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• To refresh your knowledge of the causes and risk factors associated with hard-to-heal wounds
• To enhance your understanding of the elements of a holistic wound assessment
• To consider how you could apply a wound assessment tool in your practice
A thorough, holistic wound assessment is essential to identify the aetiology of a hard-to-heal wound and formulate a diagnosis, which will underpin the treatment plan. This article describes the fundamental elements of assessing a patient with a hard-to-heal wound holistically, including taking a patient history, performing a clinical examination and investigations, and considering the patient’s physical, psychological, spiritual and social needs. The author also outlines the aspects of the TIMERS (tissue, infection/inflammation, moisture, edge, regeneration and social factors) wound assessment tool in detail, and explains some of the challenges associated with accurately assessing a wound.
Nursing Standard. doi: 10.7748/ns.2024.e12224
Peer reviewThis article has been subject to external double-blind peer review and checked for plagiarism using automated software
Correspondence Conflict of interestNone declared
Meagher H (2024) Undertaking a structured assessment of a hard-to-heal wound. Nursing Standard. doi: 10.7748/ns.2024.e12224
Published online: 27 August 2024
Wounds pose a significant burden to patients’ well-being and are costly to healthcare services (Guest et al 2015). It has been estimated that the prevalence of wounds is 7% among adults in the UK (Guest et al 2020). Although wounds can affect people at any age, the highest prevalence occurs in those aged over 65 years, who may also have significant comorbidities such as diabetes mellitus, peripheral arterial disease and cardiac disease (Guest et al 2015, O’Brien et al 2016, Meagher et al 2021).
A wound is defined as damage to the skin structure and/or function due to external forces or pre-existing medical or physiological conditions. A wound can have various causes, including trauma, surgical incision, circulatory disorders, cancer and connective tissue disorders such as scleroderma (Tudoroiu et al 2021).
Wound healing consists of four distinct but overlapping stages (Guo and DiPietro 2010):
• Haemostasis – occurs immediately after an injury and involves various physical processes to restrict bleeding, such as vasoconstriction and the formation of blot clots.
• Inflammatory – the body reacts to the wound by ‘flooding’ the area with white blood cells, growth factors and enzymes to promote healing, and which also remove damaged cells and bacteria. This stage causes redness and swelling at the wound site.
• Proliferative – the wound contracts in size as new tissue and blood vessels are formed, followed by epithelialisation, where epithelial cells ‘resurface’ the wound bed.
• Maturation – the collagen deposited in the proliferative stage begins to be ‘remodelled’ into scar tissue to increase the strength of the wound repair, and unwanted cells that were used in healing are removed by apoptosis (programmed cell death).
Acute wounds usually follow a predictable pattern to healing, whereas hard-to-heal wounds – also known as chronic wounds – follow a more unpredictable course (Tudoroiu et al 2021). In an acute wound, the body’s immune response is activated, releasing microbe-killing white blood cells such as neutrophils and macrophages, which promote wound cleansing and healing. However, if the immune response becomes dysregulated during healing (potentially between the inflammatory and proliferative stages, when the body fails to deregulate the release of inflammatory cells), this can lead to persistent inflammation in the wound and delayed healing (Raziyeva et al 2021). Healing can also be complicated by the presence of biofilms, which comprise a matrix of multiple species of microorganisms with high tolerance to both treatment and the host defence system (Haesler et al 2022, International Wound Infection Institute (IWII) 2022).
Lifestyle factors (such as smoking) and comorbidities (such as diabetes and peripheral arterial disease) can contribute to the development of a hard-to-heal wound (World Union of Wound Healing Societies (WUWHS) 2016). The most common hard-to-heal wounds include leg ulcers, pressure ulcers and diabetic foot ulcers (Greatrex-White and Moxey 2015, WUWHS 2016).
For the nurse, the aim of clinical wound assessment is to identify and manage local wound conditions – including blood supply, oedema, pressure and moisture level – through regular visual inspection of the wound bed, wound edges and the periwound skin (Moore et al 2019). The initial wound assessment provides a baseline against which the wound’s healing progress can be measured (Coleman et al 2017).
Accurate wound assessment and diagnosis is fundamental to appropriate management (Wounds UK 2018). However, 30% of unhealed wounds do not have a differential diagnosis, which could lead to inappropriate management and increased morbidity and mortality for patients (Guest et al 2015, 2020, Wounds UK 2018).
A holistic assessment includes the nurse taking a full medical and surgical patient history, including the presence of any comorbidities and allergies, to identify factors that may affect wound healing (Coleman et al 2017). Wound healing can be significantly affected by risk factors such as diabetes, autoimmune diseases, inflammatory conditions, malnutrition, dehydration, renal disease, older age, obesity, vascular disease, lifestyle factors such as smoking, and the effects of medicines (European Wound Management Association 2009, Guo and DiPietro 2010, Anderson and Hamm 2012, Guest et al 2015, Wounds UK 2018, Atkin et al 2019).
Where possible, modification of any such risk factors – in addition to managing the underlying cause of the wound – is crucial to promoting wound healing, for example optimising diabetes management in patients with diabetic foot ulcers (European Wound Management Association 2009, Wounds UK 2018, Atkin et al 2019). Recording the cause, classification, duration and whether the wound is new or recurrent is also important; one study reported that 42% of a cohort of patients with wounds had previously experienced a wound (Meagher et al 2021). Hard-to-heal wounds such as leg ulcers also have a significant risk of recurrence (Edwards et al 2018).
For the nurse, holistic assessment also includes assessing the patient’s physical, psychological, spiritual and social needs (Ousey and Cook 2012). This includes assessing the effect of the wound on their quality of life, activities of daily living and support structures, because these will be crucial to any treatment plan. In addition, this plan should be conducive to the patient’s lifestyle; for example, using hosiery instead of bandages to promote ease of self-care in patients with leg ulcers (Sibbald et al 2021).
It is essential for the nurse to have a detailed discussion with the patient and/or their family members to obtain an accurate history, including any previous wounds or illnesses, their medicines profile and any comorbidities. This history combined with a clinical examination and investigations will aid an accurate diagnosis of the patient’s wound (Atkin et al 2019). Investigations may include (Atkin et al 2019):
• Ankle brachial pressure index – a measure of the blood pressure in the upper and lower limbs to assess for peripheral arterial disease in people with leg ulcers.
• Radiology – if a foreign body or underlying osteomyelitis (bone infection) is suspected.
• Blood test and swab results – if signs of infection such as increasing volume or purulent wound fluid (exudate) are present.
Baseline and repeated wound measurements can assist the nurse in monitoring a wound’s progress. Measurement options include the use of a ruler or measuring tape, a probe or digital planimetry (software that can trace and measure the outline of a wound) (Coleman et al 2017, Wounds UK 2018). Digital measurements are most accurate because wound size can be overestimated by 10-40% when using a ruler (Rogers et al 2010, Khoo and Jansen 2016). However, in clinical practice, Atkin et al (2019) advised using the best available method since not all nurses will have access to digital tools.
A complication of some hard-to-heal wounds is undermining, where tissue damage extends underneath the skin’s surface. Nurses can record any undermining using the ‘clock face’ technique, where an imaginary clock is superimposed over the wound, which the nurse can use to record details, for example ‘undermining, 4cm, from 2pm to 6pm’. This technique enables subsequent nurses to identify the undermining and record its progress (Atkin et al 2019).
Taking photographs of the wound with the patient’s consent can also provide a useful aid for the nurse to monitor progress, but should not replace wound measurement (Wounds UK 2018). The number of wounds and their anatomical locations should also be recorded and a body diagram can be a useful tool for recording this (Dowsett et al 2015).
Reassessment of the wound at every episode of care is essential to determine the progress of hard-to-heal wounds. Wounds that have not reduced in size by around 40-50% by week four require further investigations such as a biopsy to check for malignancy, as well as onward referral to a wound, vascular, dermatology or other appropriate specialist. Wounds that fail to progress after 2-4 weeks also require a full review of the treatment plan and/or referral to a wound specialist (Atkin et al 2019).
It is also important for the nurse to identify the aim of treatment following the initial assessment; for example, the aim may be to heal the wound, or to provide palliative care where the aim is to provide comfort rather than heal the wound completely (Dowsett et al 2015, WUWHS 2016).
The use of a structured assessment framework is essential to support objective wound assessment, diagnosis and appropriate treatment (Wounds UK 2018). One example, the TIMERS (tissue, infection/inflammation, moisture, edge, regeneration and social factors) wound assessment tool, was developed from the original TIME framework (Schultz et al 2005, Atkin et al 2019). While TIME was well-validated and widely used in clinical practice to provide an evidence-based approach to wound assessment, TIMERS also acknowledges the importance of using a holistic approach to assessment in addition to examining the wound itself (Ousey et al 2018, Atkin et al 2019, Moore et al 2019).
Depending on the stage of wound healing, the tissue in the wound bed may be predominantly viable or non-viable. Non-viable tissue includes necrotic tissue (black, grey or brown in colour), slough (yellow devitalised tissue comprising dead cells or bacteria) and infected tissue (green). Conversely, viable tissue may include granulating tissue (red) or epithelialising tissue (pink) (Benbow 2016). The nurse can use these colour descriptors to provide an objective assessment of the wound bed tissue type. The type of tissue in the wound – alongside factors such as the underlying cause of the wound and the perfusion levels – will also guide the appropriate method of preparing the wound for healing, which may include (Wounds UK 2018, Atkin et al 2019):
• Debridement of non-viable necrotic tissue using sharp debridement (Figure 1) or autolytic debridement (the use of a moisture-retaining dressing to encourage the body’s own enzymes to destroy necrotic tissue).
• Maintaining moisture balance using an appropriate dressing, such as a super-absorbent dressing to absorb excess exudate, considering that increasing volumes or purulent exudate can indicate wound infection.
• Treating non-advancing wound edges, for example by debriding any necrotic tissue.
The nurse should also record any changes in the proportion of each type of tissue in the wound bed, such as a reduction or increase in green infected tissue, because this is important for objective monitoring of the wound’s progress (Fletcher 2010, Benbow 2016). In addition, it is important to be aware that necrotic tissue should not be removed in patients with arterial leg ulcers until the lower limb has been revascularised, partly because otherwise there will not be sufficient blood flow to heal the wound (Atkin et al 2019). Similarly, intact dry necrotic tissue on the heel should not be removed due to the potential risk of infection. The heel has minimal muscle or fat covering the calcaneum; therefore, the bone can be exposed if this tissue is removed, leading to an increased risk of osteomyelitis (European Pressure Ulcer Advisory Panel et al 2019).
Clinical assessment for signs of infection is a vital part of every holistic wound assessment to promote early identification. All wounds contain microorganisms that can potentially cause infection, and the risk of infection is influenced by (IWII 2022):
• Patient-related risk factors, such as immune disorders and suboptimally managed diabetes.
• Wound-related factors, such as bacterial contamination or foreign bodies such as debris in a traumatic wound.
• Environmental factors, such as a lack of hand hygiene by patients and staff.
Strategies that nurses can employ to prevent wound infection include: promoting personal and hand hygiene among colleagues and patients; using aseptic technique when managing the wound; following universal precautions such as handwashing guidelines and disinfecting clinical areas; wound cleansing with water, saline or a disinfectant solution; and debriding necrotic and sloughy tissue (IWII 2022).
Based on the findings of a holistic assessment and the IWII (2022) wound infection continuum – which details the stages of microbial burden in a wound from contamination through to systemic infection – the nurse should suspect wound infection in the presence of signs such as increasing pain and exudate, malodour, friable granulation (excess of easily bleeding granulation tissue) or delayed healing. Other signs of infection include erythema, oedema, purulent discharge and local warmth (IWII 2022). Wound swabs and exudate samples can determine the appropriate antibiotic treatment, while technologies such as digital devices that use fluorescence imaging of the wound’s bacterial load can assist in identifying infection, although these might not be available to all nurses.
Another consideration in relation to infection is the potential presence of biofilms, which can result in impaired wound healing and chronic inflammation (Haesler et al 2022, IWII 2022). Due to the challenges of identifying biofilms, the nurse should assume that they are present in all hard-to-heal wounds (Malone and Swanson 2017, Schultz et al 2017). Biofilm treatment requires debridement, effective cleansing of the wound and periwound skin, refashioning of the wound edges to remove the potential for biofilm development in necrotic tissue, and appropriate use of wound products such as an antimicrobial dressing until the wound has healed (Atkin et al 2019, Murphy et al 2020).
Exudate is essential for providing a moist environment that enables migration of growth factors, tissue-repairing cells and essential nutrients across the wound bed, as well as promoting the autolysis (breakdown) of dead cells (Lloyd Jones 2014). Conversely, excess moisture can result in maceration of the surrounding skin and easier infiltration of microorganisms.
Wound exudate is produced as part of the normal wound healing process. The volume of exudate produced by a wound is determined by its aetiology, phase of healing, size, depth and location, and it may also be related to the patient’s comorbidities (Dowsett 2012, WUWHS 2018, 2019).
Promoting the appropriate moisture balance in the wound bed is essential to provide the conditions for wound regeneration and repair, and monitoring of the level of wound exudate is a core element of a wound assessment (Anderson and Hamm 2012). Observing the wound bed for moisture levels, assessing the periwound skin for signs of maceration, observing the amount of exudate contained within removed dressings and noting the frequency of dressing changes are all methods of measuring the volume of exudate. The nurse should also record the colour, consistency, odour and amount of wound exudate at each dressing change. In critical care settings, dressings may be weighed to determine the volume of exudate and to calculate the patient’s fluid replacement needs (WUWHS 2019).
Changes in the appearance or volume of exudate, such as it becoming more serous (clear and ‘watery’) and reducing in volume, may indicate wound healing, while an increasing volume of exudate may be indicative of inflammation, infection or oedema (Cook and Barker 2013, WUWHS 2019). High volumes of wound exudate are also associated with excess protease levels in the wound. Proteases are enzymes such as the matrix metalloproteinases that assist in ‘cleansing’ the wound of damaged tissues, but can delay healing if overproduced and not managed (WUWHS 2019). Decreasing exudate levels may also be a feature of ischaemic wounds, which result from arterial insufficiency (WUWHS 2019).
Wound dressings are used to maintain a moisture balance at the wound bed to optimise conditions for healing; for example, foam dressings are used in low-to-moderately exuding wounds, while super-absorbent dressings are used to manage high exudate volumes (Atkin et al 2019). Research is ongoing into the development of biosensors that can analyse exudate to identify specific factors in a wound that are delaying healing, such as an excess of matrix metalloproteinases (Kang et al 2019).
Wounds heal by contraction and healthy wound edges are essential to promote epithelial advancement (Guo and DiPietro 2010). The condition of the wound bed affects the wound edges, with excessive moisture levels in the wound bed contributing to maceration of the wound edges and periwound skin. Therefore, removing devitalised, necrotic or sloughy tissue, promoting granulation, treating infection and monitoring moisture levels are all essential to maintaining healthy wound edges. The nurse should observe the wound edges for maceration, dehydration, callus, undermining and/or a ‘rolled’ or raised appearance (Benbow 2016). Raised or rolled wound edges can indicate cancerous malignancy (Atkin et al 2019). Non-viable tissue at the wound edge and any callus should be debrided using sharp or autolytic debridement.
The nurse should also measure and record any undermining at the wound edge to ensure the entire wound area is assessed (Dowsett et al 2015). Similarly, the periwound skin should be inspected for conditions such as eczema, psoriasis, hyperkeratosis (thickening of the outer skin layer), induration (tissue hardening due to inflammation) and signs of infection (Dowsett et al 2015). Periwound skin care – including cleansing, descaling, moisturising and oedema management – is important to optimise the patient’s skin integrity (Atkin et al 2019).
Assessment of the wound edges should be an ongoing process for the nurse, and advanced therapies such as skin grafts, skin substitute grafts or protease-modulating dressings may be indicated to encourage epithelialisation and reduce the wound dimensions (Atkin et al 2019).
Several advanced therapies have been developed to promote wound repair and closure, including systemic and topical treatments. Examples include: cellular matrices such as biomaterials derived from animal, synthetic or autologous (from the individual themselves) sources and which cover the wound bed to promote healing; cell activity stimulation (the application of biomaterials that stimulate growth factors and proteins); oxygen therapy; stem cell treatment; and advanced topical treatments and dressings. Another advanced therapy is negative pressure wound therapy, which can be used as a standalone treatment or in combination with bioengineered or autologous skin grafts. It involves applying a suction pump and a dressing to the wound to create a negative vacuum that removes excess exudate and microorganisms. However, it is important for nurses to remember that these therapies are unlikely to be effective for a hard-to-heal wound unless the patient’s underlying risk factors and wound conditions have been addressed (Atkin et al 2019).
• If the immune response to a wound becomes dysregulated during healing, it can lead to persistent inflammation in the wound and delayed healing. This may result in a hard-to-heal wound
• The aim of clinical wound assessment is to identify and manage local wound conditions through regular visual inspection of the wound bed, wound edges and the periwound skin
• A holistic assessment includes taking a full medical and surgical patient history, including the presence of any comorbidities and allergies, to identify factors that may affect wound healing
• Nurses can use wound assessment tools such as TIMERS (tissue, infection/inflammation, moisture, edge, regeneration and social factors) to identify the factors that have contributed to a hard-to-heal wound
Social and patient-related factors may include clinical factors such as comorbidities and non-clinical factors such as the patient’s level of adherence to the wound care plan, health literacy and home environment. For the nurse, developing a supportive professional relationship so that the patient is comfortable asking questions about how to care for their wound, as well as using language that the patient understands, can enable them to participate in their own care (Atkin et al 2019).
It is essential that the nurse provides patient education throughout the wound assessment process to ensure the patient can work in partnership with them as much as possible. For example, patients should be encouraged to contribute to care tasks such as applying moisturiser to the skin, or elevating their legs to reduce oedema (Wounds UK 2018, Sibbald et al 2021). Furthermore, the nurse can explain how the patient could contribute to their own care by attending to factors such as adequate sleep, mobility and smoking cessation, while also managing wound-related factors such as odour and pain, thereby encouraging the patient to adhere to the wound care plan (Atkin et al 2019).
Wound pain is often one of the most significant concerns for patients (Sibbald et al 2021). Increased pain levels may signify wound infection (IWII 2022); conversely, some patients with neuropathy (for example those with diabetic foot ulcers and damage to the nerves) may not experience any wound pain. However, this does not lessen the potential seriousness of their wounds, particularly since patients with neuropathy might not notice accidental damage to the wound bed.
Another social factor to be considered by the nurse is adequate nutrition, with effective wound healing requiring the range of nutrients supplied by a healthy diet. The nurse can use tools such as the Malnutrition Universal Screening Tool (MUST) to identify those at risk of malnutrition and enable referral to a dietitian if required (British Association for Parenteral and Enteral Nutrition 2011, Wounds UK 2018).
Finally, a multidisciplinary team approach, which provides the nurse with access to expert colleagues such as tissue viability nurses and podiatrists, promotes a holistic approach to wound assessment. Moreover, any change in treatment aims – such as from active treatment to maintenance therapy in a person receiving palliative care – should be agreed with the patient, their family members and the multidisciplinary team (Atkin et al 2019).
It is important for nurses to be aware that a hard-to-heal wound remains so until it has fully healed, with the conditions that initially caused the wound to become hard to heal – for example comorbidities such as diabetes – presenting a continual risk of regression (Murphy et al 2020). Therefore, the nurse needs to continuously reassess the wound and address any risk factors that may negatively affect healing.
A thorough holistic assessment of the patient and their wound is essential to accurately diagnose hard-to-heal wounds and enable the nurse and multidisciplinary team to implement a wound care plan. The social, patient and wound-related factors that have contributed to a hard-to-heal wound can be identified through the use of a wound assessment tool such as TIMERS.
Early identification of patients at risk of impaired wound healing also enables earlier referral to specialist wound care services.
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