Combining Negative Pressure Wound Therapy With a Lipidocolloid Dressing in the Management of Acute and Chronic Wounds: Results of a Clinical Study

Extensively described in the 1990s, negative pressure wound therapy (NPWT) promotes the wound healing process and is an effective way to manage all types of acute and chronic wounds, including those considered refractory to other therapeutic procedures.^1,2 This nonpharmacological therapy has emerged as a cutting-edge technology because it may provide an alternative solution for health care professionals involved in wound care management and as such may represent one of the most successful treatment modalities for wound healing.³ 

Despite positive clinical outcomes, reviews of the literature^4,5 regarding patients’ experiences show varying side effects of this procedure such as pain, stress, and anxiety. Qualitative research⁶ shows patients receiving NPWT felt stress relative to the care environment and the dressing change process; specifically, foam dressing change often required prescription of oral analgesics. In a more recent study⁷ that described the effect of NPWT-related pain on the daily life activities on patients following abdominal surgery, pain was mostly reported during foam dressing changes and wrap removal; in addition, that impairment caused some patients to discontinue treatment. This commonly reported pain during NPWT foam removal is probably due to the ingrowth of granulation tissue in the micropores present on the foam.⁸ 

Authors recommend a range of strategies to reduce pain at removal of the foam, including the use of analgesics or local anesthetics 30 to 60 minutes before, impregnating the foam with saline solution before removal, switching the pump off 1 hour before dressing removal, and gradually reducing the negative pressure.^9,10 Pain on removal also may be avoided or reduced by using a nonadherent dressing beneath the foam dressing. 

UrgoTul (URGO Medical, Fort Worth, TX) is a nonadhesive, nonocclusive contact layer made of nonwoven polyester mesh impregnated with hydrocolloid particles dispersed in a petroleum jelly matrix. Numerous prospective clinical trials¹¹ have demonstrated the benefits of this dressing in the local treatment of acute and chronic wounds. In France, caregivers familiar with the NPWT procedure often introduce an UrgoTul contact layer between the NPWT foam and the wound bed. Its small mesh size prevents granulation tissue from migrating into the foam, reducing the risk of damaging granulation buds at removal. This procedure allows a painless or less painful removal of the foam dressing and results in improved patient acceptability of the NPWT procedure. This dressing is widely recognized to induce a painless dressing removal, as reported in clinical pediatric trials¹² and in the management of congenital epidermolysis bullosa skin lesions,¹³ and its use is supported by a large survey¹³ (N = >5000) on the incidence of pain in patients presenting with acute and chronic wounds. 

The aim of this clinical study was to evaluate the benefits of the UrgoTul contact layer with regard to patient pain experiences when used in combination with NPWT foam in the local treatment of acute and chronic wounds.

A multicenter clinical study was conducted in French hospital units including departments of plastic and reconstructive surgery, vascular surgery, general surgery, and dermatology.

The primary objective of this clinical evaluation was to assess the protection afforded by the UrgoTul contact layer when applied in combination with the NPWT system and its capacity to reduce pain during dressing removal based on qualitative evaluations from the treated patients. Secondary objectives were to evaluate efficacy (based on wound size and depth reduction), patient tolerance, and acceptability (ease of removal) of this combination as documented by health care professionals.

In this trial, the NPWT system (V.A.C. ULTRA THERAPY SYSTEM; KCI, an Acelity Company, San Antonio, TX) utilized a polyurethane (black sponge) or polyvinyl alcohol (white sponge) foam dressing cut to match the shape of the wound, and a polyurethane film that is placed over the top to form an airtight covering. The main indications of the NPWT systems used are promotion of a granulation tissue, drainage of exudates, and wound bed preparation; these benefits of NPWT work together to promote healing. During the current study, black foam was used almost exclusively (97%) and a starting negative pressure of 100 mm Hg or 125 mm Hg was applied either continuously or intermittently at the investigator’s convenience.

Population and pathology data at baseline. A total of 66 patients were included and followed in 8 hospital units distributed throughout France. The majority of the patients were male (68%), with an average age of 57 years; nearly half (42%) had high blood pressure often associated with cardiovascular risk factors (41% had cardiovascular disease, 18% had diabetes, and 25% had hyperlipidemia; 42% were smokers). 

Nearly 64% of the treated wounds were acute; most of them were postoperative (others were trauma injuries and burns) and had been present for an average of 16 (median 7) days. Chronic wounds accounted for 36% of those evaluated in this trial; these were mainly pressure ulcers (others were chronic postoperative wounds, leg ulcers, or diabetic foot ulcers) and had been present for an average of 226 (median 90) days.

Among the treated wounds, 53% were located on the inferior limb (leg, thigh, or foot) and nearly 30% were in the abdominal and pelvic areas. Exposed structures included muscles (23.7%), adipose tissue (19.9%), aponeurosis (14.1%), tendons (11.5%), and periosteum (11.5%). Perilesional skin was considered as healthy for only 41% of the wounds at the beginning of the treatment.

Measurements taken at baseline showed the treated wounds had an average surface area of 111 cm² in and were 35.8 mm deep (calculated on the basis of 56 wounds with involvement of subcutaneous tissues). More than 40% of the treated wounds were clinically infected, and in most cases this prompted administration of systemic antibiotherapy.

Before treatment with the NPWT-  UrgoTul combination, pain was noted during dressing changes in 82% of the cases. Before the use of the contact layer was initiated, patients receiving NPWT noted their pain as severe (47%), moderate (37%), minimal (15%), and absent (18%); in addition, pain was also documented as present (severe or moderate) between 2 dressing changes in 66% of the patients, despite the fact that nearly 60% of them had an oral analgesics prescription.

Procedure. Investigating physicians were asked to treat their patients until they considered the use of the NPWT procedure was no longer justified, with a change frequency of this procedure at their total discretion. Each dressing change was documented in a case report form; clinical evaluations, including area tracings and photographs, were taken at baseline and at the end of the treatment. Wound depth also was measured when the investigator considered it to be deep (involvement of subcutaneous tissues).

After cleansing the wound bed using the routine practices of the department (saline and/or local antiseptic), the contact layer was applied directly on the wound bed; then, the NPWT foam dressing was cut to match the size of the wound and positioned on top of the UrgoTul dressing (see Figure 1, Figure 2, and Figure 3).

This clinical evaluation involved 1145 treatment days and documented 320 local care procedures, including the clinical evaluations. On average, the dressings were removed every 3.8 ± 1.1 days (all wounds considered), and mean treatment duration was 17 days.

During the treatment period, >52% of patients  deemed dressing changes to be totally painless and 35% experienced minor pain; the remaining 13% generating baseline pain scores of moderate (9%) or severe (3%) versus 73% of the dressing changes at baseline. In addition, no pain was noted between dressing changes in 66% of patients (vs. 34% at baseline), and when pain occurred, it was mainly occasional (56% vs. 34% at baseline) or minor (60% vs. 26% at baseline). 

Physicians and nursing staff evaluated acceptability at each dressing removal throughout the entire treatment period for each patient. Overall, removal of the foam and contact layer combination was considered very easy or easy in 94% of the cases (see Figure 4 and Figure 5), and adherence of the NPWT-UrgoTul combination to the wound bed was reported as absent in 88% of the cases. Bleeding on removal of the contact layer was absent or minor in 91% of cases, and maceration was absent or minor in 83% of the dressing changes. 

The evaluation of efficacy at the end of the treatment period found mean wound size area was 72.1 cm² (all wounds considered), corresponding to a mean reduction of 19%, and mean depth was 22.7 mm, a 54% average reduction). 

When acute and chronic wounds were considered separately, acute wounds reduced in surface area and depth by 33.5% and 53%, respectively, over a mean treatment period of 15 days and chronic wounds by 9% and 52%, respectively, over a mean treatment period of 21.4 days. The interval between foam removal was 3.8 and 3.7 days for acute and chronic wounds, respectively.

At the end of this evaluation, after a mean treatment duration of 17 days, 17% of the wounds were still considered by the investigating physician to be clinically infected (vs 42.4% at baseline). 

The condition of the perilesional skin of the treated wounds was documented by the physicians as improved at the end of the trial. 

NPWT is widely adopted by many clinicians and represents a viable therapeutic wound care option. Although this procedure is an effective wound treatment, research¹⁴ has highlighted a clear need for its improvement, particularly in reducing pain at removal of the wound fillers or dressings. Wound-related pain is a common phenomenon for many patients and in recent years, awareness of its impact on both wound healing and quality of life has been growing.⁷ It is important to manage pain, not only for patient well-being and treatment satisfaction, but also for the healing process, which could be delayed. The combination of the lipidocolloid contact layer UrgoTul and NPWT foam seems to be an effective part of the solution. 

The open clinical trial conducted to assess the protection afforded by this contact layer when used underneath the NPWT foam and its impact on the pain parameter at the dressing removal reported positive clinical outcomes through hundreds of care operations. This combination substantially reduced pain intensity during the dressing changes, likely because no granulation tissue was embedded into the foam, which could be removed without causing damage to the newly formed tissue.

The use of the UrgoTul dressing as part of the NPWT procedure helped decrease dressing change-associated pain, increasing patient and clinician acceptance and potential success of treatment.

Pearls for Practice is made possible through the support of Urgo Medical, Fort Worth, TX (www.urgomedical.com). The opinions and statements of the clinicians providing Pearls for Practice are specific to the respective authors and not necessarily those of Urgo Medical, Wound Management & Prevention, or HMP.