The field of wound care is evolving rapidly as novel technologies are steadily being developed.
In a session at the virtual 2020 Symposium on Advanced Wound Care fall meeting, Hollie Mangrum, PT, DPT, CWS, and Renee Cordrey, PT, PhD(c), MSPT, MPH, CWS, reviewed six new and emerging biophysical approaches.
Wounds that heal improperly, incompletely or too slowly may lead to chronic wounds and morbidity that can impose a significant burden on the patient and provider. It comes as no surprise, then, that clinicians and researchers have developed advanced wound care technologies to support safe and optimized healing.
“Physical therapists started using energy modalities, such as electrical stimulation and ultraviolet light, several decades ago,” explained Dr. Cordrey. These technologies support recovery by stimulating a patient’s natural wound-healing processes. Electrical stimulation sends electrical pulses through electrodes attached to the wound site, which increases capillary density and perfusion to support oxygenation. Because cells have an electrical charge, the polarity of the electrode can draw oppositely charged cells, through which electrical stimulation also promotes autolytic debridement and collagen deposition (Nursing 2002;32[12]:17).
“In fact, electrical stimulation earned a strength of evidence of A in the AHCPR [Agency for Health Care Policy and Research] pressure ulcer treatment guidelines in the early 1990s,” Dr. Cordrey said. “Since then, further research has improved our use of the older modalities, but a greater understanding of chronic wound physiology led to the development of new tools to promote wound healing via different pathways.”
Topical Oxygen Therapy
Topical oxygen therapy (TOT) is the topical application of pure, humidified oxygen to a wound to hinder the growth of bacteria, enhance growth factor signaling, and promote angiogenesis and collagen synthesis. TOT is delivered via sealed chambers or topical diffusers. Patients using topical oxygen chambers undergo TOT at home for 90-minute intervals several times weekly, whereas topical diffusers are worn continuously under a dressing.
Two randomized controlled trials showed significant improvements with TOT in healing rates among patients with diabetic foot ulcers, including patients with large wounds (J Wound Care 2018;27:S30-S45 and Diabetes Care 2020;43[3]:616-624). Importantly, the speakers noted precautions to take with TOT to ensure optimal oxygen penetration, for example, removing eschar and avoiding petroleum-based dressings.
Cold Atmospheric Plasma
Cold atmospheric plasma (CAP) is the application of partially ionized gases to disinfect, promote tissue growth and treat itch around a healing wound. Daily CAP treatment is indicated for chronic wounds, decreasing bacterial load, preparing donor sites for a skin graft, skin conditions such as itch and eczema, scar treatment, and pain relief. Anticancer applications of CAP are also being investigated.
Several studies have reported safe and effective reductions in bacterial load and accelerated wound healing with the use of CAP in different clinical settings (Br J Dermatol 2010;163[1]:78-82; Br J Dermatol 2012;167[2]:404-410; Clin Plasma Med 2013;1[2]:25-30; J Eur Acad Dermatol Venereol 2015;29[1]:148-155; Wound Repair Regen 2013;21[6]:800-807). CAP users should be cautious of the generation of reactive oxygen species and potential risks for skin damage.
Photobiomodulation
Photobiomodulation is a means of altering cell behavior using light to promote healing. The mechanisms of action are complex, but in general, light absorption by tissues causes broad changes in cell signaling, which triggers the release of growth factors and reactive oxygen species and modulates pain response and inflammation. Depending on the wavelength of light used (red vs. blue light), different types of cells will respond. Macrophages, lymphocytes, fibroblasts and epithelial cells all respond in ways that relieve pain and promote more rapid healing.
Clinical studies of the use of red light showed reduced pain and wound improvement. Preclinical studies using blue light found decreased bacteria levels, improved perfusion and altered keratin synthesis (Lasers Med Sci 2018;33[4]:729-735; Int J Low Extrem Wounds 2017;16[1]:29-35; Evid Based Complement Alternat Med 2013;960240; Lasers Med Sci 2017;32[2]:275-282; J Vis Exp 2017;[122]:54997; Injury 2011;42[9]:917-921). Precautions with this treatment include monitoring for inflammatory responses and potential tissue damage.
Ultraviolet-C
UV-C light is invisible light that is used to stimulate vasodilation, histamine and growth factor release, and wound contraction. At therapeutic doses, UV-C causes DNA damage that destroys pathogens without causing irreparable damage to human cells. UV-C is effective against antibiotic-resistant organisms, and UV-C resistance has not been reported. There are no standard protocols for the use of UV-C, but it can be applied in short, up to 120-second treatments. Notably, UV-C is contraindicated in patients with a history of skin cancer.
“I really think ultraviolet-C, which is covered under Medicare, is underused. It is a simple, safe and inexpensive means to treat superficial infections and critical colonization, even with organisms resistant to our antibiotics,” Dr. Cordrey said.
Extracorporeal Shock Wave Therapy
Extracorporeal shock wave therapy (ESWT) is an emerging technology that uses sound waves to promote wound healing and decrease pain by stimulating inflammation, growth factor release, and production of collagen and nitric oxide synthase; disrupting biofilms; and promoting angiogenesis, fibroblast proliferation, cell migration and keratinocyte activity. Meta-analyses show improved healing of diabetic foot ulcers with ESWT compared with standard-of-care treatment (Wound Repair Regen 2017;25[4]:697-706; Can J Diabetes 2020;44[2]:196-204.e193). Studies are ongoing to understand the role of ESWT in other etiologies, and there remain unanswered questions about its use, for example, around malignancies, near the head and in pediatric patients.
Vibration Therapy
Vibration therapy is a low-intensity treatment that may help prevent muscle breakdown and necrosis. Studies in patients with healthy feet suggest that vibration increases perfusion and decreases hyperemia (Wound Manag Prev 2020;66[8]:7-14). Although the responses were less pronounced in patients with diabetes, these small changes may still be clinically relevant (Front Bioeng Biotechnol 2019;7:310). More research is needed to understand the future roles of this therapy.
Each of the emerging technologies discussed in this session offers promising new opportunities for wound healing support. Further development and adoption of new strategies will optimize healing and help patients recover from injury and surgery more quickly and comfortably.
“I have no idea about what is next in wound care technology. That’s why it’s so interesting,” Dr. Cordrey said. “It’s a rapidly evolving field of practice, and as we learn more about how chronic wounds function, we find new ways to target them.”
This article is from the March 2021 print issue.