Clinical practice

A focus on the Triangle of Assessment — addressing the gap challenge and identifying suspected biofilm in clinical practice

Authors: Wound assessment should be comprehensive, systematic and evidence- Caroline Dowsett, Terry Swanson and Tonny Karlsmark based (World Union of Societies [WUWHS], 2016a). The Triangle of Wound Assessment offers clinicians a framework to assess the patient and their wound, taking into consideration the wound bed, wound edge and periwound skin (Dowsett et al, 2015). The framework can be adapted to incorporate new developments and new challenges in wound care such as the ‘gap challenge’ and biofilm prevention and management. Using the framework can assist in determining the status of the wound bed and support clinical decision making to prevent problems associated with exudate pooling at the wound bed and the potential for biofilm formation.

he Triangle of Wound Assessment This article will discuss how the Triangle of was established in 2014 and provides Wound Assessment identifies and T a systematic approach to wound biofilm, tackles the gap challenge, and how assessment and in setting management goals, this framework can be developed for new to guide optimal treatment choice (Dowsett et challenges in wound care. al, 2015), ensuring that the periwound skin is incorporated into the assessment. Periwound The importance of holistic assessment skin can be a significant problem in patients are a significant source of cost to with chronic wounds, with between 60–70% patients, as well as to the health economy. of wounds found to be surrounded by either Chronic wounds are often hard to heal problematic or unhealthy periwound skin resulting in a cycle of pain, anxiety and (Cartier et al, 2014). It is, therefore, fundamental reduced quality of life for the individual for these chronic wounds, and all other types of patient. Delayed wound healing and wound wounds to be assessed in three key areas: the complications add considerably to the cost of wound bed, the wound edge and the periwound care and are associated with longer and more skin, which are incorporated by the Triangle of intensive treatment, extended hospital stays Wound Assessment (Dowsett et al, 2015). or readmission, and specialist intervention More recently, the framework highlights (Dowsett, 2015). the significance of the gap challenge and the Evidence suggests that many patients potential for biofilm formation when exudate with wounds lack an accurate diagnosis and pools at the wound bed (Dowsett et al, 2018). are often managed with an inappropriate The wound gap refers to the gap that can present treatment plan (Guest et al, 2017). Accurate between the wound bed and the dressing. and timely wound assessment should be Caroline Dowsett is Clinical Nurse An appropriate wound dressing should make integral to managing a patient with a wound. Specialist Tissue Viability, East intimate contact with the wound bed, while Wound assessment needs to be comprehensive, London NHS Foundation Trust, absorbing and retaining levels of wound exudate systematic and evidence-based, providing London & Independent Nurse (Snyder, 2005; Cutting et al, 2009). It can be a baseline information against which clinicians Consultant in Wound Care, London Terry Swanson is Nurse Practitioner clinical challenge to manage and close the gap, can establish the current status of the Wound Management, South West which occurs when a dressing fails to conform to wound, set realistic treatment goals and Healthcare, Australia the wound bed. Additionally, managing wound monitor progress over time using appropriate Tonny Karlsmark is Clinical bioburden can be challenging and biofilm based interventions. Poor assessment can lead to Associate Professor, Department wound care needs to be considered in non- inappropriate treatment choices, contributing of Dermatology, Copenhagen University Hospital, Bispebjerg healing chronic wounds that are not responding to poor outcomes for patients and additional Hospital, Copenhagen to standard best practice. resource costs.

RAT A LEB IN EBR TIN E G EL G C C 34 Wounds International 2019 | Vol 10 Issue 3 | ©Wounds International 2019 | www.woundsinternational.com 10. . . . YEARS 10 YEARS We asked healthcare ...none professionals around the However, in a recent met all of the world about their priorities study of 14 wound criteria for assessment tools ... ? for wound care optimal wound assessment4

We found that most people Respondents said that The Triangle of Wound Assessment is a treating wounds are not protecting the periwound specialists in a hospital1 skin is very important1 holistic framework that allows practitioners üto assess and manage all areas of the Figure 1. The Triangle of Wound wound, including the periwound skin. Assessment. Wound bed assessment ■ Tissue type ■ Exudate ■ Infection It is a simple and systematic

Approximately Wound bed Up to approach that guides the Health 79% Care Professional from complete of wounds are 70% of WOUND being treated in wounds are wound assessment to setting 2 management goals and selecting Wound edge Periwound skin the community surrounded by Periwound skin assessment 3 relevant treatmentWound options.edge assessment unhealthy skin ■ Maceration ■ Maceration ■ Excoriation ■ Dehydration ■ Dry skin ■ Undermining 2 ■ Hyperkeratosis3 ■ Thickened/rolled edges ■ Callus ■ Eczema CPWSC_TOWA_Brochure_210x210_2018.indd 2-3 10/01/2018 15.14

The role of structured assessment tools that can be incorporated into any patient record Wound assessment and management frameworks system (Dowsett et al, 2015; WUWHS, 2016a). offer clinicians an opportunity to improve wound The concept was developed from a global assessment, patient outcomes and reduce the anthropological study conducted in 2013–2014 burden of chronic wounds. Assessment should with the aim of gaining a better understanding aim to establish the correct diagnosis to ensure of the impact of a wound on the patient. A key treatment of the underlying cause of the wound, finding from the study showed that clinicians as well as assessing size and depth of the wound and patients separated the wound into three and managing the wound. Wound assessment distinct, yet interconnected areas. should record the wound type, location, size, The Triangle of Wound Assessment focuses wound bed condition, wound edge and the on the wound bed, wound edge and periwound condition of the periwound area, and this should skin, each with significant importance in wound be ongoing as part of re-assessment. There are healing [Figure 1]. The wound bed is where many benefits to improving wound assessment clinicians seek to assess tissue type, manage of chronic wounds and best practice in holistic exudate, prevent infection, reduce inflammation, wound assessment has the potential to: remove devitalised tissue and promote ■■ Improve healing rates granulation tissue formation. At the wound edge, ■■ Reduce the physical, emotional and the aim is to reduce the barriers to healing by socioeconomic impact of wounds on patients debriding thickened and rolled wound edges, ■■ Benefit practitioners and the health economy identifying areas of undermining and improving by reducing the overall burden of wounds, exudate management. For the periwound skin potentially decreasing workload and the costs the aim is to protect the skin surrounding the associated with wound care wound from maceration, excoriation, dry skin, ■■ Raise practitioner and patient morale by hyperkeratosis, callus and eczema. improving patient outcomes (Wounds UK, 2018). Developing the Triangle of Wound Assessment for new challenges The Triangle of Wound Assessment New developments in wound care highlight the The Triangle of Wound Assessment is a well- importance of preventing exudate pooling and established and easy to use framework for reducing the dead space or ‘gap’ between the intuitive wound assessment that combines wound bed and the dressing, to avoid wound evaluation of the periwound skin within the complications, such as maceration and biofilm paradigm, while formation and infection. Highly exuding wounds acknowledging the importance of treating the and wounds with undermining and a steep angle patient as well as the wound. It was developed between the wound edge and wound bed are at to facilitate accurate and timely wound a higher risk of dead space. The Triangle of Wound assessment in a simple and easy-to-use format, Assessment can be used to (Dowsett et al, 2018):

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■■ Identify and assess the gap, and evaluate the infection. Wound exudate contains an excess impact of the interventions number of enzymes and other substances that ■■ Measure wound depth as part of wound can inhibit the healing, as well as proteins that assessment promote the growth of bacteria. Thus, pools ■■ Identify irregular wound bed topographies of exudate promote bacterial growth, leading and cavities to increased risk of infection and subsequent ■■ Identify areas of undermining. development of biofilm. An optimal wound The Triangle can also be adapted to dressing should conform to the wound bed to incorporate new developments and new manage the gap and reduce exudate pooling, challenges in wound care, such as the creating a less favourable environment for gap challenge and biofilm prevention biofilm to form. and management. Managing the gap challenge Defining the gap: ‘dead space’ between When choosing a dressing for moisture wound and dressing management, the dressing should conform to An ulcer is a sore on the skin or mucous the wound to reduce exudate pooling and have membrane, accompanied by the disintegration properties that absorb and retain wound fluid. of tissue. Ulcers can result in complete loss of One way to avoid the wound gap is to use the epidermis and often portions of the dermis a contact layer or paste that can minimise and even subcutaneous fat, fascia and muscles the cavity. However, this can be an expensive in deep pressure ulcers. In some wounds, the treatment in terms of materials and nursing deeper structures are more damaged than the time required for frequent dressing change. The epidermis, which leads to an undermining of the frequency of the dressing change will depend wound edges. Since it has been shown that a on the following requirements: moist environment is more conducive to healing ■■ Manufacturers recommendations of than a dry or a wet ulcer bed, most ulcer treatment individual products includes a dressing that keeps the ulcer bed ■■ Level and consistency of wound exudate moist. Most dressings cover not only the wound, ■■ Patient preferences and individual but also the periwound skin; the dressing often requirements firmly attached to the intact skin. As there is often ■■ Signs of acute or spreading infection a wound cavity, it can be difficult for a non- ■■ Total fluid handling capacity of the chosen conforming dressing to ensure close contact to dressing the wound bed. This results in a gap/dead space ■■ Dressing ability to manage the gap and between the wound bed and the dressing. reduce exudate pooling by conforming to the wound bed Why is the wound gap an issue? ■■ Tertiary requirements such as graduated Many chronic ulcers are stuck in the compression and pressure offloading. inflammatory stage of healing and some are A more economic approach is to use a critically contaminated with bacteria. In this dressing with a high conformability where stage, the wound bed produces a moderate-to- the primary dressing, due to its flexibility, is in high amount of wound fluid. If the dressing is contact with the wound bed and absorbs and not in contact with the wound bed, there will retains the wound fluid in the dressing to avoid be a risk of pooling of wound fluid in the cavity. the formation of a gap and the risks associated A high amount of cavity wound fluid will lead with it. to a risk of leakage from the dressing, primarily from the lower part of the dressing due to Infection and biofilm gravity. The fluid is toxic to the skin and causes Diagnosing a wound infection, either planktonic maceration and damage to the normal skin (acute infection) or with presence of biofilm barrier. Maceration causes enhancement of the (chronic infection), is done through assessment wound area and has a direct relationship with of the clinical signs and symptoms and listening wound healing, prolonging the time it takes to to the patient. A wound infection continuum heal (Haryanto et al, 2016). If the periwound skin provides the clinician with indications of clinical is not protected, for example, with zinc paste or signs and symptoms, as well as indicators of when other protecting ointments, there will be a risk to commence topical and systemic antimicrobials of damaging the wound further. [Figure 2]. Another problem with exudate pooling Awareness of biofilm and the implications in between the wound and dressing is the risk of wound management for many clinicians was

RAT A LEB IN EBR TIN E G EL G C C 36 Wounds International 2019 | Vol 10 Issue 3 | ©Wounds International 2019 | www.woundsinternational.com 10. . . . YEARS 10 YEARS Figure 2. IWII wound infection continuum. BIOFILM

Increasing microbial virulence and/or numbers

Contamination Colonisation Local infection Spreading infection Systemic infection

Vigilance required Intervention required

No antimicrobials indicated Topical antimicrobial Systemic and topical antimicrobials

first raised in 2008 (Bjarnsholt et al, 2008; James distributed within the wound, the results can et al, 2008) when publications emerged that not strongly depend on where in the wound the only was biofilm present in more than 60% of biopsy is taken from (Bjarnsholt et al, 2008). A the chronic wounds, but also had a significant normal wound culture is deemed inadequate detrimental effect on wound healing. More recent due to strong adherence of the biofilm and lack studies (Malone et al, 2017) now suggest that of equipment in normal pathology services the prevalence of biofilm in chronic wounds may (Schultz et al, 2017). However, if the clinician be greater than 80%. Biofilms can be described requires a culture for other reasons, such as as clusters of bacteria and fungi in a matrix, to determine antimicrobial resistance, then self-produced or of host origin (WUWHS, 2016b). recommendations are available on how to do a Biofilms can be both surface attached and wound culture, e.g. using the Levine technique embedded in soft tissue, for instance those found (IWII, 2016). embedded in the wound environment. There is some conflicting evidence in the literature Using the Triangle of Wound regarding the negative impact of biofilms on Assessment to identify infection wound healing, but there is growing consensus and biofilm by international groups and scientists that The Triangle of Wound Assessment assists in biofilms can cause infection, inflammation and determining the condition of the wound bed, delayed wound healing (Bjarnsholt et al, 2008; wound edge and periwound skin and is an James et al, 2008; International Wound Infection excellent guide for assessment (Dowsett and Institute [IWII], 2016; WUWHS, 2016b; Malone von Hallern, 2017), including the identification et al, 2017). of bioburden. Clinical assessment for signs and Biofilm are microscopic structures and symptoms for secondary signs of infection or can only be categorically confirmed using a local infection are most relevant for a chronic specialised microscopy. Publications and studies wound [Table 1]. As previously stated, there is to validate clinical signs of biofilm are welcomed no validated clinical consensus for the signs but at present there is not enough evidence to and symptoms for biofilm, however, there is provide consensus; a wound can appear clean agreement that presence of one or more of the and healthy but may have delayed healing due following signs are suggestive of biofilm: to biofilm being present in the deeper tissues. ■■ Lack of healing in a ‘healable’ wound that is Debate in the literature is ongoing as to whether not malignant slough or gelatinous granulation tissue (slimy ■■ Local signs of infection surface substances that reform in and on a ■■ Not responding to antimicrobial substances. wound) can be signs of presence of biofilm in the wound. Biofilm-based wound management Biofilm can only be identified after obtaining Reducing the level of biofilm can support a sample of wound tissue, following cleansing optimal healing conditions in a wound. and debriding (curette or punch biopsy), which Management of suspected biofilm or chronic is sent to a laboratory with modern microscopy. wound infection requires a multiple and holistic Even so, as biofilms are heterogeneously approach. Debridement and therapeutic wound

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Table 1. Signs and symptoms of infection. Local covert/secondary Local overt/classic Spreading/systemic Unhealthy granulation tissue: Increased or change in pain Redness/erythema >2 cm from friable, gelatinous, hypergranulated wound edge Stalled, delayed or non-healing Warmth, redness < 2 cm from wound Induration and oedema wound edge Wound breakdown or enlargement Change or increase in exudate. Satellite lesions, dehiscence or Odour, pus further deterioration of the wound

cleansing are the cornerstone for wound bed of wounds can be assessed in this way, with the preparation and create a window of opportunity ultimate goal of improving patient outcomes and for antimicrobials to act effectively. This removes promoting wound healing. non-viable tissue, crusting from desiccated This well-established framework has also been wound edges and remnant dressing material, shown to be essential in reducing the burden of therefore allowing proliferation and migration of the wound gap (Dowsett et al, 2018). As discussed epithelial cells, disruption of biofilm and removal in this article, maceration of the periwound of excess exudate. There are many debridement skin is often caused by the gap between the options for clinicians [Box 1]. Post debridement dressing and the wound bed, which can lead care includes cleansing and application of an to complications, such as infection and delayed antimicrobial wound dressing (Schultz et al, 2017; healing. Use of the framework is able to guide Høiby et al, 2015). treatment, so that appropriate dressings are selected that are able to conform to the wound Tips and tricks for managing bioburden bed, eliminate dead space, reduce exudate Assessing the wound at each wound dressing pooling and the risk of infection and biofilm. procedure will give opportunity to diagnose The Triangle of Wound Assessment can now be and treat a wound infection in the early developed, with new concepts such as wound stages, therefore, increasing the potential to biofilm and the gap challenge incorporated into prevent a limb or life threatening infection. the overall assessment framework [Figure 3], Box 1. Debridement methods. Using appropriate aseptic technique to aligned to exudate and infection prevention and ■■ Conservative sharp wound decrease inadvertent contamination and management. Preventing biofilm formation by debridement (CSWD): use appropriate hand hygiene are relevant, and reducing exudate pooling can support optimal of scissors, forceps, curette or appropriate strategies to facilitate good wound healing conditions in a wound. International best scalpel management. Antimicrobials play an important practice for promoting optimal healing conditions ■■ Autolytic: the body’s own part in wound care in the prevention and for infected wounds recommends to first cleanse enzymes and moisture management of infection. It is important to and debride the wound, creating a window of beneath a modern wound note that antimicrobials should be used within opportunity for antimicrobials to act effectively dressing liquefies non-viable antimicrobial stewardship practices and as part (IWII, 2016; WUWHS, 2016b). Wint tissue. Maintaining a balance in of an overall package of care. Modern wound moisture is important products that are proactive in optimising the References ■■ Mechanical: use of wound environment to decrease bioburden, Bjarnsholt T, Kirketerp‐Møller K, Jensen PØ et al (2008) technologies such as decrease factors of inflammation, manage Why chronic wounds will not heal: a novel hypothesis. ultrasound, debridement pads exudate and protect the periwound are Wound Repair Regen 16(1): 2–10 or using a moistened gauze available and should be used with knowledge Cartier H, Barrett S, Campbell K et al (2014) Wound with aggressive cleansing and confidence. management with the Biatain Silicone foam dressing: ■■ Biological: use of sterile larvae a multicentre product evaluation. Wounds International 10(4): 26–30 ■■ Enzymatic or chemical: use Summary Cutting K, White R, Hoekstra H et al (2009) Topical silver of products with enzymatic The Triangle of Wound Assessment is a holistic impregnated dressings and the importance of the properties, surfactants that and easy to use framework, that supports dressing technology. Int Wound J 6(5): 396–402 assist with lifting or removing accurate and timely assessment of the wound Dowsett C, Protz K, Drouard M, Harding KG (2015) The tissue and surface substance bed, wound edge and periwound skin (Dowsett Triangle of Wound Assessment Made Easy. Wounds ■■ Surgical: For appropriately et al, 2015). Management goals can be set International. Available at: https://bit.ly/2L0Td8a (accessed 27.08.2019) experienced clinicians who following this, along with selecting optimal Dowsett C (2015) Breaking the cycle of hard-to-heal debride tissue down to healthy treatment. Incorporating the framework into wounds: balancing cost and care. Wounds International tissue, most commonly done in a holistic approach, also allows for wound 6(2): 17–21 an operating theatre assessment and reassessment as the status of the Dowsett C and von Hallern B (2017) The Triangle of wound changes (Dowsett et al, 2015). All types Wound Assessment: a holistic framework from wound

RAT A LEB IN EBR TIN E G EL G C C 38 Wounds International 2019 | Vol 10 Issue 3 | ©Wounds International 2019 | www.woundsinternational.com 10. . . . YEARS 10 YEARS Figure 3. Assessment framework to include how to assess the gap Wound bedWound assessment bed Assessment and suspicion of biofilm. • Tissue type Wound bed Assessment The wound bed needs •to Exudatbe monitorede closely due to its unpredictability.Wound Assessment Tissue type Problems often arising in this area can have an impact on both the• Tissue wound type edge and the periwound• Infskin.ection6,7,8 • Exudate NecrNecroticotic % % GranulatingGranulating % % • Infection SloughySloughy % % EpithelialisingEpithelialising % % Wound bed Wound bed Wound bed Assessment Exudate • Tissue type Level Dry Low Medium High WOUND • Exudate • Infection Level Dry Low Medium High Type Thin/watery Cloudy Thick Wound bed WOUNDWound Assessment Wound Assessment Purulent Clear Pink/red Wound edge Periwound skin TypeInfection Thin/watery Cloudy Thick WOUND Local Spreading/systemic Increased painPurulent IncreasedClear erythema Pink/red Wound edge Assessment Periwound skin Assessment Erythema Pyrexia Wound edge Assessment PeriwoundWound edge Periwound skin skin Assessment Oedema Abscess/pus Wound edge Periwound skin Local warmth Wound breakdown Local Increased exudate Cellulitis Spreading/systemic Delayed healing General malaise IncrFriableeased granulation pain tissue Raised WBC count Increased erythema ErythemaMalodour Lymphangitis Pyrexia Pocketing Oedema Abscess/pus

8 assessment to management goals and treatments. Malone M, Bjarnsholt T, McBain AJ et al (2017) The 9 Wounds InternationalLocal 8(4): 34–9 warmth prevalence of biofilms in chronic wounds:Wound a systematic brea kdown Dowsett C, von Hallern B, Moura MRL (2018) Meeting review and meta-analysis of published data. J Wound report: The gap challenge in clinical practice how do you Care 26(1): 20–25 CPWSC_TOWA_Brochure_210x210_2018.indd 8-9 Increased exudate Cellulitis 10/01/2018 15.14 manage it? Int Wound J 9(3): 60–65 Schultz G, Bjarnsholt T, James GA et al (2017) Consensus Guest JF, Ayoub N, DelayMcIlwraith Ted et al (2017) healing Health guidelines for the identification andGener treatment alof malaise economic burden that different wound types impose biofilms in chronic nonhealing wounds. Wound Repair on the UK’s National Health Service. Int Wound J 14(2): Regen 25(5): 744–757 322–330 Friable granulation tissueSnyder RJ (2005) Managing dead space:Raised an overview. WBC count Haryanto H, Arisandi D, Suriadi S et al (2016) Relationship Podiatry Management 24: 171–4 between macerationMalodour and wound healing on diabetic World Union of Wound Healing SocietiesLymphangiti (WUWHS) (2016a) s foot ulcers in Indonesia: a prospective study. Int Wound J Florence Congress, Position Document. Advances in wound 14(3): 516–522 Pocketing care: the Triangle of Wound Assessment. Available at: Høiby N, Bjarnsholt T, Moser C et al (2015) ESCMID guideline https://bit.ly/2HQq5gK (accessed 27.08.2019) for the diagnosis and treatment of biofilm World Union of Wound Healing Societies (WUWHS) (2016b) 2014. Clin Microbiol Infect 21(1): S1–S25 Florence Congress, Position Document. Management of International Wound Infection Institute (IWII) (2016) Wound Biofilm. Available at: https://bit.ly/2ZmUhvO (accessed 27.08.2019) Declaration Infection in Clinical Practice. Available at: https://bit. ly/2WhwYC2 (accessed 27.08.2019) This article has been supported by Wounds UK (2018) Best Practice Statement: Improving holistic an unrestricted educational grant by James GA, Swogger E, Wolcott R et al (2008) Biofilms in assessment of chronic wounds. Available at: https://bit. ly/2u3VSUT (accessed 27.08.2019) Coloplast A/S. chronic wounds. Wound Repair Regen 16(1): 37–44

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