An in-vitro study of the pressure-relieving properties of four wound dressings for foot ulcers

Pressure Distribution Properties in Wound Dressings Using Heel and Sacrum Indenters Under Clinically Relevant Loads

OBJECTIVE

To understand the pressure distribution characteristics of a border and silicone version of a next-generation multilayered foam dressing (A and B) compared with three commercially available dressings (C, D, and E) using a novel pressure distribution model with clinically relevant pressures.

METHODS

The testing setup included a support surface analog of K45 foam covered with polyurethane fabric, a high-resolution pressure mapping system, and a silicone layer to simulate overlying tissue. The dressing was exposed to clinically relevant loads of 30 and 80 mm Hg for 60 seconds using new sacral and heel indenters. A control was conducted using the same setup without a dressing. Statistical significance was determined using a 95% CI and t test with α = .05.

RESULTS

All dressings decreased pressure and increased contact area compared with the control ( P < 0.05). Dressings A and B had lower peak pressures than dressings C and E for both indenters. Dressings D and B had the largest contact areas and lowest pressures in the heel indenters, whereas dressing E had the smallest contact area and the highest pressures for both indenters. The results also demonstrated a strong negative correlation between the average pressure and the contact area for both indenters.

CONCLUSIONS

Using anatomically accurate indenters and clinically relevant pressures, the study demonstrated that dressings A and B significantly reduced interface pressure compared with no dressing, suggesting potential advantages for pressure redistribution in vulnerable areas. Additional clinical research in various care settings is needed to validate this study's findings.

Recent advances on biomedical applications of scaffolds in wound healing and dermal tissue engineering

The tissue engineering field has developed in response to the shortcomings related to the replacement of the tissues lost to disease or trauma: donor tissue rejection, chronic inflammation and donor tissue shortages. The driving force behind the tissue engineering is to avoid the mentioned issues by creating the biological substitutes capable of replacing the damaged tissue. This is done by combining the scaffolds, cells and signals in order to create the living, physiological, three-dimensional tissues. A wide variety of skin substitutes are used in the treatment of full-thickness injuries. Substitutes made from skin can harbour the latent viruses, and artificial skin grafts can heal with the extensive scarring, failing to regenerate structures such as glands, nerves and hair follicles. New and practical skin scaffold materials remain to be developed. The current article describes the important information about wound healing scaffolds. The scaffold types which were used in these fields were classified according to the accepted guideline of the biological medicine. Moreover, the present article gave the brief overview on the fundamentals of the tissue engineering, biodegradable polymer properties and their application in skin wound healing. Also, the present review discusses the type of the tissue engineered skin substitutes and modern wound dressings which promote the wound healing.

Investigating the pressure-reducing effect of wound dressings

OBJECTIVE

Currently, polyurethane foam dressings are commercially available from many manufacturers. However, the pressure-reducing effect is expected to differ by the formulation and combination of the main and secondary ingredients and by manufacturing method. In this study, we investigated the effects of pressure reduction using dressing materials with various structural characteristics, including polyurethane foam dressings based on the engineering point of view, focusing on the dry state.

METHOD

Pressure was measured in a model that simulated compression on the sacral region in a decubitus position. Pressure was measured for different dressings: ten products, consisting of five types of material (polyurethane foam, hydropolymeric, Hydrofiber, hydrocolloid, and low-adherent absorbent).

RESULTS

All dressings used in this study showed significantly reduced pressure. ALLEVYN Non-Adhesive had the lowest pressure at 35.833 ± 1.155 mmHg, and DuoDERM Extra Thin CGF had the highest pressure at 66.867 ± 1.060 mmHg. The pressure of the control was 74.667 ± 1.405 mmHg. The other dressings were: ALLEVYN Adhesive: 44.233 ± 0.777 mmHg; ALLEVYN Gentle Border: 46.967 ± 1.537mmHg; Mepilex Border: 53.867 ± 0.231 mmHg; Biatain Silicone: 56.000 ± 0.520 mmHg; TIELLE: 57.267 ± 3.403 mmHg;Versiva XC: 65.900 ± 0.800 mmHg; DuoDERM CGF: 57.267 ± 1.007 mmHg; and Melolin: 53.433 ± 1.973 mmHg.

CONCLUSION

The pressure-reducing effect of dressing differs not only by material type but also by product. That is, the pressure-reducing effect can differ even if the dressings are of the same material type, such as polyurethane foam. Our study investigated only the effect of materials and structural characteristics on the cushion of dressings in the dry state. Therefore, further investigation is needed to confirm the effect of pressure reduction by dressing to meet the conditions in the clinic.

Dressing plantar wounds with foam dressings, is it too much pressure?

Diabetes and its associated complications have become a major concern locally, nationally and internationally. One such complication is lower extremity amputation, commonly preceded by chronic ulceration. The cause of this tissue breakdown is multi-faceted, but includes an increase in pressure, particularly plantar pressure. As such, the choice of dressing to be applied to a plantar wound should ideally not increase this pressure further. A commonly used and possibly more bulky dressing is the foam dressing. This pilot study investigates the plantar pressures associated with three common foam dressings (Allevyn(®), Lyofoam(®) and Mepilex(®)) compared with a control dressing (Melolin(®)). Twelve healthy males and 19 females [SD] age 36.6 [10.4] were measured using the F-scan plantar pressure measurement system. Substantial variations in individual pressure changes occurred across the foot. No significant differences were identified, once a Bonferroni correction was applied. In healthy adults, it could be concluded that foam dressings do not have any effect on the plantar pressures of the foot. However, the need remains for a robust trial on a pathological population.

Case reports on the use of antimicrobial (silver impregnated) soft silicone foam dressing on infected diabetic foot ulcers

This article described four patients who had an episode of an infected foot ulcer, and subsequently treated with a novel antimicrobial soft silicone foam dressing together with standard off-loading and antibiotic therapy. Qualitative description of the ulcer-healing process was documented. All four ulcers showed positive wound contraction and reduction in size throughout the follow-up period ranging from 3 to 16 weeks. In addition, clinical signs of infection were absent at the end of the follow-up period. Moreover, surrounding skin maceration and trauma were absent in all wounds. Adequate moisture control was also achieved with the evidence of a healthy red granulating base, and a thin layer of clear light exudate in three out of the four cases. However, these reports had very little evidence to show the dressing's effectiveness in combating wound infection, but there might be some possible clinical efficacies of the dressing to control infection. Appropriate antibiotic therapy and off-loading are still essential components when treating diabetic foot infection.

A pilot study of the reaction forces at the heel during walking with the application of four different wound dressings

A laboratory investigation was conducted to ascertain the shock-absorbing properties of four wound dressings applied to the heel area of a convenience sample of volunteers. Four subjects walked across a force plate. Data were recorded for each subject barefoot, and then while the subject had a wound care dressing stuck to the plantar aspect of their heel. Eight trials were undertaken in the five different conditions resulting in 40 trials per subject. The results suggest that one dressing, Allevyn (Smith and Nephew Healthcare Ltd, Hull, UK), when compared to other dressing materials, exhibits similar reaction forces to the normal barefoot walking data for all subjects. However, results from the anterior posterior force show no major differences across the dressings when compared to barefoot walking. Wound care dressings that have an inherent shock-attenuating property may be advantageous when dealing with areas of the foot that come under excessive force.

A dressing history

Over the past 30 years as caregivers, clinicians have been exposed to a plethora of new advanced wound dressings. The moist wound care revolution began in the 1970s with the introduction of film and hydrocolloid dressings, and today these are the traditional types of dressings of the advanced dressing categories. Wound-healing science has progressed significantly over the same period, as a result of intense clinical and scientific research around these product introductions. Today, the clinician understands moist wound healing, occlusion, cost effectiveness, wound bed preparation and MMP activity to name but a few of the many concepts in wound care that have flourished as a result of technology and product advancement. This review article presents a condensed history of dressing development over the past 30 years. However, in addition, such advancement is discussed in respect to its adoption in different parts of the world. The largest single markets of the world are generally the United States of America and Europe; as such, the development of both practice and technology generally begins there. Much has been written about these markets in previous review articles. For the purposes of this review, the development of wound care and the maturing of practice is discussed in respect to Canada, Japan and Australia representing smaller geographical areas where the development has been more recent but nonetheless significant.

The influence of four wound dressings on the kinetics of human walking

OBJECTIVES

This in vivo study (the second phase of a research project first described in the February issue of Journal of Wound Care) reports on the influence of various wound dressings on the dynamics of human walking. Allevyn (Smith and Nephew), Biatain (Coloplast), Lyofoam (Seton Scholl) and Tielle (Johnson and Johnson) were used in this study. The investigation aimed to assess the ground reaction forces in the foot while the dressings were applied to the plantar surface of the foot.

METHOD

A strain gauge force plate system was used. Six subjects with 'normal' gait patterns and no foot pathology were recruited into the study. Eight trials were recorded for each subject. The peak push-off force, in the vertical component of the ground reaction force, and the maximum braking and propulsive forces in the medial-lateral component of the ground reaction force were estimated and reported.

RESULTS

Among the various dressings tested, Allevyn performed closest to barefoot in the peak push-off force and demonstrated an increased braking force at the deceleration point in the gait cycle.

CONCLUSION

These findings may have implications for clinicians selecting wound dressings for the treatment of certain foot ulcerations. However, further clinical research is warranted in this area.