A Prospective, Open-Label Study to Assess the Clinical Performance of a Foam Dressing in the Management of Chronic Wounds
Treatment of patients with chronic wounds should address the underlying disease and the selection appropriate products, including the stage-adapted use of hydroactive wound dressings.1 It has been observed that hydroactive dressings (eg, hydrogels, polyurethane foams, and alginates) maintain moist wound conditions, which may encourage the migration of key cells (macrophages, keratinocytes, fibroblasts, and endothelial cells) that facilitate granulation and re-epithelialization.2 However, excessive wound fluid, burdened with excessive protease levels, has been shown to interfere with wound healing in in vivo clinical studies3 and it also has been noted that inappropriate control of wound exudate can lead to significant clinical problems, such as maceration of the surrounding skin, skin breakdown, wound enlargement, and increased pain.4 On the other hand, reviews suggest that if a wound is kept too dry, the healing process may be delayed and dressing changes more painful due to dressing adherence to the wound bed.5 Application of a dressing that can remove excessive wound exudate while retaining a moist environment that supports the healing process may help achieve the right balance of moisture to support the wound-healing process.5-7
Polyurethane foam dressings were introduced into clinical practice to facilitate maintenance of a moist wound environment and absorb excessive wound exudate.8 The foam dressing PermaFoam® Cavity (Paul Hartmann AG, Heidenheim, Germany) was developed for the management of medium to heavily exuding shallow as well as deep, cavernous wounds to absorb excessive exudate while retaining a moist wound environment. When folded, the dressing may be especially suited for packing wound cavities and deep ulcers, a frequent wound management challenge.
The purpose of this study was to assess the clinical performance, potential for supporting wound healing, and patient tolerance of this polyurethane foam dressing.
Materials and Methods
Outpatients with chronic, nonhealing or acute wounds of different etiologies in 15 German medical centers (seven physician-run, eight community nursing services were eligible to participate in the evaluation. No inclusion or exclusion criteria were provided, rendering the study exempt from IRB approval or informed consent restrictions according to European research requirements. The CE-certified foam dressing was used according to manufacturer recommendations, stated previously. Physicians recruited patients with wounds of varying depths if management with the foam dressing was indicated. A questionnaire was completed at the beginning of the study that included the patients’ age, sex, type and duration of the wound, prior treatment, physical condition, and concomitant medication. The attending physicians visually assessed the clinical appearance of the wound at the beginning of the study and after three dressing changes, estimating the proportion (%) of slough/eschar, granulation, and epithelial tissue in the wound bed. Also assessed were exudate level (rated using a four-point scale as none, sparse, moderate, heavy); periwound skin condition (no abnormal findings, edema, erythema, hyperthermia, maceration, eczema, hyperkeratosis, infection, and other); and wound pain (patient verbal rating scale: none, mild, moderate, strong). Wound size was determined using a tape measure and depth was estimated by the physicians.
Experience from previous observational studies9,10 have shown that the questionnaire was able to effectively evaluate the clinical performance of a wound dressing. Additionally, inter-observer variations were minimized by including definitions of the items recorded and involving a number of centers.
Physicians also rated absorption capacity, wound cleansing effect, patient reported tolerability, ease of product handling, contact of dressing with wound surface, conformability, and ease of dressing removal using a scale that denoted very good, good, satisfactory, adequate, and poor.
On average, dressings were changed every 3 days; the total time of the study was 9 days according to the physician-documented dressing changes. Physicians were not directed how many times to change the dressings — the dressings were changed when clinically indicated. A secondary dressing, chosen by the physician and based on wound assessment needs and personal experience, was used to cover the foam dressing. At the end of the observational study, physicians, nursing staff, and patients subjectively rated their clinical experience with the dressing as very good, good, satisfactory, adequate, or poor. Clinicians rated the dressing’s performance and documented any adverse events and patients were asked to rate dressing comfort and tolerance for dressing application and removal.
All variables were summarized using descriptive statistics (STATISTICA 6.1, StatSoft, Tulsa, Okla).
Study participants included 23 men and 34 women with a mean age of 69 years (±16 years, range 29 to 96 years) and a variety of wound etiologies. The majority of patients had chronic wounds including pressure ulcers (16 patients), venous or mixed arterial/venous ulcers (14 patients), and delayed postoperative wound healing (12 patients) (see Table 1). Other wound etiologies included pilonidal sinus (4), tumor wound (4), and acute traumatic wound (2). Five (5) patients had peripheral neuropathy, six had diabetes mellitus and a pressure ulcer, and two had diabetes mellitus and gangrene.
Physician assessment of the patients determined that 39 patients (68%) were in good physical condition or that their general health condition was consistent with age. The general health of 18 (32%) was poor due to comorbidities and 27 (48%) received concomitant drug treatment such as anticoagulants, antidiabetics, antibiotics, or antihypertensives.
Patients had their wounds for an average of 1.4 years (± 4.1 years, median 2 months, range 1 day to 25 years). Of the 57 wounds studied, 25 were non-shallow (considered cavities) and 46 had been treated previously with other wound dressings including antiseptic-containing gauze, alginates, hydrogels, laminate compresses, and foam dressings.
Concomitant to the treatment with the foam dressing, 54 patients received adjunctive treatment, including physician-applied compression therapy (14 patients), pressure relief using special mattresses or pressure-relieving shoes (26 patients), nutritional support (six patients), antibiotics (three patients), and varicose vein surgery and physical therapy (one). Six patients received “other” therapies and patients could receive more than one type of adjunctive treatment.
Because the study dressing has no adhesive border, a secondary dressing is required. For secondary wound coverage, participants used 11 different products in the course of this study. Of the 169 documented dressing changes, 102 (60%) were physician-applied gauze dressing, 34 (20%) were foam dressings, and 12 (7%) were wound dressing pads.
Clinicians documented one or multiple reasons for enrolling patients: manage chronic, poorly healing wound (49%); foam dressing treatment initial choice (26%); prior therapy not successful (23%); management or recurrent wound (7%); and/or problems with prior therapy (3%).
Wound outcomes. The average treatment time was 9 days (± 5.5 days, median 8 days) and the dressing was changed, on average, once every 3 days. Overall, 169 dressing changes were documented. In one patient, the foam dressing had been changed only twice; one patient died after the first dressing change.
At baseline evaluation, an average of 54% (± 33%, median 50%) of the wound surface was covered with slough, granulation tissue covered 41% (± 31%, median 40%), and epithelial tissue covered 4% (± 8% median 0%) of the wound bed. After three dressing changes, the relative proportion shifted to 29% (± 25%, median 20%), 59% (± 24%, median 60%), and 11% (±14%, median 10%), respectively (see Figure 1). Similarly, slough characteristics changed: necrotic slough decreased from 23% to 5%. In addition, the proportion of wounds with heavy exudate changed from 32% at baseline evaluation to 11% at final evaluation (see Figure 2). In two patients, an accumulation of exudate was observed in the folds of the foam dressing; one of these patients had exceptionally heavy amounts of exudate. The number of wounds with cavities decreased from 25 to 18.
Patient-reported pain. The proportion of patients reporting strong or moderate wound pain decreased from 45% at baseline evaluation to 26% at final evaluation. At the same time, the number of patients without wound-related pain increased from 21% to 33% (see Figure 3). Parallel to reported lower pain levels, the need for analgesic drug treatment decreased. At the beginning of the study, more than 17% of the patients had taken analgesics because of permanent wound pain or pain during dressing changes; after treatment with the foam dressing, 11% needed analgesics.
Periwound skin. At baseline evaluation, the periwound skin of 28 patients (49%) was assessed as having no abnormal findings. At final evaluation, this number increased to 67%. Reductions were observed in the proportion of patients with edema (from 17.5% to 7%), maceration (from 10.5% to 3.5%), and hyperthermia (from 16% to 7%) (see Table 2).
Dressing performance ratings. Between 80% and 90% of the physicians rated the product’s absorption capacity, wound cleansing effect, tolerability by patients, ease of product handling, contact to wound surface, conformability, and ease of removal as “very good” or “good.” When asked for their overall judgment of the effect of the foam dressing on wound healing, more than 90% of physicians rated the product “very good” and “good.” More than 85% of the physicians judged that, in comparison with the initial examination, the condition of the wounds “improved” or “clearly improved”, 13% said wound condition remained unchanged, and 2% reported that wound condition had deteriorated.
Between 80% and 85% of patients rated the dressing and dressing removal comfort as “very good” or “good.” Overall impression of treatment with the foam dressing was rated as “very good” by 39% and as “good” by 44% of patients.
The clinical performance of the foam dressing in this study suggests it is an appropriate choice for treating heavily to moderately exuding chronic wounds. The dressing was well tolerated by patients and rated as “easy to handle” by the majority of physicians and nursing staff.
The results are consistent with other studies using this product for local wound care. Open, non-comparative trials using the foam dressing to manage patients with diabetic foot lesions11 or venous leg ulcers12 resulted in a considerable reduction in wound area, pain, and exudate levels. Additionally, randomized, controlled studies involving patients with chronic wounds confirm the good clinical performance and ease of application of foam dressings in the treatment of chronic wounds.13,14
Owing to their absorption and retention capacity, foam dressings have been shown to generally maintain a balance between moisture and exudate management that supports wound healing.8,15 Because this was a small non-randomized and non-comparative clinical observational trial, information about the clinical performance and tolerance of the treatment with the foam dressing is preliminary and does not provide proof of efficacy. However, the results offer real-world outcomes obtained in a panel of patients with nonhealing wounds commonly encountered in daily practice.
Most patients in this study suffered from chronic, nonhealing wounds with correspondingly poor wound bed and periwound skin condition. In most wounds studied, more than half the area was covered with slough and one in three wounds had heavy exudate. Results indicate that an excessive amount of exudate causes the degradation of extracellular matrix proteins and growth factors, prolongs inflammation, interferes with cell proliferation, and eventually leads to the breakdown of the vulnerable granulation tissue.16,17 Therefore, it has been suggested that absorbing excessive wound fluid, while still providing a moist environment, is important for the healing process of chronic wounds.18
The skin surrounding nonhealing ulcers is sensitive and prone to macerations, erythema, edema, and erosions due to excessive wound exudate.19 This is especially true in elderly people, whose skin is often sensitive due to age-related changes.20 Dressings should protect the surrounding skin from excessive exudate. The study results suggest that the dressing effectively handles exudate because the number of patients with surrounding skin maceration was lower at the final evaluation and the percentage of patients with normal perilesional skin increased from 49% to nearly 67% at the end of the study. While the concomitant use of supportive measures (eg, pressure relief and compression bandages) most likely improved the peristomal skin condition and, in the case of venous ulcers, helped reduce exudate levels, the improvements during an average of 9 days of care were encouraging. More than 80% of examining physicians judged the foam dressing’s exudate management as “very good” or “good”.
Several published reviews on pain associated with chronic wounds has a notable impact on quality of life.21,22 Dressing removal is considered to be the most painful procedure apart from sharp debridement for most patients.23 To prevent painful dressing changes, design and material of dressings have been optimized to be less traumatic — ie, clinicians should choose dressings that do not stick to the wound.23 In this study, the proportion of patients reporting wound pain decreased and ease of removal was rated “very good” by the majority of physicians. Furthermore, the findings suggest that wound fluid handling characteristics were well balanced. If not enough fluid had been absorbed, the proportion of wounds with periwound maceration would have increased; if too much fluid been absorbed, the dressing would have adhered to the wound bed, causing pain on removal.
This study had a number of limitations. The number of patients was small and the descriptions of the wound surface and depth were based on approximations of the examining physicians and/or patients without additional confirmation from other professionals. Exudate amount also was estimated by the physicians; their subjective observations often are presented in percents as opposed to raw data. The observed reduction in the proportion of highly exudating wounds may have been attributed to the absorptive properties of the dressing, observed advancement of wounds along the healing continuum, or the effects of additional (secondary) dressings and concomitant therapies. In the absence of a control group or a larger sample size, the effects of each variable on the outcomes observed cannot be ascertained.
This non-randomized, non-comparative trial involving 57 outpatients with (mostly) nonhealing wounds provides interesting initial evidence about the clinical performance of a foam dressing. Wound state as well as periwound skin improved in the course of the study. These results suggest that the foam dressing is an appropriate choice for treating heavily to moderately exuding chronic wounds.
This study was sponsored by a grant from Paul Hartmann AG, Heidenheim, Germany.