To anybody whose professional life is in some way connected to wound care dressings, last month’s announcement that MediPlus expanded its portfolio to include silver (Ag) dressings was likely recognized as a very important headline. But why is it so important to offer silver? One way to appreciate this is to understand the evolution of wound care dressings, since many of the products in that evolutionary timeline are still sold and used today.

There have been several critical milestones in the evolution of wound care that have lead to noticeable improvements in treatment outcomes. Each step reflects a better understanding of the needs of the wound and the needs of the patient, which, when supported, have lead to an increase in the quality, speed and reliability of wound healing. Each step forward has led to a new plateau of improvement, which in turn has served as the new baseline for standards of care. In most instances, the step involved the recognition of a barrier to healing and the adoption of means to overcome that barrier.

Let There be Gauze!

Looking back approximately 100 years ago, it was an era when gauze was the first choice for wound care dressing. This era represents the first baseline and lengthiest plateau in the wound care dressing evolution.

Wounds underwent surgical, mechanical enzymatic or chemical debridement to expose viable tissue. Dry or saline-moistened gauze that was changed several times a day and packed into the wound was often accompanied by the liberal use of antiseptics at each dressing change. Under these gauze protocols, healing was frequently disrupted since multiple daily dressing changes and moist gauze enabled a direct route for microbial colonization of the wound.

Licking a Wound with Moist Wound Dressings

It would eventually be discovered that the first “advanced” moist wound dressings—transparent films—could seal the wound from further contamination and allow the natural exudate to support the physiology of wound healing

Dressing options would soon rapidly evolve to optimize moisture levels and conform to wound surfaces in ever more efficient ways. For example, dressings were left in place longer, reducing the mechanical and thermal disruptions to the healing process, reducing time to healing, and the resources expended on dressing changes. As the wound began to heal, the dressing selection could be modified to provide optimal moisture levels for healing at each stage and to reflect the changes associated with the wounds progression.

The practice of moist wound healing after wound debridement soon became state-of-the-art, and with the introduction of hydrogels, it provided an alternative to surgical and mechanical debridement. Consequently, most wounds could now be managed by non-physician practitioners at lower cost and with dramatic increases in success.

How Compression Caused an Expansion in Wound Dressings

Moist wound healing and advanced wound care represented a new healing plateau of wound care that lasted with minor changes for decades. The next evolution came from the recognition that different wound etiologies required targeted adjuvant therapy to get to the next level of healing.

The most dramatic demonstration of this philosophy came with the adoption ofcompression to support the healing of venous stasis ulcers. Once compression was accepted as a best practice, the methods to deliver effective compression proliferated from four-layer elastic to two-layer short stretch, with phenomenal changes documented in healing outcome.

Additionally, etiology focus directly improved the outcome of other chronic wound groups by demonstrating the dramatic efficacy of total contact casting for neuropathic diabetic foot ulcers and pressure relief for pressure ulcers.

Once wound etiology was addressed (e.g. restoration of circulation) and a moist wound environment was provided, additional barriers to healing became apparent. Two key related concepts arose that focused attention back to the local conditions within the wound: matrix metalloproteinases (MMPs), which surfaced as a hot topic of discussion and research, and critical colonization came forward to account for wounds stalled in the inflammatory stages of healing.

Solving the Riddle of Critical Colonization with Advanced Wound Dressings

Although all wounds might have been seen as colonized, not all colonized wounds progressed to infection, and not all colonized wounds healed routinely. Instead, as many wounds would stall in the inflammatory stage of healing, it became apparent that one of the factors involved in this barrier to healing was the presence of microbes in sufficient quantities to stimulate a chronic inflammatory response by the host.

The concept of critical colonization was recognized as a state between contamination levels that were managed and resolved by host defenses and full-blown infection with the classic signs of heat, redness, swelling and pain. The objective soon became one of shifting bioburden within the wound (i.e., the number of organisms and their toxic products) back towards levels below those that generated a chronic inflammatory state and away from the serious risk and expense involved with wound inflection.

Silver Dressings Becomes a Gold Standard

The routine use of antiseptics as prophylaxis against infection had declined dramatically as study of the stages and physiology of wound healing revealed their toxic effect on cells and the processes required for healing. Local antibiotics were known to have limited spectra of activity, with the potential to generate resistant microbial strains. Of utmost importance was the fact that neither worked well with the advanced wound care dressings, bandaging systems or TCC that had become so important in supporting efficient wound repair.

Silver, by comparison, had a long history as an antimicrobial agent from its use in silver-coated vessels in ancient times to reduce the spoilage of wine and water. It had also demonstrated great success in helping to prevent infection in burn patients when it was formulated as silver sulphadiazine cream.

Silver could be readily incorporated into advanced wound care dressings as elemental silver (e.g., Acticoat®, Silverlon®) or in any number of silver compounds (silver lactate). Silver dressings preserved the beneficial properties of advanced wound care moisture interactive dressings while adding antimicrobial activity to stop microbial populations progressing from contamination to critical colonization to infection. Silver also provided effective antimicrobial action, a broad spectrum of coverage with low cytotoxicity and the long duration of action required for efficacy under bandaging and advanced wound care dressings.

Ultimately, the evolution of wound care dressings that would manifest with a rapid adoption of silver wound care dressings would also signify acknowledgement that the prevention of infection and critical colonization has beneficial consequences on the speed and cost of wound healing treatment.

The Real Value of Silver

Although silver dressings are more expensive to produce—and in turn cost more for a treatment center—they are treated as standard wound dressings under the HCPCS Level II reimbursement system.

Inexplicably, silver foam dressings are reimbursed at the same rate as non-silver foam dressings. However, obtaining FDA 510(k) marketing approval for silver dressings has now become a more intensive and costly process, requiring significantly more supporting clinical and laboratory data.

Wound care dressing manufacturers with the most recent 510(k) clearances meet the new standards demanded by the FDA. Manufacturers of older established products should be challenged to document similar performance parameters before being considered for use in the clinic.

MediPlus’ Silver Foam dressings were recently cleared by the FDA under these new standards. MediPurpose is now marketing these dressings at a very competitive price point to be more affordable, and thus more widely available in appropriate treatment settings to a larger patient population.

Do you use or sell silver wound dressings? What are your opinions about their efficacy and value?