NHS Diabetes, 2012. nhsiq.nhs.uk/legacy-websites/nhs-diabetes-and-kidney-care.aspx (accessed 18 August 2016).
12. International Best Practice Guidelines. Wound Management in Diabetic Foot Ulcers. Wounds International, 2013. woundsinternational.com/media/issues/673/files/content_10803.pdf (accessed 18 August 2016).
13. Edwards J, Stapley S. Debridement of diabetic foot ulcers. Cochrane Database of Systematic Reviews 2010;1:CD003556.
14. Storm-Versloot MN, Vos CG, Ubbink DT et al. (2010) Topical silver for preventing wound infection. Cochrane Database of Systematic Reviews 2010;3:CD006478.
15. Carter MJ, Tingley-Kelley K and Warriner R. Silver treatments and silver-impregnated dressings for the healing of leg wounds and ulcers: A systematic review and meta-analysis. Journal of the American Academy of Dermatology 2010;63:668-79.
16. Vermeulen H, Westerbos SJ and Ubbink DT. Benefit and harm of iodine in wound care: a systematic review. Journal of Hospital Infection 2010;76:191-9.
17. NHS Supply Chain (2015). National wound care and dressings generic specification to establish “clinically acceptable” standard.
supplychain.nhs.uk/news/supplier-news/national-wound-care-and-dressings-generic-specification/ (accessed 19 September 2016).
18. Guest JF, Ayoub N, McIlwraith T, Uchegbu I, Gerrish A, Weidlich D, Vowden K, Vowden P. Health economic burden that wounds impose on the National Health Service in the UK. BMJ Open 2005;7(5):12. ncbi.nlm.nih.gov/pmc/articles/PMC4679939/ (accessed 7 February 2016).
19. Letter from the Clinical Editors of Wounds UK and Wound Essentials. Our response to the NHS supply chain generic specification for a national formulary for wound care. wounds-uk.com/pdf/content_11716.pdf (accessed 18 August 2016).