A chronic leg ulcer, defined as “any skin damage below the knee that takes more than 4 to 6 weeks to heal,”1 simplifies the classification of ulcers but fails to alert the clinician to the importance of identifying etiological and comorbid factors essential to optimal care. An Australian epidemiology study2 (N = 242) classified chronic leg ulcer etiologies by diagnosis and comorbid disease influences, singly or in combination. The etiologies identified were venous insufficiency, mixed etiology, arterial disease, diabetes, rheumatoid arthritis, thrombocythemia, trauma, skin tumor, chronic osteomyelitis, pyoderma gangrenosum, chronic dermatitis, chronic infected sinus, and Martorell ulcer. Additional types of leg ulcers identified through the authors’ clinical experience are neuropathic ulcers, surgical wound failure, pressure ulcers, vasculitis, deep vein thrombosis, calciphylaxis, burns, lymphedema, lipedema, self-mutilation, septic shock, emboli, Kaposi sarcoma, factor S ulcer, Marjolin’s ulcer, and foot deformity-related ulcers, which can be congenital or secondary to comorbid diseases such as diabetes.
The multiple etiologies of leg ulcers, combined with individual patient comorbidities and available resources of different clinical care environments, underscore the considerable challenges of their clinical management. Implementation of a periodic nursing questionnaire (1994, 1998, 2004, and 2005) that audited wound care in Sweden enabled longitudinal analysis of prevalence, etiology, treatment of hard-to-heal leg and foot ulcers, and nursing time.3,4 From 1994 to 2005, wound management improved, ulcer prevalence declined from .22% to .15%, weekly treatment time dropped from 1.7 to 1.3 hours per patient, and annual costs decreased by $6.96 million SEK. Repeated questionnaires, ongoing education, development of a wound healing center, and creation of multidisciplinary wound management recommendations all served to increase interest in and effectiveness of wound management.
A descriptive survey5 of a sample of district nurses in Norway regarding their opinions of their knowledge of foot and leg ulcer treatment (N = 102 completed questionnaires) found most nurses (60%) felt they had inadequate knowledge of wound care. They were uncertain about assessment, etiology, choice of wound healing products, and treatment. Individual clinical experience and colleagues were the main sources of their knowledge of wound care.
A descriptive observational study6 that analyzed 35 ulcer treatments provided to 32 patients with foot and leg ulcers by 31 home care nurses in Norway found no etiologic ulcer diagnosis was made in 16 cases and serious comorbidities were present in 79.9% of cases. Overall, nurses in this study were unsure of their assessment, treatment principles used often were outdated, documentation of treatment was poor, and use of compression on undiagnosed ulcers was sometimes incorrect.
An incidental sampling survey7 of podiatrists and nurses in the United Kingdom (N = 102) attending a lower extremity wounds conference explored attitudes, knowledge, and skill in lower extremity wound care to identify training needs and inform wound care education. The majority of respondents participated in continuing professional development, whereas the minority used accredited university courses. Inconsistencies in wound care knowledge and skills that were identified highlighted the importance of educational strategies to standardize wound care.
Wound assessment is fundamental to diagnosis, appropriate care, and monitoring wound progress, but the aforementioned research5,7 has found professional training programs for primary care nurses lack sufficient clinical education to provide appropriate care for patients with leg ulcers. A wound assessment tool that provides a common clinical language and encourages consultation could bridge gaps in professional knowledge between primary and specialist care providers.
Foot and Leg Ulcer Clinic. The Foot and Leg Ulcer Clinic in Victoria, British Columbia, Canada is a referral facility for patients with problematic wounds (ie, nonhealing, deteriorating, necrotic tissue, amputation risk, or other clinical problems). The core clinic team consists of 2 advanced wound care nurses and 2 physicians. Nurses admit and monitor patients in collaboration with a physiatrist who follows medical care, and a foot and ankle orthopedic surgeon evaluates and follows patients who may require surgery and postoperative care. A network of disciplines that provides expedited referral access includes vascular surgeons, infectious disease specialists, orthotists, podiatrists, pedorthists, and compression garment fitters. Consultations with physiotherapy, occupational therapy, dietetics, and social services are available on an individual basis. The nurses coordinate wound management with the primary nurses through care plans, consultation, and education.
Wound Trend Scale (WTS). The WTS, a paper-and-pen instrument developed by clinic wound speciality nurses, evolved through evaluation and modifications to improve relevance to leg ulcers and utility in a working clinic. Wound assessment theory is melded with clinical information to identify findings that are sensitive to wound healing phases, wound bed preparation, and risk identification.
The WTS systematically guides assessment of findings relevant to leg ulcer management, current wound status, significance of findings, wound trend, wound needs, and changes in the wound using 14 parameters, an infection screen, and cues for physician consultation. Each parameter has identified findings that are assigned a value from low to high corresponding to its potential to impair healing. The nurse examines the wound for each parameter and records the value of the highest finding identified (if absent, the item is left blank on the form). A decrease in value from the previous assessment is interpreted as a positive change that may predict healing or reduce impairment to healing. Increased values indicate deterioration or possibly more impairment to healing. The total WTS score is the combination of influences each parameter contributes. Healing is predicted when the total score is equal to or less than the previous total (closure, defined as complete epithelialization, is 0); an increase in the total score predicts wound deterioration. Infection risk screening is performed at every assessment. High risk of amputation, nonhealing findings, and positive infection screens are cued with an asterisk and require the nurse to consult with a physician. Assessments are recorded on the WTS documentation form and stored in the medical record.
At the authors’ clinic, patient reviews are scheduled according to wound status: twice weekly for high risk, weekly for moderate risk, or 1 to 2 months if stable. Primary care nurses or family physicians are encouraged to communicate concerns.
WTS parameter rationale and use. The WTS documentation form uses a unique number identification for each wound starting with 1, which is recorded on the care plan with the start and end dates recorded as day, month, and year (eg, #1 Left posterior heel, Start 010512, Closure 060712; #2 Left 5th toe, Start 220210, Amputation 060610). Multiple columns allow the identification number of wounds, assessment dates, and values for findings for each wound to be recorded. Wound closure or surgical procedures are recorded as end dates.
A retrospective analysis8 of 2350 heel pressure ulcers used data from the United States Wound Registry and regression models to assess factors known to be associated with healing. The analysis identified depth of tissue involved as a significant variable (P <0.05), which then was tested and validated. Variables predicting healing likelihood in nearly all pressure ulcer assessment models were wound size, wound age, number of wounds, evidence of bioburden, tissue type exposed (Wagner grade or stage), nonambulatory status, and need for hospitalization during treatment. The analysis resulted in a wound stratification system and healing index that could predict healing likelihood. With the exception of nonambulatory status and hospitalization, all of these variables are included in the WTS.
A study by Greatrex-White and Moxey9 to evaluate the ability of existing wound assessment tools to meet the needs of nurses performing wound assessment included a literature review that identified criteria of an optimal wound assessment tool. Assessment tools, which were selected using specified inclusion and exclusion criteria, then were evaluated against the optimal criteria. No evaluated tool fulfilled all criteria. The WTS addresses objective wound findings (measurement, tissue type, exudate, surrounding skin, pain and infection) and advanced subjective issues (documentation, communication, and ease of use). Greatrex-White and Moxey’s study elevates the role of wound assessment tools to support nursing practice, a practical issue for the clinic where regular nursing staff are wound specialist nurses and relief staff are not. The ultimate goal is to provide a wound assessment tool that supports both nonwound specialist nurses and specialist nurses to assess wounds systematically and consistently consult with the physician when cued risks are identified.
Surface area. Surface area is the maximum wound length multiplied by the perpendicular maximum width to the nearest 0.5 cm (a simple way to achieve this is by visualizing a square around the wound). Reduction in surface area is associated with healing, but an increase may indicate tissue loss from infection, ischemia, trauma, pressure injury, factitious injury, nonhealing, or debridement of necrotic tissue.
A review10 of the importance of wound measurement found both serial area measurement and percentage area reduction can differentiate responding from nonresponding wounds and help predict outcomes. A reduction over 2 to 4 weeks in wound area predicts healing or advises a reassessment of treatment was demonstrated in a multicenter, randomized controlled trial11 of 90 venous leg ulcers that found the 2-week percentage reduction in wound area was correlated with outcome (P = 0.002) — that is, a >30% reduction by 2 weeks is an accurate predictor of healing.
Depth. The type of tissue (injured, dead, or lost) influences the risk of amputation or nonhealing of leg ulcers. Depth value is the highest finding identified: partial-thickness or full-thickness skin loss; involvement of fascia, muscle, tendon, or bone; presence of a foreign body or medical devices; or obscure when all of the wound base cannot be seen. Anatomic knowledge of the ulcer site, including the location of blood vessels and nerves, is necessary to anticipate findings and identify if probing could be a risk. Patient consent is required before gently examining the wound base with a sterile probe to identify the type and integrity of involved tissues; clinic care standard does not allow probing wounds if the patient cannot cooperate, is at anatomical risk, the procedure causes pain, or if pathergy is known or suspected.
The anatomic structure of the foot and of the leg to a lesser extent limits the clinical significance of depth measurements, because much of the foot and parts of the leg have shallow tissue coverage of tendons and bones. As a result, injury to toes, metatarsal heads, heels, ankles, and the tibia crest may be limb-threatening but appear insignificant. A high-risk cue is assigned to tendon, capsule, bone, foreign body, medical device, or obscure.
Edge. Edge classifications include indistinct; distinct and attached; rolled and detached; or fibrotic, scar, or callus. Ousey and McIntosh12 acknowledge reduced vascularity, elasticity, and strength (about 70%) of scar tissue, compared with original tissue, may contribute to delayed healing and a fragile epithelial surface.
Undermining. Undermining, or tissue loss under the skin or between tissue planes, may present as a sinus, fistula, or abscess. The extent of undermining may be estimated by probing the undermined area and marking the end of the probe detected on the skin surface; the value recorded is the maximum length identified in cm. The amount of wound edge undermined is valued as 1: <25%, 2: 25%–50%; 3: 51%–75%; and 4: >76%.
Necrotic tissue and debridement. Debridement of necrotic tissue, such as slough and soft and hard eschar, reduces bioburden and odor, accelerates the inflammatory healing phase, and stimulates quiescent wounds.13 Selection of debridement method depends on the nature and amount of necrotic tissue, patient status, and presence of infection.
Stable eschar is dry, hard, nonfluctuant, and not infected. In cases of suspected arterial insufficiency, guidelines14 recommend stable eschar be kept dry and intact until vascular investigation of the healing potential of the wound is completed and the physician is consulted regarding debridement method.
To provide a full description of the wound base, the WTS assigns values to the percentage of necrotic and risk tissues identified in depth: 1: <25%; 2: 26%–50%; 3: 51%–75%; and 4: >76%.
Exudate. Exudate is identified by type and amount based on dressing presentation: 1) moist — exudate present, nonadherent dressing; 2) small — exudate present to saturated dressing with contained exudate; 3) moderate — exudate strikethrough; 4) large — leaking exudate onto clothing; or 5) uncontrolled — exudate leaking onto the patient, clothing, and/or bed linen within 48 hours of dressing change or dry when moist healing is desired. The need to rehydrate tissues delays healing dry wounds that require a moist environment.
Bleeding is not an expected finding for chronic wounds; the cause should be investigated. Active bleeding requires physician consultation. The surgeon is notified of serosanguineous or purulent drainage from a previously closed incision, which is an indication of surgical wound failure.
The World Union of Wound Healing Societies consensus document15 states the amount of exudate is influenced by the size of the wound and healing phase, with the maximum amount during the inflammatory and proliferative phases and with reduction to 0 with complete epithelialization. Increased exudate is associated with factors that increase capillary leakage such as cardiac, renal, or hepatic failure; edema; inflammation; increased bacterial burden; impaired lymphatic drainage; and specific wound pathology. Exudate color and viscosity are influenced by the type of necrotic tissue present, bacterial colonization, white blood cell presence, and the dressing material used. Managing exudate depends on diagnosing and treating underlying conditions and appropriate dressing selection. Figure 1 illustrates the importance of cleansing the wound before attempting to identify the type of exudate and differentiate pus from accumulated drainage.
Periwound skin. Periwound skin is examined to identify blanchable and nonblanchable erythema, maceration, tissue breakdown, trauma, or rash. Erythema can be a sign of inflammation or infection, but nonblanchable erythema indicates altered blood flow and impending tissue destruction. An exploratory study16 comparing blood flow in areas of nonblanchable erythema to undamaged skin found high perfusion in the center of the lesion and normal perfusion in unaffected areas. In her clinical review, Bianchi17 identified maceration associated with exudate enzymes increases the risk of tissue breakdown and dressing trauma. Rashes and periwound breakdown are investigated for venous eczema, autoimmune disorders, cellulitis, and contact dermatitis.18,19
Appropriate management of periwound skin includes effective cleansing. A Cochrane review20 found no evidence to suggest the use of potable tap water to cleanse wounds and the periwound skin influences infection or wound healing in acute or chronic wounds, including those with bone exposure. Showering loosens necrotic tissue and removes periwound surface debris, organisms, and exudate. In addition, a retrospective analysis21 of cleansing methods for chronic foot and leg ulcers (N = 236) found showering may lower the rate of both toe and major amputations compared with the use of foot baths (P = 0.037). Cooled boiled water, distilled water, or saline solution may be used for chronic wounds when potable water is not available.
Edema. The practice of scoring pitting edema as 1+ (2 mm), 2+ (4 mm), 3+ (6 mm), and 4+ (8 mm)22 may be unsuitable for many leg ulcers because fibrosis and shallow tissue depth may not allow sufficient tissue expansion from fluid pressure. To overcome these issues, the authors developed an edema scale (see Figure 2).
Edema has been reported to contribute to ulcer development, delayed healing, cellulitis,23 amputation risk,24 and surgical wound dehiscence.25 A prospective study24 of 575 patients with an infected diabetic foot ulcer found periwound edema was an independent risk factor for amputation, which was necessary in 159 patients (28%).
In her clinical review of managing chronic edema, Hedger26 points to the multiple local and systemic causes that require the correct etiologic diagnosis to determine appropriate management. A Cochrane review27 of compression for venous ulcers found compression increased wound healing rates compared with no compression.
Pain assessment. On admission to the authors’ clinic, comorbidities and age-associated changes that contribute to the patient’s pain experience, singly or in combination, are investigated. Patient perception of pain (presence or absence) is embedded in the infection screening. Nurses must be alert to the possibility of loss of protective sensation due to neuropathy or progression of arterial insufficiency and that infection may trigger a different sensation (eg, ache where sensation previously was absent).
Infection risk. Every assessment includes infection screening; if positive, physician consultation is required. Infected chronic wounds may increase size, undermining, or exudate amount.28 The classic signs and symptoms of infection are erythema, warmth, swelling, and pain. The Infectious Diseases Society of America’s29 clinical practice guideline for the diagnosis and treatment of diabetic foot infections requires the presence of ≥2 classic signs of infection for diagnosis of infection. Patients with diabetes may have elevated blood glucose when the ulcer is infected.
At the authors’ clinic, wound cultures are done if signs and symptoms of infection are evident. According to Dow,28 chronic wound response to infection may be subtle and require differentiation from tissue breakdown due to inadequate pressure offloading or insufficient perfusion. Biofilm is a potential source of infection, which may be controlled with maintenance debridement and topical antiseptics.13
A 2-year longitudinal cohort study30 compared the accuracy of a diagnosis of osteomyelitis in patients with diabetic wounds (N = 247) using the probe-to-bone (PTB) test and bone culture. During a mean 27.2-month follow-up, 30 patients were diagnosed with osteomyelitis. Overall, the PTB test was both highly sensitive (0.87) and highly specific (0.91). Although the negative predictive value was 0.98, the positive predictive value was only 0.57, indicating the PTB test may be better at ruling out osteomyelitis than at confirming it.
An observational study31 comparing the University of Texas (grade and stage) and Wagner (grade) ulcer classification systems as predictors of outcome in 194 patients with diabetic foot ulcers found increasing ulcer stage (which includes presence of infection) was associated with delayed healing and increased amputation risk.
The purpose of this clinical experience study was to describe lower leg ulcers and analyze wound assessment and associated clinical management data using the WTS. Specific wound assessment tool functions are examined in the following questions:
• What is the predictive performance of the WTS for wound healing or deterioration?
• What is the inter- and intrarater reliability of the WTS for clinic nurses experienced in using the WTS to assess leg ulcers?
• Can the identification or change in WTS findings be used to select or evaluate interventions and monitor response?
• What is the compliance with physician consultation when an asterisk-cued, high-risk finding or positive infection screen is identified?