Combining Hypochlorous Acid and a Hydroconductive Dressing for Wound Bed Preparation in Complex, Nonhealing Wounds

Providing patients with advanced wound care choices not only offers options for healing, but it also presents opportunities to explore and test technology synergies in wound care. One area of particular interest is the discovery of treatment regimens that improve wound bed preparation, which includes the deliberate and controlled removal of nonviable tissue, encrusted exudates, microbes, and associated biofilms. Wound healing cannot start with creating a clean wound bed.¹ We present here the synergies we have observed in the removal of unwanted matter from wounds using 2 technologies that may be synergistic: hypochlorous acid (HOCl)-containing solutions and hydroconductive dressings.

Hypochlorous acid. The use of prepackaged solutions of pure HOCl for wound cleansing is an emergent concept. Hyphochlorous acid often is confused with, but distinct from, an entirely different chemical species (ie, the hypochlorite anion or sodium hypochlorite) that is present in Dakin’s solution and is associated with cytotoxicity, even when diluted.² In contrast to the hypochlorite anion, HOCl exists naturally in mammalian tissue within the phagosomes of neutrophils and macrophages.³ Use of HOCl as a preservative in a cleansing solution does not introduce a harmful, non-natural substance to the fragile cells involved in wound healing; in fact, HOCl, in addition to acting as a powerful antimicrobial preservative, works well in the mechanical removal of microbes and necrotic tissue.^4-7 

The pH of materials introduced to the wound needs to be carefully monitored; in general, a pH between 3 and 6 is known to be associated with wound healing.^7-9 This is also the pH range associated with nonionized, pure HOCl— that is, HOCl without contamination with the problematic hypochlorite species that can be created from the HOCl at higher pH values.^9-11 A plethora of published evidence^4-7 supports the ability of this pH-controlled solution (Vashe Wound Solution, Urgo Medical North America) to mechanically remove necrotic tissue as well as microbes and biofilm matter. Additionally, recent studies show that when combined with negative pressure wound therapy in managing deep chronic and acute wounds, HOCl use can decrease length of hospital stay, decrease need for surgical debridement, and substantially improve wound healing.¹²

Hydroconductive dressings. Necrotic wounds, bioburden, and biofilm-containing wounds also benefit from the use of fiber-based technologies such as hydrofibers, alginates, and more recently, hydroconductive fibers.^13-17 The hydroconductive dressing (Drawtex; Urgo Medical North America), which has the advantage of not disintegrating in the wound, has the ability to physically transport negative elements such as microbes, debris/necrotic tissue, biofilm elements, matrix metalloproteinases, and wound exudates (substances that contain inflammatory cytokines and harmful proteases) away from the wound.^13-17 The hydroconductive dressing is available in sheets and rope and may be cut to the necessary size without affecting product integrity. The exact mechanism of a hydroconductive dressing’s ability to remove harmful components is not known and is a subject of continued research. In our practice, we use hydroconductive technology to implement wound bed preparation.

A study was conducted using both technologies to determine whether they could synergistically manage wounds of varying depths. These included a Mohs surgery wound with a failed skin graft, a large sacral wound, and a large wound of the upper thigh. Each had necrotic tissue visibly present, compromising the initiation of wound healing; in the case of the pressure ulcer, necrotic tissue hindered wound staging that would allow a treatment plan to be initiated. 

Materials and methods. Pure HOCl solution (Vashe) was utilized as the primary wound cleansing solution for patients in our practice who had both chronic and acute wounds. Performing a comprehensive wound assessment is a driving element in our wound care treatment decisions, which are always individualized and patient-centered. In addition to its use as the cleansing solution, HOCl was used to moisten the hydroconductive dressing. 

In each case, care was initially provided by our clinic staff. The wound beds first were cleansed using a 4 x 4 gauze, heavily saturated with the HOCl solution, to thoroughly and mechanically remove any debris. Then the hydroconductive dressing was lightly moistened with the HOCl solution and applied directly to the wound bed or packed into the wound. A secondary dressing that varied according to the anatomic location of the wound was applied over the hydroconductive dressing. Dressing changes were performed either every other day or every 3 days. Care was performed by a family member, staff at a skilled nursing facility, or visiting nurses. Patients followed up with the wound care specialist in the clinic to assess the wound and provide recommendations as appropriate for successful wound care. 

Case 1. A  61-year-old man with a medical history that included congestive heart failure, hypertension (HTN), atrial fibrillation, obesity, Stage V kidney disease with a previous renal transplant, hyperlipidemia, gastroesophageal reflux disease (GERD), and gout had a large squamous cell carcinoma removed from his scalp in a Mohs procedure, followed by a full-thickness skin graft that did not completely heal the wound (50% remained open). The wound measured 4.0 cm x 3.0 cm and contained 95% devitalized tissue consisting of brown eschar and yellow slough. The wound edges showed no signs of undermining, and no malodor or periwound erythema was noted. The wound was cleansed with the HOCl-based solution, and a hydroconductive dressing moistened with the HOCl solution was applied, followed by foam dressing cover. Dressing changes were performed 4 times a day, every other day. As wound healing progressed, the scalp wound decreased in size to 4.0 cm x 2.5 cm and was covered by 65% devitalized tissue, including yellow slough and brown eschar. The wound edges remained attached, and no periwound erythema or malodor was discerned (Figure 1A-C). 

Case 2. A 71-year-old man who tested positive for the novel coronavirus and who had a medical history that included schizophrenia, history of smoking, chronic kidney disease, cerebrovascular accident, chronic obstructive pulmonary disease, peripheral vascular disease, GERD, peripheral artery disease (PAD), and noninsulin-dependent diabetes mellitus type 2 was admitted to the intensive care unit with an unstageable pressure injury to the sacrum. The wound bed was covered with 100% devitalized tissue including grey/yellow slough in the center of the wound bed. The wound measured 7.0 cm x 11.4 cm, with no periwound erythema. Moderate serous drainage was observed on the previously applied dressing. The wound was cleansed with HOCl-based solution, and a hydroconductive dressing was lightly moistened with the HOCl solution and applied to the wound bed and covered using a foam dressing with an adhesive border. Dressing changes were provided daily,  4 times a day. The devitalized tissue covering the base of the wound bed began to soften, and clinicians were able to manually remove the loose, devitalized tissue, exposing red moist tissue in the wound bed. After 6 days of treatment, a substantial decrease in devitalized tissue facilitated assessment of the wound bed base as a  Stage 4 pressure injury (Figure 2A-C). Appropriate treatment subsequently was provided.

Case 3.  A 75-year-old woman with a medical history that included HTN, type 2 diabetes, history of smoking, hyperlipidemia, and PAD had a right upper thigh wound with intact eschar and +2/+3 edema. She had been seen by Dermatology, a tertiary hospital, and another wound care provider for second opinions due to the chronic nature of the wound, with no change despite multiple interventions and recommendations; treatment had included revascularization of the right lower extremity common femoral artery, endarterectomy, iliac stenting, and superficial femoral artery angioplasty, resulting in erythema and edema in the right thigh. She had been prescribed multiple antibiotics and an antihistamine and steroids without improvement. 

The patient was referred to our practice due to continued eschar presence and lack of proper wound bed preparation and healing. When she was first seen, the area on the right upper thigh was covered with brown eschar that had been present for months and was exquisitely tender. The wound measured 3.0 cm x 10.0 cm; the periwound area was pink and warm to touch. Her current treatment (which she stated had been used for months) was daily application of an enzymatic debriding agent. Treatment with Vashe and Drawtex commenced; over the 6 following months, a gradual decrease in the amount of yellow slough in the base of the wound bed was observed until the area was free of necrotic tissue (Figure 3A-C).

Moist wound healing is known to be imperative for wound healing; the moisture balance achieved using the HOCl solution combined with the hydroconductive dressing was found to be a highly effective way to remove devitalized tissue and bacteria so healing can begin. The probable synergy between HOCl and hydroconductive fibers is in keeping with the type of expectations associated with other, more expensive enzyme-based debriding products. Based largely on the outcomes of cases such as those presented herein, we consistently use the HOCl-based solution to mechanically cleanse the wound of necrotic debris and microbes, combined with the added capabilities of hydroconductive dressings, to optimize the wound bed for healing.

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 Global. This article was not subject to the Wound Management & Prevention peer-review process.